Michael Matthews's Blog, page 150
April 22, 2013
Does Alcohol Consumption Affect Weight Loss and Muscle Growth?
Alcohol and its relation to health and fitness is a tricky subject.
In small amounts—a drink or two a day—it has potential health benefits like improved insulin sensitivity, cardiac function, and blood lipids (fatty substances in your blood, which when lowered, reduces your risk of heart disease).
In larger amounts, alcohol leads to barely conscious drives home, fistfights over who’s the best NFL rusher of all time, and charges of public indecency. And to nobody’s surprise, chronic alcohol abuse basically just breaks your ass.
But this chapter isn’t about the various effects of mild or severe drinking.
Instead, it will answer a question on many people’s minds: how much alcohol can we drink before it will negatively affect our weight loss and muscle growth?
Alcohol and Weight Loss
Similar to the carbohydrate inquisition that’s in vogue these days, alcohol is the target of many criticisms. According to some people, if you drink, you’re going to get fat—end of story. And you might just lose all your muscle as a bonus.
Well, if we take a quick look at epidemiological research, we can see that moderate alcohol consumption is actually associated with lower body weight, not higher.
For instance, a study published in 1985 in the American Journal of Clinical Nutrition looked at the diets of 1,944 adults aged 18-74. Researchers found that an increase in calories from ethanol (alcohol) alone didn’t result in the weight gain that would normally occur if those calories were from protein, carbs, or fat. In fact, thanks to regular alcohol intake, drinkers took in an average of 16% more calories each day than non-drinkers, and had the same levels of physical activity, but weren’t any fatter than their alcohol-free counterparts.
Another study with obese women on a weight loss diet had one group get 10% of daily calories from white wine, and another from grape juice. The result: after 3 months, the white wine group lost about 2 pounds more than the grape juice group.
The exact mechanisms at work aren’t totally clear. A likely factor is drinking can reduce your appetite for food, but it may also be related to its effects on insulin sensitivity.
Now, while it may seem like I’m encouraging you to drink to get shredded, I’m not. Alcohol consumption actually can hinder your weight loss efforts, but in an indirect way.
While alcohol itself basically can’t be stored as body fat, it blocks fat oxidation, which in turn accelerates the rate at which your body stores dietary fat as body fat.
In short, it’s not the calories from alcohol that can make you fat, but all the crap that you eat with it, which is hard to resist when you’re hammered.
So, if you want to be able to drink while dieting and still lose weight, don’t drink more than one day per week, and use the following tips to protect yourself from excess fat storage:
Restrict your dietary fat intake that day, and don’t eat any fatty foods while you’re drinking.
Get the vast majority of your calories from protein and carbs that day (with most coming from protein).
Stay away from carb-laden drinks like beer and fruity stuff. Dry wines are a good choice, as well as spirits.
By following these advices, you can enjoy a few drinks every week without having to feel guilty, and without ruining your weight loss regimen.
Alcohol and Testosterone Levels
Alcohol is going to have to face the music here. It does suppress testosterone levels, but the magnitude of this effect varies.
For instance, a study conducted by the TNO Nutrition and Food Research Institute had 10 men drink 30-40 grams of alcohol per day (2-3 beers or ounces of liquor, or 10-15 ounces of wine). After 3 weeks, their testosterone levels had dropped by about 7% (pretty insignificant).
Another study had 9 men drink 60-70 grams of alcohol after working out, and it had no effects on testosterone levels during the following 5 hours.
What happens when we increase the post-workout dose, though?
The University of Helsinki conducted a similar study, administering 1.5 g ethanol per kg of body weight (!) to 8 healthy men aged 20-26, and found that their testosterone levels dropped by 23% on average between the 10th and 16th hour after they started drinking. Furthermore, cortisol levels were elevated by 36% on average, and growth hormone secretion was heavily suppressed.
Another study conducted by the same university agreed: post-workout binge drinking is bad for testosterone production, proving that 10 beers is a poor post-workout meal (awwww shucks).
So, all things considered, if you have a few drinks here and there, you probably have nothing to worry about in terms of testosterone levels. But doing post-workout protein shots? Not a good idea.
Alcohol and Muscle Recovery and Performance
In rat and in vitro studies, alcohol impairs protein synthesis. Some people directly apply that type of research to living, breathing humans and say it prevents you from building muscle and accelerates muscle loss.
Well, it doesn’t work like that. Rats and humans have major metabolic differences, and in vitro findings don’t always pan out in vivo.
In live humans, muscle-wasting effects of alcohol have only been seen in chronic alcoholics. If you have 7+ drinks per day, you’re going to have trouble building muscle. And walking. And remembering your name.
It’s also commonly claimed that alcohol consumption impairs strength and interferes with the body’s ability to repair muscle damage.
According to studies conducted by the University of Massachusetts and Aarhus University, however, alcohol has no effect on strength or indicators of exercise-induced muscle.
On the other hand, a study conducted by Massey University showed that 1 g of ethanol per kg of body weight after exercise magnified post-workout muscle damage. It should be noted, however, that the workout regimen used was a bit ridiculous (300 eccentric contractions on a machine for training the legs), so we can’t be sure its findings apply to more traditional, lower-volume weightlifting workouts.
To Drink or Not to Drink?
Alcohol advocates like to talk it up as some kind of superfood, but the bottom line is it’s not necessary in any way for good health, and it won’t give you any performance benefits.
If you’re like me and don’t drink, I don’t really see any reason for us to start. If you drink regularly, you have a lot more to worry about than interfering with muscle gainz.
But if you drink infrequently and moderately enough to not notice any after effects (no hangovers or lingering issues), then you probably don’t have any good reason to give it up altogether.
What’s your take on drinking and staying fit? Do you abstain completely or keep it moderate? Let me know in the comments below!
April 17, 2013
Wanted! 10 Dedicated Men and Women for a 60-Day Coaching Program
I want to do something fun.
My best friend, training partner, fellow research nut, and co-worker Jeremy and I are looking for 5 dedicated men and women (10 people total) to try out our upcoming coaching service, the 60-Day Muscle for Life Workout Program.
If you’re selected, you’ll get weekly workouts, diet plans, and coaching for FREE. Both Jeremy and I will oversee every aspect of your training and eating to get you into the best possible shape we can in 60 days.
We don’t care where you’re starting. If you need to lose 20 lbs or are skinny and need to build muscle, we want you.
To be selected, you must meet the following criteria:
Willing to take before and after pictures in a bathing suit (front, back, and side), and let us use them to promote our service when it’s launched.
Have a basic understanding of how to perform exercises correctly.
Have access to a gym with free weights, and in particular, a full set of dumbbells, a squat rack, and a bench press station.
Able to work out for 60-70 minutes per day, 5-6 times per week.
Able to prepare basic foods each week and eat what you make every day (no eating on the run or at restaurants, unless for a cheat meal).
No disease or serious injuries that may get in the way of eating normally or weightlifting.
Willing to work your ass off, stick to the program, and not make excuses. No missing workouts, and no cheating on your diet for 60 days. We’re not going to ask you to do anything you can’t do, but it’s going to require effort and persistence.
If that’s you, and you want to have some fun with us, then please write a short essay (100-300 words) on why we should pick you, and also include information on your training and diet history. Tell us what has and hasn’t worked for you, and why (if you know).
You can email the above to Jeremy at jeremy@muscleforlife.com, and use the subject line “MFL Transformation.”
We’ll review all entries as they come in, and, on May 6th, make our choices and let everyone know who has been selected and who hasn’t. The program will start the following Monday, May 13th.
Good luck, and talk soon!
April 15, 2013
Do Fructose and Fruit Make You Fat and Unhealthy?
Many health gurus claim that fruit can cause horrible things in the body due to the sugar molecule it contains, known as fructose.
I’ve known many people that were thoroughly convinced that they would get fatter if they ate any fruit (many of whom were already overweight, which is ironic), and that couldn’t believe I was able to stay in the single-digit body fat percentages eating over 100 grams of carbohydrate from fruit every day (apples, oranges, and bananas are my favorites).
Some pretty heavy claims have been leveled at fructose in the “pop culture” of nutrition and diet. A popular crusader against it is Dr. Robert H. Lustig, whose talk entitled Sugar: The Bitter Truth currently has over 3.4 million views on YouTube.
According to Lustig and others, fructose has special qualities that directly induce fat storage, and that make it toxic to the liver.
But does the current scientific evidence support these positions? Is fructose, and fruit, bad for our health?
What is Fructose Anyway, and What’s the Big Deal?
Fructose is a simple carbohydrate that, together with glucose, makes up sucrose (table sugar). It’s found in many plant sources like honey, fruits, flowers, and root vegetables., and is one of the three basic forms of sugar that our body can use as fuel (the other two are glucose and galactose).
Eating an abundance of refined sugars–fructose included–can definitely cause problems beyond just added calories. They have addictive properties normally found with drug abuse, and that can lead to cravings, bingeing, and withdrawal symptoms. Regular consumptions of sugar-sweetened beverages is particularly bad, and has been associated with weight gain and obesity, and even an increased risk of cancer in men and women.
But, if we’re to listen to fructose alarmists, this molecule in particular is to be avoided at all costs. For instance, research has indicated that regular consumption of fructose may play a causative role in the epidemic of a cocktail of disease, including hypertension, obesity, metabolic syndrome, diabetes, kidney disease, and cardiovascular disease.
These types of observational studies have led to advices to completely avoid fruit and fructose and assume the less fruit you eat, the better. But there’s more to this story.
The Big Flaw in Fructose Alarmism
When you really dig into the feeding trials that highlight the health problems associated with fructose intake, you quickly notice something.
The dosages of fructose required to produce negative effects are quite high. Not impossible to reach through dietary means, but damn near impossible through fruit alone.
For instance, one study conducted by the University of Lausanne showed that 7 days of a high-fructose diet increased fat deposits in the liver and muscle, as well as fasting triglycerides, and decreased insulin sensitivity. Bad, no doubt.
How exactly what this study conducted, though? Well, they had 16 guys consume a solution consisting of 3.5 grams of fructose per kilogram of weight every day. I weigh about 90 kilograms, so that would mean I would have to eat 315 grams of fructose per day. If I wanted to get that from bananas, I’d have to eat about 45. Or about 80 cups of strawberries. Or 800 cherries. Or 26 apples.
Another study conducted by the University of Fribourg in Switzerland had one group of the 15 volunteers drink a beverage containing 60 grams of fructose, and another a beverage with the same amount of glucose. The result: blood pressure levels were elevated for 2 hours in the fructose group, but not the glucose group.
Well, that’s the fructose found in about 9 bananas, 15 cups of strawberries, 150 cherries, or 5 apples.
Yet another study, this time conducted by the University of California, had participants get 25% of their daily calories from either fructose or glucose. After 12 weeks, both groups gained weight (due to overeating), but the fructose group experienced negative side effects not seen in the glucose group:
Increased amount of visceral fat.
Increased fat production in the liver.
Decreased insulin sensitivity.
Elevated LDL (bad) cholesterol.
Increased triglyceride levels.
Pretty nasty indeed. But wait a minute. 25% of daily calories? Well, I eat close to 3,000 calories per day, so that would call for about 175 grams of fructose per day. I won’t bother with the fruit list—you get the idea.
Okay then, so eating large amounts of fructose every day is a bad idea. But, practically speaking, reaching dangerous levels through fruit alone would require deliberate overfeeding. Not only that, but the fiber content of fruit changes how your body deals with the sugars. Fruit also contains various phytochemicals that are good for our health. Bottom line: consuming 30 grams of fructose from fruit is different than drinking 30 grams of pure fructose, or in the form of high-fructose corn syrup.
Bonus Round:
Does Fructose Magically Turn Into Body Fat and Wreck Your Liver?
One of the common claims against fructose is that, regardless of level of intake, it leads to more weight gain than other sources of carbohydrate. Another is that it’s toxic to the liver, nearly as much as alcohol.
Unfortunately, these positions just aren’t supported by studies done with humans, as opposed to mice and rats (which have very different metabolic characteristics than humans).
Research has shown that a paltry 2-3% of fructose consumed is converted into fat in the liver, whereas 50% ends up as glucose, 25% as lactate, and 15% as glycogen.
It’s not surprising, then, that a McMaster University meta-analysis published in 2012 reviewed 31 fructose feeding trials involving 637 participants, and concluded that “fructose does not seem to cause weight gain when it is substituted for other carbohydrates in diets providing similar calories.”
Some people point to the lactate production as a problem, but these claims were debunked over a decade ago. It turns out that lactate isn’t a metabolic miscreant; in fact, it plays an important role in a number of metabolic processes and is an effective aerobic fuel.
Fructose, like any other form of calories, will cause weight gain when over-eaten, but doesn’t have magical fat storage powers, and it doesn’t damage your liver at low-moderate consumption levels.
So, How Much Fructose Should You Eat Every Day?
According to a meta-analysis of clinical trials evaluating fructose intake, 25-40 grams of fructose per day is totally safe. That’s 3-6 bananas, 6-10 cups of strawberries, 10-15 cherries, or 2-3 apples per day. Or, as the old advice goes, a few servings of fruit every day.
While regular fruit eaters don’t have anything to worry about, but it’s worth noting that regular eaters of refined sugars like high-fructose corn syrup or sucrose can reach unhealthy levels very easily.
For instance, a 20-ounce bottle of soda sweetened with high-fructose corn syrup contains about 35 grams of fructose. One gram of sucrose is about half glucose, half fructose, so if you eat a dessert with 50 grams of sugar, you’re getting about 25 grams of fructose. High-fructose corn syrup is about 55% fructose and found in many processed foods, fruit juices, sports drinks, energy drinks, and so on, so this can add up quickly as well.
Even agave nectar, which is touted as healthy by many due to its low-glycemic properties, can be as high as 90% fructose. Other less processed forms can be as low as 55%.
So, the main takeaway from all of this is you can avoid all the health complications associated with simple sugars like fructose by just keeping your daily intake relatively low. The sources are many, but the effects are the same: agave, sucrose, honey, maple syrup, raw sugar, molasses, brown sugar, high-fructose corn syrup, turbinado sugar, and on and on.
What are your thoughts on fruit and fructose consumption? What are your experiences? Share them in the comments below!
April 11, 2013
Cardio and Muscle Growth: Friends or Foes?
Many guys fear the treadmill, believing it has a mystical ability to shrivel up muscle and sap strength. And many bodybuilder types bash cardio simply because they don’t like doing it.
While it’s clearly evident that excessive cardio causes muscle loss (just look at any marathon runner), what about moderate cardio? Will it interfere with your muscle growth? Or will it help?
Well, it can go both ways, actually.
3 Ways Cardio Can Help With Muscle Growth
There are 3 primary ways that cardio can help you build (and retain) more muscle. They are as follows:
It improves muscle recovery.
It improves your body’s metabolic responses to food.
It keeps up your conditioning, making the transition from “bulking” to “cutting” easier on your body.
Let’s look at these in more detail.
Cardio and Muscle Recovery
As you know, intense exercise causes damage to muscle fibers, which must then be repaired. This damage is the cause of the soreness that you feel the day or two following a workout, and is known as delayed onset muscle soreness, or DOMS.
The reparation of the damage is a complex process that is partly regulated by two simple factors: how much of the substances needed for repair are brought to the damaged muscle over time, and the speed at which waste products are removed.
Thus, low- or moderate-intensity cardio can help your body repair muscle damage quicker because it increases blood flow. This helps your body build the muscle back up quicker and remove the waste, which results in an all-around quicker recovery. This is why I always do a cardio session on legs day–it dramatically reduces leg soreness in the days to follow.
It’s worth noting, however, that these benefits are primarily seen in the legs because most forms of cardio don’t really involve the upper body. If you want to boost whole-body recovery, then you would need to do something that gets your upper body working, like a rowing machine, or even using your arms to help pump on the elliptical.
Cardio and How Your Body Metabolizes Food
In our collective dietary fantasy, all nutrients eaten would be sucked into the muscles and either absorbed or burned off, and none would result in fat storage. And when we dieted to lose weight, all energy needs would be met by burning fat, not muscle.
The reality, however, is that our bodies do these things to varying degrees. Some people’s bodies store less fat when they overeat (they burn off more excess calories instead of storing them), and lose less muscle when they diet for weight loss (more energy is sucked from fat than muscle to make up for the caloric deficit). Other people, on the other hand, are more likely to store excess calories and lose muscle when they restrict calories for weight loss.
Hormones like testosterone and cortisol play major roles in this (higher levels of testosterone promote more muscle and less fat, whereas higher levels of cortisol promote less muscle and more fat), but unfortunately there isn’t much we can do about either beyond injecting ourselves with drugs. Our genetics have basically set our normal physiological hormonal ranges and that’s that.
All is not lost if you’re not of the genetic elite, however. Another factor in what your body does with the food you eat is insulin sensitivity (how well your cells respond to insulin’s signals). As discussed in my advice for “hardgainers,” being insulin sensitive is highly beneficial when you’re eating a surplus of calories to build muscle, whereas insulin resistance inhibits muscle growth and promotes fat storage under these dietary conditions.
Now, genetics do affect natural levels of insulin sensitivity as well, but you can do various things to manipulate this mechanism. This is where cardio comes in, because it improves insulin sensitivity, and does so in a dose-dependent manner (meaning the more you do, the more benefits you get).
So, cardio can help your muscles better absorb the nutrients you eat, leaving less available for fat storage.
Cardio and Conditioning
A common issue in the bodybuilding world is the dramatic reduction in cardiovascular fitness when focusing only on heavy weightlifting for months on end.
Building one’s cardio conditioning back up is not only uncomfortable, but going from doing absolutely no cardio to several sessions per week, on top of a caloric deficit (as cardio is added back in for weight loss purposes), puts a lot of stress on the body. This added stress makes weight loss physically and psychologically tougher, and can even accelerate muscle loss.
By keeping regular cardio in during your bulking phases, however, you can maintain your metabolic conditioning and prevent the “shell shock” that many people experience during the beginning of a cut.
It’s also common for people that have bulked for months without cardio to experience an initial lag in weight loss. Those that keep their cardio in seem to better retain the ability to oxidize fat.
2 Ways Cardio Can Get in the Way of Muscle Growth
As I said earlier, cardio can both hurt and help muscle growth. The two primary ways it can negatively affect your gains are by reducing your caloric surplus too much, and by causing you to overtrain.
The surplus issue is pretty moot, however. Normal cardio sessions don’t burn that many calories (a few hundred at most), which is easy enough to correct (eat a pile of fruit afterward, for instance). But if long, intense sessions are done, that could cause caloric issues.
“Hardgainers” might have something to worry about in this regard as they usually have trouble eating enough as it is. Research has shown that low-intensity cardio stimulates the appetite, however, so including some every week can actually help with eating enough.
Issues relating to cardio and overtraining revolve around intensity and frequency. Simply put, the more cardio you do, and the more intense it is, the more your strength and growth will be negatively affected due to excessive stresses put on both the central nervous system and muscles being worked (usually the legs get it the worst).
So, Cardio While Focusing on Muscle Growth—Yes or No?
I think the positives of including cardio in your muscle growth routine clearly outweigh the negatives, especially considering the fact that the negatives are easily dealt with.
A few sessions of low-to-moderate cardio each week is enough to enjoy its benefits, while avoiding its drawbacks (stick to aerobic exercise, as opposed to anaerobic high-intensity training). And as a little added bonus, research has shown that cycling is a better choice than running when you’re trying to maximize muscle gains, probably because it mimics actual movements you perform with weights.
What are your thoughts on cardio and muscle growth? Has including or excluding cardio worked best for you? Let me know in the comments below!
April 8, 2013
Carbohydrates and Weight Loss: Should You Go Low-Carb?
The hysterical crusade against carbohydrates has reached a frantic pitch these days.
From the scientifically bankrupt theories of guys like Gary Taubes to the trendy low-carb diets like Paleo, Zone, Dukan, and so forth, the carbohydrate is now the victim of the same level of persecution that saturated fat endured for decades.
Well, we’ve come to learn that saturated fats aren’t the evil heart killers they were made out to be (excluding the processed form known as tran fat, which is known to increase risk of heart disease, among other issues).
If we’re to believe the leaders of the Carbohydrate Inquisition, this molecule will blow up our blood sugar levels, break our metabolism, force us to be fat, give us diabetes and many other diseases, and, well, just generally turn us into hungry, horrible people.
If we just ditch the diabolic carbohydrate, “experts” claim we will melt fat away and keep it off without having to count pesky calories, build an invincible immune system, live forever, and maybe even develop superpowers. And we’ll be part of the cool crowd to boot.
So, is this culture war actually justified? Does it have a basis in science?
Carbohydrates, Insulin Levels, and Weight Gain
Much of the carbohydrate controversy revolves around its relationship to the hormone insulin.
As the claims go, insulin “makes you fat,” and carbohydrate “spikes insulin,” thus, “carbohydrate makes you fat.” Sounds so simple, right? Well, yeah, the story is simple…but it’s false.
While yes, it’s true that insulin’s job is to pull glucose out of the blood and store excess as fat, it’s also responsible for driving amino acids into our muscles for protein synthesis and clearing dietary fats out of the blood as well (which are stored as body fat more efficiently than carbohydrate, I might add). On top of all that, insulin has a mild anti-catabolic effect (meaning it helps preserve your muscle).
And while it’s also true that eating carbohydrate increases insulin levels in your blood, many common sources of protein (such as eggs, cheese, beef, and fish) are comparable in their ability to do the same.
Some people claim that because your body generally produces more insulin when you eat carbohydrate, this leads to more fat storage. They’re wrong—research has shown that the amount of insulin your body produces in response to eating food (or insulin response, as it’s called) doesn’t affect the amount of fat stored.
So, in short, insulin is your friend, not a part of a conspiracy between your pancreas and fat cells to ruin your self-image.
That’s one strike against the “carbs make you fat” camp. Let’s now look directly at carbohydrate intake and fat loss.
Diet Composition and Real-World Weight Loss
Many low-carb gurus will claim that you can lose weight much quicker if you consume very few carbs every day. Some people even believe they can only lose weight if they cut their carbs to nil.
The problem with these advices and beliefs is they fly in the face of both basic physiology and scientific findings, and mask the most common weight loss roadblock: eating too much, and moving too little.
A simple review of scientific literature shows that diet composition has no effect on long-term weight loss.
For example, let’s first look at a study conducted by the University of Pennsylvania. Researchers assigned 63 obese adults to either a low-carbohydrate, high-protein, high fat diet (20 grams of carbohydrate per day, gradually increased until target weight was achieved), or a conventional diet of 60% of calories from carbohydrate, 25% from fat, and 15% from protein.
The result: the low-carbohydrate group lost more weight in the first 3 months, but the difference at 12 months wasn’t significant.
The 3-month result isn’t surprising, considering the fact that reducing carbohydrate intake decreases the amount of glycogen we store in our liver and muscles, which in turn decreases total body water retention. This, of course, causes a rapid drop in weight that has nothing to do with burning fat (and anyone that has reduced carbohydrate intake as a means of cutting calories for weight loss has experienced this).
Harvard University published a study in 2009 on the effects of diet composition and weight loss. They assigned 811 overweight adults to one of four diets, which were comprised of the following percentages of fat, protein, and carbs: 20, 15, and 65%; 40, 15, and 45%; and 40, 25, and 35%.
After 6 months of dieting, participants had lost and average of 6 kg. They began to regain weight after 12 months, and by 2 years, weight loss averaged out to 4 kg, with no meaningful differences between low-protein or high-protein, low-fat or high-fat, and low-carb or high-carb groups.
A study published by Arizona State University found that an 8-week high-carbohydrate, low-fat, low-protein diet was equally effective in terms of weight loss as a low-carbohydrate, low-fat, high-protein diet.
So, the conclusion we can derive is brutally simple and clear: as long as you keep yourself in a caloric deficit, you’ll lose weight regardless of the dietary protocol you follow.
The Exceptions to the Rule:
When Low-Carb—or High-Carb—Might Be Better
Despite the body of evidence presented above, practical experience in coaching hundreds of people has taught me that some people tend to just do better on high-carb or low-carb diets, and some do fine with either.
For instance, some people—like myself—do very well with high-carbohydrate diets. They can lose weight very easily, feel energized all day without any crashes, and are able to maintain considerable strength in the gym. Others don’t do well with a high-carb approach. Weight loss is slower than optimal, it makes them very hungry, which leads to over-eating, and it comes with frustrating energy highs and lows.
It goes the other way, too. Some people don’t do well with low-carb, high-fat diets (myself, again). They feel lethargic, mentally clouded, lose a ton of strength, and have trouble getting lean. Others thrive on it, having plenty of energy and a general sense of well-being.
What gives?
Well, while feeling like crap makes you more likely to over-eat or mess up your diet in other ways, and give less than 100% in your workouts, there’s more at work here.
Research has shown that some people’s bodies deal better with large amounts of dietary fat than others, responding with positive metabolic changes like an increase in resting energy expenditure and fat oxidation to maintain energy balance, and better appetite control. Some people’s bodies respond negatively to high amounts of dietary fat, however, and are more likely to store it as body fat. Such research sheds some light on why some people respond so well or poorly to low-carb, high-fat diets. A ketogenic diet can be a disaster for some, and a godsend for others.
The above also relates to research on how insulin sensitivity and insulin response affect diet effectiveness. (Remember that insulin sensitivity refers to how responsive your cells are to insulin’s signals, and insulin response–or insulin secretion–refers to how much insulin is secreted into your blood in response to food eaten.)
Research has shown that weight loss efforts aren’t improved or impaired by insulin sensitivity or insulin resistance per se. When we move away from a balance of nutrients, however, and use high-carb, low-fat, or low-carb, high-fat diets in conjunction with different levels of insulin sensitivity and insulin response, things change.
For instance, a study conducted by the Tufts-New England Medical Center found that a low-glycemic load diet helped overweight adults with high insulin secretion lose more weight, but not overweight adults with low insulin secretion.
A study conducted by the University of Colorado demonstrated that obese women that were insulin sensitive lost significantly more weight on a high-carb, low-fat diet than a low-carb, high-fat diet (average weight loss of 13.5% vs. 6.8% of body weight, respectively); and those that were insulin resistant lost significantly more weight on a low-carb, high-fat diet than a high-carb, low-fat diet (average weight loss of 13.4% vs. 8.5% of body weight, respectively).
What we can take away from my anecdotal observations and these studies is if you have good insulin sensitivity and low insulin secretion (good insulin response), you’ll probably do better on a high-carb, low-fat diet. On the other hand, if you have poor insulin sensitivity (insulin resistance) and high secretion (poor insulin response), you’ll probably do better on a low-carb, high-fat diet.
So, Which Approach, Then? High-Carb or Low-Carb?
Unfortunately it’s not easy to tell if you’re a “high-fat” or “low-fat” body type, but it’s fairly easy to take an educated guess regarding insulin resistance and sensitivity, and insulin response.
After eating a high-carb meal, signs of good insulin sensitivity and response are pumped muscles that feel “full,” mental alertness, stable energy levels (no crash), and satiety. Signs of insulin resistance and poor insulin response are bloat, gassiness, mental fogginess and inability to focus, sleepiness, and hunger soon after eating.
Based on the above symptoms, you can decide which approach to try. And remember these are only general guidelines—in the end, actual weight loss is what matters most. You should be able to lose 1-2 lbs per week, and if you’re not despite being absolutely certain that you’re in a proper caloric deficit, you may benefit from altering diet composition.
What are your experiences with carbohydrates and weight loss? Does low-carb or high-carb work better for you? Let me know in the comments below!
April 5, 2013
Weightlifting and Flexibility: Does It Make You Inflexible?
Athletes were once advised not to lift weights because it would make them stiff and inflexible, and hurt their performance.
Well, we now know better. Sure, being a hulking brute naturally limits your flexibility (big bodybuilders have an interesting time wiping on the toilet and showering), but research has shown that weightlifting itself, with a full range of motion, actually increases flexibility just as well as, or even better than, static stretching.
In a study conducted by the University of North Dakota, researchers divided 25 volunteers into three groups: a control group (that did nothing, of course), a static stretching group, and a resistance training group.
The result after five weeks: the researchers found no significant difference between the static stretching and resistance training groups in all measures of flexibility (hip extension, hip flexion, shoulder extension, knee extension).
Another study conducted by Castelo Branco University in Brazil showed that 8 weeks of resistance training improved flexibility better than static stretching in all but one measurement.
The reality is that weight training with proper form increases flexibility because you’re repeatedly moving muscles, joints, and ligaments through their full ranges of motion.
In fact, some exercises provide deep stretches that are hard to beat, such as the Dumbbell Fly, Romanian Deadlift, Dumbbell Pullover, Dumbbell Row, and Overhead Triceps Press.
So, improved flexibility is yet another reason to use a full range of motion in weightlifting (in addition to preventing injuries and improving strength gains and muscle growth).
Have you experienced the flexibility benefits of weightlifting? Anything else to add? Let me know in the comments below!
April 4, 2013
Water Retention and Weight Loss: You Can Lose Fat, But Not Weight?
Have you ever been rolling along nicely on a cut and then, out of nowhere, had your scale freeze up on you? That is, you go one, two, even three weeks without losing any weight, and without looking any leaner?
Weight loss plateaus like these are usually caused by accidental over-eating or under-exercising, and there are simple dietary and exercise strategies you can use to remedy those issues.
That said, increased water retention can also be the cause of “mysterious” weight stagnation. Women can really suffer from this due to the fluid retention that comes with the menstrual cycle.
If you’re not familiar with water retention and what to do about it, it can really throw you for a loop because cutting calories further and increasing cardio–the two simplest ways to get the scale moving again–can actually make it worse. This can then lead to a nice, greasy bout of frustration binging, which sets you back even further.
So, let’s learn more about fluid retention and weight loss, and how to defeat it so you can avoid this aggravating pitfall.
When a Weight Loss Plateau isn’t a Fat Loss Plateau
In a perfect world, we would always lose weight in a neat, orderly manner.
We would do our daily exercise and follow our meal plans and wake up a little lighter and leaner every morning. On we would go until we eventually have our six packs, we would celebrate with our favorite cheat meal, and that would be that.
Well, it usually doesn’t work out like that.
It turns out that weight loss can be quite erratic sometimes. You can sit at the same weight for several weeks, and then lose 3-4 pounds overnight, and it can sometimes occur after pigging out.
How is that possible? I mean, as long as you maintain a daily caloric deficit, your body is going to mobilize fat stores, so why would your weight stay the same?
The answer lies in water retention. If you lost a pound of fat in one week, it can be obscured–both on the scale and in the mirror–by an extra pound of water that your body is holding.
While daily fluctuations in the amount of water you drink and sodium you eat account for most of the water you retain, simply being in a caloric deficit can cause water retention. A major reason for this is the fact that it raises cortisol levels, which in turn increases fluid retention.
So, let’s take a closer look at this phenomenon and what we can do about it.
What a World War II Starvation Experiment Can Teach Us About Water Weight
Scientific knowledge of this phenomenon goes back decades.
A good example of this is the “Minnesota Starvation Experiment” conducted by Dr. Ancel Keys during World War II, wherein 36 men willingly submitted themselves to a semi-starvation diet of about 1,500 calories per day for 6 months. The purpose of the experiment was to study the physiology and psychology of starvation, and to work out a proper regimen for gradually helping starved war prisoners back to normal diets and metabolic functions.
While there is plenty of interesting information among his findings, I want to call your attention to one observation in particular.
Weight loss progressed in a nice, linear fashion in the beginning. Men lost about 2 lbs per week, every week. Eventually, however, it became erratic. Weight would remain stagnant for weeks with a dramatic increase in water retention, and then a “burst” of weight loss would occur as water was rapidly expelled.
I want to repeat this point: the caloric deficit did systematically reduce body fat levels, but the reductions in total body weight were often counter-balanced by increases in water retention. This extra water would suddenly flood out, causing apparent “bursts” in weight loss of several pounds overnight. Bodybuilders are very familiar with this phenomenon, calling it the “whoosh effect.”
“What triggered these whooshes in the prisoners?” you might be wondering.
Sometimes they just occurred randomly, but a reliable trigger was a dramatic increase in calories for a meal. For instance, a 2,300-calorie meal was served to celebrate the half-way mark of the experiment, and scientists noted that many of the men woke up several times to pee that night and, in the morning, were several pounds lighter than the day before.
If you’ve ever dieted down to a super-lean level (7% and below for men, 15% and below for women), you’ve probably experienced this “whoosh” after you do a nice re-feed meal/day. In fact, it’s common for weight loss to continue for several weeks even after you reach your body fat goal and start increasing your calories (this was noted in the Minnesota Experiment as well).
Practical Advice for Losing Water Weight
If you find your weight stuck for several weeks despite being absolutely sure that you’re in a caloric deficit (weighing food you eat, keeping your activity levels up through exercise), the strategies below will probably un-stick you.
Reduce Your Sodium Intake
Increasing your sodium intake above your normal daily levels increases water weight. Conversely, reducing it below the daily norm reduces water weight. Thus, an easy way to trigger a “whoosh” is reducing your sodium intake.
When I cut sodium, I bring it down to 1-1.5 grams per day for a few days (the Institute of Medicine recommends just 1.5 grams of sodium per day, by the way). That means…
No canned or pre-packaged foods (salt is used as a preservative).
No deli meat (full of sodium).
Reduce your use of table salt and spices. One teaspoon of table salt contains 2,300 mg of sodium. Use a salt substitute instead, and use it sparingly. Many spices are high in sodium–avoid them.
Watch out for sauces and salad dressings, many of which are high in sodium.
Watch out for cheese, which is often quite high in sodium.
While it might be annoying to count yet another thing in your diet, it’s worth reining in your sodium for a few days to get the scale moving again. (Oh and as a note, I’ve yet to see any valid scientific proof of claims made about “diuretic foods” like asparagus and celery.)
Drink More Water
Drinking plenty of water helps normalize your fluid retention. Shoot for around 1 gallon per day.
Get Your Cortisol Under Control
If you’re retaining a lot of water, it may be due to elevated cortisol levels. To get your cortisol back to normal, try the following:
Cut back on the exercise. Exercise elevates cortisol levels, and when combined with a caloric restriction, this can be a double-whammy of cortisol for your body. Reduce the frequency and intensity of your training for a week to help bring things back to normal.
Make sure you’re not in too severe of a caloric deficit. Go over your diet and compare it against your total daily expenditure using a calculation like the Katch McArdle (and use the “light activity” multiplier–unless you exercise less than 7 hours per week, higher multipliers will have you eating too much). Bring yourself to a 500-calorie deficit to avoid the cortisol issues that come with greater caloric restrictions.
Chill out. You can reduce cortisol levels by simply taking some time each day to relax, listen to some good music, drink some tea, and do some deep breathing. Taking a nap and getting a massage can help, too.
Get more sleep. Not getting enough sleep can result in elevated cortisol levels later in the day. Try to get 7-8 hours per night.
Eat a Bunch of Food
Don’t you love me for this one?
I’ve talked about the importance of “re-feeding” when you’re dieting, and its benefits extend to dealing with fluid retention. As was seen in the Minnesota Experiment, a jump in calories for one meal can trigger a “whoosh” of water.
So have a nice cheat meal and enjoy it. For an added bonus, include a good amount of carbs, as it can reduce cortisol levels.
What are your experiences with water retention? How have you overcome them? Let me know in the comments below!
April 3, 2013
Squatting and Your Knees and Back: Injury Risk or Safe?
Like the deadlift, the barbell squat is one of the most powerful exercises you can do, involving the strength and coordination of over 200 muscles in your body.
But, also like the deadlift, it’s avoided by many due to the fear that it’s bad for your back and knees.
The fact that many sports doctors say these things doesn’t help the squat’s cause. Consider, however, that these doctors specialize in treating people with injuries, many of whom should not be squatting in their current conditions. These people are not representative of the average, healthy gymgoer, however, and the advices that apply to those undergoing rehab don’t apply to everyone. Just because barbell squats can exacerbate a knee injury doesn’t mean it helps cause one in a healthy person.
Another common reason why these squat myths linger is even less scientific: just like how heavy, strenuous deadlifts look like they’re bad for your back (when they’re not, when performed correctly), intense squats look like they’re bad for your back and knees.
Well, to get to the bottom of these myths, let’s look to the anecdotal evidence of decades of weightlifters, and the scientific evidence of published literature.
Why Serious Lifters are in Love with the Squat
When it comes to leg training, there are usually two types of people.
The first loads up the Leg Press with every plate in the gym, and goes through an intricate ritual involving tourniquet-tight knee wraps, a weight belt cinched to its tightest notch, and pre-lift announcements and cheers. He then wiggles into the sled and grinds out a few excruciating half-reps, ending with an ear-splitting yell and high-fives with his buddies.
The other type? Well, he was in the corner with the squat rack—you know, the loneliest place in the gym—quietly going about his business with deep, heavy squats. No wraps, no belts, no swagger—just a bar bending across his back, loaded with a “measly” few hundred pounds, and a puddle of sweat on the ground.
Who’s the winner, in the end? Who will consistently get bigger and stronger, and who’s the least likely to get hurt? The latter, of course.
While many people will do anything for legs before putting the barbell on their backs, they’re missing out on what many of the top strength coaches in the world consider the absolute toughest and rewarding exercise we can do.
To nobody’s surprise, squatting strengthens every muscle in your legs, which in turn helps you not only lift more weight in the gym, but run faster, jump higher, and improve flexibility, mobility, and agility. As if those aren’t reasons enough to squat, it’s also an incredibly effective core workout.
That said, the biggest fears that keep people from including squats in their workout routines are worries of back and knee injuries. Are these valid concerns?
How Your Back and Knees Can Love the Squat Too
The myth that squatting is bad for your knees started with work done in the 1960s. Research concluded that a properly done squat stretched the knee ligaments, increasing the risk of injury. These findings spread like wildfire through the fitness world. Some US military services even cut squatting movements out of their training programs.
It was noted that the studies had serious flaws, including the choice of subjects and researcher bias (for instance, one of the studies was done with parachute jumpers, who often hurt their knees due to legs getting caught in parachute lines and violent impacts when landing), but that wasn’t enough to stop the uprising against the squat.
Well, much research has done since then, however, and a much different picture has emerged.
A rigorous study conducted by Duke University involved the analysis of over two decades of published literature to determine, in great detail, the biomechanics of the squat exercise and the stresses it places on the ankles, knees, hip joint, and spine.
Highlights from the study, and many others reviewed within, set the record straight on how the squat affects our bodies, and teach us a lot about proper squat form:
While most of the attention is given to the knee, hip, and spine, ankle strength plays a large role in power generation during squat performance. Research has shown that ankle weakness actually causes faulty movement patterns during the squat.
The hamstrings counter-act the pull on the shinbone, which helps neutralize the shearing force placed on the knee, and alleviates stress on the ACL.
Sit back into the squat during descent and resist the urge to bring the knees beyond the toes, as this increases shearing force placed on the knees.
Even in extreme cases, such as powerlifters lifting 2.5 times bodyweight, the compressive forces placed on the knee and its tendons are well within its ranges of ultimate strength.
Stress placed on the ACL is negligible considering its ultimate strength (in one study, the highest ACL force recorded when squatting was a mere 6% of its ultimate strength). Highest recorded PCL forces were well within natural strength limits as well.
Don’t let your knees bow inward at any point during the squat. Keep them in line with your toes.
Squat depth matters–a lot. The deeper you squat, the more work your legs and butt have to do. (I recommend either full squats or parallel squats, but not half squats.)
Full squats cause more muscle activity in the butt than lesser squat depths (you hear that girls?). (Use a wide stance too if you want to hit your butt even harder!)
If you maintain a neutral spine position while squatting (instead of a rigidly flexed position), you greatly reduce the shearing force placed on your vertebrae (your spine is better at dealing with compressive force than shearing).
Maintaining a posture as close to upright as possible further reduces this force, as does increasing intra-abdominal pressure, which you can create by holding your breath while you squat, and gazing straight ahead instead of down .
Squatting rapidly doubles the amount of shearing and compressive forces placed on your knees. Keep your reps at a controlled pace to avoid this (I like a 2:1:2 pace—2 seconds down, pause, 2 seconds up).
Avoid exaggerated rotation of the feed inward or outward, as they don’t make the exercise any more effective, and can potentially cause undesirable knee movements.
While the low-bar squatting position produces less torque on the knees than the high-bar position, the magnitude of both forces are well within tolerable ranges, making neither position “better” than the other in this regard. Use whichever squatting position is most comfortable for you.
The front squat produces significantly lower knee compression and low-back stress in comparison to the back squat, and thus can be a viable alternative for those suffering from various knee and back problems.
Squatting while you’re fatigued can cause poor form, and is likely a contributing factor in both short- and long-term injuries. (This is one of my gripes regarding Crossfit, wherein participants are often urged to squat and deadlift heavy weights while fatigued—an injury just waiting to happen).
In closing, researchers concluded that the squat “does not compromise knee stability, and can enhance stability if performed correctly.” Furthermore, any risks of spinal injury can be avoided by simply minimizing the amount of shearing force placed on the spine.
Let’s Get Squatting
According to the National Strength and Conditioning Association:
“Squats, when performed correctly and with appropriate supervision, are not only safe, but may be a significant deterrent to knee injuries.”
So rest easy: as long as you use proper squat form, the squat does not put your back or knees at risk of injury.
Oh and as a final note, don’t bother with the Smith Machine Squat. It forces an unnatural range of motion, which can actually lead to knee and back injuries, and research has shown it’s far less effective than the free weight, barbell squat.
What’s your take on the squat? Absolutely vital or overrated? Completely safe, or still a risk? Let me know what you think in the comments below!
April 2, 2013
The Deadlift and Your Lower Back: Harmful or Helpful?
In the ‘70s, top powerlifters like John Kuc, John Cole, and Don Reinhoudt had outstanding deadlifts, with personal bests around 900 pounds. The deadlift was considered the king of compound exercises.
These days, many powerlifters choose to compete only in the bench press, and for those that compete in all three (bench press, squat, and deadlift), the deadlift takes the back seat because of assistance gear that can add hundreds of pounds to their bench and squat, but nothing to their deadlift.
Well, the fact is the deadlift is, hands down, one of toughest—and most rewarding—exercises you can do. It’s the ultimate full-body workout, training just about every muscle group in the body: leg muscles, glutes, the entire back, core, and arm muscles. Anything that’s involved in producing whole-body power is blasted by the deadlift, and it’s an integral part of any serious strength training program.
Oddly enough, it’s also one of the most neglected compound exercises by both guys and gals; the unfortunate victim of the long-standing myth that it’s “bad for your back.”
At first, it would seem to make sense that lifting hundreds of pounds off the ground—putting all that pressure on your back, particularly your low-back and erector spinae muscles (also known as the spinal erectors)—would be a recipe for spinal disaster.
Anecdotal evidence is ambivalent: we all know or have heard of someone that “messed up their back deadlifting,” yet also know that many serious strength trainers, bodybuilders, and powerlifters swear by it.
So, is the deadlift bad for your back when performed properly?
Let’s turn to a series of scientific studies to learn more about this oft-feared, oft-revered lift.
The Science of Deadlifting
Let’s start with a study conducted by the University of Valencia to determine the most effective way to train the paraspinal muscles, which run down both sides of your spine and play a major role in the prevention of back injuries.
Researchers had 25 people with no low-back pain perform two types of exercise for their backs: body weight exercises like lumbar extensions, forward flexions, single-leg deadlifts, and bridges; and two weighted exercises, deadlifts and lunges, using 70% of their one-rep max weight. Muscle activity was measured using electromyography, a technique of evaluating and recording electrical activity produced by muscles (the more and harder a muscle contracts, the more electrical activity takes place inside it).
The result: deadlifts most activated the paraspinal muscles. And it wasn’t even close. The deadlift’s average electromyographic muscle activity was 88% and peaked at 113%, whereas the back extension produced an average activity of 58% and peak of 55%, and the lunge an average of 46% and peak of 61%. The rest of the exercises’ average activities rang in between 29-42% (the supine bridge on a BOSU ball was the least effective, in case you were wondering).
Thus, researchers concluded, the deadlift is an incredibly effective way to strengthen the paraspinal muscles.
Another study conducted by the University of Waterloo set out to determine how much low-back flexion deadlifting caused, and thus how much strain it put on the vertebrae and lumbar ligament (as there were many claims that the lift put these things under tremendous strain, which could lead to injury).
Researchers used real-time x-ray imaging (called fluoroscopy) to watch the spines of elite powerlifters while they fully flexed their spines with no weights, and while they deadlifted over 400 pounds. With the exception of one trial of one subject, all men completed their deadlifts within the normal range of motion they displayed during full flexion. Ligament lengths were unaffected, indicating that they don’t help support the load, but instead limit range of motion.
So, as we can see, a proper deadlift effectively strengthens your entire back, including your erector spinae muscles, and doesn’t force anything unnatural in terms of range of motion. And in case you’re wondering, the major “no-no” in deadlifting is rounding your back, as this shifts much of the stress away from the erector spinae muscles to the vertebrae and ligaments…and this is what’s bad for your back.
Two Useful Variations of the Deadlift:
Sumo and Hex
While you can’t go wrong doing a full-range conventional deadlift, there are two useful variations that you should know about.
The sumo deadlift uses a wide stance (1.5-2 times the width of your shoulders) to shorten the range of motion and shearing force on the lower back. It also can feel more comfortable in the hips than a conventional deadlift, depending on your biomechanics (if you walk with your toes pointed out, the sumo may be better for you).
The downside of the sumo deadlift is the reduced range of motion, which results in less work done, which means less muscle development. Nevertheless, give this variation a try if you lack the flexibility to do a conventional deadlift, if it just feels very uncomfortable (certain people’s bodies are better suited to the sumo deadlift), or if it’s causing low-back pain.
The hex bar—or trap bar—deadlift is a great way to learn to deadlift, because it doesn’t require as much hip and ankle mobility to get to the bar, and it puts less shearing stress on the spine. It also allows you to lift more weight than the conventional deadlift, which may make it a more effective exercise for developing overall lower body power. That said, the conventional deadlift is more effective in strengthening the erector spinae muscles and hip muscles, because the hex-bar deadlift is more like a squat due to the increased load it places on the quadriceps.
So there you have it: deadlifting isn’t “bad for your back,” and to the contrary, is actually a great way to protect yourself against back injury and low-back pain. I think it should be included in all workout routines, and feel free to try all three variations to see which you like best.
And while someone who already has low-back pain or a disc injury will need to do a rehabilitation program of some kind before they can perform conventional deadlifts, this will often include sumo and/or hex deadlifts to gradually strengthen the erector spinae muscles and restore structural balance.
Oh and before I sign off, a caveat and comment:
Some people advocate deadlifting on unstable surfaces like the BOSU ball. Don’t bother with this—it decreases the effectiveness of the exercise.
Some people don’t deadlift because they believe regular squatting makes it unnecessary. They’re wrong. Research has shown that these two lifts are markedly different, training very different sets of muscles.
So, do you deadlift? What’s your favorite style? Have anything else to add? Let me know in the comments below!
April 1, 2013
Stretching Before Aerobic Exercise or Weightlifting: Yes or No?
The common reasons for doing stretches that involve holding stretched positions for various lengths of time, or static stretches, before exercise are the beliefs that they help prevent injury, make you stronger and faster, reduce muscle soreness, and accelerate recovery.
While anecdotal evidence would seem to support these claims–everyone from peewee soccer players to professional athletes stretch before or after training–what does science have to say about it?
Stretching and Preventing Injury
Many people stretch before aerobic exercise and weightlifting because they believe it will ward off injury. Research says otherwise.
For instance, a paper published in 2004 by the Center for Disease Control reviewed 361 studies on stretching before all kinds of exercise, and concluded that it doesn’t reduce injury rates. A study published by the SMBD-Jewish General Hospital did an analysis of their own and found the same: “stretching before exercise does not reduce the risk of injury.” A study published by McMaster University agrees.
In fact, according to Dr. Ian Shrier, a McGill University sports medicine specialist, it’s possible that stretching before exercise can increase your chances of injury due to the cellular damage it causes to muscle and its analgesic effect (it’s probably not a good idea to damage a muscle, increase your tolerance of pain, and then strenuously exercise it).
So where did this belief that stretching prevents injury come from, anyway? Well, the faulty logic hinged on the assumption that improved flexibility (which stretching definitely accomplishes) reduces the risk of injury.
Research has shown that most muscle injuries occur within the normal range of motion, however, and specifically during the “eccentric” portions of movements (the portion of movement wherein the muscle lengthens, such as when you’re lowering a dumbbell in a curl). Therefore, improving flexibility doesn’t do anything in terms of preventing injury, unless the activity calls for actions that require great flexibility (such as doing the splits).
Another reason this issue got confused is the fact that stretching is often done as a part of a more comprehensive warm-up routine that raises body temperature and involves repeated movements within the expected range of motion, which does prevent injury, whether you add static stretching or not. Scientists mistakenly attributed these benefits to stretching without the warm-up, and the myth was born.
Stretching and Strength and Muscle Growth
Many weightlifting routines begin with a series of stretches in the hopes of increased strength and muscle growth.
Is this just another myth?
Well, consider first a study conducted by the University of Milan. Researchers had 17 young males do a series of jumps from various squat positions, with or without stretching beforehand. Jump height, power, and maximum velocity were all lower in the group that stretched for 10 minutes before the jumps.
Other research indicates that only static stretches of longer duration (over 60 seconds) negatively impact maximal muscle performance, whereas shorter static stretches (under 30 seconds) don’t improve performance, but don’t impair it either.
There are various theories for why stretching can reduce strength and power. Some researchers believe that loose muscles and tendons can’t contract as forcefully as shorter ones, whereas others point to evidence that stretching interferes with signals from the brain that tell muscles to contract.
And what about stretching and muscle growth? Well, you’re probably not surprised to learn that research has proven false the claim that stretching helps more deeply activate muscles and stimulate additional growth.
Stretching and Speed
Louisiana State University conducted a study in 2008 to determine how stretching affects the speed of sprinters.
They took 19 of their top sprinters and had them perform three 40-meter sprints in two sessions, separated by a week each. Before each session the runners performed a warm-up routine, and added four static stretches of the calf and thigh before one of the sprint sessions.
The result?
The stretching slowed them down by one-tenth of a second, with most of the loss occurring in the second half of the sprint.
Miami University conducted a similar study with 18 collegiate sprinters, and their research revealed that static stretching resulted in “a significant slowing in performance … in the second 20 (20-40) m of the [100 m] sprint trials.”
Stretching and Muscle Soreness and Recovery
Next on the chopping block is the myth (sorry for spoiling the surprise) that stretching reduces muscle soreness resulting from exercise and accelerates recovery.
It used to be believed that muscles damaged by exercise would spasm, which then blocked blood flow and caused the pain we know as delayed-onset muscle soreness (DOMS). As stretching helps alleviate spasm, it was hypothesized that it would alleviate post-workout muscle soreness.
While the spasm theory was debunked in 1986, the stretching advice has lingered to this day. Well, evidence of its ineffectiveness in reducing DOMS is readily available.
For instance, the University of Sydney published a paper in 2008 involving the review of 10 studies on stretching and muscle soreness. It concluded that “muscle stretching does not reduce delayed-onset muscle soreness in young healthy adults.”
Another study, this time by the University of Western Australia, demonstrated that neither hot/cold therapy nor post-exercise stretching helped elite rowers recover from stair-climb running. They published another study with football players demonstrating that post-game recovery is not enhanced by stretching, either.
Is Stretching Good For Anything, Then?
While static stretching doesn’t help prevent injury, increase strength, speed, or muscle growth, and doesn’t reduce soreness or accelerate recovery…it does have its uses. If you’re going to engage in a sport or activity that requires a high amount of flexibility, then static stretching can help. It’s also best to do static stretches when your muscles are warm (like after exercise, for instance).
There is one form of stretching, however, that has actually been shown to improve strength, power, muscular endurance, anaerobic capacity, speed, and agility: dynamic stretching.
Unlike static stretching, dynamic stretching involves movements that repeatedly put muscles through the expected ranges of motion, such as air squats, leg kicks, side lunges, arm circles, and so forth.
Dynamic stretching accomplishes several things that improve performance–it increases the suppleness of and blood flow to the muscles, raises body temperature, and enhances free, coordinated movement–and it can and should be done before any type of exercise (and this is why I recommend several warm-up sets when weightlifting that progressively increase blood flow to the muscles that will be trained, before you load your working weight).
What are your thoughts on stretching? Love it? Hate it? Let me know in the comments below!
