Bigger Leaner Stronger: The Simple Science of Building the Ultimate Male Body

by Michael Matthews

When it comes to improving your body composition (how much muscle and fat you have on your bones), cardio is a double-edged sword. It burns energy and thus contributes to your fat loss efforts, but it can burn up muscle too. This detracts from your ultimate goal of building a lean, powerful physique, because that requires gaining a fair amount of muscle. Furthermore, if you want to gain muscle and strength as quickly as possible, then you want to limit your cardio for two reasons: In the short term, cardio can interfere with strength and muscle gain by making you more generally fatigued, which makes it harder to progress in your weightlifting workouts.26 In the long term, cardio can interfere with strength and muscle gain by disrupting cell signaling related to muscle growth.27 That doesn’t mean you should completely shun cardio, though. It does have significant health benefits—some of which you don’t get from resistance training—and it can help you burn more energy, which means faster fat loss and easier weight maintenance.