Falsehood #3: Cardio Is Great for Weight Loss Research shows prolonged cardio—logging long runs, for example—is an ineffective means to lose weight. By upregulating cortisol, the body’s stress hormone, cardio can have the complete opposite effect of what you’re trying to accomplish. It actually can contribute to your body holding on to the kind of “stubborn fat” so many people have trouble losing with traditional exercise routines.
