One common exercise myth is that doing too much aerobic exercise, or cardio burns muscle and causes muscle loss.

While it’s certainly possible this could happen, only extreme amounts of high impact, high intensity cardio would cause large muscle losses to occur. The muscle loss issue is usually highly exaggerated. If you’re in doubt, don’t guess: Carefully track your lean body mass with skinfold testing and adjust your cardio and nutrition accordingly.

Losing muscle is most likely caused by three factors: Inadequate caloric intake, inadequate protein or dieting without including a weight training program. You’re more likely to lose muscle from not eating enough than you are from doing too much cardio. If your lean body mass drops, it’s usually because you’re missing meals or not eating enough.

Provide yourself with the proper nutritional support, including adequate meal frequency, protein, carbohydrates and total calories, and it’s not likely that you’ll lose muscle, even with daily 45-minute cardio sessions. It’s ironic that so many people are worried about losing muscle from cardio when they’re skipping meals and eating meals without protein.