Muscle Mass

The following study proves that body composition and not body mass index (BMI) is the a more important factor in determining mortality, or death.  BMI has for decades been the simple measurement used by life insurance companies and doctors to determine a person's expected health outcomes.  This study, however, found that relative muscle mass was a better predictor of how long the subjects lived.  The subjects with greater relative muscle mass lived longer than those with less muscle mass.

This is why measuring body composition (body fat:muscle mass ratio) is an important part of being involved in an exercise program.  If you're trying to lose weight, make sure your body fat percentage is going down along with your weight so that you don't lose too much muscle mass.  If you're trying to gain weight, make sure you're gaining predominantly muscle, and not fat.

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