Both maintaining muscle and building new muscle mass depends on the protein content of your diet and your resistance training workouts. A lack of either one, especially if it continues over time, can result in loss of muscle mass. Including both in your regular routine can stop muscle wasting and restore any muscle tissue you may have lost.
The protein in your body does more than support your muscle mass. It provides structure to internal organs, manufactures immune cells, forms red blood cells and is an integral part of hormones and enzymes. If you don’t eat enough protein, your body turns to your muscle fibers and breaks them down to supply the rest of your tissues with the amino acids, or protein building blocks, it needs. Your cells then use these amino acids to synthesize new proteins you require – for instance, for antibodies or insulin. As the cannibalization of your muscles continues due to lack of dietary protein, the mass of your muscle tissue slowly diminishes.
Resistance or strength training, such as lifting weights, builds and maintains muscle mass. This type of exercise places loads on your muscle tissue that encourage the muscles to grow stronger. Lifting weights can therefore help prevent the loss of muscle mass due to physical inactivity. Although cardiovascular exercise is important for heart and lung health, and can contribute to some muscle maintenance, a well-rounded strength-training routine that targets all the muscle groups is most effective for maintaining muscle mass throughout your body.
Reducing your risk of muscle loss depends in part on your protein intake. As an exercising individual, your dietary protein must cover your body’s non-muscle amino acid requirements, the amino acids your muscles need due to protein oxidation and breakdown during exercise and the protein repair and maintenance that occur following your exercise session. While strength and power athletes whose goal is to pack on muscle mass might need up to 2.0 grams of protein per kilogram of body weight, most people can benefit from including 1.4 grams per kilogram for maintaining their current muscle mass.
In addition to sufficient dietary protein, the quality and quantity of your weightlifting sessions helps determine how well you keep the muscle you have. Including two to three workouts each week that target all your major muscle groups – arms, shoulders, legs, core and back – can help keep your muscle fibers strong and in good health. For each area of your body, performing between eight and 12 repetitions using a weight that is manageable yet challenging for the last few repetitions can benefit your physical well-being and stop you from losing muscle mass.
- Oklahoma Cooperative Extension Service: Protein and the Body
- American Family Physician: ACSM Guidelines for Exercise to Maintain Fitness
- Journal of the International Society of Sports Nutrition: International Society of Sports Nutrition Position Stand: Protein and Exercise
- American Council on Exercise: Weight Training Load Calculator
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