Many body builders and weight lifters are overly concerned about what they eat and what food supplements they take. If you want to grow larger and stronger muscles, you should concentrate on lifting weights, but you can help muscles grow larger by understanding how what you eat affects how you recover from hard exercise. Just exercising will not make you strong and it will not help you to grow large muscles. If the amount of time spent exercising was what made you strong, marathon runners would have the largest muscles. The only stimulus to make muscles larger and stronger is to stretch them while they contract. When you lift a heavy weight, your muscles start to stretch before they start to contract. This tears the muscle and causes soreness on the next day and beyond. If you rest and let the muscle heal, it will be stronger than before you stretched it lifting weights.
The training principle of stress-and-recover is so strong that you can enlarge a muscle by lifting weights even if you are fasting, losing weight and all your other muscles are getting smaller. In one study, obese, un-athletic women were instructed to restrict food and lift weights. They averaged a weight loss of more than 35 pounds in three months and gained a lot of muscle.
Training for sports is done by taking a hard workout and then having sore muscles on the next day. Then you take easy workouts or you take off until the muscle soreness disappears. You improve by taking hard workouts and your muscles grow and heal while you recover on your easy days. Of course, if you could recover faster from a hard workout, you could do more work and be a better athlete. Scientists have known for years that you recover faster by eating carbohydrates immediately after you finish your hard workout (2). Other studies show that eating extra protein on the day that you take hard workouts helps you recover even faster. Eating extra protein reduces muscle damage during hard exercise (3). Eating carbohydrates along with a protein building block called leucine helps you to recover even faster (4).
Chronic muscle fatigue in athletes can be associated with low blood levels of amino acids, the building blocks of proteins (1). The sooner you eat protein after you finish your hard workout, the quicker you will recover. The benefits of eating protein soon after you lift weights does not apply just to elite athletes. A study from the University of Arkansas showed that eating protein helps older people grow large muscles when they also lift weights(5). Muscles are made primarily from protein building blocks called amino acids. Muscles heal from a hard workout when amino acids and other nutrients travel from your bloodstream into the muscles. Eating food, particularly protein, immediately after you finish your workout helps muscles heal faster. This study showed that men between the ages of 51 and 69 recovered faster and grew larger muscles when they ate meat than when they ate only dairy, fruits, vegetable, whole grains, beans, seeds and nuts. However, any source of protein will be effective, such as seafood or beans plus whole grains. You do not need to eat meat or take protein supplements to build muscle. See How Protein Builds Muscles and Protein Supplements Don't Make You Stronger
1) JE Donnelly, T Sharp, J Houmard, MG Carlson, JO Hill, JE Whatley, RG Israel American Journal of Clinical Nutrition OCT 1993;58(4) .
2) KJ Kingsbury, L Kay, M Hjelm. Contrasting plasma free amino acid patterns in elite athletes: association with fatigue and infection. British Journal of Sports Medicine 32: 1 (MAR 1998):25-32.
3) Nancy Rodriquez. The Journal of Nutrition July, 1999.
4) Hayward R et al. Effects of dietary protein on enzyme activity follwoiing exercise-induced muscle injury. Med Sci Sprts Exerc. March, 1999. 31(3):414-420.
5) WW Campbell, ML Barton, D CyrCampbell, SL Davey, JL Beard, G Parise, WJ Evans. Effects of an omnivorous diet compared with a lactoovovegetarian diet on resistance-training-induced changes in body composition and skeletal muscle in older men. American Journal of Clinical Nutrition, 1999, Vol 70, Iss 6, pp 1032-1039.