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Strength Training & Adequate Protein Intake

Strength Training & Adequate Protein Intake
by Dr. Edmund R. Burke


   Although strength training can be extremely intense, each bout is very brief, making it very unlikely that amino acid oxidation will play an important role in providing energy for this type of anaerobic exercise. Carbohydrates are the major fuel for this type of exercise. For this reason, if you train heavily with weights, you need to consume sufficient dietary carbohydrates to provide energy for this high-intensity exercise. However, published results suggest that additional dietary protein can enhance strength gains as well.

   In one study, five subjects who consumed diets consisting of 0.8 g/kg of body weight per day of protein and adequate calorie intake experienced decreased muscle cell mass over six weeks of strength training. With continued training and an increase in protein intake to 1.6 g/kg, cell mass increased. A nitrogen balance study of bodybuilders demonstrated an increased protein need relative to controls and estimated the RDA for bodybuilders to be 1.7 g/kg total. In another study, impressive strength gains of 5% and size of 6% were observed over several months of strength training in world class weight lifters when they increased their dietary protein from 1.8 to 3.5 g/kg of body weight per day.

   The protein intakes that seemingly produced substantial gains in muscle strength and size in the world-class lifters and bodybuilders are greater than the increased needs suggested by most of the studies utilizing the nitrogen balance technique. This may mean that, although a positive nitrogen balance can be maintained during a strength training program with a protein intake equal to or slightly above the RDA (0.8-1.2 g/kg), higher intakes are necessary to generate optimal gains in muscle size and strength. 

  Actually, some preliminary evidence of this possibility exists from a study which found greater nitrogen retention (estimated from dietary nitrogen minus urinary nitrogen) and greater gains in lean mass over four weeks of strength training when subjects consumed 2.4 g/kg of body weight per day compared to 0.8 g/kg. Together, these studies suggest that a protein intake in excess of the current RDA will enhance the gains in muscle strength and size induced by a strength program.

Note:  
kg = 2.2 lbs.

This report indicates the greatest gains in lean mass over four weeks of strength training when subjects consumed 2.4 g/kg of body weight in grams of protein per day.

Example: Body weight of 100 lbs. divided by 2.2 equals 45.454 kg body weight. 45.454 x 2.4 = 109 grams of protein per day.

Information provided by Universal Nutrition.