Lean Body Mass and Protein

Posted: 1st October 2012 by Jon in Exercise and Fitness, Strength

For  those individuals wanting to gain lean body mass, two important characteristics of protein consumption need to be addressed—the quantity of protein required and the types of protein consumed.

A whole host of variables influence the amount of protein for the strength and power athlete. These include energy consumption, quality of protein, carbohydrate consumption, exercise specificity, and intensity of training as well as overall nutrient timing. It is important for the reader to understand that protein recommendations are based on the assessments of nitrogen balance and amino acid tracer methodologies (1). In particular, the nitrogen balance assessment entails measuring the total amount of protein entering the body and the total amount leaving the body through excretion (1). However, many of these research studies may underestimate the amount of protein necessary for training adaptations to occur due to discrepancies in methodology, as they aren’t directly associated with areas of sports performance. Nonetheless, the International Society of Sports Nutrition (ISSN) recommends that individuals, especially athletes, ingest protein amounts ranging between 1.4 and 2.0 grams per kilogram of body mass per day. Athletes engaging in endurance sports should ingest protein at the lower level of this range. However, strength and power athletes should consume protein at the upper level of this range (2).

Whey Protein

Whey protein is still regarded as one of the premier proteins available for consumption, specifically whey isolates, which are quickly absorbed and have high levels of amino acids with almost zero lactose (i.e. < 1.0 percent). However, casein is roughly composed of 80 percent bovine milk protein, is absorbed less rapidly, and only holds 10–20 percent less of the essential amino acids per grams of protein. A 2006 study by Cribb (3) and colleagues showed that 13 recreational bodybuilders who supplemented with 1.5 grams of whey protein isolate per kilogram of body mass per day increased considerably more lean mass (4.2 kg) and strength (23 kg in the squat, 30 kg in the bench press, and 15 kg in the lat pull-down) than participants consuming an equal amount of casein during a ten-week supervised strength training protocol. Interestingly, those subjects in the whey isolate group also lost 1.4 kilograms of body composition while those in the casein group had no change.

In addition, the total protein amount was separated into four matched servings and ingested throughout the day for all meals, including post-exercise training. The results of this study demonstrate that when engaging in resistance training while supplementing with whey protein isolate, whey protein produces better improvements in lean body mass and strength and decreased body composition in comparison with casein. In another study by Wilkinson and colleagues (4), fifty-six novice weightlifters trained five days per week for twelve weeks using a split resistance training regimen. Subjects were randomly assigned to ingest fat-free milk protein, fat-free soy protein, or a control liquid carbohydrate. Each beverage was consumed immediately post-exercise and repeated one hour after. Muscle fiber size, body composition, and maximal strength were measured before and after the twelve-week training session. No changes were found for the between group as far as differences in strength and type 2 muscle fiber area.

 

However, a significant increase in lean body mass was seen in the milk group than with the soy or control group. The subjects in the milk and soy group had increased type 1 muscle fiber areas. However, the milk consuming group yielded a greater increase than the control group. A larger decrease in fat mass was also seen in the milk group than in the soy and control groups.

The results of this study indicate increased muscle hypertrophy in novice weightlifters, at least in the short term, when compared to an isoenergetic soy or carbohydrate intake.

Practical application

Due to a wide variety of factors involved, it isn’t yet possible to formulate any definitive recommendations concerning protein intake for maximizing sports performance. However, athletes and coaches are encouraged to follow these practical approaches and guidelines, which are made in accordance with the current literature:

  • Athletes aspiring to gain lean body mass should refrain from training in a fasted state and abstain from the fasted state immediately following any post-exercise training session. Although athletes should already be consuming adequate amounts of calories, any training induced increase in strength and lean body mass can be greatly enhanced when athletes adhere to appropriate pre- and post-workout dietary practices.
  • Any amino acid quantity for the highly trained athlete in the peri-workout period is most likely higher than reported in the scientific literature, especially when higher training volumes or total body training sessions are used.
  • The essential amino acids consumed prior to resistance training promote a greater increase in muscle protein synthesis than when consumed post-exercise. Conversely, whole whey proteins consumed before or following strength and power training produce parallel effects via amino acid concentrations despite any nutrient timing.
  • An important recommendation for strength and power athletes is to consume a post-workout combination of roughly a 2:1 ratio of carbohydrates to protein. Specifically, the protein intake should be 0.25–0.50 grams per kilogram of body mass. For those athletes involved in team sports, a 3:1 ratio is recommended, and endurance athletes are encouraged to increase this ratio to 4:1. In addition, these combinations should also be consumed one to two hours afterward for a minimum of six hours post-training. For example, three to four post-training meals should be ingested within a six-hour period following exercise. Some athletes may be worried about overall calorie intake. If this is the case, essential amino acids can be an effective alternative in place of whole protein with consumption of 0.15–0.30 grams per kilogram of body mass.
  • Considering that strength and power athletes have their own individual unique nutritional requirements, both athletes and coaches are persuaded to talk with qualified and credible sports nutritionists to address any issues in order to maximize their individual sports performance.

References

  1. Rand WM, Pellett PL, Young VR (2003) Meta analysis of nitrogen balance studies for estimating protein requirements in healthy adults. Am J Clin Nutr 77(1):109–27.
  2. Campbell B, Kreider RB, Ziegenfuss T, La Bounty P, Roberts M, Burke D, Landis J, Lopez H, Antonio J (2007) International Society of Sports Nutrition position stand: protein and exercise. J Int Soc Sports Nutr 4:8–20.
  3. Cribb PJ, Williams AD, Carey MF, Hayes A (2006) The effect of whey isolate and resistance training on strength, body composition, and plasma glutamine. Int J Sport Nutr Exerc Metab 16:494–509.
  4. Wilkinson SB, Tarnopolsky MA, Macdonald MJ, Macdonald JR, Armstrong D, Phillips SM (2007) Consumption of fluid milk promotes greater muscle protein accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic soy-protein beverage. Am J Clin Nutr 85:1031–40.