Protein & Muscle
In our quest for an iconic physique whilst performing ‘under pressure’ at the gym, a myriad of dietary supplements have been marketed, claiming to help us overachieve, outperform and maximise the abilities of the human muscle. Protein supplements are becoming the macronutrient receiving the most attention from the bodybuilding and fitness community. Important functions of these supplements are that they promote positive nitrogen balance, thus providing an anabolic state for the growth and repair of muscles from strenuous and prolonged exercise. Protein sources rich in branched chained amino acids (BCAAs) are known to be higher quality as they have been demonstrated to increase muscle protein synthesis (MPS) and attenuate the breakdown of muscle from strenuous workouts. Modern technology has enabled us to obtain high-quality protein from vegetable and animal sources, mainly soy and whey protein isolates. However, there is an ongoing debate whether more protein is always good, or whether selective consumption of the BCAAs is more effective.
Soy Protein & Muscle Development
Soy is known to have a high concentration of BCAAs and also health-beneficial anti-oxidants (isoflavones) which help lower bad (LDL) cholesterol. However, there is insufficient evidence to support the added health benefits of soy protein supplements as they are usually the most refined form (soy protein isolate). It is also common misconception among bodybuilders that soy protein is unfavourable, as it is does not reduce testosterone levels or produce undesirable changes in lean muscle mass as shown by Kalman et al (2007)1.
Whey Protein For Bodybuilders
Whey has become the single most consumed and popular bodybuilding supplement given the higher concentration and bio-availability of BCAAs and essential amino acids (EAAs) compared to vegetable proteins. Additionally, whey proteins also have cysteine and methionine which can be converted to glutathione, an antioxidant. Common forms of whey are whey protein isolate (WPI) and whey protein concentrate (WPC). WPI is absorbed most effectively, whilst WPC contains a higher fraction of glycomacropeptide (GMP) whichcontains casein, thus providing a gradual release post-consumption. Hydrolysed whey reduces the risk of allergy to milk proteins. A recent 2008 review by Hayes and Cribb2 has shown that use of WPI can:
- Accelerate muscle strength recovery
- Increase lean muscle mass and
- Increase muscle fibre hypertrophy,
When compared to similar doses of protein or carbohydrate alone. Additionally it is observed that consumption of whey protein post-workout is effective in promoting a positive nitrogen balance conducive for MPS leading to hypertrophy (growth in size) over time. Most commercial supplements may also promote whey components such as alpha-lactalbumin, beta-lactoglobulin or GMP which are all important bio-available sources of EAAs including BCAAs. Another component of whey protein is lactoferrin, though in low quantities, commercial whey has antioxidant and antibacterial properties thus aiding immune function.
BCAAs For Lean Muscle
Among the eight EAAs required by humans for optimal health, the BCAAs consist of isoleucine, valine and leucine, a key amino acid in MPS. Generally, excess BCAAs are toxic to the body. However, during exercise and training, oxidation of BCAAs increases in skeletal muscle and its metabolites can be used to attenuate exercise-induced muscle damage, increase MPS and in energy production pathways (refer to ATP). One study showed that supplementation with BCAAs is able to reduce cortisol (refer to cortisol article) levels significantly in response to intense training and increasing testosterone and human growth hormone levels3. It has also been shown that small amounts of BCAAs before training is able to reduce muscle soreness4. Thus, the aim is to create an anabolic hormonal profile whilst decreasing recovery time. Additionally, this is beneficial to athletes in training adaptations. To date, BCAAs are gaining popularity and is reportedly more ergogenic than protein. The effectiveness of supplementation with BCAAs only, depends on each individual’s lean mass and physiological variations such as muscle oxidation of BCAA and larger physiques would have to consume more for adequate muscle uptake. It should be noted that athletes and professional bodybuilders receive professional nutritional counselling which aids in optimising the right amount of supplement to consume to maintain an anabolic profile.
Protein For Performance
Protein supplements are irrevocably the most popular marketed product for bodybuilders and have been shown to maximise training performance. Given the vast differences in workout regimes, constitutional profile and existing research, it is still too early to take sides on which supplement works best. Timing is important, as BCAAs or WPIs are best consumed before and immediately following workouts – to be expanded on in a later article. Currently, whey protein has been shown to be most effective at promoting growth in lean mass whilst BCAA is effective in promoting muscle growth, repair and endurance to weight training.
1. Kalman D, Feldman S, Martinez M, Krieger DR, Tallon MJ. ‘Effect of protein source and resistance training on body composition and sex hormones’. J Int Soc Sports Nutr 2007;4:4.
2. Hayes A, Cribb PJ. ‘Effect of whey protein isolate on strength, body composition and muscle hypertrophy during resistance training’. Current Opinion in Clinical Nutrition & Metabolic Care; 2008:11(1), pp 40-44.
3. Carli G, Bonifazi M,, Lodi L, Lupo C, Martelli G, Viti A. ‘Changes in the exercise-induced hormone response to branched chain amino acid administration’. Eur J Appl Physiol Occup Physiol. 1992;64(3):272-7.
4. Matsumoto K, Koba T, Hamada K, Sakurai M, Higuchi T, Miyata H. ‘Branched-chain amino acid supplementation attenuates muscle soreness, muscle damage and inflammation during an intensive training program’. J Sports Med Phys Fitness;. 2009 Dec;49(4):424-31.
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