Whey proteins: Endurance, Muscles and Strength
Whey proteins have a beneficial effect on muscle synthesis; muscle strength; endurance; recovery; body composition; and the immune system.
It supplies all the necessary amino acids for muscle synthesis in approximate proportion to their skeletal muscle ratios. All the essential amino acids (Branched BCAA and essential EAA) are present at a high level compared to other natural food protein sources.
Whey protein offers both EAA and the muscle-building BCAA.
| Protein Source | BCAA (g/100 gms Protein) |
| Whey protein isolate | 26 |
| Egg white powder | 22 |
| Milk protein isolate | 20 |
| Soy protein isolate | 17 |
The oxidation of the BCAAs in skeletal muscles is increased by up to 25% during exercise (McKenzie et al. 2000).BCAAs are directly metabolised by muscle tissue, and this makes them highly important to athletes.Other amino acids are metabolised by the liver.
Athletes have to cope with several physiological challenges; dehydration, depletion of muscle fuels and deficient recovery. A large volume of scientific research demonstrates that whey proteins provide the athlete with a number of benefits for coping with some of these challenges.
1.Muscle synthesis
Leucine and the other EAA play essential roles in the protein synthetic pathway, both as signalling molecules for initiation and as a substrate to synthesise new protein. Leucine is a unique amino acid that has independently been proven to stimulate muscle protein synthesis.
| Protein Source | Biological value | Protein Efficiency Ratio | Net Protein Utilization |
| Whey | 104 | 3.6 | 92 |
| Milk | 91 | 3.1 | 87 |
| Casein | 77 | 2.9 | 76 |
| Soy Protein | 74 | 2.1 | 70 |
| Whole Egg | 100 | 3.8 | 98 |
| Beef | 80 | 2.9 | 78 |
2.Muscle strength
Whey Proteins helps in the athlete’s capacity to improve performance in many power- and strength-based events.
In several trials involving strength training, whey protein supplementation provides significant muscle strength enhancement compared to carbohydrate and/or protein control groups (Cribb et al. 2002, 2006; Hayes & Cribb 2008). One of these trials found that whey protein isolates gave a significantly increased strength in exercises such as the barbell bench press and squat (10–20% better gains than matched control groups).
3.Endurance
Maintaining glutathione (GSH) helps to minimise oxidative stress and boost athletic performance. The role of the glutathione (GSH) antioxidant system is to protect cells against oxidative damage. The direct link between GSH and exercise performance which has been established by various studies.
During exercise, there is an increase in oxidative damage, and this is thought to be a major contributor to muscle fatigue and poor athletic performance.(Sen et al. 1994).
Whey protein is a rich source of cysteine. Various studies have shown that whey proteins are exclusive in their ability to boost GSH production compared to other sources. It has also has been observed that GSH increases with the amount of whey protein ingested.
4.Recovery
It is essential to athletes that they have adequate glycogen stores in their tissues, as glycogen is the body’s storage form of energy that fuels exercise. Low tissue glycogen level is associated with fatigue and poor performance.
Blood insulin level plays a vital role in the body’s uptake and storage of nutrients and carbohydrates. Ingestion of protein combined with carbohydrate can induce an up to 100% higher plasma insulin concentration compared to carbohydrate alone and a more excellent muscle protein net balance.
In particular, whey protein hydrolysate provides a great plasma insulin response and amino acid concentration compared to glucose and other protein sources (Calbet &MacLean 2002; Morifuji et al. 2010).
How it works :
Body Recovery is influenced by the effect of whey protein to stimulate insulin secretion.
A study using whey protein supplementation has shown that, compared to carbohydrate supplementation, it accelerates recovery after intense resistant exercise (Borsheim et al. 2004) with respect to maximum strength and probably also muscle damage.
It has been found that whey protein isolate can result in a more rapid recovery of muscle force generation capacity than carbohydrates. Whey protein hydrolysate also gives a more rapid recovery than non-hydrolysed whey.
5.Body composition lean mass
Scientific evidence indicates that whey proteins are tailored to promote a better body composition, especially when combined with resistance exercise. Several studies have shown that incorporating whey in the diet results in less fat storage, more lean tissue and higher insulin sensitivity in muscles than other protein sources.
6.Immunity
The immune system is influenced by exercise. During moderate exercise, the immune system may be boosted just as it may be suppressed after high-intensity or long-duration exercise. As mentioned above, the GSH antioxidant system is also essential for the immune system.