Many sports supplements make bold claims about boosting performance but only a few are backed up by credible research. In the first article of a new 5-part series on supplements, I look at the evidence for whey protein.
What is it?
When it comes to building muscle, whey protein is by far the most researched supplement. A by-product of cheese manufacture, it provides all nine essential amino acids and is rapidly digested and absorbed into the bloodstream, reaching muscles quickly.
What does it do?
“The biggest benefits for athletes lie in faster recovery, promotion of muscle synthesis and retention of muscle mass during periods of low energy intake,” says James Morton, researcher at John Moores University and lead nutritionist for Team Sky. “Our cyclists consume a whey shake during long [five to six-hour] rides to prevent excessive muscle protein breakdown, as well as immediately afterwards.” Whey contains high levels of leucine, which is both a key signal molecule for initiation and an important substrate for muscle protein synthesis (MPS). Whey may also help enhance the immune function thanks to its high content of glutamine.
What’s the evidence?
Whey supplements may help increase MPS following resistance training. In one study those consuming 20 g of a whey and casein supplement before and after resistance exercise had greater increases in muscle mass and muscle strength over 10 weeks compared with those consuming a placebo. Another study found that when athletes consumed a whey supplement immediately before and after a training session they could perform more reps and lift heavier weights 24 hours and 48 hours after the workout compared with those taking a placebo
But whey may also speed muscle recovery following endurance exercise. “We have demonstrated that ingesting whey protein immediately after endurance exercise enhances the remodelling of contractile muscle proteins during the early recovery period,” explains Oliver Witard, researcher at the University of Stirling. In a trial involving 48 volunteers, Stirling researchers found that 20g whey protein was the optimal level for maximising muscle repair after training. This is a ballpark figure; if you weigh more than 80kg (the weight of the athletes in the study), then you may need more, and vice-versa. Consuming more than 0.25g/ kg body mass produces no further gains in mass; the excess is oxidised and used as an energy substrate.
However, in studies where volunteers were already consuming adequate amounts of protein in their diet, consuming whey supplements before and after their workouts made no difference to MPS or strength.
If you are getting enough protein from food, there’s probably little point in taking supplements. You may prefer to drink milk (which contains whey naturally) as studies (here and here) have shown that it promotes muscle synthesis after resistance training. But if you have higher-than-average requirements, whey protein may be a convenient way of adding protein to your diet. Compared with casein or soy, whey may be a better option for increasing muscle protein synthesis in the immediate post-exercise period, but whether this extends over a longer period is not clear. Whey’s benefits lie in its high concentration of essential amino acids, fast digestion rate and high leucine concentration.
If you enjoyed this article and want to find out more about sports supplements, then read the new edition of my book
Fully updated to reflect the latest research, Sports Supplements is packed with clear, reliable and unbiased advice that will help you maximise your athletic potential. Renowned sports nutritionist Anita Bean takes you through each supplement and explains what they are, how to use them and if they really work – as well as suggesting other alternatives.