A Study in the British Journal of Nutrition has lead to articles in the national press recommending the consumption of a ?pint of milk? rather than a sports nutrition drink, claiming it is ?more effective than anything else at replacing the fluid and salts lost through sweat?.
So, should you be ditching your sports drinks in favour of milk or is this just hype?
The authors studied the effects of Milk as a post-exercise rehydration drink comparing it to Milk with added sodium, Powerade and Water. The subjects were all regular exercisers.
After an overnight fast the experimental trials commenced with the ingestion of 500ml plain water approximately 90 minutes before the trial. Urine was collected at the beginning of the trial and again, five hours after exercise.
The subjects then completed a series of ten minute cycling efforts in an environmental chamber set at approximately 35°c. Exercise continued in blocks with body mass loss being measured periodically until the subjects had lost approx 1.7 per cent of their initial body mass. Twenty minutes after this exercise subjects consumed one of the four experimental drinks equaling 150 per cent of their body mass loss.
Subsequent analysis revealed that milk was superior at rehydrating the body to water and a standard sports drink, with the milk with added sodium showing no extra benefit.
The result of this study would be no surprise to the scientist. A likely reason that the study was co-funded by the milk council. Unfortunately this evidence offers little practical value. The researchers were comparing a milk product to a sports drink mixed at a concentration designed for during exercise.
The results would have been more interesting if they had compared milk for rehydration with other post-exercise products which are mixed to a greater concentration. Sports nutritionists appreciate that mixing a small amount of protein (as naturally found in milk) with carbohydrate, at a higher concentration will deliver superior recovery and rehydration than a solely carbohydrate drink mixed at a six to eight per cent solution which is designed for during exercise.
In short, don?t ditch your sports drinks yet. There is little practical value in taking a milk drink out on the bike with you, after all its effects during exercise were not measured. After sport you may wish to rehydrate and recover with milk, but better still invest in a recovery formula which is likely to be lower in lactose offering superior digestion, whilst supplying other nutrients such as glutamine which can offer benefit after a tough ride.