Whey to go to refuel after exercise
04 April 2006
Whey to go to refuel after exercise
Little Miss Muffet seemed to know a thing or two when she sat down to eat her curds and whey. Whey, once a waste by-product of cheese-making fed to pigs, is a rich cocktail of health-giving nutrients, which a new study has shown may help to refuel muscles depleted by sustained, strenuous exercise.
Massey University researchers Dr Alison Darragh, now Principal Research Scientist at global dairy company Fonterra, and Master of Science student Dean Rankin, found that athletes recover more quickly after prolonged exercise when they are given a recovery drink which combines whey protein and carbohydrate.
Most sports recovery drinks on the New Zealand market contain only carbohydrate. However, Fonterra Innovation has developed a bland-tasting, clear whey protein ingredient which provides consumers with the benefits of dairy protein nutrition without the look or taste of milk. The ingredient is sold to several leading international sports nutrition companies.
The researchers looked at post-exercise recovery in 12 elite, endurance cyclists who cycled continuously until they were exhausted. The speed of their post-exercise recovery was measured, based on key physiological indicators such as their blood glucose and insulin levels.
The independent study showed that the addition of whey protein to a carbohydrate drink, given to the cyclists for up to three hours following exercise, spiked the body’s insulin response by some 30 per cent, compared to a carbohydrate-only drink. The combined protein and carbohydrate beverage also lowered blood glucose levels.
Dr Darragh says the findings support earlier research which shows that higher levels of insulin circulating in the bloodstream enable the body to uptake glucose more quickly to replenish glycogen, the body’s energy stores, which are depleted in the muscles and liver during exercise.
Insulin is also known to play an important role in helping the body to rebuild muscles in which the protein has been broken down or damaged by exhaustive exercise.
Dr Darragh says that past most research in sports nutrition has focused mainly on enhancing performance by ensuring top nutritional practices before and during exercise with little research on post-exercise recovery. Post-exercise nutrition research has also focused extensively on carbohydrate replacement and its effect on recovery of the athlete.
Although the Massey study is small, she says, the results indicate that protein plays an important role in speeding up post-exercise recovery and in enabling athletes to perform again more quickly at their peak by stimulating the production of insulin and providing the essential building blocks needed to help muscles recovery.
Muscle protein is degraded quickly during vigorous exercise, like running, and this process continues for some hours following exercising.
“So if you can get protein into the system quickly, the body starts to resynthesise or ‘repair’ itself more rapidly. The body normally turns over something like a kilo and a half of protein every day. People who are exercising a lot turn over much more protein than this so have a greater need to replace it.”
Whey protein, which makes up 80 percent of the protein found in human milk, appears to have advantages over other types of protein in sports recovery, says Dr Darragh.
“It is classed as a ‘complete’protein. It contains all the essential amino acids in sufficient amounts to match our protein requirements and is easier to digest and to absorb than alternative proteins, making it an ideal protein for use in exercise recovery beverages.”