When football stars swig and shoot
‘CARB RINSING’ MAY JUST HELP TRICK THE BRAIN A LITTLE BIT TO GIVE THE BODY A BOOST, EXERCISE AND NUTRITION
Harry Kane, England’s captain and the World Cup’s leading scorer, has at times appeared more interested in rinsing his mouth with fluid than swallowing it during the tournament.
Late in an epic second-round match against Colombia that extended through 30 minutes of added time and penalty kicks, Kane vigorously squirted his sports-drink bottle into his mouth. Then he expectorated a geyser of fluid instead of ingesting it.
So have many players on other teams. Cristiano Ronaldo, the Portuguese star, took swigs from his bottle and expelled the drink in dots and dashes in a kind of aquatic Morse code.
Some players may want to avoid feeling bloated and are simply refreshing their mouths in the heat. But others appear more deliberate and purposeful. Players are notoriously cloistered during the World Cup and are especially loath to speak about their fitness secrets, so the contents of their bottles are not known. But they may be employing a technique called ‘carb rinsing’ or ‘mouth washing,’ according to some exercise and nutrition scientists.
For more than a decade, research in endurance sports like cycling and running has shown that athletes can gain a performance boost during intense bouts of exercise by rinsing their mouths with a carbohydrate solution, then spitting it out without swallowing.
Cycling research
Essentially, scientists say, receptors in the mouth send signals to the pleasure and reward centres of the brain, suggesting that there is more energy on the way, so the muscles can push a little harder and there is no reason to feel so fatigued.
“You’re sort of tricking the brain a little bit; that’s what we think the mechanism is,” said Asker Jeukendrup, an exercise physiologist and sports nutritionist who, with colleagues at the University of Birmingham in England, detected in 2004 that carb rinsing made cyclists about a minute faster in 40-kilometre cycling time trials.
England’s national team declined to discuss its nutritional tactics at the World Cup. But a person familiar with the team’s regimen acknowledged that carb rinsing was something the squad “has been seen to do in the past” and was considered a “fairly standard practice.”
Scientists also say that the technique can be beneficial in avoiding stomach distress that can occur from swallowing carbohydrate fluids.
The research indicates that carb rinsing can enhance performance when fluids are swished around the mouth for 5 to 10 seconds, the longer the better as more oral receptors come into contact with carbohydrates.
“I wouldn’t say it’s widespread yet” in the World Cup, though players seem to be carb rinsing more often than in the past, said Jeukendrup, who is now a professor of exercise metabolism at Loughborough University in England.
“I hope it’s all deliberate,” he said. “It’s good to see science making its way into real sport.”
Of course, carb rinsing alone cannot sustain players for an indefinite period. Carbohydrate fuel must also be ingested as the body’s muscles become depleted of glycogen, a stored form of glucose used to provide energy during exercise. Otherwise, players will eventually run out of gas.
Most research indicates that carb rinsing is optimal for intense exercise lasting between 30 minutes and an hour. Given that a football match lasts at least 90 minutes and can stretch to two hours in the knockout rounds of the World Cup, the technique might be “the wrong thing to do,” said Lindsay Bottoms, an exercise physiologist who is the lead researcher for sport, health and science at the University of Hertfordshire in
England.
Research into the potential benefits of carbohydrate ingestion for football performance is in its relative infancy. There are few chances to drink fluids beyond pregame and halftime. No one has figured out yet the optimal amount of carbs that must be swallowed to gain a boost.
Benefits to running endurance are fairly clear in the research, said Jeukendrup, the scientist behind the cycling study. But what is less certain, he has written, is whether drinking carbohydrate solutions improves football-specific skills like dribbling, passing, shooting and heading, either by postponing fatigue or by affecting processes in the brain.
Measuring football skills is extremely complicated and subject to many variables.
With carb rinsing, many tantalizing questions remain unanswered: Does it affect cognitive function? Decision-making? Reaction time?
As the World Cup nears its end, a carbohydrate rinse, manufactured by a New York company called Unit Nutrition, has become commercially available.
Researchers at Michigan State University are measuring brain activity in college-age students to try to determine how long a potential performance boost from mouth washing lasts and whether Unit Nutrition’s glucose rinse might improve the focus of athletes and other users.
Most research indicates that carb rinsing is optimal for intense exercise lasting between 30 minutes and an hour.
Brain activity study
The results are “very preliminary” but suggest the performance boost lasts about 15 minutes.
The rinse seems to counteract fatigue and enhances attention to a task, said David Ferguson, an assistant professor of exercise physiology at Michigan State.
What it is likely to do ghough, he said, is “it’s simply going to maximise their focus so that they are not succumbing to fatigue, so they can put themselves in the right position to make the right play.”