Dr. Don Kirkendall is world renowned exercise physiologist / injury specialist with experience at the highest levels of the game. He is a member of the U.S. Soccer Sports Medicine Committee, a fellow of the American College of Sports Medicine and is a member of the editorial board of Soccer Journal. Dr Kirkendall works with all the US National teams on many aspects of nutrition and sports injuries. He is a much sought after presenter and writer on subjects ranging from high performance nutrition to sports injury prevention.
Practical Nutrition Tips for Soccer Players
Key challenge: Soccer matches are long and involve infrequent stoppages, few substitutions, and substantial amounts of high-intensity action. Therefore soccer matches often result in large fluid losses due to sweating and significant depletion of muscle glycogen stores.
Late in the game, players tend to become dehydrated and fatigued. This can lead to costly mistakes (goals allowed) and injuries. Approximately 30% of goals are scored in the last 15 minutes of games. In the France World Cup, nearly 50% of all goals scored in the quarterfinals, semifinals and final match were scored in the last 20 minutes of each game.
Recently, my colleagues and I completed a three-year study on youth soccer injuries. We found that nearly 25 percent of soccer injuries occur during the last 10 to 15 minutes of games. This is similar to findings in the Premier League in England. Fatigue appears to be an important factor in the disproportionate occurrence of injuries late in matches. When players get tired, their reaction time slows and their judgment deteriorates.
The best way to limit net fluid losses and conserve muscle glycogen stores is, of course, to frequently consume a sports drink throughout games. However, due to the infrequency and brevity of stoppages and the sheer size of the playing field, drinking opportunities can be few and far between.
In order to maximize these opportunities, teams should arrive at each game supplied with at least one large squeeze bottle per player filled with a cold sports drink. Several bottles should be placed around the perimeter of the field, a couple of bottles in each goal, and several more at the bench. Coaches should encourage their players to drink from the nearest bottle once every 10 to 15 minutes, when an opportunity presents itself. The hotter the weather, the more frequently players should drink.
At halftime, players should drink at least 6 to 8 ounces of sports drink. It is also helpful to drink several ounces within 10 minutes before the start of a game. Remember, not all sports drinks are the same. A fluid and electrolyte drink is not the same as a carbohydrate replacement drink. Tests have shown that sports drinks containing carbohydrate and protein in the right balance are most effective in keeping carbohydrate levels up. (Most sports drinks have no protein.)The carbohydrate provides the fuel source while the protein helps get the fuel into the muscles more quickly.
A recent study performed at St. Cloud State University compared the effects of a sports drink containing carbohydrate and protein to a sports drink containing only electrolytes on sprinting speed at the end of a long training session. Following an intense workout of 75 minutes, the subjects participated in four speed trials with five minutes of rest after each sprint. Half the players drank the carbohydrate-protein drink while the other half drank an electrolyte-only drink. The carbohydrate-protein group actually improved their speed by 1.1 seconds between the first and last sprints, while the other group decreased their speed by 2.2 seconds.
As soon as the game is over, players should consume another 10-16 ounces of a carbohydrate-protein sports drink to accelerate muscle recovery. This is especially important in tournament situations when another game might follow in the afternoon or next morning.
This article is reprinted with permission from The Performance Zone (Basic Health, 2004).