On September 17-19, 2003 the USOC held a summit on heat, hydration and pollution, looking specifically at how these environmental factors impact athletic performance. While the overall intention of the conference was to inform coaches about what to expect at the 2004 Olympics in Athens and how to prepare for the conditions there, a number of points were made that have relevance for tennis competitions as well. Instead of summarizing the entire conference, several informational "nuggets" have been pulled out and listed below.
Did you know....
• To fully acclimate to the heat and humidity in a new environment takes 14 days? There are many physiological changes that the body goes through as it adapts to heat and humidity. The last of these is an increased sweat rate, which occurs from 8-14 days after arriving in a new environment.
• 7-10% of athletes who compete in the summer months have exercise induced asthma (EIA) but do not exhibit ANY symptoms? If you work with a player who experiences difficulty breathing or fatigues rapidly on the court, it may be beneficial to have a pulmonary function test performed by a trained professional who can diagnose EIA. One point, the test should be performed before and after a strenuous workout to best assess any pulmonary deficits that occur during play.
• Athletic performance is negatively impacted by pollution, but amazingly the body is able to adapt to most types of pollution after a period of 4-7 days? This means that if a competition is held in a polluted environment it is possible to counteract some of the negative effects by arriving, and training, at the site several days early. There is one type of pollution that this does not hold true for. See below
• After exposure to carbon monoxide (CO) - for example training in a polluted environment or even traveling on the freeway with the windows open during rush hour - the body's ability to carry oxygen to the muscles can be significantly impaired? Runners who train in NY City have been found to have levels of CO in the blood ranging from 4-7% - this can impair vision and lead to premature fatigue. The effects from a single exposure to CO can last up to 48 hours and the body DOES NOT adapt to repeated exposures to CO. Consider this when preparing for a competition. Even something as simple as walking around downtown or going outside for lunch may have a serious negative impact on performance.
• The average player will sweat between 1-2.5 liters every hour? However, there is great variability and some players can sweat over 3 L/ hour. Sweat loss does not necessarily relate to Sodium loss (Sodium is an essential electrolyte that is needed to avoid heat cramps). A player with a low sweat rate can have highly concentrated sweat and a player with a high sweat rate can have very dilute sweat (low concentration of Sodium). So even though a player may not sweat much it does not mean that he or she does not need to replace electrolytes during and after play. Sport drinks are recommended for all players, regardless of how much they sweat.
For further information on these topics, or to ask specific questions, please contact the Sport Science Department at firstname.lastname@example.org.