Rookie of the Year, Matt Kenseth, were the subjects of a hydration
study that was conducted at the Chevy Monte Carlo 400 in Richmond,
Va.Scientists from the Gatorade Sports Science Institute (GSSI) monitored Mark and Matt throughout the 400-lap, three-hour and 13-minute event to determine how well NASCAR drivers replace the fluids they lose through sweat during a race. In the grueling heat of a race, cockpit temperatures can often soar well beyond 115 degrees, placing drivers at risk for dehydration, heat illness and impaired performance.
Mark's estimated total sweat loss during the race was 4.5 liters (153 ounces), nearly equivalent to 10 lbs. of bodyweight. However, Mark replaced 78% of his total sweat loss by drinking 3.52 liters (119 ounces) of fluid. Mark still experienced a final bodyweight loss of more than 2 lbs., and a post-race urine sample indicated significant dehydration even with this modest 2-lb. fluid deficit.
"Although Mark did a pretty good job of replacing the fluids he lost, he was significantly dehydrated before the race even began," said Bob Murray, Ph.D., director of GSSI. "That means Mark has an increased potential for heat-related problems and is more likely to experience a deterioration in physical and mental performance."
Through his continued work with GSSI scientists, Mark has learned more about the important role hydration plays in his ability to perform at his best on the racetrack.
"The battle to stay hydrated during a race is as severe as I thought it would be, if not more," said Mark. "We just haven't figured out how to do a better job than we are doing, but with help from scientists and sports nutritionists, we will keep working on it."
Matt also completed the race, but was off the track and out of his car for nearly an hour due to a mid-race crash. Because he spent less time exposed to intensive cockpit temperatures, Matt's fluid loss was less dramatic than Mark's.
According to GSSI, Matt lost 2.1 liters (70 ounces) of sweat. Yet, by drinking 1.66 liters (56 ounces) of fluid during the race, Matt was able to replace 81% of the fluid he lost, leaving him fairly well hydrated.
"As far as we know, this is the first time anyone has studied fluid balance in NASCAR drivers during an actual race," added Murray. "We have a lot to learn about how these athletes physiologically cope with the rigors of their sports and need to develop specific drinking strategies to help them avoid the ill effects of dehydration and heat stress."
Overall, both Mark and Matt experienced levels of fluid loss similar to those experienced by other endurance and team sport competitors, such as marathoners and football players. But they did a better job of replacing fluids than several athletes GSSI has studied from these sports.
The Gatorade Sports Science Institute (GSSI), headquartered in Barrington, Ill., is a research and educational facility dedicated to enhancing the performance and well being of athletes. Research conducted by GSSI and in conjunction with leading universities throughout the world has resulted in hundreds of studies published in peer-reviewed scientific journals. For more information about sports nutrition and exercise science pertaining to The Gatorade Company, visit the Gatorade Sports Science Institute web site at www.gssiweb.com or www.gatorade.com.
