On Sunday during the NASCAR Cup Series race in New Hampshire driver Matt DiBenedetto lost nearly 10 pounds due to the extreme heat.
Right before the Foxwoods Resort Casino 301 began, temperatures reached 94 degrees outside, meaning it was a lot hotter for the drivers. Inside the car can get up to 120 or 130 degrees on a normal day, and that increases during heat waves like drivers saw on Sunday. Coupled with the gear they are wearing, the conditions can be borderline unbearable, and no, the cars do not have built in air conditioning.
Dale Earnhardt Jr. said on his podcast that he estimated that drivers lose an average of six to eight pounds per race. He noted this weight loss usually comes from water weight from the driver's preparation for the conditions but it is common for drivers to suffer from dehydration while racing.
Making it through the race and the extreme temperatures requires endurance from those on the track. Drivers are also dealing with G-forces that wear on the body and 130-degree turns while going 200 miles per hour.
Even for physically fit drivers like DiBenedetto, the race increases your heart rate significantly.
Landon Cassill, another fit driver who did a half-marathon just days before the Daytona 500, had a maximum heart rate of 173 beats per minute during Sunday's race.
DiBenedetto finished fifth and Cassill came in 26th at the New Hampshire race.
Former NASCAR driver now FOX Sports analyst Jamie McMurray said his average heart rate after a race in New Hampshire was comparable to his heart rate during a 100-mile cycling race up a mountain.
The race on Sunday proved just how difficult it is for drivers and how the conditions of a race affect the body.
Kevin Harvick picked up his first win of the season at the Foxwoods Resort Casino 301.