OKINAWA CITY, JAPAN -- By incorporating sprint interval training into his regular exercise regimen, 1st Lt. Rob Gerdes of the 3rd Reconnaissance Battalion has earned a spot to compete in the CrossFit Games slated for July 10-12 in Aromas, CA.

The Clara City, MN, native first discovered CrossFit training online, then began practicing it with fellow Marines. CrossFit instructors held a course in Okanawa, Japan, earlier this year that trained about 40 Marines in the 3rd Division to be Level One CrossFit trainers.

Gerdes also began attending the CrossFit Asia gym in Okinawa City to further develop his training.

One of Gerdes’ typical workouts consists of a 400-meter dash, 21 kettlebell lifts and 12 handstand push-ups—all repeated three times.

While Gerdes told military media he was initially skeptical of the benefits of CrossFit training, recent studies suggest that sprint interval training increases endurance as well as longer workouts.

Research by Martin Gibala, chair of the Department of Kinesiology at McMaster University in Hamilton, Ontario, Canada, found that two groups of college students showed nearly identical endurance increases, though one group rode stationary bikes for 90 and 120 minutes, and the other group rode for short, strenuous 20-30 second intervals. The short interval group also repeated the cycle four to six times for a total of two or three minutes of intense exercise.

"The high-intensity part is the part that makes most people back away from it [CrossFit]," Gerdes told military media. "I earned myself two days of pain, but it’s going to be a lot of fun."