In the last decade, CrossFit and similar fitness regimes have swept the nation. CrossFit alone has grown to become a global competitor, amassing more than 9000 gyms in countries all over the world. With these types of training programs, exercisers are immersed in a high intensity workout routine.

A large part of the appeal to these types of exercise programs lies in the social side to the sport. When 2014 CrossFit Games Champion Camille Leblanc Bazinet had to stop her favorite sport, gymnastics, she says, “I’m too driven to not do anything–I was trying to find a new challenge, and now I have this amazing sport that I’m actually pretty good at.”

Participants of high intensity workout programs can receive a vast amount of social support and motivation. On the flip side, athletes run the risk of health problems when their body is pushed beyond its limits. Muscles can be pulled, and some high intensity workouts have been linked to heart attack and stroke. Co-Founder of The Spun Matt Lombardi says, “I simply wanted to get back in shape. I could have killed myself in the process.” The Spun is an independent sports medium.

When Lombardi began the popular P90X training program, he found himself approaching the exercises rather easily due to his athletic past. A couple days after the first workout, and Lombardi was experiencing painful symptoms. Not only was he incredibly sore, but he also noticed swelling in the major muscle areas that had been worked out.

Another day passed and the pain in his muscles only grew, now hardly able to move them at all. His urine was dark. Lombardi had a rare but serious condition that is often linked to high intensity workout and training, rhabdomyolysis. Commonly referred to as “rhabdo”, victims of this condition can experience kidney failure or even fatality. In rhabdo, muscles continuously break down. This process continues until parts of the muscles enter the bloodstream. At this point the kidneys are overloaded.

Sometimes referred to as HIITs, or high intensity interval training, exercisers can experience a decrease in fat and slim down faster than the tried and true workout of burning fat. Auburn University Professor Michele Olson notes how one form of HIIT resulted in 13.5 calories per minute, whereas her findings revealed a burning of 6 to 8 calories per minute in a regular cardio program.

UNCW senior Alexandra Scott, 20, terminated her involvement in the CrossFit program when she realized the training might run her the risk of jeopardizing her health. She says, “The people and the atmosphere were wonderful and supportive, but physically my body couldn’t handle it.”

Preventive measures exist to keep athletes from experiencing serious conditions such as rhabdomyolysis. According to Benjamin Wedro, MD, the easiest way to avoid health risks from high intensity training programs is to carefully plan a workout. Athletes should consume plenty of water and avoid extreme heat conditions.

Lombardi spent five days in the hospital before being released by his doctor. While he recovered from his rhabdomyolysis with no lingering effects, Lombardi’s story acts as a cautionary tale to us all, serving as remembrance to the importance of preventative measures for athletes that wish to join high intensity training programs.