When Matt Lombardi decided to get in shape, he thought that the P90X home workout would be perfect. But the sports blogger ended up in the hospital after only one day of the fitness routine.

"I simply wanted to get back in shape. I could have killed myself in the process," wrote Lombardi. Lombardi is the entrepreneur behind college sports blog College Spun. He said he gained about 20 pounds since launching the site and wanted to lose the weight.

P90X uses a technique called "muscle confusion" to prevent its users from reaching a plateau. People losing weight are said to plateau when their bodies stop reacting to their workout and they stop losing weight. To combat the plateau effect, muscle confusion involves short training cycles to "keep [the] body adapting and growing."

Lombardi said that P90X does warn about the risks involved in taking on strenuous exercise, but never mentions rhabdomyolysis, the condition he fell victim to. According to the National Institutes of Health, rhabdomyolysis is a breakdown of muscle fibers that leads to those fibers being released into the bloodstream. That release can cause kidney damage and even lead to death.

The sports blogger said he began the workout on a Monday. The morning after trying it, Lombardi says he was extremely sore. The day after that, he found it difficult to move. By Thursday when he went to the bathroom, his urine was cola-colored and he knew he had a serious problem.

Lombardi immediately went to a kidney specialist who diagnosed him with rhabdomyolysis, or "rhabdo," and sent him to the emergency room.

"My blood test came back with a CPK (creatine phosphokinase) level of over 16,800 (the max they can test for)," he wrote. "Normal CPK levels, I was told, usually run between 10-200 micrograms per liter. These levels are a huge indicator of severe rhabdomylolysis."

Lombardi is currently recovering from the ordeal and says he's grateful to be alive.

"My two biggest takeaways from the entire ordeal? You can't put your muscles through a strenuous workout without leading up to it, and you need to recognize when your body is telling you that there is something wrong," wrote Lombardi. "The first could have killed me, while the second may have saved me. Stay safe out there."