Speaking of exercise leading to very bad things, approximately a quarter of the lacrosse players who participated in a recent workout at Tufts University were later diagnosed with a very serious medical condition.

About 50 team members participated in the voluntary, 45-minute workout session on campus Monday, according to Patrick Collins, Tufts executive director of media relations. The session was led by a Tufts alum and recent graduate of the BUD/S Navy SEAL training program.

Collins said 12 members of the lacrosse team have been diagnosed with rhabdomyolysis, or rhabdo, which the Centers for Disease Control and Prevention says is “a serious medical condition that can lead to permanent disability or death.” It occurs when muscle breaks down, often from overexertion, and releases its contents into the bloodstream. Symptoms can appear similar to heat-related illnesses and dehydration.

Once again, yikes.