Certified CrossFit Trainer (CCFT) L3 Practice Test

Rhabdomyolysis risk climbs when muscles experience sustained, high-tension eccentric contractions. Eccentric work is when the muscle is lengthening under load, and it tends to cause more micro-tearing and sarcolemmal disruption than purely concentric or short, explosive actions. Movements like pull-ups and GHDSU sit-ups involve long lowering phases under fatigue, producing a heavy eccentric load, especially if the athlete is unaccustomed or dehydrated. This makes them more likely to trigger rhabdomyolysis than activities that are mostly explosive or concentric, such as short, high-velocity movements; brisk stair-climbing, which is cardio with less eccentric overload; or light mobility work, which is low intensity and unlikely to cause such damage. The key idea is the extent of muscle damage from lengthening under tension, particularly when the body hasn’t adapted.