Spin classes have become one of the most popular forms of cardio, but a new study is warning of the life-threatening condition which has become more common as high-intensity interval training (HIIT) increases in popularity.
Rhabdomyolysis, also known as 'rhabdo', is a rare but serious condition often caused by extreme exercise and an injured muscle. Typically, it occurs when muscle fibres work too hard and become destroyed, releasing toxic contents into the bloodstream.
Though rhabdo has long been documented - usually found in victims who have suffered a crush injury - doctors are seeing a sudden rise in cases of people who favour high-intensity workouts, in particular, spinning, The Independent reports.
The condition is particularly dangerous for first-time spinners and those who don't exercise often: rhabdomyolysis generally isn't an issue if your body is used to exercise.
The American Journal of Medicine highlighted 47 instances of spinning-induced rhabdomyolysis, 42 of which were patients who had taken the class for the very first time.
Doctors recommend getting into exercise with low-intensity options first, before gently pushing your limits as your body gets used to working out.