Step by step instructions, muscle activation and variants for the Crunch (on Bosu ball).
A crunch variation performed with the lower back resting on a Bosu ball, which increases the range of motion compared to floor crunches and challenges the abs through a fuller arc. The unstable surface also recruits stabiliser muscles for enhanced core activation.
The Crunch (on Bosu ball) is a foundational movement that builds strength and muscle through controlled, progressive overload. Train it 1 to 2 times per week with 3 to 5 working sets per session, gradually adding weight or reps as form holds up.
