This page is a glossary of exercise terminology. A :The stretching of muscles by the force of their antagonist pair, e.g. biceps contract to stretch triceps. :Literally "with oxygen"; refers to exercises such as running and cycling where the body supplies oxygen to muscles for fuel. :Literally "without oxygen"; refers to exercises such as weighlifting where the body is unable to supply oxygen for fuel. :Antagonistic muscles are found in pairs, consisting of an extensor opens the joint and a flexor which closes it. B :A form of stretching that incorporates a bouncing motion. :Body Mass Index