By some estimates, calcium handling eats up 30-50% of the ATP used in muscle contraction, so a change in calcium sensitivity could indeed explain why nitrate makes endurance exercise more efficient.

A research group led by Dr. Keisuke Obara, Dr. Kento Yoshioka, and Professor Yoshio Tanaka from the Department of Chemical ...

Huxley, A. F. & Niedergerke, R. Structural changes in muscle during contraction: Interference microscopy of living muscle fibres. Nature 173 , 971–973 (1954) doi:10.1038/173971a0.

The flow of water within a muscle fiber may dictate how quickly muscle can contract, according to a University of Michigan study.

A research group has uncovered important details about how platelet-activating factor (PAF)—a powerful molecule involved in inflammation and allergic reactions—triggers contractions in the smooth ...

How to do a 'negative' rep . Most traditional exercises also include a concentric contraction, which involves shortening the muscle, often by lifting a weight.