Researchers believe that caffeine affects central and peripheral sites during submaximal contractions of varying speeds. Central nervous system activity may be impacted, quieting the sensations of pain and effort. Increased supraspinal motor unit activation accompanied by greater sarcolemmal and fast twitch motor unit excitability may also be elicited.1 The peripheral effects are equally important and focus on intracellular calcium concentration. To be specific, researchers state that calcium release from the sarcoplasmic reticulum and calcium sensitivity in myofibrils may be improved. Caffeine may also decrease calcium reuptake, leading to greater availability.1 These mechanisms work to improve action potential propagation and ultimately promote greater muscle recruitment and peak torque. 2. What is novel in this study and what is the rationale leading to the purpose and hypothesis? …show more content…
Surface electromyography (sEMG) displays central and peripheral activity in the nervous system while electrically induced contractions helped differentiate between the two. Muscle fibre conduction velocity (CV) estimations outline changes in motor unit recruitment, contractile capability and sarcolemmal excitability.1 The effects of caffeine on CV have not been previously studied. These tests underpin the creation of a complete torque-velocity relationship for the muscles of the upper limb following caffeine supplementation. The methods are suitable to test the hypothesis, stating that caffeine will improve contractions of varying speeds due to greater muscle recruitment and enhanced fibre conduction