Effect of hypohydration on peripheral and corticospinal excitability and voluntary activation.

We investigated whether altered peripheral and/or corticospinal excitatory output and voluntary activation are implicated in hypohydration-induced reductions in muscle isometric and isokinetic (90°.s(-1)) strength. Nine male athletes completed two trials (hypohydrated, euhydrated) comprising 90 min cycling at 40°C, with body weight losses replaced in euhydrated trial.

Respiratory modulation in response to high-frequency airway occlusion delivered during inspiration or expiration.

To investigate whether 30 breaths performed against a high-frequency airway occlusion stimulus modulates ventilatory control both within-phase (within the phase of breathing that the stimulus was presented) and opposite-phase (in the opposite-phase of breathing to that in which the stimulus was presented) of the respiratory cycle. Ten healthy subjects (3 female, 7 male; 22-44 years old) completed 30 breaths prior to and following 30 inspirations or expirations against a high-frequency occlusion stimulus (youbreathe, Exoscience Ltd., London, UK), pressure-matched resistive loading or resting tidal breathing (no load) presented in a random order.