Following this a 30 minute exercise bout shall be completed in two of the trials, with 30 minutes of seated rest carried out in the control trial. Participants shall walk on a motorised treadmill at a predetermined speed designed to reflect 55% of estimated maximal aerobic capacity. Heart rate and perceived exertion will be sampled every three minutes, while expired air shall be sampled for two minute periods at 5, 15 and 25 minutes.