Blood Flow Restriction Does Not Impair Single, All-Out Sprint Cycling Performance.

This study examined the effects of sprint duration and blood flow restriction due to cuff pressure applied only during exercise on sprint cycling performance and psychophysiological responses. On separate days, 12 physically active young adults (9 men and 3 women) performed six 'all-out' cycling sprints (5, 10, 15, 20, 25 and 30 s) in a randomised order under three cuff pressure conditions (0%, 40% and 60% of arterial occlusion pressure [AOP]). BFR was applied exclusively during exercise bouts, with passive rest periods of 5-15 min between sprints depending on sprint duration. Power output, peripheral oxygen saturation, vastus lateralis muscle oxygenation, heart rate and ratings of perceived exertion were measured. Mean and peak power output and total work done decreased with longer sprints (i.e., 20-30 s) than shorter efforts (i.e., 5-15 s), with no differences observed between cuff pressure conditions. Ventilatory responses, heart rate and muscle oxygenation variables increased with longer sprints. Peripheral oxygen saturation remained unaffected. BFR at 40% and 60% AOP increased limb discomfort for 15-, 25- and 30-s sprints compared to 0% AOP. In conclusion, increasing the sprint duration decreased mechanical output (external load) and increased physiological strain (internal load), with these effects largely unaffected by moderate-to-high (40%-60% AOP) external limb compression.