Ischaemic preconditioning improves upper-body endurance performance without altering V?O2 kinetics

Purpose: Whilst pre-exercise ischaemic preconditioning (IPC) can improve lower-body exercise performance, its impact on upper-limb performance has received little attention. This study examines the influence of IPC on upper-body exercise performance and oxygen uptake (V?O-2) kinetics. Methods: Eleven recreationally-active males (24 +/- 2 years) completed an arm-crank graded exercise test to exhaustion to determine the power outputs at the ventilatory thresholds (VT1 and VT2) and V?O-2peak (40.0 +/- 7.4 ml center dot kg(-1)center dot min(-1)). Four main trials were conducted, two following IPC (4 x 5-min, 220 mmHg contralateral upper-limb occlusion), the other two following SHAM (4 x 5-min, 20 mmHg). The first two trials consisted of a 15-minute constant work rate and the last two time-to-exhaustion (TTE) arm-crank tests at the power equivalents of 95% VT1 (LOW) and VT2 (HIGH), respectively. Pulmonary V?O-2 kinetics, heart rate, blood-lactate concentration, and rating of perceived exertion were recorded throughout exercise. Results: TTE during HIGH was longer following IPC than SHAM (459 +/- 115 vs 395 +/- 102 s, p = .004). Mean response time and change in V?O-2 between 2-min and end exercise (Delta V?O-2) were not different between IPC and SHAM for arm-cranking at both LOW (80.3 +/- 19.0 vs 90.3 +/- 23.5 s [p = .06], 457 +/- 184 vs 443 +/- 245 ml [p = .83]) and HIGH (96.6 +/- 31.2 vs 92.1 +/- 24.4 s [p = .65], 617 +/- 321 vs 649 +/- 230 ml [p = .74]). Heart rate, blood-lactate concentration, and rating of perceived exertion did not differ between conditions (all p >= .05). Conclusion: TTE was longer following IPC during upper-body exercise despite unchanged V?O-2 kinetics.