abstract
- Peripheral arterial distensibility is improved with sprint interval exercise training in young healthy participants (Rakobowchuk et al. in Am J Physiol Regul Integr Comp Physiol 295:R236-R242, 2008). To fully understand the mechanisms contributing to these training effects it is useful to examine the acute responses to sprint interval exercise. Following supine rest, nine healthy males completed either a single sprint interval (Wingate test) or a multiple sprint interval exercise session (4 Wingate tests each separated by 4.5 min). Following exercise, participants recovered for 60 min while central and peripheral arterial distensibility measurements were conducted at discrete time points, using applanation tonometry and ultrasound imaging and continuously, using central and peripheral pulsewave velocity (PWV). Single and multiple sprint interval exercise sessions caused similar changes in all variables. Heart rate was increased throughout recovery (p < 0.05), while central artery PWV was increased until 20 min of recovery (p < 0.05) and lower extremity PWV was decreased until ~45 min (p < 0.05). Distensibility of the superficial femoral artery showed a trend for a reduction at 2 min post-exercise (p = 0.06). These results indicate that extremely high intensity exercise transiently increases central artery stiffness, while metabolite induced vasodilation reduces peripheral stiffness in exercised limbs well into recovery.