Post-exercise hypotension time-course is influenced by exercise intensity: a randomised trial comparing moderate-intensity, high-intensity, and sprint exercise

Reductions in blood pressure (BP) induced by exercise training may be associated with the acute reduction in BP observed minutes to hours following an exercise session, termed post-exercise hypotension (PEH). However, the magnitude and time-course of PEH, including the optimal exercise characteristics to maximise it, are still unclear. Using a randomised crossover design, 16 normotensive participants (median age (range) 22 (19–31) years; 50% female) undertook three different exercise sessions: sprint interval exercise (SIE, 30 × 8-s sprints with 32 s recovery), high-intensity interval exercise (HIIE, 15 × 1-min intervals at 90% peak heart rate (HR) with 1-min recovery), and moderate-intensity continuous exercise (MICE, 48 min at 65% peak HR). BP and HR were monitored before and up to 90 min following each session. The three exercise sessions each showed distinct PEH and of similar overall magnitude up to 90 min post exercise; however, there were distinct differences in the time-course. Systolic BP was lower 40 min after MICE compared to HIIE (−7.7 (−13.9 to −2.4) mmHg) and diastolic BP was higher 5 min after HIIE compared to SIE (8.5 (2.3–14.7) mmHg). MICE induced lower HR up to 40 min after exercise compared to HIIE and SIE. HIIE and SIE induced PEH of similar magnitude to MICE. A phasic or ‘W-shaped’ time-course of PEH observed following HIIE and SIE contrasted to a distinct ‘V-shaped’ PEH following MICE, indicating the physiological mechanisms driving BP regulation after exercise are influenced by exercise intensity.