Interval and continuous exercise elicit equivalent postexercise hypotension in prehypertensive men, despite differences in regulation

Equicaloric bouts of interval (IE: 5 × 2:2 min at 85% and 40% maximal oxygen uptake) and steady state (SS: 21 min at 60% maximal oxygen uptake) exercise were performed by 13 older prehypertensive males on separate days, at equivalent times of day, to assess the influence of exercise mode on postexercise hypotension (PEH). Exercise conditions were compared with a control session. Cardiovascular measures were collected for 30 min prior to, and 60 min following exercise. PEH, as measured by mean postexercise systolic blood pressure (SBP) decrease (IE: -4 ± 6 mm Hg; SS: -3 ± 4 mm Hg; control: 4 ± 4 mm Hg), area under the SBP curve (IE: -240 ± 353 mm Hg·min; SS: -192 ± 244 mm Hg·min), and minimum SBP achieved (IE: -15 ± 7 mm Hg; SS: -13 ± 7 mm Hg), was equivalent after both conditions. Stroke volume was significantly reduced (IE: -14.6 ± 16.0 mL; SS: -10.1 ± 14.2 mL, control -1.7 ± 2.2 mL) and heart rate was significantly elevated (IE: 13 ± 8 beats·min⁻¹; SS: 7.9 ± 8 beats·min⁻¹; control: -2 ± 3 beats·min⁻¹) postexercise after both conditions. Cardiac output and total peripheral resistance were nonsignificantly decreased and increased postexercise, respectively. Baroreflex sensitivity (BRS) was reduced following IE (p < 0.05) and heart rate variability (HRV) parameters were reduced after both conditions, with IE eliciting larger and longer reductions in some indices. The results from the current study indicate that older prehypertensive adults experience similar PEH following equicaloric bouts of IE and SS exercise despite larger alterations in HRV and BRS elicited by IE.