Comparing Post-Exercise Hypotension After a High-Intensity Interval Training in Matched Younger and Older Adults

Abstract

Objective:An acute reduction in blood pressure (BP) can be observed after a single bout of exercise. Termed postexercise hypotension (PEH), this phenomenon has been well documented in different populations after exercise of various intensities, durations, and modalities. Even though PEH has been documented in young and older adults, no previous studies have directly compared different age groups. The present study aimed to compare the PEH effect after high-intensity interval training (HIIT) in matched older and younger adults. Furthermore, within-session oxygen consumption was assessed and compared.Design and method:Forty-three participants were recruited for this study. All participants performed baseline examinations assessing body mass index (BMI), resting BP, and maximum oxygen consumption (VO2max). Thereafter, twelve younger (24.4 ± 3.1 years) and 12 older (49.5 ± 7.4 years) participants matched for BMI, BP, and VO2max-percentiles were selected for further analysis. All participants completed a HIIT protocol consisting of 4x 30-seconds exercise bouts interspersed by 3 minutes of active recovery. Both before and throughout the 45 minutes after the training, peripheral systolic (pSBP) and diastolic (pDBP) blood pressure, central systolic (cSBP) and diastolic (cDBP) blood pressure, pulse wave velocity (PWV), and heart rate (HR) were assessed. Throughout the HIIT, oxygen consumption was continuously monitored, and time spent above 75%, 85%, 95%, and 100% of VO2max was computed.Results:Both groups revealed significant (p < .001) reductions over time in pSBP, pDBP, cSBP, cDBP, PWV, and HR. No significant group x time effects could be detected for pSBP (p = .581), pDBP (p = .937), cSBP (p = .691), cDBP (p = .965), PWV (p = .233), and HR (p = .711). There were no significant differences in times spent at different percentages of VO2max (p = .643).Conclusions:If matched for BMI, resting BP, and VO2max-percentiles, older and younger adults experience similar PEH effects after HIIT. Furthermore, within-session oxygen consumption was similar in both groups revealing comparable exercise intensities during the protocol. According to the present results, age does not affect PEH after HIIT.