This study aimed to examine the effects of manipulating the rest intervals during sprint interval training (SIT) on post-exercise hypotension and within-session oxygen consumption.Thirty healthy, trained adults (aged 30.9 ± 8.7 years; 14 males, 16 females; BMI 22.1 ± 2.3 kg/m 2 ; VO 2 max 50.7 ± 7.8 ml/kg/min) completed two different SIT protocols (4x 30-seconds all-out cycling sprints) with a one-week washout period. Sprint bouts were separated by either 1 (R1) or 3 (R3) minutes of active recovery. Both before and throughout the 45 min after the training, peripheral systolic (pSBP) and diastolic (pDBP) blood pressure, central systolic (cSBP) and diastolic (cDBP) blood pressure, aortic pulse wave velocity (aPWV), stroke volume (SV), and heart rate (HR) were assessed. Throughout the SIT protocols, oxygen consumption (VO 2 ) was monitored.There were no significant differences in time spent at 75%, 85%, 95%, and 100% of maximal VO 2 between R1 and R3. After R3, there was a significant reduction in pSBP, pDBP, cSBP, cDBP, and aPWV. After R1, there were no changes in the respective parameters. There were significant interaction effects in pSBD (p < 0.001), pDBP (p < 0.001), cSBP (p < 0.001), cDBP (p = 0.001), and aPWV (p = 0.033). HR significantly increased after both conditions. Only R1 resulted in a significant reduction in SV.Longer resting intervals during SIT bouts seem to result in more substantial post-exercise hypotension effects. Time spent at a high percentage of maximal VO 2 was not affected by rest interval manipulation. KEYWORDSSprint interval training; postexercise hypotension; blood pressure; hemodynamics; rest interval manipulation Highlights-Previous studies assessing the health and performance effects of sprint interval training mainly follow very uniform protocols. Little attention has been given to assessing whether training variables can be modulated to achieve beneficial cardiometabolic adaptations.-3-minute resting intervals during sprint interval training bouts result in more substantial post-exercise hypotension effects compared to 1-minute resting intervals. Time spent at a high percentage of maximal oxygen consumption was not affected.-The presented findings have important implications for cardiovascular prevention programs as modified sprint interval training protocols potently stimulate post-exercise hypotension in a time-efficient manner.

This study assessed the post-exercise hypotension (PEH) effect in a sample of matched young and older adults after different sprint interval training (SIT) protocols. From forty-three participants enrolled in this study, twelve younger (24 ± 3 years) and 12 older (50 ± 7 years) participants, matched for the body mass index, systolic blood pressure, and VO2max-percentiles, were selected. The participants completed two SIT protocols consisting of 4 × 30 s exercise bouts interspersed by either one (SIT1) or three minutes (SIT3) of active rest. The 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 obtained before and at different measurement time points (t5, t15, t30, t45) after the exercise. No significant time × group interactions were detected in pSBP (p = 0.242, η² = 0.060), pDBP (p = 0.379, η² = 0.046), cSBP (p = 0.091, η² = 0.861), cDBP (p = 0.625, η² = 0.033), PWV (p = 0.133, η² = 0.076), and HR (p = 0.190, η² = 0.123) after SIT1. For SIT3 no significant time × group interactions could be detected for pSBP (p = 0.773, η² = 0.020), pDBP (p = 0.972, η² = 0.006), cSBP (p = 0.239, η² = 0.060), cDBP (p = 0.535, η² = 0.036), PWV (p = 0.402, η² = 0.044), and HR (p = 0.933, η² = 0.009). Matched samples of young and older adults reveal similar PEH effects after HIIT. Accordingly, age does not seem to affect PEH after SIT. These results show that rest interval length and age modulate the PEH effect after SIT.

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.