Coe, LN and Astorino, TA. No sex differences in perceptual responses to high-intensity interval training or sprint interval training. J Strength Cond Res 36(6): 1025-1032, 2024-High-intensity ...interval training (HIIT) elicits similar and, in some cases, superior benefits vs. moderate-intensity continuous training (MICT). However, HIIT is typically more aversive than MICT because of the higher intensity and in turn, greater blood lactate accumulation (BLa). This study explored potential sex differences in perceptual responses to acute HIIT and sprint interval training. Fifteen men (age and V̇O2max = 29 ± 8 years and 39 ± 3 ml·kg-1·min-1) and 13 women (age and V̇O2max = 22 ± 2 years and 38 ± 5 ml·kg-1·min-1) who are healthy and recreationally active initially underwent testing of maximal oxygen uptake (V̇O2max) on a cycle ergometer. In randomized order on 3 separate occasions, they performed the 10 × 1-minute protocol at 85% of peak power output, 4 × 4-minute protocol at 85-95% maximal heart rate (%HRmax), or reduced exertion high intensity interval training consisting of 2 "all-out" 20-second sprints at a load equal to 5% body mass. Before and throughout each protocol, rating of perceived exertion (rating of perceived exertion RPE 6-20 scale), affective valence (+5 to -5 of the Feeling Scale), and BLa were assessed. Five minutes postexercise, enjoyment was measured using the Physical Activity Enjoyment scale survey. Results showed no difference in RPE (p = 0.17), affective valence (0.27), or enjoyment (p = 0.52) between men and women. Blood lactate accumulation increased in response to all protocols (p < 0.001), and men showed higher BLa than women (p = 0.03). Previous research suggests that interval exercise protocols are not interchangeable between men and women, yet our data reveal that men and women having similar V̇O2max exhibit no differences in perceptual responses to interval exercise.
Abstract
Astorino, TA, Robson, T, and McMillan, DW. Classifying intensity domains from arm cycle ergometry differs versus leg cycling ergometry.
J Strength Cond Res
37(11): 2192–2199, 2023—This study ...compared the distribution of exercise intensity domains in response to progressive leg cycle ergometry (LCE) and arm cycle ergometry (ACE). Seventeen active men and women (age and body fat = 26 ± 7 years and 18 ± 3%) initially performed graded exercise on each modality to assess maximal oxygen uptake (V̇
o
2
max) and peak power output (PPO). Using a randomized crossover design, they subsequently performed moderate intensity continuous exercise consisting of three 15-minute bouts at 20, 40, and 60% PPO on each modality. Gas exchange data (V̇
o
2
, V̇
co
2
, and V
E
), respiratory exchange ratio, heart rate (HR), blood lactate concentration (BLa), and perceptual responses were acquired. Only 2 subjects were classified in the same intensity domains across modalities, with LCE eliciting more subjects exercising at “vigorous” and “near-maximal” intensities than ACE. Time spent above 70 (22 ± 7 vs. 15 ± 8 minutes,
d
= 1.03) and 80 %HRmax (15 ± 6 vs. 9 ± 6 minutes,
d
= 1.04) was significantly greater with LCE vs. ACE. Compared with ACE, LCE revealed significantly higher (
p
< 0.05) peak (94 ± 6 vs. 88 ± 9 %HRmax,
d
= 0.81) and mean HR (73 ± 6 vs. 66 ± 6 %HRmax,
d
= 1.20), V̇
o
2
(54 ± 5 vs. 50 ± 7 %V̇
o
2
max,
d
= 0.68), and BLa (5.5 ± 2.0 vs. 4.7 ± 1.5 mM,
d
= 0.48). The results exhibit that progressive leg cycling at identical intensities elicits a greater cardiometabolic stimulus than ACE.
•Affect is positive at low to moderate exercise intensities yet is more aversive at intensities characteristic of high intensity interval training.•It has been suggested that inactive persons will ...find supramaximal interval training to be aversive.•This study examined if fitness level alters the perceptual response to reduced exertion high intensity interval training (REHIT).•Data show no differences in perceptual responses to REHIT in individuals with disparate aerobic fitness.•Clinicians do not need to consider aerobic fitness when implementing this interval regimen in their clients.
Reduced exertion high intensity interval training (REHIT) is an extremely low-volume approach of sprint interval exercise (SIE) that increases maximal oxygen uptake (VO2max) and reduces body fat. However, there are concerns regarding implementation of SIE including REHIT in untrained populations due to generation of supramaximal power outputs and potential feelings of displeasure. This study examined perceptual responses to a single REHIT session in adults with above (n = 43, VO2max = 41 ± 6 mL/kg/min) and below average VO2max (n = 42, VO2max = 33 ± 5 mL/kg/min). Initially, incremental exercise was completed to determine VO2max. Subsequently, participants completed REHIT consisting of two 20 s “all-out” sprints at resistance equal to 5 % body mass. Rating of perceived exertion (RPE), affective valence, and physical activity enjoyment (PACES) were determined. Tolerance and preference to exercise intensity were also measured to examine if they moderated the responses. Compared to participants with below average VO2max, those with above average VO2max revealed similar change in affective valence (p = 0.86), RPE (p = 0.41), and enjoyment (p = 0.64) despite attaining significantly higher peak and mean power output in response to REHIT. The lowest value of affective valence ranged from 1.0–1.5, representing “fairly good.” Overall, one session of REHIT elicits positive affective valence and similar pleasure:displeasure and enjoyment responses in individuals having diverse cardiorespiratory fitness, although we recommend that REHIT should be individualized for each client as greater frequency of aversive responses was shown in our participants with low fitness.
ABSTRACT
Introduction
High-intensity interval training and sprint interval training significantly increase maximal oxygen uptake (V̇O
2max
), which enhances endurance performance and health status. ...Whether this response is due to increases in central cardiovascular function (cardiac output (CO) and blood volume) or peripheral factors is unknown.
Purpose
This study aimed to conduct a systematic review and meta-analysis to assess the effects of high-intensity interval training and sprint interval training (referred to as intense interval training) on changes in central cardiovascular function.
Methods
We performed a systematic search of eight databases for studies denoting increases in V̇O
2max
in which CO, stroke volume (SV), blood volume, plasma volume, end-diastolic/systolic volume, or hematocrit were measured.
Results
Forty-five studies were included in this analysis, comprising 946 men and women of various health status (age and V̇O
2max
, 20–76 yr and 13–61 mL·kg
−1
·min
−1
) who performed 6–96 sessions of interval training. Results showed an increase in V̇O
2max
with intense interval training that was classified as a large effect (
d
= 0.83). SV (
d
= 0.69), and CO (
d
= 0.49) had moderate effect sizes in response to intense interval training. Of 27 studies in which CO was measured, 77% exhibited significant increases in resting CO or that obtained during exercise. Similarly, 93% of studies revealed significant increases in SV in response to intense interval training. Effect sizes for these outcomes were larger for clinical versus healthy populations. Plasma volume, blood volume, and hematocrit had small effect sizes after training (
d
= 0.06–0.14).
Conclusions
Increases in V̇O
2max
demonstrated with intense interval training are attendant with increases in central O
2
delivery with little contribution from changes in hematocrit, blood volume, or plasma volume.
ABSTRACTWood, KM, Olive, B, LaValle, K, Thompson, H, Greer, K, and Astorino, TA. Dissimilar physiological and perceptual responses between sprint interval training and high-intensity interval ...training. J Strength Cond Res 30(1)244–250, 2016—High-intensity interval training (HIIT) and sprint interval training (SIT) elicit similar cardiovascular and metabolic adaptations vs. endurance training. No study, however, has investigated acute physiological changes during HIIT vs. SIT. This study compared acute changes in heart rate (HR), blood lactate concentration (BLa), oxygen uptake (VCombining Dot AboveO2), affect, and rating of perceived exertion (RPE) during HIIT and SIT. Active adults (4 women and 8 men, age = 24.2 ± 6.2 years) initially performed a VCombining Dot AboveO2max test to determine workload for both sessions on the cycle ergometer, whose order was randomized. Sprint interval training consisted of 8 bouts of 30 seconds of all-out cycling at 130% of maximum Watts (Wmax). High-intensity interval training consisted of eight 60-second bouts at 85% Wmax. Heart rate, VCombining Dot AboveO2, BLa, affect, and RPE were continuously assessed throughout exercise. Repeated-measures analysis of variance revealed a significant difference between HIIT and SIT for VCombining Dot AboveO2 (p < 0.001), HR (p < 0.001), RPE (p = 0.03), and BLa (p = 0.049). Conversely, there was no significant difference between regimens for affect (p = 0.12). Energy expenditure was significantly higher (p = 0.02) in HIIT (209.3 ± 40.3 kcal) vs. SIT (193.5 ± 39.6 kcal). During HIIT, subjects burned significantly more calories and reported lower perceived exertion than SIT. The higher VCombining Dot AboveO2 and lower BLa in HIIT vs. SIT reflected dissimilar metabolic perturbation between regimens, which may elicit unique long-term adaptations. If an individual is seeking to burn slightly more calories, maintain a higher oxygen uptake, and perceive less exertion during exercise, HIIT is the recommended routine.
Adults who have had an amputation face barriers to having an active lifestyle which attenuates cardiorespiratory fitness. Prior studies in amputees typically involve treadmill walking or arm ...ergometry, yet physiological responses to bilateral leg cycling are less understood. This study assessed the hemodynamic and metabolic responses to moderate and vigorous cycle ergometry in men who have had a transtibial amputation (TTA). Five men who had had a unilateral TTA (age = 39 ± 15 yr) and six controls (CONs) without an amputation (age = 31 ± 11 yr) performed two 20 min bouts of cycling differing in intensity. Cardiac output (CO), stroke volume (SV), and oxygen consumption (VO
) were measured during moderate intensity continuous exercise (MICE) and high intensity interval exercise (HIIE) using thoracic impedance and indirect calorimetry. In response to MICE and HIIE, the HR and VO
levels were similar (
> 0.05) between groups. Stroke volume and CO were higher (
< 0.05) in the CONs, which was attributed to their higher body mass. In men with TTAs, HIIE elicited a peak HR = 88%HRmax and substantial blood lactate accumulation, representing vigorous exercise intensity. No adverse events were exhibited in the men with TTAs. The men with TTAs show similar responses to MICE and HIIE versus the CONs.
The postural transition from sitting to standing is a moment of dysautonomic occurrence in individuals with Spinal Cord Injury (SCI). Different tools can be used to minimize this event, such as ...virtual reality. Thus, we aimed to analyze cardiac autonomic modulation in individuals with SCI during postural transition from the sitting to orthostatism position using a cognitive virtual reality (VR) task.
Individuals with and without SCI were positioned on the Easy Stand® device, sitting at rest, at 0° considering the angle between the seat and the floor, elevation at 45°, and orthostatism at 90°, for 5 minutes in each position. Heart rate variability (HRV) measures of sympathovagal balance were collected (heart rate receiver: Polar V800). The groups were subdivided into two groups, one that performed VR as an intervention during the postural angle changes and another group that did not perform VR.
We evaluated 76 individuals, 40 with a medical diagnosis of SCI and 36 who composed the able-bodied control group without SCI, matched by age and sex. The HRV results showed that the SCI group who performed the task in VR demonstrated no significant difference in parasympathetic activation and global variability between the sitting versus 90° positions. There was better sympathovagal balance in SCI and able-bodied control groups who performed the VR task between the sitting versus 90° positions.
The use of a VR task seems to contribute to better sympathovagal balance, with the potential to reduce dysautonomia during postural changes.
A plateau in oxygen uptake (Formula: see text) during an incremental cardiopulmonary exercise test (CPET) to volitional exhaustion appears less likely to occur in special and clinical populations. ...Secondary maximal oxygen uptake (Formula: see text) criteria have been shown to commonly underestimate the actual Formula: see text. The verification phase protocol might determine the occurrence of 'true' Formula: see text in these populations. The primary aim of the current study was to systematically review and provide a meta-analysis on the suitability of the verification phase for confirming 'true' Formula: see text in special and clinical groups. Secondary aims were to explore the applicability of the verification phase according to specific participant characteristics and investigate which test protocols and procedures minimise the differences between the highest Formula: see text values attained in the CPET and verification phase.
Electronic databases (PubMed, Web of Science, SPORTDiscus, Scopus, and EMBASE) were searched using specific search strategies and relevant data were extracted from primary studies. Studies meeting inclusion criteria were systematically reviewed. Meta-analysis techniques were applied to quantify weighted mean differences (standard deviations) in peak Formula: see text from a CPET and a verification phase within study groups using random-effects models. Subgroup analyses investigated the differences in Formula: see text according to individual characteristics and test protocols. The methodological quality of the included primary studies was assessed using a modified Downs and Black checklist to obtain a level of evidence. Participant-level Formula: see text data were analysed according to the threshold criteria reported by the studies or the inherent measurement error of the metabolic analysers and displayed as Bland-Altman plots.
Forty-three studies were included in the systematic review, whilst 30 presented quantitative information for meta-analysis. Within the 30 studies, the highest mean Formula: see text values attained in the CPET and verification phase protocols were similar (mean difference = -0.00 95% confidence intervals, CI = -0.03 to 0.03 L·min-1, p = 0.87; level of evidence, LoE: strong). The specific clinical groups with sufficient primary studies to be meta-analysed showed a similar Formula: see text between the CPET and verification phase (p > 0.05, LoE: limited to strong). Across all 30 studies, Formula: see text was not affected by differences in test protocols (p > 0.05; LoE: moderate to strong). Only 23 (53.5%) of the 43 reviewed studies reported how many participants achieved a lower, equal, or higher Formula: see text value in the verification phase versus the CPET or reported or supplied participant-level Formula: see text data for this information to be obtained. The percentage of participants that achieved a lower, equal, or higher Formula: see text value in the verification phase was highly variable across studies (e.g. the percentage that achieved a higher Formula: see text in the verification phase ranged from 0% to 88.9%).
Group-level verification phase data appear useful for confirming a specific CPET protocol likely elicited Formula: see text, or a reproducible Formula: see text, for a given special or clinical group. Participant-level data might be useful for confirming whether specific participants have likely elicited Formula: see text, or a reproducible Formula: see text, however, more research reporting participant-level data is required before evidence-based guidelines can be given.
PROSPERO (CRD42021247658) https://www.crd.york.ac.uk/prospero.
Affect is typically positive at intensities below the lactate or ventilatory threshold, yet more aversive responses occur at supra-threshold intensities which may reduce positive perceptions of ...exercise. Completion of high intensity interval exercise (HIIE) typically elicits a reduction in affect, yet greater post-exercise enjoyment has been reported in response to HIIE versus moderate intensity continuous exercise (MICE). This study examined affectual responses to HIIE and sprint interval exercise (SIE) in 71 active men and women (age = 24.0 ± 4.8 year). Participants performed various HIIE and SIE regimes on the cycle ergometer during which affect (+5 – −5 scale), rating of perceived exertion (RPE, Borg 1–10 scale), and blood lactate concentration (BLa) were determined. Enjoyment was measured post-exercise using the PACES scale. Predictors of change in these variables in response to exercise were identified using multiple regression. Results showed a significant reduction in affect (p = .001) which was greater (p = .03) with SIE (−5.7 ± 2.7) compared to HIIE (−4.3 ± 2.4). Nevertheless, there was marked variability in the affect response across participants, as its change ranged from −1 to −7 units from pre- to post-exercise in 85% of all sessions. Sixty two percent of the change in affect seen across regimes was explained by baseline affect, BLa, and enjoyment. Significant associations were shown between the change in affect and baseline affect (r = −0.46, p < .001) and change in RPE (r = −0.59, p < .001). In addition, RPE significantly increased in response to HIIE (6.1 ± 1.7) and SIE (6.9 ± 2.0) but was not different (p = .050) between regimes. Our findings document an intensity-dependent relationship between affect and intensity during interval training, as supramaximal intensities elicit a larger decline in affect compared to submaximal intensities. In addition, pre-exercise affect is associated with the magnitude of change in affect reported in response to interval exercise.
•Affect is positive at low to moderate exercise intensities yet is more aversive at intensities above the lactate threshold.•Affect is aversive during high intensity interval exercise (HIIE) although it may be more enjoyable than moderate exercise.•This study identified predictors of the affective response to HIIE and its more intense form, sprint interval exercise (SIE).•We show lower affect in SIE versus HIIE, and that pre-exercise affect and blood lactate concentration predict this response.•Marked variability in affective responses were shown, likely due to disparate blood lactate responses across participants.
ObjectiveTo investigate the effects of high-intensity interval training (HIIT) and sprint interval training (SIT) on fat oxidation during exercise (FatOx) and how they compare with the effects of ...moderate-intensity continuous training (MICT).DesignSystematic review and meta-analysis.Data sourcesAcademic Search Ultimate, CINAHL, Networked Digital Library of Theses and Dissertations, Open Access Theses and Dissertations, OpenDissertations, PubMed/MEDLINE, Scopus, SPORTDiscus and Web of Science.Eligibility criteria for selecting studiesStudies using a between-group design, involving adult participants who were not trained athletes, and evaluating effects of HIIT or SIT on FatOx (vs no exercise or MICT) were included.ResultsEighteen studies of fair-to-good quality were included; nine comparing HIIT or SIT with no exercise and eleven comparing HIIT or SIT with MICT. A significant pooled effect of these types of interval training on FatOx was found (mean difference in g/min (MD)=0.08; 95% confidence interval (CI) 0.04 to 0.12; p<0.001). Significant effects were found for exercise regimens lasting ≥4 weeks, and they increased with every additional week of training (β=0.01; 95% CI 0.00 to 0.02; p=0.003). HIIT and/or SIT were slightly more effective than MICT (MD=0.03; 95% CI 0.01 to 0.05; p=0.005). The effects on FatOx were larger among individuals with overweight/obesity.ConclusionEngaging in HIIT or SIT can improve FatOx, with larger effects expected for longer training regimens and individuals with overweight/obesity. While some effects seem small, they may be important in holistic approaches to enhance metabolic health and manage obesity.
