No Sex Differences in Perceptual Responses to High-Intensity Interval Training or Sprint Interval Training.

ABSTRACT: 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.

When Studying Affective Responses to Exercise, the Definition of "Intensity" Must Reference Homeostatic Perturbations: A Retort to Vollaard et al.

In articles on the methodology of studies investigating affective and enjoyment responses to high-intensity interval training, we noted that, occasionally, exercise conditions described as involving "high" intensity exhibited heart rates that were only as high as, or even lower than, heart rates recorded during comparator conditions described as being of "moderate" intensity. Drs. Vollaard, Metcalfe, Kinghorn, Jung, and Little suggest instead that exercise intensity in high-intensity interval-training studies can be defined in terms of percentages of peak workload. Although we maintain that defining exercise intensity in terms of percentages of maximal heart rate is a suboptimal way to quantify the degree of homeostatic perturbations in response to exercise, we are unconvinced that definitions of intensity relying solely on workload are appropriate for studies investigating affective and enjoyment responses to exercise. The reason is that affect is theorized to have evolved to relay information about homeostatic perturbations to consciousness.

Exercise in the workplace: examining the receptivity of practical and time-efficient stair-climbing "exercise snacks".

In the workplace, people are often sedentary for prolonged time and do not regularly engage in physical activity-two factors independently linked to premature morbidity and mortality. This study aimed to determine the receptivity of incorporating practical stair-climbing "exercise snacks" (Snacks; three isolated bouts of ascending 53-60 stairs performed sporadically throughout the day) into workplace settings compared to more traditional high-intensity interval training (HIIT; performed as three bouts of 53-60 stairs within a structured HIIT workout) and to explore if these exercise strategies could influence sedentary and physical activity behaviour. Fourteen participants (12 women; Mage = 38.9 ± 10.2 years) completed two supervised exercise trials (Snacks and HIIT) followed by 1 week participating in either form of exercise in their workplace. Ratings of perceived exertion (RPE), affective valence, enjoyment, and self-efficacy were measured at the supervised exercise sessions. During the follow-up period, sedentary behaviour and physical activity were measured with an accelerometer. Affective valence was more positive (p = 0.03; η2 p = 0.21) and there was a lower rise in RPE (p = 0.01; η2 p = 0.29) during Snacks than HIIT. Post-exercise enjoyment of, and self-efficacy towards, Snacks and HIIT were high and similar (ps > 0.05). After the supervised trials, 10/14 of the participants preferred Snacks and 4/14 preferred HIIT (p = 0.18). On days when participants chose to perform either exercise modality, the average number of sit-to-stands in a 24 h period was increased (48.3 ± 8.7 to 52.8 ± 7.8; p = 0.03; Hedge's g = 0.73) and moderate-to-vigorous physical activity tended to increase (21.9 ± 18.2 to 38.1 ± 22.1 min; p = 0.06; Hedge's g = 0.60) compared to days when they chose not to exercise. Stair-climbing exercise snacks may be an attractive approach to implement in the workplace setting and has potential to positively impact sedentary behaviour and physical activity metrics.

Physiological and psychological outcomes of high intensity interval training in patients with heart failure compared to moderate continuous training and usual care: A systematic review with meta analysis.

BACKGROUND: An important component of secondary prevention of CVD (including HF) is comprehensive cardiac rehab, including exercise. Novel, individualised approaches are needed to increase uptake and adherence to exercise programmes, one area offering potential is HIIT. HIIT has been shown to be both safe and effective for improving cardiovascular fitness in both coronary artery disease and HF patients. OBJECTIVES: To provide a current and up to date evaluation of the physiological and psychological outcomes of HIIT in patients with HF compared to MCT and UC. Secondly to perform sub-group analyses comparing short and long HIIT protocols. METHODS: A systematic review and meta-analysis of randomised controlled trials was undertaken. Medline, Embase, Scopus, CINAHL and SportDISCUS were searched up to July 2022. Trials were included if they carried out a HIIT intervention (defined at intensity ≥ 80% peak HR or ≥ 80% VO2peak) in HF patients (HFpEF or HFrEF) for at least 6 weeks. Comparator group was UC or MCT. RESULTS: HIIT was shown to be superior to MCT and UC for improving VO2peak (HIIT mean improvement 3.1 mL.kg-1min-1). HITT was superior to MCT and UC for improving LVEF (HIIT mean improvement 5.7%). HIIT was superior to MCT and UC for improving HRQoL, using the MLHFQ (HIIT mean point change of -12.8). Subgroup analysis showed no difference between long and short HIIT. CONCLUSION: HIIT improves VO2peak, LVEF and HRQoL in patients with HF, the improvements seen in VO2peak and LVEF are superior in HIIT compared to MCT and UC.

A Methodological Checklist for Studies of Pleasure and Enjoyment Responses to High-Intensity Interval Training: Part I. Participants and Measures.

For decades, the exercise psychology research literature echoed the conclusion that exercise makes most people feel better, with no clear evidence that this "feel-better effect" is moderated by intensity. An overhaul of the methodological approach subsequently showed that high-intensity exercise is experienced as unpleasant, and the "feel-better effect," although possible, is conditional and therefore not as robust or prevalent as initially thought. Recently, several studies investigating high-intensity interval training (HIIT) have concluded that HIIT is pleasant and enjoyable, despite the high intensity. Considering that HIIT is emerging as an option in physical activity recommendations and exercise prescription guidelines, in part due to these claims, a methodological checklist is presented to aid researchers, peer reviewers, editors, and other readers in critically appraising studies examining the effects of HIIT on affect and enjoyment. This first part addresses the characteristics and number of participants, as well as the selection of measures of affect and enjoyment.

A Methodological Checklist for Studies of Pleasure and Enjoyment Responses to High-Intensity Interval Training: Part II. Intensity, Timing of Assessments, Data Modeling, and Interpretation.

Recent studies have concluded that high-intensity interval training should be seen as a "viable alternative" to, and may be more enjoyable than, moderate-intensity continuous exercise. If true, these claims have the potential to revolutionize the science and practice of exercise, establishing high-intensity interval training as not only a physiologically effective exercise modality but also a potentially sustainable one. However, these claims stand in contrast to voluminous evidence according to which high levels of exercise intensity are typically experienced as less pleasant than moderate levels. To help researchers, peer reviewers, editors, and critical readers appreciate possible reasons for the apparently conflicting results, we present a checklist that identifies crucial methodological elements in studies investigating the effects of high-intensity interval training on affect and enjoyment. This second installment covers how "high-intensity" and "moderate-intensity" experimental conditions are defined, the timing of assessments of affect, the modeling of affective responses, and data interpretation.

High-intensity interval training in children and adolescents with special educational needs: a systematic review and narrative synthesis.

BACKGROUND: High-intensity interval training (HIIT) has been promoted as a time-efficient exercise strategy to improve health and fitness in children and adolescents. However, there remains little consensus in the literature regarding its efficacy in children and adolescents with special educational needs (SEN). This study aimed to examine HIIT as a means of improving key health and fitness parameters in children and adolescents with SEN. METHODS: A systematic search was conducted on eight databases (MEDLINE, Embase, SPORTDiscus, Web of Science, Scopus, PsycINFO, CINAHL, and Cochrane Library). Studies were eligible if they 1) included an HIIT protocol, 2) examined parameters related to both physical and mental aspects of health and fitness, and 3) examined children and adolescents with SEN aged 5-17 years. RESULTS: Of the 1727 studies yielded by the database search, 13 (453 participants) were included and reviewed. We found that HIIT generally improved body composition, physical fitness, and cardiometabolic risk biomarkers across a spectrum of SEN (e.g., attention deficit hyperactivity disorder, cerebral palsy, developmental coordination disorder, and mental illness). Improvements in mental health and cognitive performance following HIIT have also been observed. CONCLUSION: This review provides up-to-date evidence for HIIT as a viable exercise strategy for children and adolescents with SEN. Further research investigating the benefits of HIIT in a wider range of SEN populations is warranted. TRIAL REGISTRATION: This study was registered in the International Prospective Register of Systematic Review (PROSPERO; registration number CRD42022352696).

Effects of high-intensity interval training on health-related quality of life in chronic lymphocytic leukemia: A pilot study.

INTRODUCTION: Chronic lymphocytic leukemia (CLL) is the most common incurable leukemia/lymphoma in the United States. Individuals with CLL are at risk for disability, frailty, and cancer-specific complications that negatively affect health-related quality of life (HRQOL). High-intensity interval training (HIIT) and resistance training (RT) are safe and feasible for individuals with chronic diseases and when combined, they may be beneficial for reducing cancer-related fatigue, symptom burden, and global quality of life. However, no studies have examined the impact of HIIT or RT on HRQOL in CLL. The purpose of this study was to investigate the effects of a 12-week HIIT and RT (HIIT+RT) intervention on HRQOL in adults with treatment naïve CLL. MATERIALS AND METHODS: Changes in HRQOL was a secondary outcome in this pilot study. Individuals with CLL (63.9 ± 8.5 yrs) were non-randomly assigned to 12 weeks of HIIT+RT or a control group. The HIIT+RT protocol consisted of three 30-min sessions/week of HIIT and two sessions/week of RT. The control group maintained usual daily activities. We assessed pre and post HRQOL using the Functional Assessment of Cancer Therapy-Lymphoma (FACT-Lym) questionnaire with domains of physical (PWB), social (SWB), emotional (EWB), functional (FWB), and general (FACT-G) well-being as well as a lymphoma-specific subscale (LymS). We used a two-way mixed analysis of variance to assess changes in HRQOL. We calculated effect size (ES) using Cohen's d. RESULTS: Fifteen participants (HIIT+RT: n = 9; Control: n = 6) completed the study and questionnaire. Scores for FWB improved following HIIT+RT (21.7 ± 3.4 to 23.9 ± 3.2; ES = 1.38) compared to controls (25.7 ± 2.2 to 25.7 ± 2.3). The HIIT+RT group experienced clinically meaningful improvements in total FACT-Lym, FWB, FACT-G, and LymS. The control group had clinically meaningful changes only in LymS. DISCUSSION: The large effect sizes and clinically meaningful improvements associated with 12 weeks of HIIT+RT support the potential benefits of this type of exercise program for FWB, lymphoma-specific symptoms, and general well-being in CLL. A future randomized trial with an adequately powered sample size is needed to evaluate these findings. TRIAL REGISTRATION: NCT04950452.

Impact of high-intensity interval training including Indigenous narratives on adolescents' mental health: a cluster-randomised controlled trial.

OBJECTIVES: We investigated the efficacy of teacher-delivered high-intensity interval training (HIIT) with Indigenous narrative options on the mental health of school students in low-mid socioeconomic areas, compared to standard curriculum physical education practice. METHODS: A cluster-randomised controlled trial was conducted in eight schools (N=368, age range 11-13 years) over 16 weeks. The primary outcome was the Strengths and Difficulties Questionnaire (SDQ) score. Generalised linear mixed models, controlling for the SDQ at baseline were applied, expressed as ß, 95% confidence intervals, standardised effect, and p-value. Focus groups elicited experiences with participating in and delivering the intervention. RESULTS: There were no clear effects for SDQ total score (ß -0.15, CI -0.98 - 0.67, SE 0.42, p=0.714). Teachers did not deliver the Indigenous narrative options consistently owing to the perceived preparation needed and lack of confidence. CONCLUSIONS: HIIT delivered in this manner had no effect on self-perceived psychological difficulty or mental wellbeing in a cohort of young adolescents. IMPLICATIONS FOR PUBLIC HEALTH: Future research should continue to explore opportunities to improve mental wellbeing via physical activity, but HIIT should not be implemented as a universal intervention for mental health gains alone. Teachers need more support to utilise Indigenous narratives as part of HIIT delivery.

Effects of music on psychophysiological responses during high intensity interval training using body weight exercises.

The use of music in exercise sessions is considered an interesting strategy as it facilitates, through motivation, an improvement in physical performance, as well as a reduction in the subjective perception of effort and an improvement in mood. Such factors are important for the maintenance of physical exercise programs, however, considering high intensity interval training, the effects of music remain inconclusive. Thus, the objective of this study was to evaluate the influence of music during high intensity interval training sessions using body weight (HIIT-B) on the physiological parameters and mood state of adults. METHODS: 11 CrossFit male practitioners were randomly submitted to three sessions of HIIT-B under the following experimental conditions: preference music (PM), non-preference music (nPM) and without music (WM). The HIIT-B protocol consisted of 20 sets of 30 s of stimulus using maximal intensities followed by 30 s of passive recovery. The following exercises were used: jumping jacks, burpee, mountain climber and squat jumping. The following parameters were analyzed: heart rate (HR), lactate (La), total amount of movements (TAM), affective response (AR), rating of perceived exertion (RPE), recovery (RPR) and mood states. RESULTS: although an increase (p< 0.05) of HR, RPE and La, reduction of RPR was found after performing the HIIT session, no differences were found between the three conditions to these parameters. The nPM condition promoted lower (p< 0.001) TAM compared to the WM and PM conditions, which also differed from each other. However, for AR, a music effect was found among the protocols (p< 0.0001), indicating that the PM session promoted an increase in pleasure, unlike WM and nPM session which provided pleasure reduction and displeasure respectively. The WM session did not promote any changes. There were no main effects on time for depression and anger, which were different for vigor, fatigue, mental confusion, tension and mood disturbance. Additionally, differences were found after session to tension (p = 0.0229), vigor (p = 0.0424) and fatigue (p = 0.0400) for PM condition, vigor (p = 0.0424), fatigue (p = 0.0400) mental confusion (p = 0.0302) and mood disturbance (p = 0.0129) for nPM and vigor (p = 0.0363) and fatigue (p = 0.0468) to WM conditions. CONCLUSION: Listening to preferred music during an 'all out' HIIT-B session increases exercise performance and elicits more positive affective responses in recreationally active adult males, despite similar HR, blood lactate, RPE and fatigue compared to nonpreferred music or no-music.

Effects of High-Intensity Interval Training and Continuous Aerobic Training on Health-Fitness, Health Related Quality of Life, and Psychological Measures in College-Aged Smokers.

The study examined the effects of exercise on health-fitness, health related quality of life (HRQOL), and psychological measures in college-aged smokers. Outcomes included HRQOL, hemodynamic, anthropometric, lung function, and cardiorespiratory endurance. Sixty physically inactive college-aged male smokers (18-30 years) were randomly assigned into three groups: high-intensity interval training (HIIT), continuous aerobic training (CAT), and a control (CON). Both HIIT and CAT groups completed 8 weeks of non-consecutive cycling sessions thrice weekly. The CON group were not subjected to the exercise intervention. Sixty participants met the inclusion criteria. Of these, 48 (HIIT: n = 18, CAT: n = 16, CON: n = 14) participants completed the study and were included in the final analysis. Compared to CON, HIIT significantly (p = 0.01) improved forced expiratory flow (FEF_75%) more than the CAT group (p = 0.29). HIIT provided a significant (p = 0.04) improvement in FEF_75% compared to CAT. Recovery heart rate (RHR) was significantly improved in participants assigned to HIIT (p = 0.00) and CAT (p = 0.002) groups compared with the CON. A significant difference in RHR was found in HIIT compared to CAT. The study findings indicate that both HIIT and CAT exercise interventions significantly improve markers of lung function and cardiorespiratory endurance, respectively. However, findings suggested that HIIT should be the preferred form of exercise regime among college-aged smokers for more significant, healthier benefits.

Exercise for affect and enjoyment in overweight or obese males: a comparison of high-intensity interval training and moderate-intensity continuous training.

High-intensity interval training (HIIT) is effective for generating positive cardiovascular health and fitness benefits. This study compared HIIT and moderate-intensity continuous training (MICT) for affective state and enjoyment in sedentary males with overweight or obesity.Twenty-eight participants performed stationary cycling for 6 weeks × 3 sessions/week. Participants were randomly allocated to HIIT (N=16) (10 × 1-minute intervals at ~90% peak heart rate) or MICT (N=12) (30 minutes at 65-75% peak heart rate). Affective state changes were assessed after 6-weeks training. Enjoyment and acute change in affect were assessed after individual training sessions.HIIT participants reported improved positive affect following 6 weeks training (∆ 3.6 ± 4.6, p = 0.007, effect size d = 0.70), without corresponding improvement in negative affect (p = 0.48, d = -0.19). MICT did not induce any improvement in positive affect (p = 0.56, d = 0.16) or negative affect (p = 0.23, d = -0.41). Enjoyment ratings were comparable for both exercise formats (HIIT: 4.4 ± 0.4 on a 7-point scale; MICT: 4.3 ± 0.3; p = 0.70, d = 0.15).Six weeks of HIIT induced improvement in positive affect in sedentary participants with overweight or obesity. Enjoyment of training was only slightly above neutral levels for both training formats.What's already known about this topic? Exercise training can improve general affect however the optimal exercise characteristics for improving affect are unclear.Studies assessing the relative enjoyment of HIIT in comparison to MICT have largely been equivocal to date.What does this study add? HIIT can improve affective state in males with overweight or obesity.Six weeks of stationary cycling HIIT were rated as only mildly enjoyable, comparable to ratings for MICT.

Probiotic Supplementation and High-Intensity Interval Training Modify Anxiety-Like Behaviors and Corticosterone in High-Fat Diet-Induced Obesity Mice.

Evidence supports the role of exercise training and probiotics on reducing obesity. Considering the relationship between obesity and high-fat diet with anxiety indices, the aim of this study was to assess the effect of probiotic supplementation and high-intensity interval training (HIIT) on anxiety-like behaviors, corticosterone and obesity indices in high-fat diet (HFD)-induced obesity mice. Thirty male adult C57BL/6 mice were randomly divided into five groups: (1) Control with normal diet (CON), (2) High-fat diet (HFD), (3) HFD + exercise training (HT), (4) HFD + probiotics supplement (HP) and (5) HFD + exercise training +probiotics (HTP). Exercise training consisted of 8 weeks of high-intensity interval training (HIIT) programs. Probiotics supplement included 0.2 mL Lactobacillus rhamnosus GG. Anxiety-like behaviors were measured by open field (OF) and Elevated plus maze (EPM). OF and EPM tests, visceral fat mass (VFM) measurement, and blood sampling for corticosterone were performed after the intervention. Bodyweight was measured at different stages during the intervention. HFD regime in C57BL/6 mice increased bodyweight, VFM, and serum corticosterone levels and anxiety-like behaviors (p < 0.05). HIIT, probiotic and their combination, decreased bodyweight, VFM, and serum corticosterone levels and improved anxiety-like behavior in the HFD mice (p < 0.05). The effect of a combination of HIIT and probiotic on most of the anxiety indices was more than each one separately (p < 0.5). HIIT and probiotic supplements separately or above all in combination, may have beneficial effects in reducing obesity and anxiety indices.

The sub-acute effects of high-intensity interval training in healthy young adults: respiratory parameters, aerobic capacity and perceived stress.

BACKGROUND: Although the effects of sub-maximal continuous aerobic training (SCT) and high-intensity interval training (HIIT) are well studied in performance athletes and in several patient groups, there is not much evidence about the effects of these exercises in sedentary healthy young population. The aim of the study was to compare the effects of these two different types of aerobic exercises on respiratory parameters, aerobic capacity and perceived stress in healthy university students. METHODS: Thirty-six healthy, young subjects with a mean age of 20.83±0.97 years were included in the study (N.=19 in HIIT and N.=17 in SCT). Pulmonary function tests (PFTs) and respiratory muscle strength (RMS) assessments were done using a desktop spirometer. Aerobic capacity was estimated with the Bruce treadmill exercise test. The Perceived Stress Scale (PSS) was used for the assessment of stress perception. All participants exercised 3 times per week for 4 weeks (a total of 12 sessions). RESULTS: After 12 sessions, the peak expiratory flow parameter (a PFT value) of both groups showed significant increases, but there was no difference between the groups. The RMS of the subjects increased significantly in both the groups (P<0.05), but there was no significant difference between the groups. Both groups showed significant increases in terms of aerobic capacity (P>0.05), and the improvement was significantly higher in the HIIT group. Perceived stress values showed a significant increase in the SCT group. CONCLUSIONS: Based on the results of this study, the two exercise types were found to have similar effects on RMS. Also, when compared with SCT, HIIT was found to have more effect on aerobic capacity.

Effects of Interval-Training Exercise on People Who Have Had Persistent Post-Concussive Symptoms for Less Than One Year: A Pilot Study.

This study is to examine the effects of a 12-session moderate intensity-interval-training program with blood flow restriction (BFR) and body cooling (BC) on people who have had persistent post-concussive symptoms (PPCS) for <1 year. A single-blind randomized controlled trial of interval-training exercise with BFR and BC was conducted. Twenty-five adults with PPCS were assigned to the experimental group (n = 14) or the control group (n = 11). Both groups rode a recumbent elliptical machine for 21 min at moderate intensity (65% predicted maximum heart rate) twice a week for 6 weeks, but only the experimental group received BFR and BC while riding. The variances of overall PPCS scale scores and their sub-domain scores for individuals during the 6-week intervention and 6-week follow-up period were calculated. During the intervention, the fluctuation of overall symptom severity, severity in the cognitive domain and severity in the mood domain were significantly less in the experimental group (p = 0.03; p = 0.02; p = 0.02). During the follow-up period, the number of symptoms remained more stable in the experimental group (p = 0.02), and a trend toward less fluctuation of symptom severity (p = 0.05) was also observed. The reduced number of symptoms in the cognitive and sleep domains remained more stable in the experimental group following the intervention (p = 0.007; p = 0.02). The severity of mood and sleep symptoms also remained more stable during the follow-up period in the experimental group (p = 0.04). More stable recovery was found in individuals who exercised using BFR and BC than in those who underwent exercise without BFR and BC. Moderate intensity-interval-training exercise with BFR and BC alleviated post-concussive symptoms in people who have had PPCS <1 year.

Influence of Sprint Duration during Minimal Volume Exercise on Aerobic Capacity and Affect.

The aims of this study were to investigate the influence of reduced-exertion, high-intensity interval training (REHIT), comparing a novel shortened-sprint protocol (SSREHIT) against a traditional protocol (TREHIT), on perceptual responses and to determine if changes in peak oxygen uptake (V˙O2peak) are attenuated with shorter sprints. Twenty-four healthy men undertook 15 sessions of SSREHIT or TREHIT. V˙O2peak was determined at baseline and after completion of each exercise condition. Affective (pleasure-displeasure) responses and perceived exertion were assessed during exercise to capture peak responses. Enjoyment was recorded 5-min after cessation of exercise. Compared to baseline, V˙O2peak increased in both groups (6% for SSREHIT [d=- 0.36] and 9% for TREHIT [d=- 0.53], p=0.01). Affective responses were more favourable for SSREHIT (p=0.001, d=1.62), but both protocols avoided large negative peaks of displeasure. Peak ratings of perceived exertion were lower for SSREHIT (p=0.001, d=- 1.71), although there were no differences in enjoyment (d=0.25). The results demonstrate both exercise conditions can increase V˙O2peak without overly compromising perceptual responses. Decreased sprint duration might further circumvent negative perceptual responses but might also attenuate physiological adaptations.

Psychological responses to HIIT and MICT over a 2-week progressive randomized trial among individuals at risk of type 2 diabetes.

The purpose of this secondary analysis study was to examine the affective and social cognitive responses to low-volume high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) over a progressive two-week supervised intervention for individuals at risk of type 2 diabetes. Ninety-nine adults that were low-active and overweight were randomized into one of two exercise conditions and had affective and social cognitive measures assessed before, during, and after intervention. Increases over time in post-exercise enjoyment, attitudes towards exercise, and intentions to exercise were noted for both HIIT and MICT conditions (ps <.05). The patterns of change in acute affective responses over the two-week intervention were consistent for both conditions, with participants in MICT reporting more positive in-task affect and affective attitudes throughout (ps <.001). Positive correlational relationships between affective and social cognitive responses were revealed throughout the intervention (ps <.05), highlighting the relationship between reflexive responses and reflective cognitions. Research is warranted to determine whether findings are a consequence of familiarization with exercise, whether such findings are translatable to real-world environments and non-progressive exercise protocols, and whether these reflexive responses and reflective cognitions are predictive of future exercise behaviour for individuals at risk of type 2 diabetes.

Acute high-intensity interval training improves motor skill acquisition.

BACKGROUND: It is well established that acute exercise improves cognitive function. However, less is known about the effects of exercise on motor skill acquisition. Therefore, this study investigated the effects of acute high-intensity interval training (HIIT) on motor skill acquisition. METHODS: Sixty individuals (27 males, 33 females) between 18 and 40 years of age participated in two testing sessions separated by one week. During visit 1, participants performed one block of a continuous tracking, force control task to establish baseline ability. Participants were then randomized to either an aerobic-only HIIT group (HIIT-A), an aerobic/resistance HIIT group (HIIT-AR), or a resting control group. Both exercise groups performed a 20-minute, digital versatile disc (DVD)-delivered HIIT exercise protocol during visit 2. Following exercise or rest, all participants performed five blocks of the same force control task to assess skill acquisition. RESULTS: On visit 2, the HIIT-A group had a significantly lower total performance error (E) compared to the control group (P<0.05). Both exercise groups (HIIT-A and HIIT-AR) had a significantly lower peak amplitude error (PE) following exercise compared to the control group (P<0.05). No significant group differences were observed for temporal error (TE). Additionally, no significant differences were observed between the exercise groups (P>0.05). CONCLUSIONS: These findings suggest that acute HIIT-A improves motor skill acquisition compared to rest. Furthermore, improvements in acquisition appeared to be a result of improved spatial accuracy. Therefore, performing HIIT-A prior to practicing a motor task may help reduce total error during the motor skill acquisition phase.

Integrating high-intensity interval training into the workplace: The Work-HIIT pilot RCT.

The purpose of this study was to assess the feasibility and preliminary efficacy of a high-intensity interval training (HIIT) intervention integrated into the workplace on physical and mental health outcomes in a sample of adults. The Work-HIIT intervention was evaluated at the University of Newcastle (March-July 2019). University employees (18+ years) who self-identified as predominantly sedentary at work (n = 47, 43.0 ± 10.7 years; 41 female) were recruited, screened, and randomized after baseline assessments into Work-HIIT (n = 24) or wait-list control (n = 23) conditions. Participants were asked to attend 2-3 researcher-facilitated HIIT sessions/week (weeks 1-8). Sessions included a 2-minute gross-motor warm-up, followed by various combinations of aerobic and muscular fitness exercises lasting 8 minutes (using 30:30 second work: rest intervals). Program feasibility was assessed using measures of satisfaction, compliance, adherence, fidelity, and retention. Physiological and psychological outcomes were measured at baseline and 9 weeks. Feasibility data were investigated using descriptive statistics and efficacy outcomes determined using linear mixed models and Cohen's d effect sizes. Participant ratings showed high levels of satisfaction (4.6/5); 71% of participants attended ≥2 sessions/wk and averaged 85.9% HRmax across all sessions (including rest and work intervals). Small-to-medium positive effects resulted for cardiorespiratory fitness [+2.9 laps, 95% CI (-4.19-10.14); d = 0.34] and work productivity [+0.26, d = 0.47]. Large positive effects resulted for muscular fitness [push-ups +3.5, d = 0.95; standing jump +10.1 cm, d = 1.12]; HIIT self-efficacy [+16.53, d = 1.57]; sleep [weekday +0.76 hours, d = 1.05]; and autonomous motivation [+0.23, d = 0.76]. This study supports the feasibility and preliminary efficacy of facilitator-led Work-HIIT as a time-efficient, enjoyable, and convenient workplace exercise option for adults.

Affective responses to high-intensity interval training with continuous and respite music.

Music has been shown to enhance affective responses to continuous exercise, but the most effective application of music during interval exercise is poorly understood. This study examined two contrasting applications of music designed to assuage the decline in pleasure often experienced during high-intensity interval training (HIIT). In a repeated measures crossover design, 18 recreationally active participants (10 men and 8 women; M age = 25.1 ± 5.1 years; M BMI = 23.08 ± 2.01 kg/m 2; M VO2max = 38.82 ± 10.73 ml/kg/min) completed three HIIT sessions (10 x 60 s efforts at 100% Wmax, separated by 75 s recovery) on a cycle ergometer. Participants completed two experimental conditions: respite music (applied only during the recovery periods), continuous music (applied throughout the entire HIIT session); and a no-music control condition. Results indicated that music did not influence affective valence during the work bouts or recovery periods of the HIIT sessions (ps >.05), but that listening to music continuously elicited greater post-task enjoyment (p =.032, d = 0.66) and remembered pleasure (p =.044, d = 0.5). This study is the first to investigate the application of music during a practical HIIT protocol and to compare the effects of respite versus continuous music during interval exercise.