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.

Post-exercise hypotension time-course is influenced by exercise intensity: a randomised trial comparing moderate-intensity, high-intensity, and sprint exercise.

Reductions in blood pressure (BP) induced by exercise training may be associated with the acute reduction in BP observed minutes to hours following an exercise session, termed post-exercise hypotension (PEH). However, the magnitude and time-course of PEH, including the optimal exercise characteristics to maximise it, are still unclear. Using a randomised crossover design, 16 normotensive participants (median age (range) 22 (19-31) years; 50% female) undertook three different exercise sessions: sprint interval exercise (SIE, 30 × 8-s sprints with 32 s recovery), high-intensity interval exercise (HIIE, 15 × 1-min intervals at 90% peak heart rate (HR) with 1-min recovery), and moderate-intensity continuous exercise (MICE, 48 min at 65% peak HR). BP and HR were monitored before and up to 90 min following each session. The three exercise sessions each showed distinct PEH and of similar overall magnitude up to 90 min post exercise; however, there were distinct differences in the time-course. Systolic BP was lower 40 min after MICE compared to HIIE (-7.7 (-13.9 to -2.4) mmHg) and diastolic BP was higher 5 min after HIIE compared to SIE (8.5 (2.3-14.7) mmHg). MICE induced lower HR up to 40 min after exercise compared to HIIE and SIE. HIIE and SIE induced PEH of similar magnitude to MICE. A phasic or 'W-shaped' time-course of PEH observed following HIIE and SIE contrasted to a distinct 'V-shaped' PEH following MICE, indicating the physiological mechanisms driving BP regulation after exercise are influenced by exercise intensity.

Sex Differences in Cardiometabolic Health Indicators after HIIT in Patients with Coronary Artery Disease.

PURPOSE: Cardiorespiratory fitness (CRF) is an independent predictor of mortality, and females typically achieve smaller improvements in CRF than males after exercise-based cardiac rehabilitation. High-intensity interval training (HIIT) has been shown to produce superior improvements in CRF than traditional cardiac rehabilitation, but the sex differences are unknown. The purpose of this systematic review and meta-analysis was to evaluate sex differences for changes in CRF and cardiometabolic health indicators after HIIT in adults with coronary artery disease (CAD). METHODS AND RESULTS: A systemic search of five electronic databases for studies examining the effect of HIIT on measured CRF and cardiometabolic health indicators in adults with CAD was performed. Data (published and unpublished) from 14 studies were included in the meta-analyses with approximately eightfold greater male than female participation (n = 836 vs n = 103). Males with CAD achieved a near-significant absolute improvement in CRF (mean difference [MD] = 1.07, 95% confidence interval [CI] = -0.08 to 2.23 mL·kg-1⋅min-1, P = 0.07) after HIIT when compared with control; there were insufficient data to conduct such an analysis in females. Significantly smaller improvements in CRF were experienced by females than males (MD = -1.10, 95% CI = -2.08 to -0.12 mL·kg-1⋅min-1, P = 0.03); there was no sex difference for the relative (percentage) change in CRF after HIIT. Females achieved significantly smaller reductions in body mass index (MD = -0.25, 95% CI = -0.03 to -0.47 kg·m-2, P = 0.02) and fasting blood glucose (MD = -0.38, 95% CI = -0.05 to -0.72, P = 0.03); no sex differences were observed for other cardiometabolic health indicators. CONCLUSION: There are no sex differences for relative improvements in CRF after HIIT; however, females are greatly underrepresented in trials. Future studies should increase female participation and perform sex-based analyses to determine sex-specific outcomes following HIIT.

High-intensity interval training for patients with coronary artery disease: Finding the optimal balance.

BACKGROUND: The optimal characteristics of high-intensity interval training (HIIT) for patients with coronary artery disease (CAD) within cardiac rehabilitation (CR) are unclear. We assessed a HIIT protocol designed to balance patient safety, efficacy and enjoyment. METHODS: Twenty-nine patients with CAD completed 6-weeks (× 2 sessions per week) of HIIT within outpatient (phase 2) CR. HIIT comprised 15 repetitions × 30-seconds cycling at ∼85-90% maximum heart rate, interspersed with 30-seconds of active recovery. Key outcomes covered patient safety, efficacy (peak aerobic capacity, body composition, blood pressure and vascular function), and patient adherence and enjoyment. RESULTS: No cardiovascular-related adverse events were reported in relation to HIIT sessions. Patients showed significant improvement in peak aerobic capacity (mean +12%, p < 0.001, effect size d = 0.38), blood pressure (brachial systolic -7mmHg, p < 0.001, d = -0.59) and total body fat (-4%, p < 0.001, d = -0.49). Central adaptations were prominent (aortic systolic BP -5mmHg, p = 0.001, d = -0.50; visceral fat -10%, p = 0.001, d = -0.41). Patient enjoyment of training was high (5.5 out of 7 using the Exercise Enjoyment Scale) and measures of affective state improved following training (assorted p < 0.018). CONCLUSIONS: This HIIT protocol appears safe, effective and enjoyable for patients with CAD within CR. Improved aerobic fitness, blood pressure and body fat levels were observed indicating improved cardiovascular-risk. High patient enjoyment and improved mood suggest the HIIT could be sustainable for patients in the longer-term.

High-intensity interval training for reducing blood pressure: a randomized trial vs. moderate-intensity continuous training in males with overweight or obesity.

The optimal exercise-training characteristics for reducing blood pressure (BP) are unclear. We investigated the effects of 6-weeks of high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on BP and aortic stiffness in males with overweight or obesity. Twenty-eight participants (18-45 years; BMI: 25-35 kg/m2) performed stationary cycling three times per week for 6 weeks. Participants were randomly allocated (unblinded) to work-matched HIIT (N = 16; 10 × 1-min intervals at 90-100% peak workload) or MICT (N = 12; 30 min at 65-75% peak heart rate). Central (aortic) and peripheral (brachial) BP and aortic stiffness was assessed before and after training. There were no significant group × time interactions for any BP measure (all p > 0.21). HIIT induced moderate reductions in central (systolic/diastolic ∆: -4.6/-3.5 mmHg, effect size d = -0.51/-0.40) and peripheral BP (-5.2/-4 mmHg, d = -0.45/-0.47). MICT induced moderate reductions in diastolic BP only (peripheral: -3.4 mmHg, d = -0.57; central: -3 mmHg, d = -0.50). The magnitude of improvement in BP was strongly negatively correlated with baseline BP (r = -0.66 to -0.78), with stronger correlations observed for HIIT (r = -0.73 to -0.88) compared with MICT (r = -0.43 to -0.61). HIIT was effective for reducing BP (~3-5 mmHg) in the overweight to obese cohort. Exercise training induced positive changes in central (aortic) BP. The BP-lowering effects of exercise training are more prominent in those with higher baseline BP, with stronger correlation in HIIT than MICT.

High-Intensity Interval Training for Patients With Cardiovascular Disease-Is It Safe? A Systematic Review.

Background Cardiac rehabilitation ( CR ) for patients with cardiovascular disease has traditionally involved low- to moderate-intensity continuous aerobic exercise training ( MICT ). There is growing and robust evidence that high-intensity interval training ( HIIT ) shows similar or greater efficacy compared with MICT across a range of cardiovascular and metabolic measures, in both healthy populations and populations with a chronic illness. However, there is understandable concern about the safety aspects of applying HIIT in CR settings. This systematic review analyzed safety data drawn from recent proof-of-concept studies of HIIT during CR among patients with cardiovascular disease. Methods and Results We included trials comparing HIIT with either MICT or usual care in patients with coronary artery disease or heart failure participating in tertiary care services, such as phase 2 (outpatient) CR . Adverse events occurring during or up to 4 hours after an exercise training session were collated. There were 23 studies included, which analyzed 1117 participants ( HIIT =547; MICT =570). One major cardiovascular adverse event occurred in relation to an HIIT session, equating to 1 major cardiovascular event per 17 083 training sessions (11 333 training hours). One minor cardiovascular adverse events and 3 noncardiovascular adverse events (primarily musculoskeletal complaints) were also reported for HIIT . Two noncardiovascular events were reported in relation to MICT . Conclusions HIIT has shown a relatively low rate of major adverse cardiovascular events for patients with coronary artery disease or heart failure when applied within CR settings.

Autonomic nervous system function, activity patterns, and sleep after physical or cognitive challenge in people with chronic fatigue syndrome.

OBJECTIVE: To explore changes in autonomic functioning, sleep, and physical activity during a post-exertional symptom exacerbation induced by physical or cognitive challenge in participants with chronic fatigue syndrome (CFS). METHODS: Thirty-five participants with CFS reported fatigue levels 24-h before, immediately before, immediately after, and 24-h after the completion of previously characterised physical (stationary cycling) or cognitive (simulated driving) challenges. Participants also provided ratings of their sleep quality and sleep duration for the night before, and after, the challenge. Continuous ambulatory electrocardiography (ECG) and physical activity was recorded from 24-h prior, until 24-h after, the challenge. Heart rate (HR) and HR variability (HRV, as high frequency power in normalized units) was derived from the ECG trace for periods of wake and sleep. RESULTS: Both physical and cognitive challenges induced an immediate exacerbation of the fatigue state (p<0.001), which remained elevated 24-h post-challenge. After completing the challenges, participants spent a greater proportion of wakeful hours lying down (p=0.024), but did not experience significant changes in sleep quality or sleep duration. Although the normal changes in HR and HRV during the transition from wakefulness to sleep were evident, the magnitude of the increase in HRV was significantly lower after completing the challenge (p=0.016). CONCLUSION: Preliminary evidence of reduced nocturnal parasympathetic activity, and increased periods of inactivity, were found during post-exertional fatigue in a well-defined group of participants with CFS. Larger studies employing challenge paradigms are warranted to further explore the underlying pathophysiological mechanisms of post-exertional fatigue in CFS.

Gene Expression in Response to Exercise in Patients with Chronic Fatigue Syndrome: A Pilot Study.

Chronic fatigue syndrome (CFS) is a debilitating disorder of unknown pathogenesis, characterized by fatigue, which is exacerbated after minimal exercise. We examined the effect of a single bout of aerobic exercise on leucocyte mRNA expression of genes putatively linked to exaggerated afferent signaling as an under-pinning of the fatigue state. A carefully-characterized sample of patients with CFS (N = 10) and healthy matched control participants (N = 12) were included. Participant ratings of fatigue and other symptoms, as well as blood samples, were obtained at baseline, and five other time-points up to 72 h after 25 min of moderate-intensity cycling exercise. Leucocyte mRNA of 19 metabolite-sensing, adrenergic, immune, and neurotransmission genes was examined using quantitative polymerase chain reaction. Patients with CFS reported substantial fatigue, functional impairment, and poor sleep at baseline (all p < 0.02), and exercise immediately induced worsened patients' fatigue (effect size, ES = 1.17). There were no significant changes in gene expression after exercise and patients did not differ from control participants at any time point. Higher levels of expression of ficolin (FCN1) and a purinergic receptor (P2RX4) in patients with CFS were found when all time points were combined. Patients with CFS did not show significant exercise-induced changes in leucocyte mRNA of 19 metabolite-sensing, adrenergic, immune and neurotransmission genes despite a prominent exacerbation of fatigue.

Capturing the post-exertional exacerbation of fatigue following physical and cognitive challenge in patients with chronic fatigue syndrome.

OBJECTIVE: To design and validate an instrument to capture the characteristic post-exertional exacerbation of fatigue in patients with chronic fatigue syndrome (CFS). METHODS: Firstly, patients with CFS (N=19) participated in five focus group discussions to jointly explore the nature of fatigue and dynamic changes after activity, and inform development of a self-report instrument - the Fatigue and Energy Scale (FES). The psychometric properties of the FES were then examined in two case-control challenge studies: a physically-demanding challenge (moderate-intensity aerobic exercise; N=10 patients), and a cognitively-demanding challenge (simulated driving; N=11 patients). Finally, ecological validity was evaluated by recording in association with tasks of daily living (N=9). RESULTS: Common descriptors for fatigue included 'exhaustion', 'tiredness', 'drained of energy', 'heaviness in the limbs', and 'foggy in the head'. Based on the qualitative data, fatigue was conceptualised as consisting of 'physical' and 'cognitive' dimensions. Analysis of the psychometric properties of the FES showed good sensitivity to the changing symptoms during a post-exertional exacerbation of fatigue following both physical exercise and driving simulation challenges, as well as tasks of daily living. CONCLUSION: The 'fatigue' experienced by patients with CFS covers both physical and cognitive components. The FES captured the phenomenon of a post-exertional exacerbation of fatigue commonly reported by patients with CFS. The characteristics of the symptom response to physical and cognitive challenges were similar. Both the FES and the challenge paradigms offer key tools to reliably investigate biological correlates of the dynamic changes in fatigue.