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Despite an abundance of evidence that exercise benefits cognition and mood, physical activity levels among older adults remain low, with time and inaccessibility posing major barriers. Interval stair climbing is an accessible time-efficient form of physical activity demonstrated to benefit cognition and mood in young adults, but effectiveness in older adults remains unknown. To address this, 28 older adults (Mage = 69.78 years, 16 females) undertook cognitive and mood assessments twice, 1 week apart, once preceded by interval stair climbing. A fairly large, albeit only marginally significant, effect size () indicated improved cognition following the moderate- to high-intensity intervention; however, rather than improving mood, older adults reported feeling more tired (g = 0.51). These outcomes provide initial indications that this mode of exercise that can easily translate to naturalistic settings offers promise as an intervention strategy, but more research is needed to optimize the protocol to suit aged populations (ACTRN1261900169014).

Attention deficit hyperactivity disorder (ADHD) is one of the most commonly neurodevelopmental disorders with a complex symptomatology in children, and frequently suffer from deficits in executive functions and motor abilities. Although medication-based treatments usually have a positive effect, possible side effects may result in a need for an adjunctive intervention. Present studies show positive effect of physical exercise on cognitive function. Therefore, the purpose of the current study is thoroughly examine the effects of physical exercise in children with ADHD. Preliminary evidence shows both acute and chronic physical exercise are beneficial to ADHD symptoms, executive function, and motor abilities. Benefits of acute exercise may gradually accumulate over time. Such benefits reflect the positive correlation between cognition and physical activity, and these benefits will also lead to changes in executive function after long-term training. Aerobic could induce to increase the neurotransmitter ie. serotonin, dopamine, brain-derived neurotrophic factor (BDNF) and brain blood flow. Perceptual motor and meditation could lead to neuroplasticity in nerve cells and synaptic connections; furthermore, strengthening the sensory-motor base contributes to the improvement of attention. An exercise program for children with ADHD include to moderate to high intensity interval training and cognitive tasks are suitable. The preliminary state of the evidence supports physical exercise as an adjunctive treatment for ADHD at this time.

The effects of a 6-week cycling high-intensity interval training (HIIT) concurrently with protein supplementation on aerobic and anaerobic fitness and body composition in collegiate dancers was investigated. Eighteen participants enrolled in a collegiate dance program were matched into three groups: high-protein (HP; 90 g˙d−1), moderate-protein (MP; 40 g˙d−1), and control (C; 0 g˙d−1). All participants performed a 6-week HIIT intervention. Participants completed a graded exercise test, Wingate anaerobic test (Wingate), and dual energy x-ray absorptiometry scan before and after the intervention. Peak heart rate (HRpeak), peak oxygen uptake (VOpeak), peak power output (PPO), lactate threshold (LT), and ventilatory thresholds 1 (VT1 ) and 2 (VT2) were assessed during the graded exercise test. Peak power output, mean power output (MPO), and fatigue index (FI) were assessed during the Wingate. Lean mass (LM), fat mass (FM), visceral adipose tissue, appendicular skeletal muscle mass, and appendicular skeletal muscle mass index were assessed during dual energy x-ray absorptiometry. Body composition index (BCI) was calculated from pre and post LM and FM. Habitual diet was recorded weekly. Significance was set at p ≤ 0.05. No significant differences in VO2peak and percent fat mass (%FM) were observed between groups prior to the intervention. Significant main effects for time were observed for HRpeak (p = 0.02), VO2peak (p < 0.001), PPO (p < 0.01), LT (p < 0.001), VT1 (p < 0.001), and VT2 (p < 0.001) during the graded exercise test, and PPO (p < 0.01) and FI (p < 0.01) during the Wingate. Significant main effects for time were observed for LM (kg; p = 0.01) and FM (kg; p < 0.01). Body composition index was improved for all groups, however, no significant differences by group were observed. No significant differences were observed between groups for the measured outcomes (p > 0.05). Therefore, there was no effect of protein supplementation in the short 6-week intervention. This cycling based HIIT routine increased physical fitness, optimized aesthetics, and was a simple addition to an existing collegiate dance curriculum.

The primary objective of this pilot randomized controlled trial was to study the feasibility (recruitment and retention rates) for interval training and sleep hygiene (SH) in adults aged above 60 years. Thirteen out of 46 screened individuals from a home for older adults in Shirdi (Maharashtra, India) were randomly assigned by permuted block randomization to either an interval training with SH group (n = 6) or an SH alone group (n = 7). The authors measured sleep with the S+ sleep monitor manufactured by ResMed (USA) Pittsburgh Sleep Quality Index and quality of life with Short Form-12 health survey version 2. Interval training consisted of 8 weeks of stationary cycling, whereas SH consisted of lecture and handouts. Recruitment was 38.2%, retention was >80% for both the interventions, and there was one loss to follow-up in SH. Interval training and SH were feasible for older adults and supported a full-scale randomized controlled trial.

The majority of women do not meet the recommended levels of exercise during their pregnancies, frequently due to a lack of time. High-intensity interval training offers a potential solution, providing an effective, time-efficient exercise modality. This exercise modality has not been studied in pregnancy therefore, the objective of this study was to evaluate fetal response to a high-intensity interval training resistance circuit in the late second and early third trimesters of pregnancy. Fourteen active, healthy women with uncomplicated, singleton pregnancies participated in a high-intensity interval training resistance circuit between 28 + 0/7 and 32 + 0/7 weeks. A Borg rating of perceived exertion of 15–17/20 and an estimated heart rate of 80%–90% of maternal heart-rate maximum was targeted. Fetal well-being was evaluated continuously with fetal heart-rate tracings and umbilical artery Doppler velocimetry conducted pre-and post-exercise. Fetal heart rate tracings were normal throughout the exercise circuit. Post-exercise, umbilical artery end-diastolic flow was normal and significant decreases were observed in the mean systolic/diastolic ratios, pulsatility indexes and resistance indexes. Therefore, in a small cohort of active pregnant women, a high-intensity interval training resistance circuit in the late second and early third trimesters of pregnancy appears to be a safe exercise modality with no acute, adverse fetal effects but further study is required. Novelty: High-intensity interval training, at an intensity in excess of current recommendations, does not appear to be associated with any adverse fetal effects in previously active pregnant women. High-intensity interval training is an enjoyable and effective exercise modality in previously active pregnant women.

This study assessed the feasibility of a phase II randomized controlled trial of high-intensity interval training (HIIT), resistance training (RT), and usual care (UC) in men with prostate cancer (PCa) on active surveillance and evaluated changes in clinically relevant outcomes. Eighteen men undergoing active surveillance for PCa were randomized to HIIT (n = 5), RT (n = 7), or UC (n = 6). Exercise participants attended 2 supervised sessions weekly and were instructed to complete 1 home-based session weekly for 8 weeks. UC participants were provided with physical activity guidelines. Feasibility was met for attendance, compliance, and retention, but not recruitment. HIIT increased leg press (mean: +8.2 kg, 95% CI 1.1 to 15.3) from baseline to 8 weeks. RT increased seated row (mean: +11.7 kg, 95% CI 6.1 to 17.3), chest press (mean: +10.4 kg, 95% CI 5.3 to 15.5), leg press (mean: +13.1 kg, 95% CI 5.9 to 20.3), serum insulin-like binding protein-3 (IGFBP-3) (mean: +400.0 ng/mL, 95% CI 94.5 to 705.5), and decreased interferon-γ (mean: −3.1 pg/mL, 95% CI −5.7 to −0.4). No changes were observed in the UC group. HIIT and RT may be effective strategies for improving muscle strength; however, only RT may increase serum IGFBP-3. Strategies that can enhance recruitment in men on active surveillance are important prior to conducting a phase II trial. Trial registration number: ClinicalTrials.gov number NCT04266262. Novelty: High-intensity interval training or resistance training are feasible during active surveillance for prostate cancer. Resistance training may suppress the tumour-promoting effects of insulin-like growth factor-I (IGF-I) via increased expression of IGFBP-3.

INTRODUCTION Physical exercise appeared to be effective, when implemented as an adjuvant to the pharmacotherapy option, in a variety of painful conditions. Peripheral neuropathic pain (PNP) is very prevalent and affects up to two-thirds of individuals with polyneuropathy (PN), regardless of etiology. The aim of this systematic review was to evaluate the currently available studies that assess adjuvant physical exercise for the management of PNP. METHODS A systematic literature search was conducted in the PubMed international database. For the systematic search, three medical subject headings (MeSH) were used. Term A was 'physical exercise' OR 'exercise' OR 'activity' OR 'workout' OR 'training'; term B was 'pain' OR 'painful'; term C was 'neuropathy' OR 'polyneuropathy.' Additionally, three filters were used: human subjects, English language, and full text. The reference lists of eligible papers and relevant reviews were also meticulously searched in order to include further relevant studies. Six papers eligible to be included were identified. RESULTS Physical exercise in various forms can be of benefit in the management of PNP when used as an adjuvant to the standard care. Overall, using the American Society of Interventional Pain Physicians (ASIPP) criteria, the current best available evidence exists for both aerobic and muscle strengthening exercise programs (level II evidence). The intensity of the exercise seems to play a significant role, with higher intensity interval training programs being more promising, though this remains to be confirmed in future studies. CONCLUSIONS Physical exercise is a promising non-pharmacological intervention for the management of PNP. Future RCTs should be conducted to make a face-to-face comparison of the available exercise treatments with the aim to design specific exercise programs for patients with PNP.

This study aimed to examine the effectiveness of high-intensity interval training (HIIT) on pulmonary function and exercise capacity in individuals with chronic obstructive pulmonary disease (COPD). Ten databases (PubMed, the Cochrane Library, Web of Science, EMBASE, MEDLINE, CINAHL, CNKI, Wanfang, Weipu, and CBM) were searched for relevant articles published from inception to 30 June 2020. Studies were included if they were randomized controlled trials (RCTs) comparing a HIIT group with usual care or other training groups. Quality was assessed using the Physiotherapy Evidence Database (PEDro) scale, and the overall quality of evidence was assessed using the GRADE approach. The primary outcomes were peak VO2 and FEV1% predicted, and the secondary outcomes were FEV1/FVC, peak VE, peak WR, 6MWD, dyspnea, health-related quality of life, and adverse event. Twelve articles (689 patients) were included. HIIT was shown to have a positive effect on exercise capacity (peak WR, 6MWD), pulmonary function (FEV1% pred, peak VE), dyspnea, and quality of life. However, sensitivity analyses for dyspnea were unstable, and the result changed from positive to negative after removing one study (SMD = − 0.13, 95% CI [− 0.44, 0.17], P = 0.40). HIIT could improve pulmonary function, exercise capacity, and quality of life but may not decrease dyspnea in patients with COPD. It can be recommended as a safe and effective exercise modality in rehabilitation programs. Given that the overall results were based on a limited number of studies with significant heterogeneity and some of the results were based on low GRADE rating evidence, more high-quality, larger sample size, multicenter, and long-term follow-up RCTs are needed to confirm the clinical efficacy of HIIT in patients with COPD. CRD42020165897.

Objective: The aim of this study is to review the effects of high-intensity interval training (HIIT)/sprint interval training (SIT) on asthma symptoms, cardiorespiratory functions, and other variables among asthmatic patients.Data Sources: Randomized controlled trials published between January 2000 and January 2021 were searched in PubMed/MEDLINE, Web of Science, and Cochrane Library databases.Study Selections: Following pre-specified inclusion criteria, this review included 7 randomized controlled studies that compare HIIT/SIT as an intervention with any other intervention and/or control group.Results: Of the included studies only 4 reported the chronic phase effects of the HIIT/SIT protocols. HIIT and SIT protocols applied in studies differ. HIIT improved forced expiratory volume in 1 s (FEV1) in the acute phase and maximal oxygen consumption (VO2max) in the chronic phase in the asthmatic patients (p < 0.05).Conclusion: To our knowledge, our systematic review is the first study evaluating the effects of HIIT/SIT protocols on asthma patients. HIIT/SIT protocols have beneficial effects on asthma patients. In order to better understand the results of these training procedures, studies that will be designed with high methodology are needed. 2-s2.0-85119153256 WOS:000716785000001 34706200 Q3

Training-intensity distribution (TID) is considered the key factor to optimize performance in endurance sports. This systematic review aimed to: I) characterize the TID typically used by middle-and long-distance runners; II) compare the effect of different types of TID on endurance performance and its physiological determinants; III) determine the extent to which different TID quantification methods can calculate same TID outcomes from a given training program. The keywords and search strategy identified 20 articles in the research databases. These articles demonstrated differences in the quantification of the different training-intensity zones among quantification methods (i. e. session-rating of perceived exertion, heart rate, blood lactate, race pace, and running speed). The studies that used greater volumes of low-intensity training such as those characterized by pyramidal and polarized TID approaches, reported greater improvements in endurance performance than those which used a threshold TID. Thus, it seems that the combination of high-volume at low-intensity (≥ 70% of overall training volume) and low-volume at threshold and high-intensity interval training (≤ 30%) is necessary to optimize endurance training adaptations in middle-and long-distance runners. Moreover, monitoring training via multiple mechanisms that systematically encompasses objective and subjective TID quantification methods can help coaches/researches to make better decisions.

Purpose: There has been paucity in research investigating the individualization of recovery interval duration during cycling-based high-intensity interval training (HIIT). The main aim of the study was to investigate whether individualizing the duration of the recovery interval based upon the resolution of muscle oxygen consumption would improve the performance during work intervals and the acute physiological response of the HIIT session, when compared with a standardized (2:1 work recovery ratio) approach. Methods: A total of 16 well-trained cyclists (maximal oxygen consumption: 60 [7] mL·kg−1·min−1) completed 6 laboratory visits: (Visit 1) incremental exercise test, (Visit 2) determination of the individualized (IND) recovery duration, using the individuals’ muscle oxygen consumption recovery duration to baseline from a 4- and 8-minute work interval, (Visits 3–6) participants completed a 6 × 4- and a 3 × 8-minute HIIT session twice, using the IND and standardized recovery intervals. Results: Recovery duration had no effect on the percentage of the work intervals spent at >90% and >95% of maximal oxygen consumption, maximal minute power output, and maximal heart rate, during the 6 × 4- and 3 × 8-minute HIIT sessions. Recovery duration had no effect on mean work interval power output, heart rate, oxygen consumption, blood lactate, and rating of perceived exertion. There were no differences in reported session RPE between recovery durations for the 6 × 4- and 3 × 8-minute HIIT sessions. Conclusion: Individualizing HIIT recovery duration based upon the resolution of muscle oxygen consumption to baseline levels does not improve the performance of the work intervals or the acute physiological response of the HIIT session, when compared with standardized recovery duration.

Context Non-alcoholic fatty liver disease, characterized by excess fat accumulation in the liver, is considered the hepatic manifestation of metabolic syndrome. Recent findings have shown that high-intensity interval training (HIIT) can reduce liver fat but it is unclear whether this form of exercise is superior to traditional moderate-intensity continuous training (MICT). Objective The aim of this systematic review was to determine the effect of HIIT vs MICT on liver fat in adults. A secondary aim was to investigate the interaction between total weekly exercise volume and exercise-related energy expenditure and change in liver fat. Methods Relevant databases were searched up to December 2020 for randomized trials, comparing HIIT to control, MICT to control, or HIIT to MICT. Studies were excluded if they did not implement 2 or more weeks’ intervention or assess liver fat using magnetic resonance-based techniques. Weighted mean differences and 95% CIs were calculated. Regression analyses were undertaken to determine the interaction between weekly exercise volume in minutes and kilocalories (kcal) with change in liver fat content. Results Of the 28 268 studies screened, 19 were included involving 745 participants. HIIT and MICT both elicited moderate reductions in liver fat content when compared to control (HIIT: –2.85%, 95% CI, –4.86 to –0.84, P = .005, I2 = 0%, n = 114, low-certainty evidence; MICT: –3.14%, 95% CI, –4.45 to –1.82, P Conclusion HIIT elicits comparable improvements in liver fat to MICT despite often requiring less energy and time commitment. Further studies should be undertaken to assess the relative importance of aerobic exercise prescription variables, such as intensity, on liver fat.

Accumulating evidence now shows that supplemental antioxidants including vitamin C, vitamin E and N-Acetylcysteine consumption can suppress adaptations to endurance-type exercise by attenuating reactive oxygen and nitrogen species (RONS) formation within skeletal muscle. This emerging evidence points to the importance of pro-oxidation as an important stimulus for endurance-training adaptations, including mitochondrial biogenesis, endogenous antioxidant production, insulin signalling, angiogenesis and growth factor signaling. Although sustained oxidative distress is associated with many chronic diseases, athletes have, on average, elevated levels of certain endogenous antioxidants to maintain redox homeostasis. As a result, trained athletes may have a better capacity to buffer oxidants during and after exercise, resulting in a reduced oxidative eustress stimulus for adaptations. Thus, higher levels of RONS input and exercise-induced oxidative stress may benefit athletes in the pursuit of continuous endurance training redox adaptations. This review addresses why athletes should be looking to enhance exercise-induced oxidative stress and how it can be accomplished. Methods covered include high-intensity interval training, hyperthermia and heat stress, dietary antioxidant restriction and modified antioxidant timing, dietary antioxidants and polyphenols as adjuncts to exercise, and vitamin C as a pro-oxidant.

PURPOSE The aim of this study was to analyze the blood pressure (BP) and heart rate variability (HRV) responses in untrained postmenopausal women submitted to acute single sessions of high-intensity interval training (HIT). METHOD Sixteen postmenopausal women (59.9 ± 5.6 years, 26.7 ± 3.0 kg/m2) participated in a random order of two acute sessions in a balanced crossover format: control without exercise in sitting position or HIT session. BP and heart rate (HR) were recorded before and during 60 min following the sessions. RESULTS Diastolic (DBP), mean BP (MBP), and double product (DPO) showed interaction (p

This study sought to determine the physiological (oxygen uptake, heart rate, and blood lactate concentration) and perceptual (rating of perceived exertion) responses during an endurance interval training at the critical speed in elite handcyclists with spinal cord injury.Eight handcyclists performed an incremental test, three tests to exhaustion at a constant speed to determine critical speed, and the endurance interval training. The endurance interval training consisted of 6 × 5 mins at the individualized critical speed, with passive recovery of 50 secs. All testing was performed using their own handcycles on an oversized motorized treadmill. Physiological and perceptual responses were assessed during the incremental and endurance interval training tests.There was no significant difference in average oxygen uptake from the first to the sixth repetition. The mean ∆[La-]10_last between the 10th to the 30th minute of the exercise was -0.36 mmol·l-1, and no difference was detected from the first to the sixth repetition. The heart rate also remained stable during endurance interval training, whereas rating of perceived exertion increased significantly throughout the session.Repetitions of 5 mins at the critical speed in elite handcyclists are associated with cardiorespiratory and lactate steady state, whereas the perceived exertion increased systematically.

Introduction Moderate aerobic, high-intensity and sprint running or cycling training can transiently impair postural control. However, the acute effects of modified sprint interval training (mSIT) at different muscle working modes have not yet been examined. Thus, this study aimed at investigating acute effects of time-matched eccentric (ECC) versus concentric mSIT cycling session (CON) on jumping and functional balance performance. Methods Twenty-five healthy and active males (30.0 ± 6.0 years; 80.1 ± 9.1 kg; VO2max: 64.2 ± 7.9 mL kg−1 min−1) were enrolled in this acute randomized controlled crossover trial. Counter-Movement-Jump (CMJ) and functional balance testing (Y-Balance-Test composite score [YBTCS]; Posturomed total distance: PosturomedTD) were assessed as primary outcomes before, and immediately after cessation of ECC and CON (10 × 10 s maximum sprints and 50 s of active recovery). Results A significant mode × time interaction effect for CMJ (F = 9.620, p = 0.005, ηp2 = 0.29) was observed. Subsequent post-hoc testing revealed significant moderate reductions in jumping height after CON (0.31 ± 0.06 vs. 0.27 ± 0.06m; p = 0.004, SMD = 0.59), whilst ECC remained unchanged. YBTCS (mode × time interaction: F = 6.880, p = 0.015, ηp2 = 0.22) showed small but significant balance impairments after CON (0.964 ± 0.068 vs. 0.960 ± 0.063 AU; p = 0.009, SMD = 0.28) and did not significantly change after ECC. Although large significant interaction effects (p = 0.029, ηp2 = 0.18) were observed for PosturomedTD, follow up post-hoc testing did not reveal relevant pre-post differences, neither for ECC nor CON. Conclusion Both functional balance and jumping performance are deteriorated after acute concentric but not eccentric mSIT cycling. Although higher pedal forces at lower perceived efforts and heart rates during eccentric mSIT were observed, it seems that the cardiocirculatory demanding CON session elicited more pronounced balance and jump performance impairments than eccentric cycling.

The aim of the study was to evaluate the safety of high-intensity, low-volume interval training (HIIT-low volume) compared with moderate-intensity continuous aerobic training (MICT) in adults with metabolic syndrome.This is a controlled, randomized, clinical trial in patients without history of ischemic heart disease or diabetes, who underwent a supervised, 3 sessions/week, 12-week treadmill exercise program. The HIIT-low volume (n = 29) sessions consisted of 6 intervals with 1-minute, high-intensity phases at 90% of peak oxygen consumption (VO2peak). The MICT (n = 31) trained at 60% of VO2peak for 30 minutes. A new approach to record and classify all clinical events according to possible causality based on Naranjo's algorithm was developed.Patients were 50.8 ± 6.0 years old, 70% women, with body mass index of 30.6 ± 4.0 kg/m2 and VO2peak of 29.0 ± 6.3 mL·kg-1·min-1. In total, 60 clinical events were recorded in the HIIT-low volume group and 48 in the MICT group, with 59.3% classified as general disease. Only 21 events were classified as adverse reactions possibly related to exercise, without any serious adverse reactions. Both interventions had a similar incidence of musculoskeletal events (incidence rate ratio, 1.1; 95% confidence interval, 0.6-1.8), but HIIT-low volume had a higher incidence of cardiovascular events (incidence rate ratio, 2.9; 95% CI, 0.4-22.8) after adjusting for age, sex, and body mass index (HIIT-low volume: chest pain [n = 1] and symptoms of venous insufficiency of lower limbs [n = 2]; MICT: chest pain [n = 1]).The HIIT-low volume and MICT are safe in patients with metabolic syndrome. We recommend a muscle-conditioning program prior to both and to avoid HIIT-low volume in treadmill in patients with venous insufficiency of the lower limbs.Trial registration number NCT03087721.

Growing evidence shows that aerobic exercise improves cognitive function. However, it is unclear how exercising at different exercise intensities affects cognitive inhibitory control in overweight/obese adults. Herein we compared the effects of 12 weeks of high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and self-selected intensity training (SSIT) on cognitive inhibitory control in overweight/obese adults. A total of 64 adults (59.4% women, 31.3 ± 7.1 years, 29 ± 2.5 kg/m²) were randomized into three walking/running groups: HIIT, MICT and SSIT. All groups performed three exercise sessions per week on an outdoor running track for 12 weeks. Cognitive inhibitory control was assessed at baseline and after the exercising programs using a computerized version of the Stroop Color-Words test. The HIIT and SSIT resulted in a faster Stroop effect (i.e. enhanced performance) when compared to MICT (p=.018; p= .026), however, there were no significant differences between the HIIT and SSIT groups (p> .05). The enhanced Stroop effect was correlated with increases in cardiorespiratory fitness after HIIT (r= -.521, p= .018) and decreases in body fat after MICT (r= .671, p= .001). These findings may suggest that overweight/obese adults performing exercise interventions at higher intensities or self-selected intensity may enhance their cognitive ability to inhibit automated behavioral responses.

Purpose: Cyclists may increase exercise intensity by prolonging exercise duration and/or shortening the recovery period during self-paced interval training, which could impact the time spent near . Thus, the main objective of this study was to compare the time spent near during 4 different self-paced interval training sessions. Methods: After an incremental test, 11 cyclists (mean [SD]: age = 34.4 [6.2] y; ) performed in a randomized order 4 self-paced interval training sessions characterized by a work–recovery ratio of 4:1 or 2:1. Sessions comprised 4 repetitions of 4 minutes of cycling with 1 minute (4/1) or 2 minutes (4/2) of active recovery or 8 minutes of cycling with 2 minutes (8/2) or 4 minutes (8/4) of active recovery. Time spent at 90% to 94% (), ≥95% (), and 90% to 100% () was analyzed in absolute terms and relative to the total work duration. Power output, heart rate, blood lactate, and rating of perceived exertion were compared. Results: The 8/4 session provided higher absolute and than 8/2 (P = .015 and .029) and 4/1 (P = .002 and .047). The 4/2 protocol elicited higher relative (47.7% [26.9%]) and (23.5% [22.7%]) than 4/1 (P = .015 and .028) and 8/2 (P P Conclusions: Self-paced interval training composed of 4-minute and 8-minute work periods efficiently elicit , but protocols with a work–recovery ratio of 2:1 (ie, 4/2 and 8/4) could be prioritized to maximize .

Objective To assess the effects of high-intensity interval training (HIIT) on physical, mental, and cognitive functioning after stroke. Design The HIIT Stroke Study was a single-blind, multicenter, parallel-group randomized controlled trial. Setting Specialized rehabilitation units at 3 Norwegian hospitals. Participants Adult stroke survivors (N=70) 3 months to 5 years after a first-ever stroke. Mean age was 57.6±9.2 years and 58.7±9.2 years in the intervention and control groups, respectively. Interventions Participants were randomized to standard care in combination with 4×4 minutes of treadmill HIIT at 85%-95% of peak heart rate or standard care only. Outcomes Outcomes were measured using physical, mental, and cognitive tests and the FIM and Stroke Impact Scale. Linear mixed models were used to analyze differences between groups at posttest and 12-month follow-up. Results The intervention group showed a significant treatment effect (95% confidence interval [CI]) from baseline to posttest on a 6-minute walk test of 28.3 (CI, 2.80-53.77) meters (P=.030); Berg Balance Scale 1.27 (CI, 0.17-2.28) points (P=.025); and Trail Making Test Part B (TMT-B; −24.16 [CI, −46.35 to −1.98] s, P=.033). The intervention group showed significantly greater improvement on TMT-B at the 12-month follow-up (25.44 [CI, −49.01 to −1.87] s, P=.035). The control group showed significantly greater improvement in total Functional Independence Measure score with a treatment effect of −2.37 (CI, −4.30 to −0.44) points (P=.016) at 12-month follow-up. No significant differences were identified between groups on other outcomes at any time point. Conclusions HIIT combined with standard care improved walking distance, balance, and executive function immediately after the intervention compared with standard care only. However, only TMT-B remained significant at the 12-month follow-up.

Kendall, BJ, Siekirk, NJ, and Lai, Q. Effects of acute high-intensity interval training on information processing speed. J Strength Cond Res XX(X): 000-000, 2021-This study investigated the effects of acute exercise on reaction time (RT), premotor time (i.e., central processing), and motor time (i.e., peripheral processing) using surface electromyography to fractionate RT. Fifty-eight young adults (27 men, 31 women) between the age of 18 and 40 years participated in 2 testing sessions. During visit one, subjects performed a simple RT task under regular (i.e., consistent timing) and irregular (i.e., variable timing) foreperiods. Subjects were then randomized to either an aerobic-only high-intensity interval training (HIIT) group (HIIT-A), an aerobic/resistance HIIT group (HIIT-AR), or a resting control group (CG). Both exercise groups performed a 20-minute, digital video disc-delivered HIIT exercise protocol. After exercise or rest, when controlling for cardiovascular fitness, no statistical differences were observed for the regular foreperiod conditions (p > 0.05). For the irregular foreperiod conditions, the HIIT-A group (M = 219.8, SE = 6.5) and the HIIT-AR group (M = 218.2, SE = 5.8) had significantly faster mean RTs than the CG (M = 248.1, SE = 8.1). In addition, the HIIT-A (M = 172.1, SE = 4.6) and HIIT-AR exercise groups (M = 171.3, SE = 4.8) had significantly faster mean PMTs than the CG (M = 189.7, SE = 5.7). These findings suggest that tasks dependent on central processing may benefit from an acute bout of exercise.

Ronnestad, BR, Haugen, OC, and Daehlin, TE. Superior on-ice performance after short-interval vs long-interval training in well-trained adolescent ice hockey players. J Strength Cond Res 35(12S): S76-S80, 2021-The purpose of this study was to compare the effects of 9 weeks with 3 weekly sessions of short intervals (SIs) against long intervals (LIs) on endurance performance in well-trained adolescent ice hockey players. Eighteen male adolescent ice hockey players volunteered to participate and were randomly allocated to perform SIs (n = 9; 3 series with 13 × 30 seconds work intervals) or LIs (n = 7; 4 series of 5 minutes work intervals). Subjects completed a skating multistage aerobic test (SMAT), maximal oxygen consumption, maximal power output, and maximal isokinetic knee-extensor strength tests before and after the intervention, and changes in performance were assessed using analysis of variance (p ≤ 0.05). Short intervals improved SMAT performance more from pretest to post-test than LIs (13.9 ± 8.1% vs. 3.7 ± 5.2%, respectively; p = 0.030, effect size [ES] = 1.48). No significant differences were observed between SIs and LIs in change of maximal oxygen uptake (SI: 3.8 ± 6.1% vs. LI: -0.4 ± 10.2%; p = 0.30) or 60 seconds maximal power output (SI: 1.0 ± 4.9% vs. LI: -3.7 ± 4.1%; p = 0.053). However, ESs were moderate (ES = 0.55) and large (ES = 1.07), respectively, in favor of SI for these dependent variables. There were no changes in isokinetic knee-extension strength (p > 0.05). The present SI protocol induced superior improvements in on-ice endurance performance compared with the LI protocol. Practitioners seeking to improve ice hockey players' on-ice endurance performance should consider including SI in their conditioning protocol.

Progressive resistance training (PRT) and high-intensity interval training (HIIT) improve cardiometabolic health in older adults. Whether combination PRT+HIIT (COMB) provides similar or additional benefit is less clear. This systematic review with meta-analysis of controlled trials examined effects of PRT, HIIT and COMB compared to non-exercise control in older adults with high cardiometabolic risk. Databases were searched until January 2021, with study quality assessed using the PEDro scale. Risk factor data was extracted and analysed using RevMan V.5.3. We analysed 422 participants from nine studies (7 PRT, n=149, 1 HIIT, n=10, 1 COMB, n=60; control n=203; mean age 68.1±1.4 years). Compared to control, exercise improved body mass index (mean difference (MD) −0.33 [−0.47, −0.20], p≤0.0001), body fat% (standardised mean difference (SMD) −0.71 [−1.34, −0.08], p=0.03), aerobic capacity (SMD 0.41 [0.05, 0.78], p=0.03), low-density lipoprotein (SMD −0.27 [−0.52, −0.01], p=0.04), and blood glucose (SMD −0.31 [−0.58, −0.05], p=0.02). Therefore, PRT, HIIT and COMB can improve cardiometabolic health in older adults with cardiometabolic risk. Further research is warranted, particularly in HIIT and COMB, to identify the optimal exercise prescription, if any, for improving older adults cardiometabolic health. (PROSPERO: CRD42019128527).

INTRODUCTION High-intensity interval training is an effective tool to improve cardiovascular fitness and maximal anaerobic power. Different methods of high-intensity interval training have been studied but the effects of repeated maximal effort cycling with very short exercise time (i.e., 4 s) and short recovery time (15-30 s) might suit individuals with limited time to exercise. PURPOSE We examined the effects of training at near maximal anaerobic power during cycling (PC) on maximal anaerobic power, peak oxygen consumption (V˙O2peak), and total blood volume in 11 young healthy individuals (age: 21.3 ± 0.5 yr) (six men, five women). METHODS Participants trained three times a week for 8 wk performing a PC program consisting of 30 bouts of 4 s at an all-out intensity (i.e., 2 min of exercise per session). The cardiovascular stress progressively increased over the weeks by decreasing the recovery time between sprints (30-24 s to 15 s), and thus, total session time decreased from 17 to

The current study aimed to compare time spent above 90% V̇O2max (tV̇O2max) during 3 work-matched interval training protocols comprising 8×60-second exercise efforts with decreasing, increasing, or constant work rate distribution within each exercise interval. Ten healthy male subjects (age: 27.6±5.0 years; V̇O2max: 3.82±0.52 L•min–1) performed an incremental test to determine V̇O2max and peak power output (P max). During visits 2, 3, and 4, three work-matched interval training sessions comprising 8×60 s efforts: 60 s active recovery with the power output held constant (100%Pmax; ITCON), decreasing (from 110 to 90%Pmax; ITDEC), or increasing (from 90 to 110%Pmax; ITINC) linearly throughout each work interval. Time sustained above 90% of V̇O2max (tV̇O2max) or HRmax (tHRmax), blood lactate concentrations (BLC) and rating of perceived exertion (RPE) were measured. The tV̇O2max (ITCON: 274±132; ITDEC: 313±102; ITINC: 310±113 s, P=0.37), tHRmax (ITCON: 396±180; ITDEC: 441±207; ITINC: 390±212 s, P=0.47), BLC (P=0.73), and final RPE (P=0.75) were similar among protocols. In conclusion, work-matched interval training induced similar time near V̇O2max and associated physiological responses regardless of work rate manipulation.

OBJECTIVE To characterize the effect of 12 weeks of high and moderate-intensity interval training on pulmonary and functional parameters in miners with chronic obstructive pulmonary disease working in the polluted environment. METHODS Forty-five miners with COPD (average degree: 60 > FEV1

This study determined the effect of a single session of sprint interval training in hypoxia on muscle glycogen content among athletes. Ten male college track and field sprinters (mean ± standard error of the mean: age, 21.1 ± 0.2 years; height, 177 ± 2 cm; body weight, 67 ± 2 kg) performed two exercise trials under either hypoxia [HYPO; fraction of inspired oxygen (FiO2), 14.5%] or normoxia (NOR: FiO2, 20.9%). The exercise consisted of 3 × 30 s maximal cycle sprints with 8-min rest periods between sets. Before and immediately after the exercise, the muscle glycogen content was measured using carbon magnetic resonance spectroscopy in vastus lateralis and vastus intermedius muscles. Moreover, power output, blood lactate concentrations, metabolic responses (respiratory oxygen uptake and carbon dioxide output), and muscle oxygenation were evaluated. Exercise significantly decreased muscle glycogen content in both trials (interaction, P = 0.03; main effect for time, P

Purpose: To examine the influence of temporal location of high-intensity interval training (HIIT) within a cycling session on the time spent ≥90% of maximal oxygen consumption and physiological and perceptual responses. Methods: In a randomized, crossover design, 16 trained cyclists (male, n = 13 and female, n = 3) completed three 90-minute cycling sessions with HIIT placed at the beginning, middle, or end of the session (13, 36, and 69 min, respectively). Intervals consisted of three 3-minute efforts at 90% of the power output associated with maximal oxygen consumption interspersed with 3 minutes of recovery. Oxygen consumption, minute ventilation, respiratory rate, and heart rate were recorded continuously during work intervals. Rate of perceived exertion was recorded at the end of work intervals, and sessional rate of perceived exertion was collected 20 minutes after session completion. Results: No differences were observed for mean oxygen consumption (P = .479) or time spent ≥90% maximal oxygen consumption (P = .753) between condition. The mean rate of perceived exertion of all intervals were greater in the Middle (P P P = .015, effect size = 0.63). However, no differences in mean respiratory rate were observed between conditions (P = .297). Conclusions: Temporal location of HIIT has no impact on oxygen consumption or cardiovascular stress within a cycling session. However, HIIT performed later in the session resulted in higher ventilation, which may indicate the need for greater anaerobic contribution to these intervals.

Highlights • This is the first study showing that 6 high-intensity interval training (HIIT) sessions over just 5 days is just as effective in increasing maximal oxygen uptake and endurance capacity and is more effective at improving submaximal exercise fat oxidation than 6 HIIT sessions over 2 weeks. • Five days of HIIT that lasts 60 min in total may be a potent stimulus to improve exercise performance and substrate oxidation. • Our findings reveal that this protocol achieves the fastest adaptation in response to a HIIT regime. • This study represents an important conceptual advance in demonstrating the remarkable ability of the human body to adapt to exercise stress in less than 2 weeks., Background High-intensity interval training (HIIT) induces similar or even superior adaptations compared to continuous endurance training. Indeed, just 6 HIIT sessions over 2 weeks significantly improves maximal oxygen uptake (VO2max), submaximal exercise fat oxidation, and endurance performance. Whether even faster adaptations can be achieved with HIIT is not known. Thus, we aimed to determine whether 2 sessions of HIIT per day, separated by 3 h, every other day for 5 days (double HIIT (HIIT-D), n = 15) could increase VO2max, submaximal exercise fat oxidation, and endurance capacity as effectively as 6 sessions of HIIT over 2 weeks (single HIIT (HIIT-S), n = 13). Methods Each training session consisted of 10 × 60 s of cycling at 100% of VO2max interspersed with 75 s of low-intensity cycling at 60 watt (W). Pre- and post-training assessments included VO2max, time to exhaustion at ∼80% of VO2max, and 60-min cycling trials at ∼67% of VO2max. Results Similar increases (p < 0.05) in VO2max (HIIT-D: 7.7% vs. HIIT-S: 6.0%, p > 0.05) and endurance capacity (HIIT-D: 80.1% vs. HIIT-S: 79.2%, p > 0.05) were observed. Submaximal exercise carbohydrate oxidation was reduced in the 2 groups after exercise training (HIIT-D: 9.2%, p = 0.014 vs. HIIT-S: 18.8%, p = 0.012) while submaximal exercise fat oxidation was significantly increased in HIIT-D (15.5%, p = 0.048) but not in HIIT-S (9.3%, p = 0.290). Conclusion Six HIIT sessions over 5 days was as effective in increasing VO2max and endurance capacity and was more effective in improving submaximal exercise fat oxidation than 6 HIIT sessions over 2 weeks., Graphic Abstract Image, graphical abstract

Background: Surgical resection remains the primary curative treatment for intra-cavity cancer. Low physical fitness and psychological factors such as depression are predictive of post–operative morbidity, mortality and length of hospital stay. Prolonged post-operative morbidity is associated with persistently elevated risk of premature death. We aim to investigate whether a structured, responsive exercise training programme, a psychological support programme or combined exercise and psychological support, delivered between treatment decision and major intra-cavity surgery for cancer, can reduce length of hospital stay, compared with standard care. Methods: WesFit is a pragmatic, 2x2 factorial-design, multi-centre, randomised-controlled trial, with planned recruitment of N=1560. Participants will be randomised to one of four groups. Group 1 (control) will receive usual pre-operative care, Group 2 (exercise) patients will undergo 2/3 aerobic, high-intensity interval training sessions per week supervised by personal trainers. Group 3 (psychological support) patients are offered 1 session per week at a local cancer support centre. Group 4 will receive both exercise and psychological support. All patients undergo baseline and pre-operative cardiopulmonary exercise testing, complete self-report questionnaires and will be followed up at 30 days, 12 weeks and 12 months post-operatively. Primary outcome is post-operative length-of-stay. Secondary outcomes include disability-adjusted survival at 1-year postoperatively, post-operative morbidity, and health-related quality of life. Exploratory investigations include objectively measured changes in physical fitness assessed by cardiopulmonary exercise test, disease-free and overall mortality at 1-year postoperatively, longer-term physical activity behaviour change, pre-operative radiological tumour regression, pathological tumour regression, pre and post-operative body composition analysis, health economics analysis and nutritional characterisation and its relationship to post-operative outcome. Conclusions: The WesFit trial will be a randomised controlled study investigating whether a high-intensity exercise training programme +/- psychological intervention results in improvements in clinical and patient reported outcomes in patients undergoing major inter-cavity resection of cancer. ClinicalTrials.gov registration: NCT03509428 (26/04/2018)

BACKGROUND High-intensity interval training protocols using the body weight (WBHIIT) as resistance could be an interesting and inexpensive alternative due to the absence of equipment required (low cost) and the possibility to be performed in a wide range of locations. Therefore, the purpose of the present study was to analyze the effects of a short-term WBHIIT protocol on muscle thickness (MT), muscular endurance (ME), one maximum repetition test (1RM), and maximum oxygen uptake (VO2max) of untrained individuals. METHODS Fifty healthy men (28.2 ± 6.7 years, 77.5 ± 26.2 kg, 171 ± 10 cm, 23.2 ± 8.2 % Fat) were randomized into WB-HIIT (n = 25) or control (CON, n = 25) group. The WB-HIIT performed 9 exercises (40-second stimulus in all out intensity/ 20-second of passive recovery) divided into 3 blocks with 2 sets each for 6 weeks (three times a week). RESULTS Only WB-HIIT resulted in a significant increase in MT, ME, 1RM, and VO2max (all p < 0.05) outcomes and were significantly greater compared to CON (all p < 0.05). CONCLUSIONS Our results demonstrate that a WB-HIIT program can be a time-efficient strategy to promote changes on fitness, morphological and functional parameters in previously untrained sedentary individuals.

Objectives This animal study aimed to demonstrate the synergistic effect of high-intensity interval training (HIIT) and alcoholic extract of nettle on serum chemerin and beta cells function in type 2 diabetic male rats. Methods Thirty-two STZ-induced diabetic male Wistar rats were randomly divided into four groups including the control group, the supplemented group with 200 mg/day of nettle, the training group with five sessions per week of HIIT, and the group with combined nettle and HITT intervention. Body weight, lipid profile, beta cells function, and chemerin level were assessed after eight weeks of the intervention. Results The values of chemerin significantly decreased in combined HIIT and nettle intervention group compared to the control group (p=0.001). The levels of glucose and insulin decreased significantly in nettle group, exercise group, and combined HIIT and nettle group (p=0.001). Conclusions The present study found that intense interval exercise with the consumption of alcoholic extract of nettle can affect the performance of beta cells, glucose, and insulin. Future human studies are warranted.

To assess the performance change and physiological adaptations following nine sessions of short high-intensity interval training (HIIT) or sprint-interval training (SIT) in sprint kayakers. Twelve trained kayakers performed an incremental test and 3 time trials (200 m, 500 m and 1000 m) on a kayak ergometer. Oxygen consumption (VO2) and muscle oxygenation of the latissimus dorsi, biceps brachii, and vastus lateralis were measured. Athletes were then paired for sex and VO2max and randomized into a HIIT or a SIT training group, and performed nine training sessions before repeating the tests. Training improved performance in HIIT (200 m: + 3.8 ± 3.1%, p = 0.06; 500 m: + 2.1 ± 4.1%, p = 0.056; 1000 m: + 3.0 ± 4.6%, p = 0.13) but changes in performance remained within the smallest worthwhile change in SIT (200 m: + 0.8 ± 4.1%, p = 0.59; 500 m: + 0.5 ± 4.1%, p = 0.87; 1000 m: + 1.3 ± 4.6%, p = 0.57). In the 1000 m, training led to a greater deoxygenation in the biceps brachii and vastus lateralis in HIIT, and in the latissimus dorsi in SIT. In HIIT, the best predictors of improvements in 1000 m performance were increases in latissimus dorsi and vastus lateralis maximal deoxygenation. In a group of trained sprint kayakers, greater improvements in performance can be obtained with HIIT compared with SIT, for any distance. Training did not change VO2peak, but increased muscle maximal deoxygenation, suggesting both HIIT and SIT elicit peripheral adaptations. Performance improvement in the 1000 m was associated with increased maximal muscle deoxygenation, reinforcing the contribution of peripheral adaptations to performance in sprint kayaking.

This study was supported by the Spanish Ministry of Universities (FPU14/04172, FPU16/01093 and FPU18/03357). This study was partially supported by the University of Granada - Plan Propio de Investigacion 2016 Excellence actions: Units of Excellence; Unit of Excellence on Exercise and Health (UCEES), Plan Propio de Investigacion 2018-Beca de iniciacion a la investigacion para estudiantes de masteres oficiales, and Plan Propio de Investigacion 2019-Programa Contratos-Puente, by the Junta de Andalucia, Consejeria de Conocimiento, Investigacion y Universidad, by the European Regional Development Fund (ERDF), ref. SOMM17/6107/UGR, and by Redes Tematicas de Investigacion Cooperativa RETIC grant Red SAMID RD16/0022., To determine the acute effect of a single high-intensity interval training (HIIT) session on testosterone and cortisol levels in healthy individuals, a systematic search of studies was conducted in MEDLINE and Web of Science databases from inception to February 2020. Meta-analyses were performed to establish the acute effect of HIIT on testosterone and cortisol levels immediately after a single HIIT session; after 30 min and 60 min (primary outcomes); and after 120 min, 180 min, and 24 h (secondary outcomes, only for pre-post intervention groups). Potential effect-size modifiers were assessed by meta-regression analyses and analyses of variance. Study quality was assessed using the Cochrane's risk of bias tool and the Physiotherapy Evidence Database scale. The meta-analyses of 10 controlled studies (213 participants) and 50 pre-post intervention groups (677 participants) revealed a significant increase in testosterone immediately after a single HIIT session (d = 0.92 and 0.52, respectively), which disappeared after 30 min (d = 0.18 and -0.04), and returned to baseline values after 60 min (d = -0.37 and -0.16). Significant increases of cortisol were found immediately after (d = 2.17 and 0.64), after 30 min (d = 1.62 and 0.67) and 60 min (d = 1.32 and 0.27). Testosterone and cortisol levels decreased significantly after 120 min (d = -0.48 and -0.95, respectively) and 180 min (d = -0.29 and -1.08), and returned to baseline values after 24 h (d = 0.14 and -0.02). HIIT components and participant's characteristics seem to moderate the effect sizes. In conclusion, testosterone and cortisol increase immediately after a single HIIT session, then drop below baseline levels, and finally return to baseline values after 24 h. This meta-analysis provides a better understanding of the acute endocrine response to a single HIIT session, which would certainly be valuable for both clinicians and coaches in the prescription of exercise programs to improve health and performance. Testosterone and cortisol may be used as sensitive biomarkers to monitor the anabolic and catabolic response to HIIT., Spanish Ministry of Universities FPU14/04172 FPU16/01093 FPU18/03357, University of Granada - Plan Propio de Investigacion 2016 Excellence actions: Units of Excellence, Unit of Excellence on Exercise and Health (UCEES), Junta de Andalucia, European Commission SOMM17/6107/UGR, Redes Tematicas de Investigacion Cooperativa RETIC grant Red SAMID RD16/0022, University of Granada - Plan Propio de Investigacion 2018-Beca de iniciacion a la investigacion para estudiantes de masteres oficiales, University of Granada - Plan Propio de Investigacion 2019-Programa Contratos-Puente

Purpose The objective of this study was to investigate sex and age differences in anxiety and depression among patients with cardiovascular disease at baseline and following aerobic interval training (AIT)-based cardiac rehabilitation (CR) and secondarily to compare dropout rates between sexes and age groups. Methods Participants were younger (≤44 yr), middle-aged (45-64 yr), and older adults (≥65 yr). The AIT protocol consisted of: 4 × 4-min of high-intensity work periods at 85-95% peak heart rate (HR) interspersed with 3 min of lower-intensity intervals at 60-70% peak HR, twice weekly for 10 wk. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale at baseline and following CR. Results At baseline, of 164 participants (32% female), 14 (35% female) were younger, 110 (33% female) were middle-aged, and 40 (30% female) were older. Older adults reported lower anxiety levels versus younger (4.4 ± 2.6 vs 7.8 ± 3.4 points, P = .008) and middle-aged adults (4.4 ± 2.6 vs 6.1 ± 3.6 points, P = .05). Baseline depression levels did not differ between age groups (P = .749). All age groups experienced a reduction in anxiety (younger =-2.67; middle-aged =-1.40; older =-0.85) and depression (younger =-1.50; middle-aged =-0.83; older =-0.70) levels following CR. Differences in dropout rates were observed between age groups (χ2[1] = 13.4, P = .001). Within each age group, 43% (female n = 2, male n = 4) of younger, 10% (female n = 8, male n = 3) of middle-aged, and 2.5% (female n = 0, male n = 1) of older participants dropped out. Conclusions Younger and middle-aged adults experience higher levels of anxiety upon entry into CR compared with older adults. Cardiac rehabilitation was associated with significant reductions in anxiety and depression severity, yet dropout rates were highest among younger adults.

Background Declines in cardiorespiratory fitness (CRF) and fat-free mass (FFM) with age are linked to mortality, morbidity and poor quality of life. High-intensity interval training (HIIT) has been shown to improve CRF and FFM in many groups, but its efficacy in the very old, in whom comorbidities are present is undefined. We aimed to assess the efficacy of and physiological/metabolic responses to HIIT, in a cohort of octogenarians with comorbidities (e.g. hypertension and osteoarthritis). Methods Twenty-eight volunteers (18 men, 10 women, 81.2 ± 0.6 years, 27.1 ± 0.6 kg·m−2) with American Society of Anaesthesiology (ASA) Grade 2–3 status each completed 4 weeks (12 sessions) HIIT after a control period of equal duration. Before and after each 4 week period, subjects underwent body composition assessments and cardiopulmonary exercise testing. Quadriceps muscle biopsies (m. vastus lateralis) were taken to quantify anabolic signalling, mitochondrial oxidative phosphorylation, and cumulative muscle protein synthesis (MPS) over 4-weeks. Results In comorbid octogenarians, HIIT elicited improvements in CRF (anaerobic threshold: +1.2 ± 0.4 ml·kg−1·min−1, P = 0.001). HIIT also augmented total FFM (47.2 ± 1.4 to 47.6 ± 1.3 kg, P = 0.04), while decreasing total fat mass (24.8 ± 1.3 to 24 ± 1.2 kg, P = 0.0002) and body fat percentage (33.1 ± 1.5 to 32.1 ± 1.4%, P = 0.0008). Mechanistically, mitochondrial oxidative phosphorylation capacity increased after HIIT (i.e. citrate synthase activity: 52.4 ± 4 to 67.9 ± 5.1 nmol·min−1·mg−1, P = 0.005; membrane protein complexes (C): C-II, 1.4-fold increase, P = 0.002; C-III, 1.2-fold increase, P = 0.03), as did rates of MPS (1.3 ± 0.1 to 1.5 ± 0.1%·day−1, P = 0.03). The increase in MPS was supported by up-regulated phosphorylation of anabolic signalling proteins (e.g. AKT, p70S6K, and 4E-BP1; all P < 0.05). There were no changes in any of these parameters during the control period. No adverse events were reported throughout the study. Conclusions The HIIT enhances skeletal muscle mass and CRF in octogenarians with disease, with up-regulation of MPS and mitochondrial capacity likely underlying these improvements. HIIT can be safely delivered to octogenarians with disease and is an effective, time-efficient intervention to improve muscle mass and physical function in a short time frame.

Objective Exercise is recommended for polycystic ovary syndrome (PCOS), but the most effective exercise prescription is unclear. This trial compared effects of high‐intensity interval training (HIIT), continuous aerobic exercise training (CAET) and no‐exercise control on reproductive, anthropometric and cardiometabolic outcomes in PCOS. Design Pilot randomized controlled trial. Participants Previously inactive women aged 18–40 years with PCOS. Measurements Feasibility outcomes included recruitment, retention, adherence to exercise and daily ovulation prediction kit (OPK) testing. Preliminary efficacy outcomes included reproductive, anthropometric and cardiometabolic health markers. Results Forty‐seven women were randomized to no‐exercise control (n = 17), HIIT (n = 16), or CAET (n = 14). Forty (85%) participants completed the trial. Median exercise adherence was 68% (IQR 53%, 86%). Median daily OPK‐testing adherence in the first half of the intervention was 87% (IQR 61%, 97%) compared with 65% (IQR 0%, 96%) in the second half. Body mass index decreased significantly in CAET compared with control (−1.0 kg/m2, p = .01) and HIIT (−0.9 kg/m2, p = .04). Mean waist circumference decreased in all groups (−7.3 cm, −6.9 cm, −4.5 cm in HIIT, CAET and control) with no significant between‐group differences. Mean LDL‐C was significantly reduced for HIIT compared to CAET (−0.33 mmol/L, p = .03). HDL‐C increased in HIIT compared with control (0.18 mmol/L, p = .04). Conclusions There were feasibility challenges with adherence to daily ovulation assessment limiting the ability to analyse the effect of the exercise interventions on ovulation. CAET and HIIT were both effective at improving anthropometrics and some cardiometabolic health markers. Further studies need to determine optimal and acceptable exercise prescriptions for this population.

de L. Corrêa, H, Ribeiro, HS, Maya, ÁTD, Neves, RP, de Moraes, MR, Lima, RM, Nóbrega, OT, and Ferreira, AP. Influence of the ACTN3 genotype and the exercise intensity on the respiratory exchange ratio and excess oxygen consumption after exercise. J Strength Cond Res 35(5): 1380-1388, 2021-This study aimed to assess the respiratory exchange ratio (RER) and excess postexercise oxygen consumption (EPOC) after high-intensity interval training and continuous moderate-intensity aerobic training in accordance with the ACTN3 genotype. A cross-sectional study with 30 physically active individuals who participated in 3 experimental sessions, as follows: a high-intensity interval aerobic exercise, for 3 minutes at 115% anaerobic threshold, with 90 seconds of passive recovery; a continuous moderate-intensity aerobic exercise at 85% anaerobic threshold; and a control session. Respiratory exchange ratio and V̇o2 were obtained through an indirect, calorimetry-based gas analysis method, using a breath-by-breath approach, assessed at baseline, during the trials, and at 1, 2, 3, and 4 hours after exercise. We found that lower postexercise RER values were observed only in subjects with the X allele, in both the high- and the moderate-intensity training protocols. Homozygous RR subjects showed no differences in postexercise RER compared with the scores at the control day. After both sessions of exercise, EPOC levels were higher compared with scores at the control day for 2 hours among X allele carriers, and only in the first hour among RR homozygous. Thus, the RER and EPOC presented different responses after moderate and intense exercise according to the ACTN3 genotype. Moreover, individuals with the X allele of the ACTN3 gene show a higher oxidation of fats in the postexercise period.

High-intensity interval training (HIIT) and aerobic training (AT) both improve cardiac function; however, their effects on cardiac function after myocardial infarction (MI) and the molecular mechanisms are unclear. In this study, HIIT, AT and sedentary (SED) interventions were performed for 4 weeks to compare the effects on cardiac function after MI and explore a more suitable approach for clinical application and the potential mechanisms.Twenty-four (24) male rats were randomly divided into a control group (CON), MI-sedentary group (MI-SED), MI-aerobic training group (MI-AT), and MI-high-intensity interval training group (MI-HIIT). After 4 weeks of intervention the exercise capacity, heart rate (HR), left ventricular end-diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF), AMP-activated protein kinase α1 (AMPKα1), cardiomyocyte morphology, and cardiac mitochondria were assessed.After intervention: 1) exercise capacity in the MI-AT (49.08±3.141 m; p0.001) and MI-HIIT (51.70±7.572 m; p0.001) groups was significantly more increased than the MI-SED group; there was no significant difference between the MI-AT and MI-HIIT group (p=0.33). 2) LVEDD and LVESD in the MI-SED (p0.01) and MI-HIIT (p0.01) groups was significantly more increased than the CON group; the MI-AT group showed no significant difference in LVEDD and LVESD compared with the CON group; LVEF in the MI-AT (53.47±7.913%; p=0.03) and MI-HIIT (56.20±7.224%; p=0.006) groups was significantly more increased than the MI-SED group, and there was no statistical difference between the MI-AT and MI-HIIT groups. 3) AMPKα1 expression was significantly increased in the MI-AT (1.15±0.264; p=0.001) and MI-HIIT (1.04±0.238; p=0.003) groups and decreased in the MI-SED group (0.71±0.257; p0.001) when compared with the CON group. 4) The MI-SED group exhibited sarcoplasmic dissolution and fibrous hyperplasia in the myocardium, cardiac mitochondrial damage and reduced mitochondrial numbers; the MI-HIIT group displayed swollen and vacuolated cardiac mitochondria with disrupted cristae; the MI-AT and MI-HIIT groups had significantly increased cardiac mitochondrial numbers than the MI-SED group; there was no statistical difference between the MI-AT and MI-HIIT groups.Aerobic training and HIIT for 4 weeks had similar cardioprotection and were superior to SED intervention. Both AT and HIIT improved cardiac function and exercise capacity by upregulating AMPKα1 expression. However, 4 weeks of intervention resulted in left ventricular dilation and cardiac myocardial mitochondrial injury in the MI-HIIT group.

Objectives We investigated psycho-physiological responses to perceptually regulated interval walks in hypoxia versus normoxia in obese individuals. Design Within-participants repeated measures. Methods Ten obese adults (BMI=32±3kg/m−2) completed a 60-min interval session (15×2min walking at a rating of perceived exertion of 14 on the 6–20 Borg scale with 2min of rest) either in hypoxia (FiO2 =13.0%, HYP) or normoxia (NOR). A third trial replicating the HYP speed pattern was carried out in normoxia as a control (CON). Exercise responses were analysed comparing the average of 1st to 3rd exercise bouts to those of the 4th–6th, 7th–9th, 10th–12th and 13th–15th exercise bouts (block 1 versus 2, 3, 4 and 5). Results Treadmill speed was slower during block 4 (6.14±0.67 versus 6.24±0.73km/h−1) and block 5 (6.12±0.64 versus 6.25±0.75km/h−1) in HYP compared to NOR or CON (p=0.009). Compared to NOR and CON, heart rate was +6–10% higher (p=0.001), whilst arterial oxygen saturation (−12–13%) was lower (p

BACKGROUND In severe chronic obstructive pulmonary disease (COPD), interval training (IT) can be performed with oxygen support, which provides beneficial effect on metabolic processes, tissue perfusion, and peripheral muscle function. METHODS A prospective cohort study with matched controls was performed on patients in Budapest at the Department of Pulmonary Rehabilitation of the National Koranyi Institute of Pulmonology between January 1, 2020 and March 1, 2020. After a complex condition assessment, both case and control patients participated in a 3-week long complex pulmonary rehabilitation (PR) program that included individual training, education, nutrition, and psychological counseling. Anthropometric and functional data of patients were recorded at both the beginning and end of the PR program. Our research aimed to assess the effect of non-invasive ventilation (NIV) in patients with severe COPD who underwent IT. RESULTS A total of 18 [male/female: 10 (55.6%)/8 (44.4%)] patients were enrolled in our study. IT with NIV significantly improved the patients' 6-minute walking distance (6MWD) (m) [216.0 (211.5-233.7) vs. 274.0 (247.5-313.5); P

Elderly is a part of life that is associated with physical and mental disorders. The present study aimed to investigate the effect of 8 weeks of high-intensity interval training (HIIT) along with genistein (Ge) on memory, anxiety, physical persistence and aerobic power in elderly rats. Forty elderly rats were randomly assigned to five groups of eight rats including 1) control (C), 2) sham (Sh), 3) HIIT, 4) HIIT+Ge, and 5)Ge. During 8-week groups 3 and 4 performed HIIT for three sessions per week and groups 4 and 5 received 60 mg/kg/day Ge peritoneally. Physical persistence (by forced swimming test), memory (by shuttle box and Y maze tests), anxiety (by elevated plus-maze test) and aerobic power (by exhaustive running on treadmill) were measured. HIIT, Ge, and HIIT+Ge significantly increased physical persistence and memory (P ≤0.05), HIIT and HIIT+Ge significantly decrease anxiety and increased aerobic power (P ≤0.05) and HIIT+Ge had higher effect on the decrease of anxiety and increase of memory compared to HIIT and Ge (P≤0.05). Although HIIT and Ge alone can enhance physical persistence, memory and anxiety in elderly rats nevertheless it seems that HIIT simultaneously with Ge has more favorable mental health benefits compared to HIIT and Ge alone.

High-intensity interval training (HIIT) appears to be safe and effective in cardiovascular diseases. However, there is a paucity of data on the effect of HIIT for patients with acute pulmonary embolism (PE). The present randomized controlled trial (RCT) therefore examined the efficiency and safety of HIIT in patients with acute PE.In single-center parallel open-label RCT, 24 patients (5 women) discharged recently with a diagnosis of intermediate-high-risk acute PE were randomized (1:1) to supervised HIIT (n = 12) or control (n = 12) group. The primary outcomes were exercise capacity evaluated in terms of the estimated maximal oxygen uptake (eV˙O2max), lung function (forced expiratory volume in 1 s [FEV1]), right ventricular (RV) function (RV/left ventricular diameter [LV] ratio), and health-related quality of life (HRQoL). Safety was the secondary outcome.Eight weeks of HIIT improved eV˙O2max (+65%, P0.001), FEV1 (%) (+17%, P = 0.031), and RV/LV ratio diameter (-27%, P = 0.005), as well as HRQoL. All patients in the HIIT group tolerated exercise training without serious adverse events. The control group did not improve (P0.05) eV˙O2max, RV/LV ratio diameter, or HRQoL; however, FEV1 (%) was slightly reduced (-6%, P = 0.030).The present RCT of a tailored center-based HIIT intervention provides preliminary evidence that this intervention could improve exercise capacity, lung function, RV function, and HRQoL without serious adverse events, which could provide marked clinical benefits after PE. Further larger multicenter randomized controlled studies are needed to confirm these promising findings.

Introduction Whether short-term, single-mode exercise training can improve physical fitness before a period of reduced physical activity (e.g., postsurgery recovery) is not well characterized in clinical populations or middle-age adults. We investigated skeletal muscle adaptive responses after endurance exercise training (ENT), high-intensity interval training (HIIT), or resistance exercise training (RET), and a subsequent period of detraining, in sedentary, middle-age men. Methods Thirty-five sedentary men (39 +/- 3 yr) were randomized to parallel groups and undertook 6 wk of either ENT (n = 12), HIIT (n = 12), or RET (n = 11) followed by 2.5 wk of detraining. Skeletal muscle fiber characteristics, body composition, muscle thickness, muscle strength, aerobic capacity, resting energy expenditure, and glucose homeostasis were assessed at baseline, and after exercise training and detraining. Results Lean mass increased after RET and HIIT (+3.2% +/- 1.6% and +1.6% +/- 2.1%, P < 0.05). Muscle strength (sum of leg press, leg extension, and bench press one-repetition maximums) increased after all training interventions (RET, +25% +/- 5%; HIIT, +10% +/- 5%; ENT, +7% +/- 7%; P < 0.05). Aerobic capacity increased only after HIIT and ENT (+14% +/- 7% and +11% +/- 11%, P < 0.05). Type I and II muscle fiber size increased for all groups after training (main effect of time, P < 0.05). After a period of detraining, the gains in lean mass and maximal muscle strength were maintained in the RET and HIIT groups, but maximal aerobic capacity declined below posttraining levels in HIIT and ENT (P < 0.05). Conclusions Six weeks of HIIT induced widespread adaptations before detraining in middle-age men. Exercise training-induced increases in aerobic capacity declined during 2.5 wk of detraining, but gains in lean mass and muscle strength were maintained.

Aims Physical exercise has been associated with a reduction in arterial stiffness, a subclinical process underlying cardiovascular disease. However, the effect of different types of exercise (aerobic, resistance, combined, interval training, stretching, or mind–body modalities) on arterial stiffness is unclear. This network meta-analysis aimed to examine the effectiveness of different types of exercise on arterial stiffness as measured by pulse wave velocity in adults. Methods and results We searched Cochrane Central Register of Controlled Trials, CINAHL, MEDLINE (via Pubmed), Embase, and Web of Science databases, for randomized clinical trials including at least a comparison group, from their inception to 30 June 2020. A frequentist network meta-analysis was performed to compare the effect of different types of physical exercise on arterial stiffness as measured by pulse wave velocity. Finally, 35 studies, with a total of 1125 participants for exercise intervention and 633 participants for the control group, were included. In the pairwise meta-analyses, the exercises that improved arterial stiffness were: interval training [effect size (ES) 0.37; 95% confidence interval (CI) 0.01–0.73], aerobic exercise (ES 0.30; 95% CI 0.13–0.48) and combined exercise (ES 0.22; 95% CI 0.04–0.40). Furthermore, the network meta-analysis showed that mind–body interventions were the most effective type of exercise to reduce the pulse wave velocity (ES 0.86; 95% CI 0.04–1.69). In addition, combined exercise (ES 0.35; 95% CI 0.08–0.62), aerobic exercise (ES 0.33; 95% CI 0.09–0.57), and interval training (ES 0.33; 95% CI 0.02–0.64) showed significant improvements. Conclusion Our findings showed that aerobic exercise, combined exercise, interval training, and mind–body exercises were the most effective exercise modalities for reducing arterial stiffness, assuming an important role in the prevention of cardiovascular diseases.

This study examined the effects of a nine-week intervention of four different high-intensity training modalities [high-intensity functional training (HIFT), high-intensity interval training (HIIT), high-intensity power training (HIPT), and high-intensity endurance training (HIET)] on the resting concentration of brain-derived neurotropic factor (BDNF). In addition, we evaluated the BDNF responses to Graded Exercise Test (GXT) and Wingate Anaerobic Test (WAnT) in men. Thirty-five healthy individuals with body mass index 25.55 ± 2.35 kg/m2 voluntarily participated in this study and were randomly assigned into four training groups. During nine-weeks they completed three exercise sessions per week for one-hour. BDNF was analyzed before and after a GXT and WAnT in two stages: (stage 0—before training and stage 9—after nine weeks of training). At stage 0, an increase in BDNF concentration was observed in HIFT (33%; p 0.05). At stage 9, higher BDNF levels after GXT were seen only for the HIFT (30%; p 2max (8%; p

This study assessed the feasibility and benefits of high-intensity interval training (HIIT) plus lifestyle education among inactive adults with celiac disease. Forty-one participants were randomized to receive the intervention (HIIT plus lifestyle education; HIIT+) for 12 weeks or waitlist control (WLC). Testing was completed at baseline, immediately post-intervention, and 3 months post-intervention. Generalized estimating equations were used to assess changes in the outcome variables over time between the groups. Mean percent of age-predicted maximum heart rate was 97.9% and average rating of perceived exertion was 6.33 (out of 10) during HIIT intervals. Following the intervention, the HIIT+ showed enrichment in relative abundance of Parabacteroides and Defluviitaleaceae_UCG_011 while WLC showed enrichment in relative abundance of Roseburia intestinalis, Klebsiella, and Adlercreutzia. A unique set of taxa were differentially abundant between the groups at 3 months post-intervention. HIIT+ participants experienced a reduction in resting heart rate (−6.6 bpm) immediately post-intervention compared with WLC. Further research is needed to establish an optimal HIIT protocol that may improve maximal oxygen uptake and metabolic syndrome biomarkers. Findings from this pilot study provide preliminary evidence that an HIIT intervention is feasible for inactive adults with celiac disease and leads to favourable changes in resting heart rate alongside potentially beneficial shifts in gut microbiota. Trial registration number: ClinicalTrials.gov number NCT03520244. Novelty: HIIT leads to potentially beneficial changes in the gut microbiota of adults with celiac disease. An HIIT exercise intervention is feasible and well tolerated for patients with celiac disease.

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.