Reduced Exertion High-Intensity Interval Training is More Effective at Improving Cardiorespiratory Fitness and Cardiometabolic Health than Traditional Moderate-Intensity Continuous Training

A systematic review and meta-analysis of the effectiveness of high-intensity interval training for physical fitness in university students

BACKGROUND

Extensive research has demonstrated the effectiveness of high-intensity interval training (HIIT) in children and adults; however, evidence specific to university students remains limited. This study aimed to evaluate the effects of HIIT on promoting physical health in university students and to identify potential factors influencing intervention outcomes.

METHOD

A systematic search was conducted across five electronic databases (Web of Science, Scopus, PubMed, SportDiscus, and MEDLINE) up to December 2024 using Boolean operators and keywords related to HIIT and university students.

INCLUSION CRITERIA

(1) Experimental studies; (2) Physical-related outcomes; (3) Intervention duration of at least 3 weeks; (4) Meets the definition of high-intensity activity; (5) Participants are general university students. A meta-analysis was conducted using RevMan 5.4 software, comparing intervention and control groups. Effect sizes were calculated using Cohen's d, and heterogeneity was assessed with the I² statistic. Subgroup analyses were performed based on intervention duration and rest interval duration.

RESULTS

Results showed that HIIT significantly reduced BMI, body fat percentage, waist-to-hip ratio, and heart rate, while significantly improving VO2max and muscle strength in university students. Interventions lasting longer than eight weeks demonstrated greater improvements in muscle strength compared to those lasting eight weeks or less. However, there are no significant differences in rest interval across any of the groups. Notably, HIIT also has positive effects on agility and speed with varying effect sizes.

CONCLUSION

The unique characteristics of university students make HIIT a time-efficient and effective intervention strategy for this population. Future studies should consider the specific needs of the university environment, incorporating the latest technological advancements and developing tailored intervention strategies that align with students' preferences.

Meta-analysis of high-intensity interval training effects on cognitive function in older adults and cognitively impaired patients

Background

Cognitive enhancement treatments are limited, and while High-Intensity Interval Training (HIIT) has been suggested to improve cognitive function, high-quality evidence remains scarce. This meta-analysis evaluates the effects of HIIT on cognitive performance compared to moderate-intensity continuous training (MICT) and control groups in older adults and cognitively Impaired Patients.

Methods

A systematic search of PubMed, Embase, and Cochrane Library databases was conducted for articles published until 10 October 2024. Eighteen studies were included, comparing cognitive outcomes across HIIT, MICT, and control groups. Cognitive tests evaluated included the Stroop test, Digit Span Test (DST), Trail Making Test (TMT), and the MOST test.

Results

HIIT significantly improved performance compared to MICT in the Stroop test (SMD = -0.8, 95% CI: -1.3 to -0.2) and DST (SMD = 0.3, 95% CI: -0.0-0.5). Compared to control groups, HIIT significantly enhanced performance in the TMT (SMD = -0.7, 95% CI: -1.3 to 0.0) and MOST test (SMD = -1.2, 95% CI: -1.8 to -0.7).

Conclusion

This meta-analysis supports the efficacy of HIIT in enhancing cognitive functions, particularly in cognitive flexibility, working memory, task switching, attention control, and inhibitory control. These findings suggest that HIIT can be an effective intervention for improving cognitive behavior in older adults and cognitively Impaired Patients.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, Identifier CRD42023413879.

Optimizing concurrent training programs: A review on factors that enhance muscle strength

The purpose of this study is to explore the factors that should be considered when designing concurrent training programs to minimize the "interference effect." This study provides a comprehensive summary of various perspectives from existing studies on factors such as the ability level of the target group, the frequency and intensity of concurrent training, the order and interval time of resistance and endurance training, nutritional arrangements during training, and gender differences in concurrent training. The results of this study suggest that the emergence of the "interference effect" in concurrent training is influenced by several factors, with a particular emphasis on the adaptation status of muscle fitness when compared to resistance training alone. However, it is important to note that the current understanding of this theory remains somewhat ambiguous. The ability level of participants plays a crucial role in training adaptation and the specificity of post-training skeletal muscle molecular responses. Therefore, the participant's capacity level is likely a key determinant of the extent of the interference effect in concurrent training. In addition to training-related factors such as frequency, duration, intensity, volume, training sequence, recovery time, and nutritional intake, non-training-related variables, including the methodology used to assess various metrics, also significantly impact the design of concurrent training programs. These factors collectively influence the overall outcomes and provide insight into the extent of the "interference effect" in concurrent training. Understanding these aspects is essential for comprehending the phenomenon of the "interference effect" in concurrent training.

Physiological and perceptual responses to sprint interval exercise using arm versus leg cycling ergometry

Increases in power output and maximal oxygen consumption (V ˙ O 2 max) occur in response to sprint interval exercise (SIE), but common use of "all-out" intensities presents a barrier for many adults. Furthermore, lower-body SIE is not feasible for all adults. We compared physiological and perceptual responses to supramaximal, but "non-all-out" SIE between leg and arm cycling exercise. Twenty-four active adults (mean ​± ​SD age: [25 ​± ​7] y; cyclingV ˙ O 2 max: [39 ​± ​7] mL·kg-1·min-1) performed incremental exercise using leg (LCE) and arm cycle ergometry (ACE) to determineV ˙ O 2 max and maximal work capacity (Wmax). Subsequently, they performed four 20 ​s bouts of SIE at 130% Wmax on the LCE or ACE at cadence ​= ​120-130 ​rev/min, with 2 ​min recovery between intervals. Gas exchange data, heart rate (HR), blood lactate concentration (BLa), rating of perceived exertion (RPE), and affective valence were acquired. Data showed significantly lower (p ​< ​0.001) absolute mean ([1.24 ​± ​0.31] L·min-1 vs. [1.59 ​± ​0.34] L·min-1; d ​= ​1.08) and peakV ˙ O 2 ([1.79 ​± ​0.48] L·min-1 vs. [2.10 ​± ​0.44] L·min-1; d ​= ​0.70) with ACE versus LCE. However, ACE elicited significantly higher (p ​< ​0.001) relative mean ([62% ​± ​9%]V ˙ O 2 max vs. [57% ​± ​7%]V ˙ O 2 max, d ​= ​0.63) and peakV ˙ O 2 ([88% ​± ​10%]V ˙ O 2 max vs. [75% ​± ​10%]V ˙ O 2 max, d ​= ​1.33). Post-exercise BLa was significantly higher ([7.0 ​± ​1.7] mM vs. [5.7 ​± ​1.5] mM, p ​= ​0.024, d ​= ​0.83) for LCE versus ACE. There was no significant effect of modality on RPE or affective valence (p ​> ​0.42), and lowest affective valence recorded (2.0 ​± ​1.8) was considered "good to fairly good". Data show that non "all-out" ACE elicits lower absolute but higher relative HR andV ˙ O 2 compared to LCE. Less aversive perceptual responses could make this non-all-out modality feasible for inactive adults.

Impact of diverse aerobic exercise plans on glycemic control, lipid levels, and functional activity in stroke patients with type 2 diabetes mellitus

Aims

This study aimed to assess the effects of Low-to-Moderate Intensity Continuous Training (LMICT), Moderate-Intensity Interval Training (MIIT), and Reduced-Exertion High-Intensity Training (REHIT) on blood glucose regulation, functional recovery, and lipid levels in individuals who have experienced a stroke and are diagnosed with Type 2 Diabetes Mellitus (T2DM).

Methods

Forty-two T2DM stroke patients were randomly allocated to four groups: LMICT, MIIT, REHIT, and a control group (CON). Participants continuously monitored their blood glucose levels throughout the intervention using continuous glucose monitoring (CGM) devices. The study comprised two exercise intervention cycles: the first lasting from Day 3 to Day 14 and the second from Day 15 to Day 28, with the initial two days serving as contrasting periods. Primary outcomes encompassed CGM-derived blood glucose measurements, the Barthel Index (BI), Fugl-Meyer Assessment lower-extremity subscale (FMA-LE), and alterations in triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c).

Results

Compared with the CON, the MIIT group showed significant improvements in mean glucose (MG), glucose standard deviation (SD), time above range (TAR), and time in range (TIR). The REHIT group exhibited significantly reduced time below range (TBR), glucose SD, and coefficient of variation (CV). Regarding lipid levels, although the REHIT group achieved a significant reduction in TG levels compared with the CON, the overall effects of LMICT, MIIT, and REHIT on lipid profiles were relatively modest. Concerning functional recovery, the REHIT group significantly improved the BI and FMA-LE.

Conclusion

Although the short-term quantitative impact of exercise on lipid levels may be limited, both REHIT and MIIT significantly improved glycemic management and reduced glucose variability in post-stroke patients with Type 2 Diabetes Mellitus. Additionally, REHIT notably enhanced functional recovery.

Exercise snacks are a time-efficient alternative to moderate-intensity continuous training for improving cardiorespiratory fitness but not maximal fat oxidation in inactive adults: a randomized controlled trial

The aims of this study were (1) to determine how stair-climbing-based exercise snacks (ES) compared to moderate-intensity continuous training (MICT) for improving cardiorespiratory fitness (CRF), and (2) to explore whether ES could improve maximal fat oxidation rate (MFO) in inactive adults. Healthy, young, inactive adults (n: 42, age: 21.6 ± 2.3 years, BMI: 22.5 ± 3.6 kg·m-2, peak oxygen uptake (VO2peak): 33.6 ± 6.3 mL·kg-1·min-1) were randomly assigned to ES, MICT, or Control. ES (n = 14) and MICT (n = 13) groups performed three sessions per week over 6 weeks, while the control group (n = 15) maintained their habitual lifestyle. ES involved 3 × 30 s "all-out" stair-climbing (6 flight, 126 steps, and 18.9 m total height) bouts separated by >1 h rest, and MICT involved 40 min × 60%-70% HRmax stationary cycling. A significant group × time interaction was found for relative VO2peak (p < 0.05) with ES significantly increasing by 7% compared to baseline (MD = 2.5 mL·kg-1·min-1 (95% CI = 1.2, 3.7), Cohen's d = 0.44), while MICT had no significant effects (MD = 1.0 mL·kg-1·min-1 (-1.1, 3.2), Cohen's d = 0.17), and Control experienced a significant decrease (MD = -1.7 mL·kg-1·min-1 (-2.9, -0.4), Cohen's d = 0.26). MFO was unchanged among the three groups (group × time interaction, p > 0.05 for all). Stair climbing-based ES are a time-efficient alternative to MICT for improving CRF among inactive adults, but the tested ES intervention appears to have limited potential to increase MFO.

Physiological and Metabolic Responses to Low-Volume Sprint Interval Exercises: Influence of Sprint Duration and Repetitions

PURPOSE

This study aimed to determine physiological and metabolic responses to two different sprint interval exercises (SIE) matched for total sprint duration and sprint-rest ratio.

METHODS

After having measured peak oxygen uptake (V̇O 2peak ), 14 healthy males (27.1 ± 4.8 yr, 169.6 ± 6.0 cm, 64.5 ± 8.4 kg, V̇O 2peak : 47.2 ± 7.7 mL·kg -1 ·min -1 ) performed four 10-s sprints with 80-s recovery (SIE10) and two 20-s sprints with 160-s recovery (SIE20) on different occasions in a counterbalanced crossover manner. Pulmonary V̇O 2 and changes in tissue oxygenation index (∆TOI) at vastus lateralis (VL) and rectus femoris (RF) were measured during the SIE. Furthermore, T2-weighted magnetic resonance imaging was taken immediately before and after the SIE to determine the activation levels of VL, RF, vastus medialis, vastus intermedius, adductor magnus, biceps femoris long head, semitendinosus, and semimembranosus at 50% of right thigh length.

RESULTS

In SIE10, increases in V̇O 2 and ∆TOI at VL and RF plateaued after the second sprint, whereas session-averaged ∆TOI was greater in SIE20 than SIE10 in both muscles (VL: 20.9 ± 7.4 vs 14.2% ± 5.9%, RF: 22.8 ± 9.3 vs 12.9% ± 6.6%, P = 0.00). Although both SIE significantly increased T2 values in all eight muscles, those magnitudes were similar between the conditions (SIE10 vs SIE20: 5%-16% vs 8%-16%).

CONCLUSIONS

This study showed blunted responses of whole-body (V̇O 2 ) and peripheral (∆TOI) oxidative responses with successive sprints (sprint 1 < sprints 2-4) in SIE10, suggesting that increasing sprint repetitions does not necessarily induce greater oxidative metabolism or stimulus. Moreover, greater peripheral oxygen extraction (∆TOI) was achieved with SIE20, whereas %changes of T2 indicates that the thigh muscles were similarly activated between the SIE conditions.

Reduced-exertion high-intensity interval training (REHIT): a feasible approach for improving health and fitness?

In recent years, research investigating the dose-response to sprint interval training (SIT) has provided evidence that the number and duration of repetitions in a SIT session can be reduced whilst preserving the beneficial health-related adaptations. Together this research has led to the development of protocols involving minimal doses of SIT: regularly performing just two or three 20-30 s all-out sprints in a 10 min training session has been shown to elicit beneficial metabolic and cardiovascular adaptations. These SIT protocols, which we originally termed "reduced-exertion high-intensity interval training" (or REHIT), have the potential to remove many of the common barriers associated with other SIT protocols, as well as with HIT and aerobic exercise. Here, we critically review the evidence on the efficacy, feasibility and acceptability, and effectiveness of REHIT for improving health and fitness.

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

ABSTRACT

Coe, LN and Astorino, TA. No sex differences in perceptual responses to high-intensity interval training or sprint interval training. J Strength Cond Res 36(6): 1025-1032, 2024-High-intensity interval training (HIIT) elicits similar and, in some cases, superior benefits vs. moderate-intensity continuous training (MICT). However, HIIT is typically more aversive than MICT because of the higher intensity and in turn, greater blood lactate accumulation (BLa). This study explored potential sex differences in perceptual responses to acute HIIT and sprint interval training. Fifteen men (age and V̇O2max = 29 ± 8 years and 39 ± 3 ml·kg-1·min-1) and 13 women (age and V̇O2max = 22 ± 2 years and 38 ± 5 ml·kg-1·min-1) who are healthy and recreationally active initially underwent testing of maximal oxygen uptake (V̇O2max) on a cycle ergometer. In randomized order on 3 separate occasions, they performed the 10 × 1-minute protocol at 85% of peak power output, 4 × 4-minute protocol at 85-95% maximal heart rate (%HRmax), or reduced exertion high intensity interval training consisting of 2 "all-out" 20-second sprints at a load equal to 5% body mass. Before and throughout each protocol, rating of perceived exertion (rating of perceived exertion [RPE] 6-20 scale), affective valence (+5 to -5 of the Feeling Scale), and BLa were assessed. Five minutes postexercise, enjoyment was measured using the Physical Activity Enjoyment scale survey. Results showed no difference in RPE (p = 0.17), affective valence (0.27), or enjoyment (p = 0.52) between men and women. Blood lactate accumulation increased in response to all protocols (p < 0.001), and men showed higher BLa than women (p = 0.03). Previous research suggests that interval exercise protocols are not interchangeable between men and women, yet our data reveal that men and women having similar V̇O2max exhibit no differences in perceptual responses to interval exercise.

Comparison of HIIT and MICT and further detraining on metabolic syndrome and asprosin signaling pathway in metabolic syndrome model of rats

Physical activity promotes various metabolic benefits by balancing pro and anti-inflammatory adipokines. Recent studies suggest that asprosin might be involved in progression of metabolic syndrome (MetS), however, the underlying mechanisms have not been understood yet. This study aimed to evaluate the effects of high-intensity interval training (HIIT), moderate-intensity continuous training (MICT), and further detraining on MetS indices, insulin resistance, serum and the liver levels of asprosin, and AMP-activated protein kinase (AMPK) pathway in menopause-induced MetS model of rats. A total of 64 Wistar rats were used in this study and divided into eight groups: Sham1, OVX1 (ovariectomized), Sham2, OVX2, OVX + HIIT, OVX + MICT, OVX + HIIT + Det (detraining), and OVX + MICT + Det. Animals performed the protocols, and then serum concentrations of asprosin, TNF-α, insulin, fasting blood glucose, and lipid profiles (TC, LDL, TG, and HDL) were assessed. Additionally, the liver expression of asprosin, AMPK, and P-AMPK was measured by western blotting. Both HIIT and MICT caused a significant decrease in weight, waist circumference, BMI (P = 0.001), and serum levels of glucose, insulin, asprosin (P = 0.001), triglyceride, total cholesterol, low-density lipoprotein (LDL), and TNF-α (P = 0.001), but an increase in the liver AMPK, P-AMPK, and P-AMPK/AMPK (P = 0.001), compared with OVX2 noexercised group. MICT was superior to HIIT in reducing serum asprosin, TNF-a, TG, LDL (P = 0.001), insulin, fasting blood glucose, HOMA-IR, and QUEKI index (P = 0.001), but an increase in the liver AMPK, and p-AMPK (P = 0.001). Although after two months of de-training almost all indices returned to the pre exercise values (P < 0.05). The findings suggest that MICT effectively alleviates MetS induced by menopause, at least partly through the activation of liver signaling of P-AMPK and the reduction of asprosin and TNF-α. These results have practical implications for the development of exercise interventions targeting MetS in menopausal individuals, emphasizing the potential benefits of MICT in mitigating MetS-related complications.

The impact of sprint interval training versus moderate intensity continuous training on blood pressure and cardiorespiratory health in adults: a systematic review and meta-analysis

Background

Although aerobic exercise is the primary modality recommended for the treatment of hypertension, it remains unclear whether high-intensity all-out sprint interval training (SIT) can result in greater reductions of blood pressure (BP) and cardiorespiratory health. This systematic review aims to compare the impact of SIT versus Moderate-intensity continuous training (MICT) on improvements in resting systolic blood pressure (SBP), diastolic blood pressure (DBP) and maximal oxygen uptake (VO2 max) among adults.

Methods

We conducted a systematic search of three online databases (PubMed, Embase, and Web of Science) from January 2000 to July 2023 to identify randomized controlled trials that compared the chronic effects of SIT versus MICT on BP in participants with high or normal blood pressure. We extracted information on participant characteristics, exercise protocols, BP outcomes, and intervention settings. Furthermore, the changes in VO2 max between the two groups were analyzed using a meta-analysis. The pooled results were presented as weighted means with 95% confidence intervals (CI).

Results

Out of the 1,874 studies initially were found, eight were included in this review, totaling 169 participants. A significant decrease in SBP (MD = -2.82 mmHg, 95% CI [-4.53 to -1.10], p = 0.08, I2 =45%) was observed in the SIT group compared to before the training, but no significant decrease in DBP (MD = -0.75 mmHg, 95% CI [-1.92 to 0.42], p = 0.16, I2 = 33%) was observed. In contrast, both SBP (MD = -3.00 mmHg, 95% CI [-5.31 to -0.69], p = 0.68, I2 = 0%) and DBP (MD = -2.11 mmHg, 95% CI [-3.63 to -0.60], p = 0.72, I2 = 0%) significantly decreased in the MICT group with low heterogeneity. No significant difference was found in resting SBP and DBP between SIT and MICT after the intervention. Both SIT and MICT significantly increased VO2 peak, with SIT resulting in a mean difference (MD) of 1.75 mL/kg/min (95% CI [0.39-3.10], p = 0.02, I2 = 61%), and MICT resulting in a mean difference of 3.10 mL/kg/min (95% CI [1.03-5.18], p = 0.007, I2 = 69%). MICT was more effective in improving VO2 peak (MD = -1.36 mL/kg/min, 95% CI [-2.31 to 0.40], p = 0.56, I2 = 0%). Subgroup analysis of duration and single sprint time showed that SIT was more effective in reducing SBP when the duration was ≥8 weeks or when the sprint time was <30 s.

Conclusion

Our meta-analysis showed that SIT is an effective intervention in reducing BP and improving cardiorespiratory fitness among adults. Consequently, SIT can be used in combination with traditional MICT to increase the variety, utility, and time efficiency of exercise prescriptions for different populations.

Is low-volume high-intensity interval training a time-efficient strategy to improve cardiometabolic health and body composition? A meta-analysis

The present meta-analysis aimed to assess the effects of low-volume high-intensity interval training (LV-HIIT; i.e., ≤5 min high-intensity exercise within a ≤15 min session) on cardiometabolic health and body composition. A systematic search was performed in accordance with PRISMA guidelines to assess the effect of LV-HIIT on cardiometabolic health and body composition. Twenty-one studies (moderate to high quality) with a total of 849 participants were included in this meta-analysis. LV-HIIT increased cardiorespiratory fitness (CRF, SMD = 1.19 [0.87, 1.50]) while lowering systolic blood pressure (SMD = -1.44 [-1.68, -1.20]), diastolic blood pressure (SMD = -1.51 [-1.75, -1.27]), mean arterial pressure (SMD = -1.55 [-1.80, -1.30]), MetS z-score (SMD = -0.76 [-1.02, -0.49]), fat mass (kg) (SMD = -0.22 [-0.44, 0.00]), fat mass (%) (SMD = -0.22 [-0.41, -0.02]), and waist circumference (SMD = -0.53 [-0.75, -0.31]) compared to untrained control (CONTROL). Despite a total time-commitment of LV-HIIT of only 14%-47% and 45%-94% compared to moderate-intensity continuous training and HV-HIIT, respectively, there were no statistically significant differences observed for any outcomes in comparisons between LV-HIIT and moderate-intensity continuous training (MICT) or high-volume HIIT. Significant inverse dose-responses were observed between the change in CRF with LV-HIIT and sprint repetitions (β = -0.52 [-0.76, -0.28]), high-intensity duration (β = -0.21 [-0.39, -0.02]), and total duration (β = -0.19 [-0.36, -0.02]), while higher intensity significantly improved CRF gains. LV-HIIT can improve cardiometabolic health and body composition and represent a time-efficient alternative to MICT and HV-HIIT. Performing LV-HIIT at a higher intensity drives higher CRF gains. More repetitions, longer time at high intensity, and total session duration did not augment gains in CRF.

Excess post-exercise oxygen consumption after reduced exertion high-intensity interval training on the cycle ergometer and rowing ergometer

PURPOSE

To examine differences in oxygen consumption ([Formula: see text]O2), ventilation ([Formula: see text]E), excess post-exercise oxygen consumption (EPOC), energy expenditure (EE), and blood lactate concentration (BLa) between reduced exertion high-intensity interval training (REHIT) performed on the cycle- and rowing ergometer.

METHODS

Fourteen active participants (age = 27 ± 7 yr) initially completed two assessments of maximal oxygen uptake. On two subsequent days, participants completed REHIT requiring three 20 s "all-out" sprints on the cycle-(REHIT-CE) and rowing ergometer (REHIT-RE), followed by 60 min rest during which gas exchange data and BLa were measured.

RESULTS

During exercise, [Formula: see text]O2 increased significantly in response to REHIT-CE (0.21 ± 0.04 L/min vs. 1.34 ± 0.37 L/min, p < 0.001) and REHIT-RE (0.23 ± 0.05 L/min vs. 1.57 ± 0.47 L/min, p < 0.001) compared to rest, and [Formula: see text]O2 remained elevated at 15, 30, and 45 min post-exercise in REHIT-CE (p < 0.001). However, [Formula: see text]O2 was only elevated 15 min after REHIT-RE (0.23 ± 0.05 L/min vs. 0.40 ± 0.11 L/min, p < 0.001). [Formula: see text]O2 (1.57 ± 0.47 L/min vs. 1.34 ± 0.37 L/min, p = 0.003) and EE (94.98 ± 29.60 kcal vs. 82.05 ± 22.85 kcal, p < 0.001) were significantly greater during REHIT-RE versus REHIT-CE. EPOC was significantly greater after REHIT-CE versus REHIT-RE (6.69 ± 2.18 L vs. 5.52 ± 1.67 L, p = 0.009). BLa was ~ twofold higher in response to REHIT-CE vs. REHIT-RE (11.11 ± 2.43 vs. 7.0 ± 2.4, p < 0.001).

CONCLUSION

Rowing-based REHIT elicits greater oxygen consumption and EE during exercise, yet lower EPOC and BLa. Whether rowing-based REHIT augments reductions in fat loss remains to be determined.

Physical Exercise Methods and Their Effects on Glycemic Control and Body Composition in Adults with Type 2 Diabetes Mellitus (T2DM): A Systematic Review

The prevalence of T2DM represents a challenge for health agencies due to its high risk of morbidity and mortality. Physical Activity (PA) is one of the fundamental pillars for the treatment of T2DM, so Physical Exercise (PE) programs have been applied to research their effectiveness. The objective of the study was to analyze the effects of PE methods on glycemic control and body composition of adults with T2DM. A systematic review without meta-analysis was performed, using the PubMed database. Quasi-experimental and pure experimental clinical trials were included, which were available free of charge and were published during 2010-2020. In the results, 589 articles were found and 25 passed the inclusion criteria. These were classified and analyzed according to the methods identified (AE, IE, RE, COM, and others), duration and variable(s) studied. It is concluded that PE is effective for glycemic control and body composition in adults with T2DM using different methods (AE, IE, RE, COM, and others), both in the short and long term. Adequate organization of PE components such as frequency, duration, volume, and intensity, is essential.

Effect of resistance training and high-intensity interval training on metabolic parameters and serum level of Sirtuin1 in postmenopausal women with metabolic syndrome: a randomized controlled trial

BACKGROUND

The present study analyzes the influence of resistance training (RT) and high-intensity interval training (HIIT) on metabolic indices and serum levels of Sirtuin1 (SIRT1) in postmenopausal women who suffer from the metabolic syndrome (MetS).

METHODS

45 postmenopausal women aged 45-65 years with MetS were divided into two intervention groups (RT and HIIT) and one control group, each consisting of 15 people. The RT group performed resistance training for both the upper and lower body, while the HIIT group completed 3 min(min) of high-intensity training at 80-90% of their maximum heart rate (HRmax), followed by moderate walking for 3 min at 55-65% of HRmax. These sessions were conducted for a duration of eight weeks and three times a week, with the samples being collected at the baseline and at the end of the treatment, i.e., week 8.

RESULTS

The results showed that weight, waist circumference, body mass index, fat mass, low-density lipoprotein, triglyceride, cholesterol, fasting blood sugar (FBS), hemoglobin A1c (HbA1C), systolic and diastolic blood pressure decreased, and SIRT1 increased significantly in both training groups. Systolic blood pressure, cholesterol, HbA1C, and FBS decreased more in the HIIT group. Skeletal muscle mass and 1-repetition maximum (1-RM) increased more in the RT group.

CONCLUSIONS

RT and HIIT serve as one of the most effective strategies for therapeutically treating patients with metabolic syndrome.

TRIAL REGISTRATION

IRCT, IRCT20221120056548N1. Registered 23 November 2022 - Retrospectively registered.

Exercise Effects on Health-Related Quality of Life (HRQOL), Muscular Function, Cardiorespiratory Function, and Body Composition in Smokers: A Narrative Review

Smoking is amongst the leading global threats with high incidences of preventable premature mortality, morbidity, and various chronic diseases. The World Health Organization (WHO) proclaims a decrease in the prevalence of daily smoking in both males and females from 1980 to 2012, however, the number of regular smokers since then has exponentially increased. The low socio-income status individuals contribute greatly towards tobacco-attributable diseases due to limited access to healthcare systems, mostly in developing countries as compared to developed countries. Smoking affects the optimal functioning of the human body, which results in altered body system processes. Although a high intake of nicotine can lead to prolonged adherence and dependence on smoking, other factors, such as an individual's level of health-related quality of life (HRQOL), stress, depression, and anxiety, can produce similar effects. Smoking has a wide impact on lifestyle factors, which explains the increase in the number of sedentary smokers with decreased health fitness levels and poor lifestyle conditions. Therefore, this study seeks to investigate the exercise effects on health-related quality of life (HRQOL), muscular function, cardiorespiratory function, and body composition in smokers. Concurrently, exercise as an intervention has been sourced as a rehabilitation strategy during smoking cessation programmes to restore the diminishing health components, however, a high rate of relapse occurs due to intolerable withdrawal symptoms.

Short High-Intensity Interval Exercise for Workplace-Based Physical Activity Interventions: A Systematic Review on Feasibility and Effectiveness

BACKGROUND

Workplace exercise interventions showed good results, but lack of time was often reported as a barrier to participation. To overcome this problem, several studies attempted to implement short high-intensity interval training (HIT) within the workplace.

OBJECTIVES

The aim of this systematic review is to explore the feasibility and effectiveness of HIT interventions within the workplace setting.

DATA SOURCES

A systematic literature search was conducted in PubMed and SPORTDiscus to identify articles related to HIT within the workplace.

STUDY ELIGIBILITY CRITERIA

Only interventions that consisted of HIT programmes within the workplace and tested at least one physiological, psychological, or work-related outcome were included.

RESULTS

Seven studies (317 participants) met the inclusion criteria. HIT interventions lasted 6-12 weeks, with a frequency of 2-4 sessions/week and a duration of 8-30 min per session. Feasibility was qualitatively investigated in four studies, with key positive aspects reported for HIT time-appeal, the sense of competence driven by individual intensity, and improved intention to exercise; five studies reported adherence rates > 80%. Small-to-large effect sizes were reported for improvements in cardiorespiratory and muscular fitness. Small-to-medium effect sizes were reported for blood parameters and health-related quality of life.

CONCLUSIONS

HIT interventions in the workplace showed limited effectiveness in improving health-related outcomes, while promising results regarding feasibility were reported, mainly due to the time-efficiency and the positive post-exercise psychosocial responses. However, further high-quality studies involving more participants are still needed to make firm conclusions on HIT effectiveness and feasibility compared to other types of exercise in this context.

Effects of high-intensity interval training versus moderate-intensity continuous training on blood pressure in patients with hypertension: A meta-analysis

BACKGROUND

This meta-analysis aimed to compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on blood pressure in patients with essential hypertension to explore more suitable training.

METHODS

PubMed, EBSCO, Cochrane Library, Web of Science, CNKI, and VIP databases were searched for randomized controlled trials published between January 2002 and November 2022. Weighted mean differences (WMDs) with 95% confidence intervals (CIs) were selected as the effect scale indices for the evaluation of the differences in post-intervention systolic blood pressure (SBP), and diastolic blood pressure (DBP), heart rate, maximum oxygen uptake (VO2max), and flow-mediated vasodilation. All these were compared using Review Manager 5.3 and Stata 14.0.

RESULTS

A total of 13 randomized controlled trials and 442 patients were included. The meta-analyses revealed no statistically significant differences between HIIT and MICT in improving SBP and DBP in patients with hypertension. Subgroup analyses revealed that HIIT was better than MICT in reducing SBP during daytime monitoring (WMD = -4.14, 95%CI: [-6.98, -1.30], P < .001). In addition, HIIT increased flow-mediated vasodilation more than MICT in hypertensive patients (WMD = 2.75, 95%CI: [0.43, 5.07], P = .02).

CONCLUSION

HIIT and MICT have similar effects on the overall resting SBP and DBP in patients with hypertension and prehypertension. However, HIIT is better than MICT at reducing SBP during daytime monitoring. In addition, HIIT can improve vasodilation.

Nonpharmacological Strategies in Heart Failure with Preserved Ejection Fraction

Patients with heart failure with preserved ejection fraction (HFpEF) suffer from a high rate of cardiometabolic comorbidities with limited pharmaceutical therapies proven to improve clinical outcomes and cardiorespiratory fitness (CRF). Nonpharmacologic therapies, such as exercise training and dietary interventions, are promising strategies for this population. The aim of this narrative review is to present a summary of the literature published to date and future directions related to the efficacy of nonpharmacologic, lifestyle-related therapies in HFpEF, with a focus on exercise training and dietary interventions.

The Influence of Acute Sprint Interval Training on Cognitive Performance of Healthy Younger Adults

There is considerable evidence showing that an acute bout of physical exercises can improve cognitive performance, but the optimal exercise characteristics (e.g., exercise type and exercise intensity) remain elusive. In this regard, there is a gap in the literature to which extent sprint interval training (SIT) can enhance cognitive performance. Thus, this study aimed to investigate the effect of a time-efficient SIT, termed as "shortened-sprint reduced-exertion high-intensity interval training" (SSREHIT), on cognitive performance. Nineteen healthy adults aged 20-28 years were enrolled and assessed for attentional performance (via the d2 test), working memory performance (via Digit Span Forward/Backward), and peripheral blood lactate concentration immediately before and 10 min after an SSREHIT and a cognitive engagement control condition (i.e., reading). We observed that SSREHIT can enhance specific aspects of attentional performance, as it improved the percent error rate (F%) in the d-2 test (t (18) = -2.249, p = 0.037, d = -0.516), which constitutes a qualitative measure of precision and thoroughness. However, SSREHIT did not change other measures of attentional or working memory performance. In addition, we observed that the exercise-induced increase in the peripheral blood lactate levels correlated with changes in attentional performance, i.e., the total number of responses (GZ) (rm = 0.70, p < 0.001), objective measures of concentration (SKL) (rm = 0.73, p < 0.001), and F% (rm = -0.54, p = 0.015). The present study provides initial evidence that a single bout of SSREHIT can improve specific aspects of attentional performance and conforming evidence for a positive link between cognitive improvements and changes in peripheral blood lactate levels.

Acute RyR1 Ca2+ leak enhances NADH-linked mitochondrial respiratory capacity

Sustained ryanodine receptor (RyR) Ca²⁺ leak is associated with pathological conditions such as heart failure or skeletal muscle weakness. We report that a single session of sprint interval training (SIT), but not of moderate intensity continuous training (MICT), triggers RyR1 protein oxidation and nitrosylation leading to calstabin1 dissociation in healthy human muscle and in in vitro SIT models (simulated SIT or S-SIT). This is accompanied by decreased sarcoplasmic reticulum Ca²⁺ content, increased levels of mitochondrial oxidative phosphorylation proteins, supercomplex formation and enhanced NADH-linked mitochondrial respiratory capacity. Mechanistically, (S-)SIT increases mitochondrial Ca²⁺ uptake in mouse myotubes and muscle fibres, and decreases pyruvate dehydrogenase phosphorylation in human muscle and mouse myotubes. Countering Ca²⁺ leak or preventing mitochondrial Ca²⁺ uptake blunts S-SIT-induced adaptations, a result supported by proteomic analyses. Here we show that triggering acute transient Ca²⁺ leak through RyR1 in healthy muscle may contribute to the multiple health promoting benefits of exercise.

Using Focus Groups and Interviews to Inform the Design of a Workplace Exercise Programme: An Example From a High-Intensity Interval Training Intervention

OBJECTIVE

Using a formative evaluation of a high-intensity interval training (HIIT) intervention, we illustrate how qualitative data can inform the development of workplace exercise interventions.

METHOD

Eight focus groups and four interviews were conducted with employees (n = 38) and management (n = 4) from six office-based organisations before intervention implementation.

RESULTS

Some participants thought workplace-based HIIT would be practical, given the limited time required. Others perceived it may not be acceptable for all individuals, given the exercise intensity. With consideration of identified barriers (workload/family commitments effecting time availability) and facilitators (flexible working conditions) participants' perspectives were incorporated into the intervention protocol. A short-term group-based intervention was preferred, with a choice of exercise modes (based on stair climbing, stepping or boxing).

CONCLUSION

This study provides a framework to incorporate stakeholders' perspectives into the development of workplace exercise interventions.

Brief Exercise at Work (BE@Work): A Mixed-Methods Pilot Trial of a Workplace High-Intensity Interval Training Intervention

Introduction: The efficacy of high-intensity interval training (HIIT) for improving markers of physical fitness and cardiometabolic health is promising. The workplace is one non-laboratory setting where the effectiveness of HIIT could be explored. The aim of this study was to undertake a mixed-methods exploratory pilot trial of a workplace HIIT intervention named Brief Exercise at Work (BE@Work). Methods: Fifty-four healthy employees (mean ± standard deviation [SD] age 46 ± 10 years) from two workplaces in Northeast England were allocated to 8 weeks of thrice-weekly workplace HIIT based on boxing, stair climbing and stepping, comprising 4-7 60 s high-intensity intervals interspersed with 75 s rest (n = 30), or a no-intervention control (n = 24). The primary outcome was the change SD of predicted maximal oxygen consumption (VO2max). Markers of physical fitness, cardiometabolic health and mental well-being were also measured at baseline and follow-up. Participant perceptions of the intervention were explored in post-intervention focus groups (n = 9). Results: Mean (±SD) session attendance was 82% (±15%). Mean peak heart rate across the intervention was 87% of age-predicted maximal heart rate with a within- and between-subject SD of 5.5% and 3.7%, respectively. The SD of changes in predicted VO2max was 6.6 mL·kg-1·min-1 across both groups, which can be used to inform sample size estimations for a future full trial. The control-adjusted mean increase (95% confidence interval) in predicted VO2max was 3.9 (-0.2 to 8.1) mL·kg-1·min-1, corresponding to a Cohen's D of 0.47. We also observed preliminary evidence of small to moderate effects in favour of the intervention group for non-dominant leg extensor muscle power, markers of health-related quality of life, well-being and perceived stress and small to moderate effects in favour of the controls in perceived pain, physical activity and high-density lipoprotein cholesterol. During HIIT, focus group participants reported physiological responses they perceived as unpleasant or tiring (e.g., breathlessness, local muscular fatigue), but also that they felt alert and energised afterwards. Conclusion: The findings of this exploratory pilot trial support the implementation of a definitive randomised controlled trial to quantify the effectiveness of a workplace HIIT intervention.

Feasibility of procedures for a randomised pilot study of reduced exertion, high-intensity interval training (REHIT) with non-diabetic hyperglycaemia patients

Background

Physical activity and exercise interventions to improve health frequently bring about intended effects under ideal circumstances but often fail to demonstrate benefits in real-world contexts. The aim of this study was to describe the feasibility of an exercise intervention (reduced-exertion, high-intensity interval training) in non-diabetic hyperglycaemia patients delivered in a National Health Service setting to assess whether it would be appropriate to progress to a future large-scale study.

Methods

The intention was to recruit 40 participants from a single centre (specialist diabesity centre). Patients were eligible to take part if they were diagnostically defined as non-diabetic hyperglycaemic based on a glycated haemoglobin (HbA_1c) value of 42–46 mmol mol. Study procedures including recruitment, occurrence of adverse events, intervention acceptability, and intervention adherence were used to assess feasibility.

Results

Key criteria for progression to a larger study were not met. The study revealed several issues including patient eligibility, challenges to recruitment, patient consent, and poor clinician engagement. Furthermore, despite the simplicity and convenience of using HbA_1c to screen for diabetes risk, the process of accurately screening and case finding eligible patients was problematic. The small sample recruited for this trial (n = 6) also limits the interpretation of data, thus it is not possible to estimate the variability of intended outcomes to use in a formal sample size calculation for a full-scale trial. Some aspects of the intervention worked well. The acceptability of the exercise intervention and outcome measures met progression criteria thresholds and adherence was very high, with 97% of exercise sessions completed for participants that finished the study.

Conclusions

Given the issues, the trial is not feasible in its current form. Yet, this preparatory stage of trial design pre-empted problems with the intervention that could be changed to optimise the design and conduct of future studies. Solutions to the issues identified in this study revolve around using a dedicated local recruiter with a strong relationship among the healthcare team and patients, using participant incentives to take part, and allowing for a longer recruitment period.

Trial registration

ClinicalTrials.gov, NCT04011397. Registered 07 July 2019—retrospectively registered.

HIIT is not superior to MICT in altering blood lipids: a systematic review and meta-analysis

Objective

To compare the effects of moderate intensity continuous training (MICT) and high intensity interval training (HIIT) on adult lipid profiles; to identify training or participant characteristics that may determine exercise-induced change in total cholesterol (TC), triglycerides (TRG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C).

Design

Systematic review and meta-analysis.

Data sources

English language searches of several databases were conducted from inception until September 2019.

Eligibility criteria for excluding studies

Inclusion: (1) published randomised controlled human trials with group population n≥5; (2) intervention duration ≥4 weeks; (3) comparing HIIT with MICT; and (4) reporting pre–post intervention lipid measurements. Exclusion: subjects with chronic disease, <18 years, pregnant/lactating, in elite athletic training; and studies with a dietary or pharmaceutical intervention component.

Results

Twenty-nine data sets (mmol/L) of 823 participants were pooled and analysed. Neither HIIT nor MICT was better in decreasing TC (0.10 (−0.06 to 0.19), p=0.12, I²=0%), TRG (−0.05 (−0.11 to 0.01), p=0.10, I²=0%), LDL-C (0.05 (−0.06 to 0.17), p=0.37, I²=0%), or TC/HDL-C (−0.03 (−0.36 to 0.29), p=0.85, I²=0%). HIIT significantly raised HDL-C (0.07 (0.04 to 0.11), p<0.0001, I²=0%) compared with MICT.

Conclusion

Neither HIIT nor MICT is superior for altering TC, TRG, or LDL-C, or TC-HDL-C ratio. Compared with MICT, HIIT appeared to significantly improve HDL-C. Clinicians may prescribe either protocol to encourage participation in exercise and reduce cardiovascular risk. To raise HDL-C, HIIT may result in a larger effect size compared with MICT.

PROSPERO registration number

CRD42019136722.