Acute effect of high-intensity interval training versus moderate-intensity continuous training on appetite perception: A systematic review and meta-analysis.

Interval training protocols have gained popularity over the years, but their impact on appetite sensation compared to officially recommended training method, moderate intensity continuous training (MICT) is not well understood. Thus, this systematic review and meta-analysis aimed to compare a single session of high intensity interval training (HIIT) including sprint interval training (SIT) with MICT on appetite perception measured by the visual analog scale (VAS). After searching up articles published up to September 2021, 13 randomized controlled studies were included in the meta-analysis. Outcomes of meta-analysis demonstrated that both acute sessions of HIIT/SIT and MICT suppressed appetite compared to no-exercise control groups immediately post exercise but there were no significant effects 30-90 min post exercise or in AUC values, indicating a transient effect of exercise on appetite sensations. Moreover, differences in appetite sensations between HIIT/SIT and MICT were negligible immediately post exercise, but HIIT/SIT suppressed hunger (MD = -6.347 [-12.054, -0.639], p = 0.029) to a greater extent than MICT 30- to 90-min post exercise, while there was a lack of consistency other VAS subscales of appetite. More studies that address the impact of exercising timing, nutrient compositions of energy intake (energy intake (EI)) and differences in participants' characteristics and long-term studies analyzing chronic effects are needed to comprehensively examine the differences between HIIT/SIT and MICT on appetite and EI. SYSTEMATIC REVIEW REGISTRATION: [https://www.crd.york.ac.uk/PROSPERO], Identifier [CRD42021284898].

Comparative Effectiveness of Multiple Exercise Interventions in the Treatment of Mental Health Disorders: A Systematic Review and Network Meta-Analysis.

BACKGROUND: The efficacy of exercise interventions in the treatment of mental health disorders is well known, but research is lacking on the most efficient exercise type for specific mental health disorders. OBJECTIVE: The present study aimed to compare and rank the effectiveness of various exercise types in the treatment of mental health disorders. METHODS: The PubMed, Web of Science, PsycINFO, SPORTDiscus, CINAHL databases, and the Cochrane Central Register of Controlled Trials as well as Google Scholar were searched up to December 2021. We performed pairwise and network meta-analyses as well as meta-regression analyses for mental health disorders in general and each type of mental health disorder, with alterations in symptom severity as the primary outcome. RESULTS: A total of 6456 participants from 117 randomized controlled trials were surveyed. The multimodal exercise (71%) had the highest probability of being the most efficient exercise for relieving depressive symptoms. While resistance exercise (60%) was more likely to be the most effective treatment for anxiety disorder, patients with post-traumatic stress disorder (PTSD) benefited more from mind-body exercise (52%). Furthermore, resistance exercise (31%) and multimodal exercise (37%) had more beneficial effects in the treatment of the positive and negative symptoms of schizophrenia, respectively. The length of intervention and exercise frequency independently moderated the effects of mind-body exercise on depressive (coefficient = 0.14, p = .03) and negative schizophrenia (coefficient = 0.96, p = .04) symptoms. CONCLUSION: Multimodal exercise ranked best for treating depressive and negative schizophrenic symptoms, while resistance exercise seemed to be more beneficial for those with anxiety-related and positive schizophrenic symptoms. Mind-body exercise was recommended as the most promising exercise type in the treatment of PTSD. However, the findings should be treated with caution due to potential risk of bias in at least one dimension of assessment and low-to-moderate certainty of evidence. Trial Registration This systematic review was registered in the PROSPERO international prospective register of systematic reviews (CRD42022310237).

Sprint Interval Exercise Improves Cognitive Performance Unrelated to Postprandial Glucose Fluctuations at Different Levels of Normobaric Hypoxia.

Objective: The aim of our study was to examine cognition response to sprint interval exercise (SIE) against different levels of hypoxia. Research design and methods: 26 recreational active males performed SIE (20 × 6 s of all-out cycling bouts, 15 s of passive recovery) under normoxia (FIO2: 0.209), moderate hypoxia (FIO2: 0.154), and severe hypoxia (FIO2: 0.112) in a single-blinded crossover design. Cognitive function and blood glucose were assessed before and after 0, 10, 30, and 60 min of the SIE. Heart rate (HR), peripheral oxygen saturation (SpO2), and ratings of perceived exertion (RPE, the Borg 6−20-point scale) during each SIE trial were recorded before and immediately after every five cycling bouts, and after 0, 10, 30, and 60 min of the SIE. Results: All the three SIE trials had a significantly faster overall reaction time in the Stroop test at 10 min after exercise as compared to that of the baseline value (p = 0.003, ƞ2 = 0.606), and returned to normal after 60 min. The congruent RT at 10 min after SIE was significantly shorter than that of the baseline (p < 0.05, ƞ2 = 0.633), while the incongruent RT at both 10 min and 30 min were significantly shorter than that measured at baseline (p < 0.05, ƞ2 = 0.633). No significant differences in terms of accuracy were found across the three trials at any time points (p = 0.446, ƞ2 = 0.415). Blood glucose was significantly reduced at 10 min and was sustained for at least 60 min after SIE when compared to pre-exercise in all trials (p < 0.05). Conclusions: Acute SIE improved cognitive function regardless of oxygen conditions, and the sustained improvement following SIE could last for at least 10−30 min and was unaffected by the altered blood glucose level.

The Impact of Sprint Interval Exercise in Acute Severe Hypoxia on Executive Function.

Kong, Zhaowei, Qian Yu, Shengyan Sun, On Kei Lei, Yu Tian, Qingde Shi, Jinlei Nie, and Martin Burtscher. The impact of sprint interval exercise in acute severe hypoxia on executive function. High Alt Med Biol. 23: 135-145, 2022. Objective: The present study evaluated executive performance responses to sprint interval exercise in normoxia and relatively severe hypoxia. Methods: Twenty-five physically active men (age 22 ± 2 years; maximal oxygen uptake 43 ± 2 ml/[kg·min]) performed four trials including two normoxic (FIO2 = 0.209) and two normobaric hypoxic trials (FIO2 = 0.112), at rest (control) and exercise at the same time on different days. The exercise scheme consisted of 20 sets of 6-seconds all-out cycling sprint interspersed with 15-seconds recovery. The Stroop task was conducted before, 10, 30, and 60 minutes after each trial, whereas peripheral oxygen saturation (SpO2), heart rate, ratings of perceived exertion, and feelings of arousal were additionally recorded immediately after the interventions. Results: Despite the low SpO2 levels, both resting and sprint interval exercise in hypoxia had no adverse effects on executive function. Exercise elicited executive improvements in normoxia (-5.3% and -3.4% at 10 and 30 minutes after exercise) and in hypoxia (-7.8% and -4.3%), which is reflected by ameliorating incongruent reaction time and its 30-minutes sustained effects (p = 0.018). Conclusions: The findings demonstrate that sprint interval exercise caused sustained executive benefits, and exercise in relatively severe hypoxia did not impair executive performance.

Effects of Low-Carbohydrate Diet and Exercise Training on Gut Microbiota.

Objective: This study was aimed to evaluate the effects of low-carbohydrate diet (LC) and incorporated high-intensity interval training (HIIT) or moderate-intensity continuous training (MICT) on gut microbiota, and the associations between changes in gut microbiota and cardiometabolic health-related profiles. Methods: Fifty overweight/obese Chinese females (age 22.2 ± 3.3 years, body mass index 25.1 ± 3.1 kg/m-2) were randomized to the groups of LC, LC and HIIT (LC-HIIT, 10 repetitions of 6-s sprints and 9-s rest), and LC and MICT group (LC-MICT, cycling at 50-60% V̇O2peak for 30 min). The LC-HIIT and LC-MICT experienced 20 training sessions over 4 weeks. Results: The 4-week LC intervention with/without additional training failed to change the Shannon, Chao 1, and Simpson indexes (p > 0.05), LC increased Phascolarctobacterium genus, and LC-HIIT reduced Bifidobacterium genus after intervention (p < 0.05). Groups with extra exercise training increased short-chain fatty acid-producing Blautia genus (p < 0.05) and reduced type 2 diabetes-related genus Alistipes (p < 0.05) compared to LC. Sutterella (r = -0.335) and Enterobacter (r = 0.334) were associated with changes in body composition (p < 0.05). Changes in Ruminococcus, Eubacterium, and Roseburia genera were positively associated with blood pressure (BP) changes (r = 0.392-0.445, p < 0.05), whereas the changes in Bacteroides, Faecalibacterium, and Parabacteroides genera were negatively associated with BP changes (r = -0.567 to -0.362, p < 0.05). Conclusion: LC intervention did not change the α-diversity and overall structure of gut microbiota. Combining LC with exercise training may have additional benefits on gut physiology. Specific microbial genera were associated with LC- and exercise-induced regulation of cardiometabolic health.

Hypoxic repeated sprint interval training improves cardiorespiratory fitness in sedentary young women.

OBJECTIVE: The purpose of this study was to investigate the effects of repeated sprint interval training (RSIT) under different hypoxic conditions in comparison with normoxic RSIT on cardiorespiratory fitness (CRF) and metabolic health in sedentary young women. METHODS: Sixty-two sedentary young women (age: 21.9 ± 2.8 years, peak oxygen uptake [V̇O2peak] 25.9 ± 4.5 ml kg-1·min-1) were randomized into one of the four groups, including a normoxic RSIT group (N), RSIT simulating an altitude of 2500 m (H2500), RSIT simulating an incremental altitude of 2500-3400 m (H2500-3400) and a non-exercise control group (C). The training intervention (80 × 6 s all-out cycling sprints with 9 s recovery) was performed three times/week for 4 weeks. Anthropometric measures, V̇O2peak, fasting blood glucose and lipids were assessed during the follicular phase of the menstrual cycle before and after the intervention. RESULTS: Compared with the control group, significant increases in V̇O2peak were found in both hypoxic groups (H2500: +8.2%, p < 0.001, d = 0.52; H2500-3400: +10.9%, p < 0.05, d = 0.99) but not in the N group (+3.6%, p > 0.05, d = 0.21) after the intervention, whereas the two hypoxic groups had no difference in V̇O2peak. Blood glucose and lipids, and body composition remained unchanged in all groups. CONCLUSION: The present study indicates that combining hypoxia with RSIT can enhance the improvement of CRF compared with normoxic RSIT alone in the sedentary young population. Yet, compared with RSIT under stable hypoxia, incremental hypoxia stress in the short-term does not additionally ameliorate CRF.

Carbohydrate Restriction with or without Exercise Training Improves Blood Pressure and Insulin Sensitivity in Overweight Women.

OBJECTIVE: The purpose of this study was to evaluate the effects of a 4-week low-carbohydrate diet (LC) with or without exercise training on cardiometabolic health-related profiles in overweight/obese women. METHODS: Fifty overweight/obese Chinese women (age: 22.2 ± 3.3 years, body mass index (BMI): 25.1 ± 3.1 kg·m-2) were randomized to either a LC control group (LC-CON, n = 16), a LC and high-intensity interval training group (LC-HIIT, n = 17), or a LC and moderate-intensity continuous training group (LC-MICT, n = 17). All groups consumed LC for 4 weeks, while the LC-HIIT and LC-MICT groups followed an additional five sessions of HIIT (10 × 6 s cycling sprints and 9 s rest intervals, 2.5 min in total) or MICT (cycling continuously at 50-60% of peak oxygen uptake (VO2peak) for 30 min) weekly. Blood pressure, fasting glucose, insulin sensitivity, and several metabolic or appetite regulating hormones were measured before and after intervention. RESULTS: Significant reductions in body weight (- ~2.5 kg, p < 0.001, η2 = 0.772) and BMI (- ~1 unit, p < 0.001, η2 = 0.782) were found in all groups. Systolic blood pressure was reduced by 5-6 mmHg (p < 0.001, η2 = 0.370); fasting insulin, leptin, and ghrelin levels were also significantly decreased (p < 0.05), while insulin sensitivity was improved. However, there were no significant changes in fasting glucose, glucagon, and gastric inhibitory peptide levels. Furthermore, no group differences were found among the three groups, suggesting that extra training (i.e., LC-HIIT and LC-MICT) failed to trigger additional effects on these cardiometabolic profiles. CONCLUSIONS: The short-term carbohydrate restriction diet caused significant weight loss and improved blood pressure and insulin sensitivity in the overweight/obese women, although the combination with exercise training had no additional benefits on the examined cardiometabolic profiles. Moreover, the long-term safety and effectiveness of LC needs further study.

Severe Hypoxia Does Not Offset the Benefits of Exercise on Cognitive Function in Sedentary Young Women.

Purpose: To examine the effect of acute moderate-intensity continuous exercise performed under normobaric severe hypoxia on cognition, compared to sea-level normoxia. Methods: Thirty healthy inactive women randomly performed two experimental trials separated by at least three days but at approximately the same time of day. Executive functions were measured during the follicular stage via an interference control task before (rest) and during exercise with 45% peak power output under normobaric normoxia (PIO2 = 150 mmHg, FIO2 = 0.21), and (2) hypoxia (PIO2 = 87 mmHg, FIO2 = 0.12, simulated at an altitude of 4000 m). Reaction time (RT), accuracy rate (AC), heart rate, ratings of perceived exertion, and peripheral oxygen saturation (SpO2) were collected before and during exercise. Results: RT (p < 0.05, η²p = 0.203) decreased during moderate exercise when compared at rest, while a short bout of severe hypoxia improved RT (p < 0.05, η²p = 0.134). Exercise and hypoxia had no effects on AC (p > 0.05). No significant associations were found between the changes of RT and SpO2 under the conditions of normoxia and hypoxia (p > 0.05). Conclusions: At the same phase of the menstrual cycle, a short bout of severe hypoxia simulated at 4000 m altitude caused no impairment at rest. RT during moderate exercise ameliorated in normoxia and severe hypoxia, suggesting that both exercise and short-term severe hypoxia have benefits on cognitive function in sedentary young women.