Session Of High-intensity Interval Exercise Research Articles

Effects of 12 Weeks of Moderate-intensity Continuous Exercise and High-intensity Interval Exercise on Cognitive Function in Elderly Subjects

OBJECTIVES This study analyzed the possibility of brain function activation after exercise training of high-intensity interval exercise and moderate-intensity continuous exercise in elderly people.METHODS The subjects of the study were elderly female people aged 65 years or older and were divided into three groups : control group, moderate-intensity continuous training (MICT), and high-intensity interval training (HIIT). Changes of body composition, physical fitness, cognitive function, and cognitive function-related blood variables were compared between before and after 12 weeks of exercise training.RESULTS Body weight, BMI (body mass index), and WHR (waist hip ratio) of body composition in HIIT group decreased significantly (p<0.05) after exercise training, and there was no significant difference in MICT group and the control group. HIIT group significantly (p<0.05) improved in grip strength, muscular endurance, flexibility, balance, cardiorespiratory endurance, and walking ability after exercise training, while MICT group showed significant (p<0.05) improvements only in flexibility, balance, and cardiorespiratory endurance. Regarding blood variables, HIIT group showed significant (p<0.05) differences in BDNF (brain-derived neurotrophic factor), irisin, and β-amyloid after exercise training, MICT group showed significant (p<0.05) differences only in β-amyloid. Cognitive function in HIIT group and MICT group significantly (p<0.05) improved in terms of temporal and spatial orientation, memory, and total scores after exercise training. During the recovery phase after one session of high-intensity interval exercise, blood lactic acid concentration increased significantly.CONCLUSIONS This study was confirmed the possibility of giving that high-intensity interval exercise for the elderly not only produces positive changes in body composition and improves physical fitness and cognitive function, but also frequently stimulates lactate production, helping to activate brain function through changes in BDNF and irisin in the blood.

Effect of acute high-intensity interval exercise on a mouse model of doxorubicin-induced cardiotoxicity: a pilot study

BackgroundIt is unknown whether high-intensity interval exercise (HIIE) may potentiate or attenuate the cardiotoxic effect of chemotherapy agents such as doxorubicin (DOX) when performed shortly after treatment. The study aimed to investigate the effect of acute HIIE on cardiac function and structure performed either 1, 2 or 3 days after DOX injection in an animal model.MethodsFemale C57bl/6 mice (n = 28), 70 days old, received a bolus 20 mg/kg intravenous tail vein DOX injection. Three exercise groups performed 1 HIIE session (16 sets of 1 min at 85–90% of peak running speed) at 1 (n = 7), 2 (n = 7), and 3 days (n = 8) following the DOX injection. A sedentary (SED) group of mice (n = 6) did not exercise. Animals underwent echocardiography under light anesthesia (isoflurane 0.5-1%) before and 7 days after the DOX injection. Animals were sacrificed on day 9 and hearts were collected for morphometric and histological analysis.ResultsAnimals exercising on day 3 had the smallest pre-post reduction in left ventricular fractional shortening (LVFS) (MΔ= -1.7 ± 3.3; p = 0.406) and the SED group had the largest reduction (MΔ=-6.8 ± 7.5; p = 0.009). After reclassification of animals according to their exercise compliance (performing > 8/16 of high-intensity bouts), LVFS in compliant mice was unchanged over time (LVFS MΔ= -1.3 ± 5.6; p = 0.396) while non-compliant animals had a LVFS reduction similar to sedentary animals. There were no significant differences in myocardial histology between groups.ConclusionsIn this pilot murine study, one single HIIE session did not exacerbate acute doxorubicin-induced cardiotoxicity. The timing of the HIIE session following DOX injection and the level of compliance to exercise could influence the negative impact of DOX on cardiac function.

Validation and Calibration for Embedding Rating of Perceived Exertion Into High-Intensity Interval Exercise in Adolescents: A Lab-Based Study

Purpose: Rating of perceived exertion (RPE) is a convenient and cost-effective tool that can be used to monitor high-intensity interval exercise (HIIE). However, no methodological study has demonstrated the validity of RPE in this context. Therefore, the aim of this study was to validate and calibrate RPE for monitoring HIIE in adolescents. Methods: RPE, heart rate (HR), and oxygen uptake () data were retrospectively extracted from 3 lab-based crossover studies, with a pooled sample size of 45 adolescents, performing either cycling-based or running-based HIIE sessions. Within-participant correlations were calculated for RPE-HR and RPE-, and receiver operator characteristic curve analysis was used to establish RPE cut points. Results: The results showed that RPE-HR demonstrated acceptable criterion validity (r = .53–.74, P < .01), while RPE- had poor validity (r = .40–.48, P < .01), except for HIIE at 100% peak power (r = .59, P < .01). RPE cut points of 4 and 5 were established in corresponding to based thresholds. Conclusion: RPE has some utility in evaluating intensity during lab-based running or cycling HIIE in adolescents. Future studies should expand the validation and calibration of RPE for prescribing and monitoring HIIE in children and adolescents in field-based contexts.

Glucose tolerance status associates with improvements in cognitive function following high-intensity exercise in adults with obesity

PurposeObesity, insulin resistance (IR), and proinflammatory cytokines associate with cognitive decline. Numerous studies document cognitive benefits of acute exercise bouts in lean individuals. However, how co-morbidities such as obesity and IR influence cognitive changes induced by acute exercise is unclear. We examined the effects of acute high-intensity aerobic exercise on cognitive function in age-matched and BMI-matched obese adults with normal glucose tolerance (NGT) or impaired glucose tolerance (IGT) and in lean, NGT adults. Methods49 adults (15 Lean, 18 Obese-NGT, 16 Obese-IGT) performed one session of high-intensity interval exercise (four cycles of 4-min at 75% Wmax with 3-min rest). Cognitive function testing and blood sampling were performed pre- and post-exercise. ResultsFollowing exercise, measurements of executive function and working memory were improved in Lean and Obese-NGT (p < 0.05), but not Obese-IGT. Changes in cognitive function following exercise negatively correlated with 2-hr glucose during an OGTT after controlling for body weight and body composition (rp = -0.40, p = 0.007). Serum levels of inflammatory cytokines IL-6 and CRP remained increased 60-minutes post-exercise in Obese-IGT, but not in Lean or Obese-NGT, which positively associated with 2-hr glucose during an OGTT (p < 0.01) and negatively with changes in cognitive function following exercise (p < 0.01). Greater insulin levels in Obese-IGT post-exercise also negatively correlated with changes in cognitive function following exercise (p < 0.01). ConclusionImprovements in cognition following acute high-intensity exercise positively associate with glucose tolerance, independent of body weight and body composition. Further, poorer changes in cognitive performance following exercise associate with persistent peripheral inflammation.

Sex differences in hemodynamic response to high-intensity interval exercise.

Sex differences in the cardiorespiratory and hemodynamic response to exercise exist due to differences in heart size, blood volume, and hemoglobin mass, eliciting higher maximal oxygen uptake (VO2max ) in men versus women. Data are equivocal whether sex differences in training responsiveness occur. This study investigated potential sex differences in the hemodynamic response (stroke volume (SV) and cardiac output (CO)) to high-intensity interval exercise (HIIE). Habitually active men (n = 15) and women (n = 13) underwent VO2max testing, followed by three HIIE sessions consisting of the 4 × 4, 10 × 1, and reduced exertion high-intensity training (REHIT), whose order was randomized. During exercise, oxygen uptake (VO2 ) and hemodynamic responses were determined. Results showed no sex difference in peak relative VO2 (p = 0.263), CO (p = 0.277), or SV (p = 0.116), although absolute values were higher in men (p < 0.05). Peak absolute (127.3 ± 20.6 vs. 115.2 ± 16.6 mL/beat, p = 0.004, d = 0.66) and relative SV (111.0 ± 15.5 vs. 100.7 ± 11.1% max, p = 0.005, d = 0.78) were higher with REHIT versus 4 × 4. No sex differences in mean relative VO2 , CO, or SV occurred (p > 0.05). Data showed lower mean VO2 during REHIT versus 4 × 4 (59.3 ± 6.8 vs. 65.8 ± 5.8 %VO2max , p < 0.001, d = 1.05) and 10 × 1 (59.3 ± 6.8 vs. 69.1 ± 7.4 %VO2max , p < 0.001, d = 1.4). Mean CO was lower in REHIT than 10 × 1 (79.8 ± 8.6 vs. 84.0 ± 7.4% max, p = 0.012, d = 0.53). Previously reported differences in VO2max response to HIIE may not be due to unique hemodynamic responses.

The Effect of High-Intensity Interval Exercise on Short-Term Glycaemic Control, Serum Level of Key Mediator in Hypoxia and Pro-Inflammatory Cytokines in Patients with Type 1 Diabetes-An Exploratory Case Study.

Type 1 diabetes (T1D) is associated with hyperglycaemia-induced hypoxia and inflammation. This study assessed the effects of a single bout of high-intensity interval exercise (HIIE) on glycaemia (BG) and serum level of pro-inflammatory cytokines, and an essential mediator of adaptive response to hypoxia in T1D patients. The macronutrient intake was also evaluated. Nine patients suffering from T1D for about 12 years and nine healthy individuals (CG) were enrolled and completed one session of HIIE at the intensity of 120% lactate threshold with a duration of 4 × 5 min intermittent with 5 min rests after each bout of exercise. Capillary and venous blood were withdrawn at rest, immediately after and at 24 h post-HIIE for analysis of BG, hypoxia-inducible factor alpha (HIF-1α), tumour necrosis factor alpha (TNF-α) and vascular-endothelial growth factor (VEGF). Pre-exercise BG was significantly higher in the T1D patients compared to the CG (p = 0.043). HIIE led to a significant decline in T1D patients' BG (p = 0.027) and a tendency for a lower BG at 24 h post-HIIE vs. pre-HIIE. HIF-1α was significantly elevated in the T1D patients compared to CG and there was a trend for HIF-1α to decline, and for VEGF and TNF-α to increase in response to HIIE in the T1D group. Both groups consumed more and less than the recommended amounts of protein and fat, respectively. In the T1D group, a tendency for a higher digestible carbohydrate intake and more frequent hyperglycaemic episodes on the day after HIIE were observed. HIIE was effective in reducing T1D patients' glycaemia and improving short-term glycaemic control. HIIE has the potential to improve adaptive response to hypoxia by elevating the serum level of VEGF. Patients' diet and level of physical activity should be screened on a regular basis, and they should be educated on the glycaemic effects of digestible carbohydrates.

The effect of sleep restriction, with or without high-intensity interval exercise, on behavioural alertness and mood state in young healthy males.

Mood state and alertness are negatively affected by sleep loss, and can be positively influenced by exercise. However, the potential mitigating effects of exercise on sleep-loss-induced changes in mood state and alertness have not been studied comprehensively. Twenty-four healthy young males were matched into one of three, 5-night sleep interventions: normal sleep (NS; total sleep time (TST) per night = 449 ± 22 min), sleep restriction (SR; TST = 230 ± 5 min), or sleep restriction and exercise (SR + EX; TST = 235 ± 5 min, plus three sessions of high-intensity interval exercise (HIIE)). Mood state was assessed using the profile of mood states (POMS) and a daily well-being questionnaire. Alertness was assessed using psychomotor vigilance testing (PVT). Following the intervention, POMS total mood disturbance scores significantly increased for both the SR and SR + EX groups, and were greater than the NS group (SR vs NS; 31.0 ± 10.7 A.U., [4.4-57.7 A.U.], p = 0.020; SR + EX vs NS; 38.6 ± 14.9 A.U., [11.1-66.1 A.U.], p = 0.004). The PVT reaction times increased in the SR (p = 0.049) and SR + EX groups (p = 0.033) and the daily well-being questionnaire revealed increased levels of fatigue in both groups (SR; p = 0.041, SR + EX; p = 0.026) during the intervention. Despite previously demonstrated physiological benefits of performing three sessions of HIIE during five nights of sleep restriction, the detriments to mood, wellness, and alertness were not mitigated by exercise in this study. Whether alternatively timed exercise sessions or other exercise protocols could promote more positive outcomes on these factors during sleep restriction requires further research.

Impact of high intensity interval exercise with and without heat stress on cardiovascular and aerobic performance: a pilot study

BackgroundHeat stress during aerobic exercise training may offer an additional stimulus to improve cardiovascular function and performance in a cool-temperate environment. However, there is a paucity of information on the additive effects of high-intensity interval exercise (HIIE) and acute heat stress. We aimed to determine the effects of HIIE in combination with acute heat stress on cardiovascular function and exercise performance.MethodsTwelve active (peak O2 consumption [VO2peak]: 47 ± 8 ml·O2/min/kg) young adults were counterbalanced to six sessions of HIIE in hot (HIIE-H, 30 ± 1 °C, 50 ± 5% relative humidity [RH]) or temperate conditions (HIIE-T, 20 ± 2 °C, 15 ± 10% RH). Resting heart rate (HR), HR variability (HRV), central (cBP) and peripheral blood pressure (pBP), peripheral mean arterial pressure (pMAP), pulse wave velocity (PWV), VO2peak, and 5-km treadmill time-trial were measured pre- and post-training.ResultsResting HR and HRV were not significantly different between groups. However, expressed as percent change from baseline, cSBP (HIIE-T: + 0.9 ± 3.6 and HIIE-H: -6.6 ± 3.0%, p = 0.03) and pSBP (HIIE-T: -2.0 ± 4.6 and HIIE-H: -8.4 ± 4.7%, p = 0.04) were lower in the heat group. Post-training PWV was also significantly lower in the heat group (HIIE-T: + 0.4% and HIIE-H: -6.3%, p = 0.03). Time-trial performance improved with training when data from both groups were pooled, and estimated VO2peak was not significantly different between groups (HIIE-T: 0.7% and HIIE-H: 6.0%, p = 0.10, Cohen’s d = 1.4).ConclusionsThe addition of acute heat stress to HIIE elicited additive adaptations in only cardiovascular function compared to HIIE alone in active young adults in temperate conditions, thus providing evidence for its effectiveness as a strategy to amplify exercise-induced cardiovascular adaptations.

Effect of acute exercise on cognitive flexibility: Role of baseline cognitive performance

A wealth of evidence has shown that acute aerobic exercise can enhance executive function. However, empirical evidence lacks consensus regarding whether acute aerobic exercise has a beneficial effect on cognitive flexibility when individual baseline cognitive differences are considered. Therefore, the aim of our study was to examine the effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on cognitive flexibility in young adults with differences in baseline cognitive performance. One hundred and ten college students (mean age = 20.17 ± 1.15 years) were divided into lower-performers (n = 55) and higher-performers (n = 55) groups based on their cognitive performance on the pre-test of the first cognitive flexibility test. Both groups were asked to complete a more-odd shifting task, which assesses cognitive flexibility, before and approximately 5 min after a 20 min HIIE session, a 20 min MICE session, and a reading control session. The results showed that individuals with lower baseline cognitive performance gained greater cognitive flexibility benefits from the 20 min HIIE and the 20 min MICE, whereas those with higher baseline cognitive performance had improved cognitive flexibility only from the 20 min HIIE. These findings indicate that baseline cognitive performance is a variable that influences the beneficial effects of acute exercise on cognitive flexibility. We recommend that young adults should consider their individual cognitive capacity when adopting effective and appropriate exercise modalities to improve cognitive performance.

High-intensity interval vs. continuous moderate-intensity aerobic exercise for improving neurotransmitter level and neurocognitive performance in individuals with Parkinson's disease

In individuals with Parkinson's disease (PD), cognitive impairments can cause their quality of life to deteriorate and aggravate their motor symptoms. No studies have yet explored the neurophysiological and neurobiochemical mechanisms of changes in cognitive processing underlying neuropsychological problems exhibited by this group. The current study aimed to investigate and compare the acute effects of high-intensity interval exercise (HIIE) and continuous moderate-intensity exercise (CMIE) on the neurocognitive performance and neurotransmitter levels of individuals with PD. In addition, the relationship between changes in neurocognitive performance and those in the peripheral dopamine level induced by HIIE and CMIE interventions were also examined. Using a within-subjects design, twenty-three participants with mild to moderate PD completed a single session of both HIIE and CMIE, as well as a session in a control condition (REST) in counterbalanced order. The neurocognitive indices of working memory [i.e., accuracy rate (AR), reaction time (RT), and latencies and amplitudes of N2 and P3 event-related potentials (ERPs)] were assessed. Blood samples were taken before and after the three intervention modes. During the working memory task, acute HIIE and acute CMIE brought about faster RTs and P3 ERP waves with higher amplitudes in individuals with PD. Furthermore, better ARs and a shorter N2 latency were associated with engaging in HIIE and CMIE, respectively. On the other hand, only the acute CMIE intervention was associated with significant increases in the plasma dopamine level. Finally, no significant correlation was obtained between changes in neurocognitive performance and those in the dopamine level which were assessed both before and after taking part in the interventions. For individuals with mild to moderate PD, acute HIIE and CMIE proved to be tolerable, safe, and effective modes of aerobic exercise. These types of exercise are well-suited to be practiced at home and in a community setting in order to decrease the risk of cognitive impairment in general and more specifically the risk of developing dementia as a comorbidity of PD. However, the acute benefits underlying the two dynamic forms of exercise appear to be intensity-dependent in PD.

Is There a Dose-Response Relationship between High-Intensity Interval Exercise (HIIE) Intensity and Affective Valence? Analysis of Three HIIE Sessions Performed with Different Amplitudes.

The inverse relationship between exercise intensity and affective valence is well established for continuous exercise but not for high-intensity interval exercise (HIIE). The objective was to verify the dose-response relationship between exercise intensity and affective valence in HIIE sessions. Eleven young men underwent a vigorous-intensity continuous exercise (VICE) and three HIIE sessions at the same average intensity (70% of peak power-WPeak) and duration (20 min) but with different amplitudes: 10 × [1 min at 90% WPeak/1 min at 50% WPeak]-HIIE-90/50; 10 × [1 min at 100% WPeak/1 min at 40% WPeak]-HIIE-100/40; 10 × [1 min at 110% WPeak/1 min at 30% WPeak]-HIIE-110/30. During the exercise sessions, psychophysiological variables were recorded (VO2, VCO2, heart rate, perceived exertion CR10, and Feeling Scale (FS)). Higher correlations were found between CR10 and FS for all conditions (VICE = -0.987; HIIE-90/50 = -0.873; HIIE-100/40 = -0.908; HIIE-110/30 = -0.948). Regarding the physiological variables, the %HRMax presented moderate inverse correlations with FS for all exercise conditions (VICE = -0.867; HIIE-90/50 = -0.818; HIIE-100/40 = -0.837; HIIE-110/30 = -0.828) while the respiratory variables (%VO2Peak and %VCO2Peak) presented low-to-moderate correlations only for VICE, HIIE-90/50, and HIIE-100/40 (ranging from -0.523 to -0.805). Poor correlations were observed between the %VO2Peak (r = -0.293) and %VCO2Peak (r = -0.020) with FS. The results indicated that perceived exertion is more sensible than physiological variables to explain the intensity-affective valence relationship in HIIE sessions. RPE should be used for HIIE prescription with a focus on affect.

Acute effect of high-intensity interval aerobic exercise on serum myokine levels and resulting tumour-suppressive effect in trained patients with advanced prostate cancer.

Although skeletal muscle releases cytokines called myokines during exercise, the kinetics of the acute myokine response to exercise (exercise-induced circulatory myokine level alteration) is unknown in patients with advanced prostate cancer. We measured myokine levels in serum obtained from patients with metastatic castrate-resistant prostate cancer (mCRPC) before and after exercise and assessed the growth-suppressive effect of the serum by applying it to a PCa cell line. Nine patients with mCRPC (age = 67.8 ± 10.1 years, time since mCRPC diagnosis 36.2 ± 22.5 months) undertook 34 min of a high-intensity interval exercise session on a cycle ergometer. Blood was collected immediately pre, post and 30 min post. Serum levels of secreted protein acidic and rich in cysteine (SPARC), oncostatin M (OSM), interleukin-6 (IL-6), interleukin-15 (IL-15), decorin, irisin, and IGF-1 were determined. Growth of the androgen-independent PCa cell line DU-145 exposed to serum collected at three points was measured. There was a significant elevation of SPARC (19.9%, P = 0.048), OSM (11.5%, P = 0.001), IL-6 (10.2%, P = 0.02) and IL-15 (7.8%, P = 0.023) in serum collected immediately after exercise compared to baseline, returning to baseline after 30 min rest. A significant reduction in DU-145 Cell growth and the Cell Index area under the curve at 72 h incubation was observed with the presence of serum obtained immediately post-exercise (Cell Index at 72 h: 16.9%, P < 0.001; area under the curve: 15.2%, P < 0.001) and with the presence of serum obtained 30 min post-exercise compared to baseline (Cell Index at 72 h: 6.5%; area under the curve: 8.8%, P < 0.001). This study provides preliminary evidence for an acute exercise-induced myokine response and tumour growth suppression in serum after a bout of high-intensity interval exercise in patients with advanced PCa.

Acute and protocol-dependent effects of aerobic exercise on neurobiochemical indices and neuropsychological performance of working memory

This study aimed to clarify the effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) protocols on peripheral neurotransmitters and on the neuropsychological performance of working memory and to explore underlying correlations. In a randomised cross-over trial, twenty-two adults in late middle age or older completed a single session of HIIE, MICE, or a control condition (rest) in counterbalanced order with a 7-day washout. Neuropsychological indices of working memory and neurotransmitter (norepinephrine, dopamine, and serotonin) levels were measured at baseline and after an intense bout of either HIIE or MICE, or an intervention without exercise. Analyses of the results revealed no significant effect of HIIE on the neurotransmitters, but significantly high levels of norepinephrine and serotonin were induced by MICE. In terms of neuropsychological performance, a single session of HIIE and MICE shortened the participants' reaction times (RTs), whereas only MICE caused a significant increase in accuracy rates (ARs). Significant correlations were found between the changes in norepinephrine levels and ARs/RTs before and after the HIIE and MICE interventions, respectively. The results of this study suggest that an intense MICE protocol triggers higher norepinephrine and serotonin levels than HIIE does. The possible neurobiochemical factor (i.e., norepinephrine) underlying the HIIE/MICE-induced neuropsychological benefits (i.e., improved ARs and RTs) for working memory encoding and maintenance appears to be protocol-dependent. Systematic and prolonged investigations are required to further understand the effects/mechanisms specific to each exercise protocol in order to optimize the benefits of aerobic exercise interventions for long-term neurobiochemical and neuropsychological health.

Effect of Single Bout of Moderate and High Intensity Interval Exercise on Brain Derived Neurotrophic Factor and Working Memory in Young Adult Females.

The objectives of the study were to determine the effect of moderate-intensity exercise (MIE) and high-intensity interval exercise (HIIE) on serum brain-derived neurotrophic factor (BDNF) levels and working memory (WM) in young adult females. This study was conducted in the Physiology Department, Khyber Girls Medical College Peshawar. Young adult females (n = 22), with a mean age of 20±2 years were recruited for two experimental sessions of MIE and HIIE, respectively. Baseline and post exercise blood samples were taken for determination of serum BDNF level and backward digit span test (BDST) for assessment of working memory in both sessions. Serum BDNF levels pre and post MIE were 707±448 pg/ml and 829±476 pg/ml (p = 0.006) respectively while pre and post HIIE were 785±329 pg /ml and 1116±379 pg/ml (p < 0.001) respectively. BDST scores were significantly high at post intervention for both MIE (p = 0.05) and HIIE (p 0.001). Altogether our findings showed that both MIE and HIIE significantly increased serum BDNF levels and working memory in young adult females.

Memory Modulation by Exercise in Young Adults Is Related to Lactate and Not Affected by Sex or BDNF Polymorphism.

Simple SummaryThe health and cognitive benefits associated with physical exercise are widely acknowledged. However, exercise characteristics responsible for the improvement in cognition, along with the underlying mechanisms, remain to be elucidated. In an attempt to resolve these questions, our study compares cognitive outcomes after two distinct exercise modes in young adults. Specifically, we have examined the differences between high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MIE) on visuospatial and declarative memory, contemplating the influence of exercise-associated parameters such as released lactate and non-modifiable factors, including BDNF polymorphism and biological sex. Our results demonstrate the relevance of exercise intensity and intensity-dependent lactate release in modulating cognitive improvement following exercise with no association with the non-modifiable factors mentioned above. These data suggest that the exercise characteristics and intensity of exercise sessions should be carefully considered to optimize cognitive response in young adults. Conversely, the consideration of genotype and biological sex is inappreciable.Currently, high-intensity interval exercise (HIIE) is on the rise compared to moderate-intensity exercise (MIE) due to its similar benefits for health and performance with low time requirements. Recent studies show how physical exercise can also influence cognitive function, although the optimal dose and underlying mechanisms remain unknown. Therefore, in our study, we have compared the effects on visuospatial and declarative memory of different exercise intensities (HIIE vs. MIE), including possible implicated factors such as lactate released after each session and the Brain-Derived Neurotrophic Factor (BDNF) genotype. Thirty-six undergraduate students participated in this study. The HIIE session consisted of a 3 min warm-up, four 2 min sets at 90–95% of the maximal aerobic speed (MAS) with 2 min of passive recovery between sets, and a 3 min cooldown, and the MIE session implies the same total duration of continuous exercise at 60% of the MAS. Better improvements were found after HIIE than MIE on the backward condition of the visuospatial memory test (p = 0.014, ηp2 = 0.17) and the 48 h retention of the declarative memory test (p = 0.04; d = 0.34). No differences were observed in the forward condition of the visuospatial memory test and the 7-day retention of the declarative memory test (p > 0.05). Moreover, non-modifiable parameters such as biological sex and BDNF polymorphism (Val/Val, Val/Met, or Met/Met) did not modulate the cognitive response to exercise. Curiously, the correlational analysis showed associations (p < 0.05) between changes in memory (visuospatial and declarative) and lactate release. In this sense, our results suggest an important role for intensity in improving cognitive function with exercise, regardless of genetic factors such as biological sex or BDNF Val66Met polymorphism.

Enjoyment And Tolerance Of Exercise Intensity In Objectively Versus Subjectively Regulated Interval Exercise In Older Adults

High-intensity interval exercise (HIIE) has led to significant improvements in fitness in healthy and clinical populations, including older adults. Recent evidence suggests that treadmill based HIIE using subjectively regulated HIIE may be more practically applicable to the real world and generates a similar training load for older adults to heart rate regulated HIIE. According to the guidelines of the American College of Sports Medicine, information regarding exercise enjoyment and individual preference for and tolerance of exercise intensity should be considered when developing and modifying exercise prescriptions for successful exercise adherence. PURPOSE: To examine the associations of preference for and tolerance of exercise intensity with physiological performance and perceptual outcomes during single sessions of HIIE using either subjectively (SUB) or objectively (OBJ) prescribed exercise in a treadmill in apparently healthy older adults. METHODS: Fourteen participants (71 ± 9 yrs) completed the Physical Activity Enjoyment Scale to measure exercise enjoyment and Preference for and Tolerance of the Intensity of Exercise Questionnaire to measure Preference (PREF) and Tolerance (TOL). Participants underwent an incremental exercise test on a treadmill in order to prescribe the OBJ session. This was followed by two randomly assigned HIIE sessions wherein the intensity of the exercise was prescribed and regulated by either heart rate (OBJ) or ratings of perceived exertion (RPE; SUB). The HIIE bouts consisted of 10 cycles of 1-min intervals at 80-90% and 30-40% HRpeak and at 8-9 and 3-4 RPE values for the OBJ and SUB sessions, respectively. Oxygen consumption (VO2), speed, and incline were measured during the OBJ and SUB sessions. RESULTS: Enjoyment was positively associated with speed during the OBJ (r = .60, p = .02) and SUB (r = .84, p < .01) sessions, incline during the OBJ (r = .60, p.03) session, and VO2 during the SUB (r = .73, p < .01) session. PREF was not significantly associated with any of the outcomes. TOL was negatively associated with incline during the SUB session (r = -.51, p = .05). CONCLUSIONS: Enjoyment and TOL scores, through associations with speed and VO2 in subjectively-regulated HIIT sessions, may be important for personalizing and modifying exercise prescriptions in older adults.

Interleukin-6, undercarboxylated osteocalcin, and brain-derived neurotrophic factor responses to single and repeated sessions of high-intensity interval exercise

ObjectivesThe purpose of this study was to compare the effects of a single session of high-intensity interval exercise (HIIE) with 2 consecutive HIIEs, separated by 3 h of recovery, on plasma interleukin-6 (IL-6), undercarboxylated osteocalcin (ucOC), and brain-derived neurotrophic factor (BDNF) responses. MethodsTwenty male recreational endurance athletes completed two HIIE trials in a randomized crossover design: a single session of HIIE on the single exercise day (HIIE-S) and two sessions of HIIE 3 h apart on the double exercise day (HIIE-D). The HIIE protocol consisted of 10 × 1 min cycling at 100 % of peak oxygen uptake, with 75 s of low-intensity cycling at 60 W. Blood samples were collected to analyze IL-6, ucOC, and BDNF levels before and immediately after HIIE on the HIIE-S and before and immediately after the second HIIE on the HIIE-D. ResultsBoth HIIE interventions significantly increased (p < 0.001) plasma IL-6 (HIIE-S 33.90 % vs HIIE-D 31.04 %; p = 0.64), ucOC (HIIE-S 37.18 % vs HIIE-D 39.54 %; p = 0.85), and BDNF levels (HIIE-S 236.01 % vs HIIE-D 216.68 %; p = 0.69), with no group effect. ConclusionsOur results demonstrate that performing two consecutive HIIEs on the same day with a 3-h rest results in similar changes in plasma levels of IL-6, BDNF, and ucOC compared with a single session of HIIE.

The Effect of Sleep Restriction, With or Without Exercise, on Skeletal Muscle Transcriptomic Profiles in Healthy Young Males.

BackgroundInadequate sleep is associated with many detrimental health effects, including increased risk of developing insulin resistance and type 2 diabetes. These effects have been associated with changes to the skeletal muscle transcriptome, although this has not been characterised in response to a period of sleep restriction. Exercise induces a beneficial transcriptional response within skeletal muscle that may counteract some of the negative effects associated with sleep restriction. We hypothesised that sleep restriction would down-regulate transcriptional pathways associated with glucose metabolism, but that performing exercise would mitigate these effects.Methods20 healthy young males were allocated to one of three experimental groups: a Normal Sleep (NS) group (8 h time in bed per night (TIB), for five nights (11 pm – 7 am)), a Sleep Restriction (SR) group (4 h TIB, for five nights (3 am – 7 am)), and a Sleep Restriction and Exercise group (SR+EX) (4 h TIB, for five nights (3 am – 7 am) and three high-intensity interval exercise (HIIE) sessions (performed at 10 am)). RNA sequencing was performed on muscle samples collected pre- and post-intervention. Our data was then compared to skeletal muscle transcriptomic data previously reported following sleep deprivation (24 h without sleep).ResultsGene set enrichment analysis (GSEA) indicated there was an increased enrichment of inflammatory and immune response related pathways in the SR group post-intervention. However, in the SR+EX group the direction of enrichment in these same pathways occurred in the opposite directions. Despite this, there were no significant changes at the individual gene level from pre- to post-intervention. A set of genes previously shown to be decreased with sleep deprivation was also decreased in the SR group, but increased in the SR+EX group.ConclusionThe alterations to inflammatory and immune related pathways in skeletal muscle, following five nights of sleep restriction, provide insight regarding the transcriptional changes that underpin the detrimental effects associated with sleep loss. Performing three sessions of HIIE during sleep restriction attenuated some of these transcriptional changes. Overall, the transcriptional alterations observed with a moderate period of sleep restriction were less evident than previously reported changes following a period of sleep deprivation.

The effect of acute high-intensity interval exercise on post-exercise blood pressure in post coronary artery bypass graft surgery patients: a pilot study

Coronary artery disease is the main cause of death worldwide. Coronary artery bypass graft (CABG) is a preferred treatment option for multi-vessel disease and left main disease patients. Physical training (recovery) enhances exercise tolerance, an activity of daily living, and quality of life in this patient. For this, the aim of the current study was to investigate the effect of acute high-intensity interval exercise on post-exercise blood pressure in CABG patients. In this study, all patients underwent open-heart surgery at least 1 month before involvement in the study. All Subjects were included after Medical rigorous screening. Participants carried out two experimental sessions of high-intensity interval exercise (HIIE) and mild continuous exercise (MCE) with a minimum of 72 h intervals: This study employed a randomized, cross-over design, Brachial systolic blood pressure (SBP) and diastolic blood pressure (DBP) and heart rate (HR) were measured Immediately before (pre) and after (post) and approximately15 min(post-15) and 30 min (post-30) after each exercise bout. The Split-Plot Analysis of Variance with repeated measures (group × time) was used to analyze the data. Significant post-exercise increases in SBP, and HR were seen following each protocol (p&amp;lt;0.05). Following two bouts, SBP decreased at 15- and 30-min post-exercise in two groups but this decline was more in the HIIE group than MCE. Based on the findings of this study, both high-intensity intermittent and continuous exercise can improve heart function in CABG patients by diminishing BP.

Comparison of systemic and peripheral responses during high-intensity interval exercise under voluntary hypoventilation vs. hypoxic conditions.

[Purpose] This study aimed to determine the systemic and peripheral responses to high-intensity interval exercise (HIIE) with voluntary hypoventilation at low lung volume (VHL) or HIIE under hypoxic conditions.[Methods] Ten male participants completed a single session of HIIE (three sets of 6 × 8-s high-intensity pedaling at 170% of maximal oxygen uptake [VO2max]) under three different conditions: normoxia with normal breathing (NOR: 23 °C, 20.9% of fraction of inspired oxygen [FiO2]), hypoxia with normal breathing (HYP: 23 °C, 14.5% FiO2), and normoxia with VHL (VHL: 23 °C, 20.9% FiO2). A randomized crossover design was used. Power output, arterial oxygen saturation (SpO2), heart rate, and muscle oxygenation were monitored during the exercise and the 16-s recovery. Muscle blood flow (mBF) of the vastus lateralis was also evaluated.[Results] SpO2 during the exercise and the 16-s recovery in the VHL group was significantly lower than in that of the NOR group. However, this parameter in the VHL group was significantly higher than that of the HYP group (NOR: 94.9 ± 0.4%, HYP: 82.8 ± 1.2%, VHL: 90.4 ± 0.5%; p < 0.001). Muscle oxygen saturation was significantly lower in the HYP group than those in the VHL and NOR groups (NOR: 79.6 ± 17.4%, HYP: 65.5 ± 7.7%, VHL: 74.4 ± 7.8%; p = 0.024). No significant difference in this parameter was observed between the VHL and NOR groups (p > 0.05). Additionally, the exercise-induced increase in mBF did not differ significantly among three groups (p > 0.05).[Conclusion] HIIE-induced SpO2 decrease was smaller under hypoxic conditions than during VHL. Moreover, mBF was not enhanced by the addition of VHL during HIIE.