Bout Of Moderate-intensity Exercise Research Articles

The effect of an acute bout of exercise on circulating vitamin D metabolite concentrations: a randomised crossover study in healthy adults.

The effect of acute exercise on circulating concentrations of vitamin D metabolites is unclear. To address this knowledge gap, we examined the effect of a bout of treadmill-based exercise versus rest on circulating concentrations of 25(OH)D3, 25(OH)D2, 3-epi-25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D3, and vitamin D2 and D3 in healthy men and women. Thirty-three healthy adults (14 females, 41 (15) years, body mass index 26.2 (3.7) kg/m2, 36.2 (9.2) ml/kg/min; mean (SD)) completed two laboratory visits involving 60min of moderate-intensity treadmill exercise (60% ) versus 60min of seated rest, both in an overnight fasted-state, as part of a randomised crossover design. Venous blood samples were drawn at baseline, immediately (0h), 1h and 24h after the exercise or rest-period. There was a significant time × trial interaction effect for total circulating 25(OH)D (P=0.0148), 25(OH)D3 (P=0.0127) and 1,25(OH)2D3 (P=0.0226). Immediately post-exercise, 25(OH)D, 25(OH)D3 and 1,25(OH)2D3 concentrations were significantly elevated compared to the control resting condition, and 1,25(OH) 2D3 remained significantly elevated 1 h later. Circulating albumin, vitamin D binding protein, calcium and parathyroid hormone were elevated immediately post-exercise. Thus, an acute bout of moderate intensity exercise transiently increases concentrations of circulating 25(OH)D and 1,25(OH)2D3 compared to resting conditions. KEY POINTS: Observational studies suggest that acute exercise might change circulating concentrations of vitamin D metabolites, but this has not been investigated using randomised crossover studies and using robust analytical procedures. In this study, we used a randomised crossover design to examine the effect of a bout of treadmill-based exercise (vs. rest) on circulating concentrations of a wide range of vitamin D metabolites in healthy humans. We show that an acute bout of moderate intensity exercise transiently increases concentrations of circulating 25(OH)D and 1,25(OH)2D3 compared to resting conditions. These findings indicate that regular exercise could lead to transient but regular windows of enhanced vitamin D biological action.

Menstrual cycle status does not impact exercise-based changes in cerebral blood flow or executive function benefits

ABSTRACT A single bout of exercise enhances executive function (EF) and may relate to an increase in cerebral blood flow (CBF). A limitation in the current literature is that biologically female participants are underrepresented given some evidence that changes in hormone levels across the menstrual cycle impact physiological and psychological variables. Here, biologically female participants completed separate single bouts of moderate intensity exercise (80% of estimated lactate threshold) during the follicular (FOL) and luteal (LUT) phases of their menstrual cycle. In addition, biologically male participants completed a same duration/intensity exercise session. Middle cerebral artery velocity (MCAv) was used to estimate CBF and pre- and postexercise EF was assessed via the antisaccade task. Results showed that resting MCAv was larger in the LUT than FOL phase; however, the exercise-mediated increase in MCAv was equivalent between menstrual cycle phases, and between female and male participants. Antisaccade reaction times reliably decreased from pre- to postexercise and frequentist and non-frequentist statistics demonstrated that the magnitude of the decrease was equivalent across FOL and LUT phases, and between female and male participants. Thus, results evince that menstrual cycle status should not serve as a basis limiting biologically female participants’ inclusion in research examining exercise and EF.

Can just 15 minutes of moderate-intensity exercise mobilize cytotoxic NK cells into circulation?

Intro: Acute exercise transiently mobilizes natural killer (NK) cells into the bloodstream with the degree of mobilization directly related to the intensity of the exercise. This increase in NK cells is thought to offer a period of heightened immune activity during exercise and is of particular interest to cancer patients as NK cells can kill tumor cells without prior sensitization. Previous work demonstrating the benefits of exercise on NK cells used vigorous bouts of exercise lasting 30 minutes or longer, which may not be attainable for cancer patients. The objective of this study was to determine whether a short bout of moderate-intensity exercise can mobilize activated, cytotoxic NK cells into circulation. We hypothesized that i) a bout of moderate-intensity exercise would significantly increase NK cells in the blood and ii) the exercise-induced NK-cell mobilization would occur rapidly, such that the relative increase in blood NK cells would not differ after 15 minutes of exercise and 30 minutes of exercise. Methods: In this pilot study, ten healthy, non-athletes (4 female; aged 18-40 years) cycled for 30 minutes at 55% of their heart rate reserve. Venous blood was obtained pre-, after 15 minutes, and after 30 minutes of exercise, and was analyzed by flow cytometry. The proportion of NK cells, CD16+ and CD57+ NK-cells were compared between the three time points by repeated measures ANOVA with Greenhouse Geisser corrections. Sidak-corrected post-hoc tests were used to further analyze significant main effects. Results: All subjects successfully completed the exercise (mean ± standard deviation heart rate: 144 ± 2 bpm; rating of perceived exertion: 11 ± 0.25 (of 20)). There was a significant main effect of time on the proportion of NK cells present in the blood (F(1.253, 10.025)= 7.719, p= 0.016). Post-hoc analyses indicate that there was a significant increase at minute 15 relative to baseline (p=.050), with no further increase at minute 30 relative to minute 15 (p=.175). There was no main effect of time on the proportion of CD57+NK cells (F(1.451, 10.159)= 0.335, p= 0.656) or CD16+ NK cells (F(1.154, 9.231)= 3.020, p= 0.113) in our sample. Conclusion: The results from this pilot study indicate that 15 minutes of moderate-intensity cycling mobilizes NK cells into the bloodstream. However, we did not detect significant differences in NK cells with an activated, highly cytotoxic phenotype. While limited by a small sample, these results build upon prior work demonstrating a significant effect of longer-lasting, vigorous-intensity exercise. The current results suggest that a more accessible exercise intervention for individuals with health limitations can also significantly increase NK cells into the blood, but that greater intensity exercise may be required to mobilize particular subsets of NK cells. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A study on the influence of a single bout of moderate-intensity exercise on processing bias towards emotional information of individuals with high psychosocial stress levels

To explore the impact of a single bout of moderate-intensity exercise on cognitive bias of individuals with high psychosocial stress levels. 42 college students with high stress levels were recruited and divided into a exercise group (N = 21) and a no-exercise group (N = 21). The psychological and behavioral characteristics were studied using word-face stroop task, memory bias task, and interpretion bias task. College students with high psychosocial stress levels have attention bias, memory bias, and Interpretion bias towards negative emotional information, and a single bout of moderate-intensity exercise can increase attention bias towards neutral and positive emotional information, and memory bias towards neutral emotional information, interpretation bias towdrds positive emotional information. A single bout of moderate-intensity exercise can increase the positive cognitive bias towards emotional information, which is beneficial for regulating psychosocial stress levels.

GH and IGF-1 in skin interstitial fluid and blood are associated with heat loss responses in exercising young adults.

Sweat glands and cutaneous vessels possess growth hormone (GH) and insulin-like growth factor 1 (IGF-1) receptors. Here, we assessed if exercise increases GH and IGF-1 in skin interstitial fluid, and whether baseline and exercise-induced increases in GH and IGF-1 concentrations in skin interstitial fluid/blood are associated with heat loss responses of sweating and cutaneous vasodilation. Sixteen young adults (7 women) performed a 50-min moderate-intensity exercise bout (50% VO2peak) during which skin dialysate and blood samples were collected. In a sub-study (n = 7, 4 women), we administered varying concentrations of GH (0.025-4000ng/mL) and IGF-1 (0.000256-100µg/mL) into skin interstitial fluid via intradermal microdialysis. Sweat rate (ventilated capsule) and cutaneous vascular conductance (CVC) were measured continuously for both studies. Exercise increased sweating and CVC (both P < 0.001), paralleled by increases of serum GH and skin dialysate GH and IGF-1 (all P ≤ 0.041) without changes in serum IGF-1. Sweating was positively correlated with baseline dialysate and serum GH levels, as well as exercise-induced increases in serum GH and IGF-1 (all P ≤ 0.044). Increases in CVC were not correlated with any GH and IGF-1 variables. Exogenous administration of GH and IGF-1 did not modulate resting sweat rate and CVC. (1) Exercise increases GH and IGF-1 levels in the skin interstitial fluid, (2) exercise-induced sweating is associated with baseline GH in skin interstitial fluid and blood, as well as exercise-induced increases in blood GH and IGF-1, and (3) cutaneous vasodilation during exercise is not associated with GH and IGF-1 in skin interstitial fluid and blood.

The effects of sleep deprivation, acute hypoxia, and exercise on cognitive performance: A multi-experiment combined stressors study

IntroductionBoth sleep deprivation and hypoxia have been shown to impair executive function. Conversely, moderate intensity exercise is known to improve executive function. In a multi-experiment study, we tested the hypotheses that moderate intensity exercise would ameliorate any decline in executive function after i) three consecutive nights of partial sleep deprivation (PSD) (Experiment 1) and ii) the isolated and combined effects of a single night of total sleep deprivation (TSD) and acute hypoxia (Experiment 2). MethodsUsing a rigorous randomised controlled crossover design, 12 healthy participants volunteered in each experiment (24 total, 5 females). In both experiments seven executive function tasks (2-choice reaction time, logical relations, manikin, mathematical processing, 1-back, 2-back, 3-back) were completed at rest and during 20 min semi-recumbent, moderate intensity cycling. Tasks were completed in the following conditions: before and after three consecutive nights of PSD and habitual sleep (Experiment 1) and in normoxia and acute hypoxia (FIO2 = 0.12) following one night of habitual sleep and one night of TSD (Experiment 2). ResultsAlthough the effects of three nights of PSD on executive functions were inconsistent, one night of TSD (regardless of hypoxic status) reduced executive functions. Significantly, regardless of sleep or hypoxic status, executive functions are improved during an acute bout of moderate intensity exercise. ConclusionThese novel data indicate that moderate intensity exercise improves executive function performance after both PSD and TSD, regardless of hypoxic status. The key determinants and/or mechanism(s) responsible for this improvement still need to be elucidated. Future work should seek to identify these mechanisms and translate these significant findings into occupational and skilled performance settings.

The Influence of Exercise-Associated Small Extracellular Vesicles on Trophoblasts In Vitro.

Exercise induces the release of small extracellular vesicles (sEVs) into circulation that are postulated to mediate tissue cross-talk during exercise. We previously reported that pregnant individuals released greater levels of sEVs into circulation after exercise compared to matched non-pregnant controls, but their biological functions remain unknown. In this study, sEVs isolated from the plasma of healthy pregnant and non-pregnant participants after a single bout of moderate-intensity exercise were evaluated for their impact on trophoblasts in vitro. Exercise-associated sEVs were found localized within the cytoplasm of BeWo choriocarcinoma cells, used to model trophoblasts in vitro. Exposure to exercise-associated sEVs did not significantly alter BeWo cell proliferation, gene expression of angiogenic growth factors VEGF and PLGF, or the release of the hormone human chorionic gonadotropin. The results from this pilot study support that exercise-associated sEVs could interact with trophoblasts in vitro, and warrant further investigation to reveal their potential role in communicating the effects of exercise to the maternal-fetal interface.

Dietary Fermentation Product of Aspergillus Oryzae Prevents Increases in Gastrointestinal Permeability (‘Leaky Gut’) in Horses Undergoing Combined Transport and Exercise

Equine leaky gut syndrome is characterized by gastrointestinal hyperpermeability and may be associated with adverse health effects in horses. The purpose was to evaluate the effects of a prebiotic Aspergillus oryzae product (SUPP) on stress-induced gastrointestinal hyperpermeability. Eight horses received a diet containing SUPP (0.02 g/kg BW) or an unsupplemented diet (CO) (n = 4 per group) for 28 days. On Days 0 and 28, horses were intubated with an indigestible marker of gastrointestinal permeability (iohexol). Half the horses from each feeding group underwent 60 min of transport by trailer immediately followed by a moderate-intensity exercise bout of 30 min (EX), and the remaining horses stayed in stalls as controls (SED). Blood was sampled before iohexol, immediately after trailering, and at 0, 1, 2, 4, and 8 h post-exercise. At the end of the feeding period, horses were washed out for 28 days before being assigned to the opposite feeding group, and the study was replicated. Blood was analyzed for iohexol (HPLC), lipopolysaccharide (ELISA), and serum amyloid A (latex agglutination assay). Data were analyzed using three-way and two-way ANOVA. On Day 0, the combined challenge of trailer transport and exercise significantly increased plasma iohexol in both feeding groups; this increase was not seen in SED horses. On Day 28, EX increased plasma iohexol only in the CO feeding group; this increase was completely prevented by the provision of SUPP. It is concluded that combined transport and exercise induce gastrointestinal hyperpermeability. Dietary SUPP prevents this and therefore may be a useful prophylactic for pathologies associated with gastrointestinal hyperpermeability in horses.

Short, frequent high-intensity physical activity breaks reduce appetite compared to a continuous moderate-intensity exercise bout.

A single exercise session can affect appetite-regulating hormones and suppress appetite. The effects of short, regular physical activity breaks across the day on appetite are unclear. This study investigated the effects of breaking up sitting with high-intensity physical activity vs a single bout of moderate-intensity exercise and prolonged sitting on appetite control. In this randomised crossover trial, 14 sedentary, inactive adults (7 women) completed 3, 8-h experimental conditions: (i) prolonged sitting (SIT); (ii) 30 min of moderate-intensity exercise followed by prolonged sitting (EX-SIT), and (iii) sitting with 2 min 32 s of high-intensity physical activity every hour (SIT-ACT). Physical activity energy expenditure was matched between EX-SIT and SIT-ACT. Subjective appetite was measured every 30 min with acylated ghrelin and total peptide-YY (PYY) measured hourly in response to two standardised test meals. An ad libitum buffet meal was provided at the end of each condition. Based on linear mixed model analysis, total area under the curve for satisfaction was 16% higher (P = 0.021) and overall appetite was 11% lower during SIT-ACT vs EX-SIT (P = 0.018), with no differences between SIT-ACT and SIT. Time series analysis indicated that SIT-ACT reduced subjective appetite during the majority of the post-lunch period compared with SIT and EX-SIT, with some of these effects reversed earlier in the afternoon (P < 0.05). Total PYY and acylated ghrelin did not differ between conditions. Relative energy intake was 760 kJ lower during SIT-ACT vs SIT (P = 0.024). High-intensity physical activity breaks may be effective in acutely suppressing appetite; yet, appetite-regulating hormones may not explain such responses.

Metabolic impact of feeding prior to a 60-min bout of moderate-intensity exercise in females in a fasted state.

The metabolic impact of pre-exercise feeding of protein or carbohydrate on fat oxidation and energy expenditure rates, especially, in females, is poorly understood. Recreationally active females (n = 15, 32 ± 10 years, 164.8 ± 5.6 cm, 63.5 ± 9.3 kg, 23.4 ± 3.2 kg/m2) completed four testing sessions in a randomized, double-blind, crossover fashion after fasting overnight. Participants ingested isovolumetric and isoenergetic solutions containing either 25 g of whey protein, casein protein, carbohydrate (CHO), or a non-caloric placebo (PLA). Participants then completed 60 min of treadmill exercise at 15% below ventilatory threshold 30 min after ingestion. Respiratory exchange ratio (RER) was evaluated throughout exercise and resting energy expenditure (REE) was assessed pre-exercise, and 0-, 60-, and 120-min post-exercise. A significant condition x time interaction was observed for RER (p = 0.008) during exercise, with CHO exhibiting higher RER values (vs. PLA) at four time points. A significant main effect for condition was observed for carbohydrate (p = 0.001) and fat (p = 0.02) oxidation rates during exercise, with fat oxidation rates being higher in PLA vs. CHO (p = 0.01). When total fat oxidized was calculated across the entire exercise bout, a significant main effect for condition was observed (p = 0.01), with PLA being greater than CHO (p = 0.04). A significant condition x time interaction (p = 0.02) was found for both absolute and normalized REE, with casein and whey protein having significantly higher values than CHO (p < 0.05) immediately post-exercise. When compared to a fasted control (PLA), consuming CHO, but not protein, decreased total fat oxidation prior to a 60-min bout of moderate-intensity exercise in females.

Acute effects of a single moderate-intensity exercise bout performed in fast or fed states on cell metabolism and signaling: Comparison between lean and obese rats

AimsAlthough the benefits of exercise can be potentiated by fasting in healthy subjects, few studies evaluated the effects of this intervention on the metabolism of obese subjects. This study investigated the immediate effects of a single moderate-intensity exercise bout performed in fast or fed states on the metabolism of gastrocnemius and soleus of lean and obese rats. Main methodsMale rats received a high-fat diet (HFD) for twelve weeks to induce obesity or were fed standard diet (SD). After this period, the animals were subdivided in groups: fed and rest (FER), fed and exercise (30 min treadmill, FEE), 8 h fasted and rest (FAR) and fasted and exercise (FAE). Muscle samples were used to investigate the oxidative capacity and gene expression of AMPK, PGC1α, SIRT1, HSF1 and HSP70. Key findingsIn relation to lean animals, obese animals' gastrocnemius glycogen decreased 60 %, triglycerides increased 31 %; glucose and alanine oxidation decreased 26 % and 38 %, respectively; in soleus, triglycerides reduced 46 % and glucose oxidation decreased 37 %. Exercise and fasting induced different effects in glycolytic and oxidative muscles of obese rats. In soleus, fasting exercise spared glycogen and increased palmitate oxidation, while in gastrocnemius, glucose oxidation increased. In obese animals' gastrocnemius, AMPK expression decreased 29 % and SIRT1 increased 28 % in relation to lean. The AMPK response was more sensitive to exercise and fasting in lean than obese rats. SignificanceExercise and fasting induced different effects on the metabolism of glycolytic and oxidative muscles of obese rats that can promote health benefits in these animals.

Acute, but not chronic, aerobic exercise alters the impact of ex vivo LDL and fatty acid stimulation on monocytes and macrophages from healthy, young adults.

Elevated low-density lipoprotein (LDL) and triglyceride concentrations are associated with future cardiovascular risk in young adults. Conversely, chronic physical activity is generally accepted to reduce CVD risk. Atherosclerosis is a major underlying cause of CVD, and atherogenesis is mediated by peripheral monocytes and monocyte-derived macrophages. The study aimed to determine if an individual's physical activity level impacts the phenotype of monocytes and monocyte-derived macrophages when stimulated with LDL and fatty acid ex vivo. Peripheral blood mononuclear cells (PBMCs) were obtained from healthy, young adults of differing physical activity levels before and after a single bout of moderate intensity exercise (25min at 60% of VO2peak). PBMCs were stimulated with LDL and palmitate ex vivo prior to differentiation into macrophages. Monocyte subset percentages and monocyte-derived macrophage expression of phenotypic (CD86, CD206) and functional (CCR2, ERK 1/2) markers were evaluated by flow cytometry. Compared to baseline, ex vivo LDL and palmitate stimulation decreased (p = 0.038) non-classical monocyte percentage from 24.7 ± 3.2 to 21.5 ± 2.6% in all participants. When ex vivo lipid stimulation was preceded by acute exercise, non-classical monocyte percentage was similar to baseline levels (p = 0.670, 25.8 ± 2.15%). Macrophage CD86/CD206 was increased from 1.30 ± 0.14 to 1.68 ± 0.19 when preceded by acute exercise in all participants. No differences were observed between participants of differing physical activity levels. Findings suggest that acute exercise modulates monocyte phenotype after LDL and palmitate stimulation in a protective manner, however, chronic physical activity does not alter monocyte/macrophage responses to any experimental condition in this population.

Dietary Nitrate Supplementation Enhances Performance and Speeds Muscle Deoxyhaemoglobin Kinetics during an End-Sprint after Prolonged Moderate-Intensity Exercise.

Short-term dietary nitrate (NO3-) supplementation has the potential to enhance performance during submaximal endurance, and short-duration, maximal-intensity exercise. However, it has yet to be determined whether NO3- supplementation before and during submaximal endurance exercise can improve performance during a short-duration, maximal-intensity end-sprint. In a randomised, double-blind, crossover study, 9 recreationally active men ingested NO3--rich (BR: 8 mmol NO3-/day) and NO3--depleted (PL: 0.75 mmol NO3-/day) beetroot powder for 7 days. On day 7, participants completed 2 h of moderate-intensity cycling, which immediately transitioned into a 60 s maximal-intensity end-sprint, with supplements ingested 2 h before and 1 h into the moderate-intensity exercise bout. Plasma [NO3-] and [NO2-] were higher in BR compared to PL pre- and post-exercise (p &lt; 0.05). Post-exercise plasma [NO3-] was higher than pre-exercise (562 ± 89 µM vs. 300 ± 73 µM; p &lt; 0.05) and plasma [NO2-] was not significantly different pre- (280 ± 58 nM) and post-exercise (228 ± 63 nM) in the BR condition (p &gt; 0.05). Mean power output during the final 30 s of the end-sprint was greater after BR (390 ± 38 W) compared to PL (365 ± 41 W; p &lt; 0.05). There were no differences between BR and PL in any muscle oxygenation variables during moderate-intensity cycling (p &gt; 0.05), but muscle [deoxyhaemoglobin] kinetics was faster during the end-sprint in BR (6.5 ± 1.4 s) compared to PL (7.3 ± 1.4 s; p &lt; 0.05). These findings suggest that NO3- supplementation has the potential to improve end-sprint performance in endurance events when ingested prior to and during exercise.

Neurotrophic and growth factor response to acute exercise across the lifespan

AbstractBackgroundThere is evidence that aerobic exercise is beneficial to the brain and may reduce risk for cognitive decline and dementia. However, clinical trials have shown the benefits of exercise programs vary amongst individuals. This variability may occur in part due to differences in the physiological biomarker response to acute exercise. Characteristics such as age, sex, and apolipoprotein E4 (APOE4) genotype may affect these responses, but differences in blood processing protocols may introduce additional variability into the measures.MethodWe characterized the blood biomarker response to acute exercise in 80 individuals, including older adults (n=62, mean age 73y) and 18 young controls (n=18, mean age 37). Participants engaged in an acute, 15 minute bout of moderate intensity exercise (45‐55% HRR) following a 5 minute warm‐up. Blood was collected immediately prior to exercise, immediately post exercise, and 40 minutes post exercise. After collection, each timepoint sample was immediately processed for plasma and platelet poor plasma and frozen; this was done to limit release of growth factors from activated platelets post‐blood draw. Time course responses of brain derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), insulin like growth factor 1 (IGF1) were measured using ELISA in platelet poor plasma. Lactate was measured in plasma (YSI 2500).ResultLinear mixed modeling performed with age, sex, and APOE4 genotype as covariates revealed a significant change in BDNF (p&lt;0.001) and lactate (p&lt;0.001) over time, with the highest levels of lactate observed immediately post‐exercise, while BDNF was elevated at 40 minutes post‐exercise in both young and older adults. There was no significant change with either VEGF or IGF1 over time in response to exercise, although older adults had significantly higher VEGF (p=0.01) and lower IGF1 (p&lt;0.001) compared to young controls across all timepoints.ConclusionWe report here that analysis of the acute exercise response reveals a significant increase in circulating BDNF and lactate, but not VEGF or IGF1, following aerobic exercise in both young controls and older adults. Further investigation into the mechanisms that contribute to these changes and the relevance to additional fluid and imaging brain health biomarkers in this cohort is ongoing.

Hippocampal blood flow rapidly and preferentially increases after a bout of moderate-intensity exercise in older adults with poor cerebrovascular health.

Over the course of aging, there is an early degradation of cerebrovascular health, which may be attenuated with aerobic exercise training. Yet, the acute cerebrovascular response to a single bout of exercise remains elusive, particularly within key brain regions most affected by age-related disease processes. We investigated the acute global and region-specific cerebral blood flow (CBF) response to 15minutes of moderate-intensity aerobic exercise in older adults (≥65years; n = 60) using arterial spin labeling magnetic resonance imaging. Within 0-6min post-exercise, CBF decreased across all regions, an effect that was attenuated in the hippocampus. The exercise-induced CBF drop was followed by a rebound effect over the 24-minute postexercise assessment period, an effect that was most robust in the hippocampus. Individuals with low baseline perfusion demonstrated the greatest hippocampal-specific CBF effect post-exercise, showing no immediate drop and a rapid increase in CBF that exceeded baseline levels within 6-12minutes postexercise. Gains in domain-specific cognitive performance postexercise were not associated with changes in regional CBF, suggesting dissociable effects of exercise on acute neural and vascular plasticity. Together, the present findings support a precision-medicine framework for the use of exercise to target brain health that carefully considers age-related changes in the cerebrovascular system.

Effect of fixed 7.5 minutes' moderate intensity exercise bouts on body composition and blood pressure among sedentary adults with prehypertension in Western-Kenya.

Prehypertension is a modifiable risk factor for cardiovascular disease observed to affect an estimated 25-59% of global population and closely associated with body composition. Without appropriate interventions, one-third of individuals with prehypertension would develop full-blown hypertension within 4 years. The existing exercise recommendations need substitutes that appeal more yet accord similar or better outcomes in desire to halt this progression. This study evaluated the effect of Fixed 7.5-minute Moderate Intensity Exercise (F-7.5m-MIE) bouts on Body Composition and Blood Pressure (BP) among sedentary adults with prehypertension in Western-Kenya in a Randomized Control Trial (RCT) performed throughout the day compared to the single-continuous 30-60-minute bouts performed 3 to 5 times weekly. This RCT, with three arms of Experimental Group1 (EG1) performing the F-7.5m-MIE bouts, Experimental Group 2 (EG2) performing current World Health Organization (WHO) recommendation of ≥30-min bouts, and, control group (CG), was conducted among 665 consenting pre-hypertensive sedentary adults enrolled from western Kenya. EG1 and EG2 performed similar weekly cumulative minutes of moderate intensity exercises. Adherence was determined using activity monitors and exercise logs. Data regarding demographic characteristics, heart rate, BP, and anthropometric measures were collected at baseline and 12th week follow-up. Data regarding univariate, bivariate and multivariate (repeated measurements between and within groups) analysis were conducted using STATA version 13 at 5% level of significance. The study revealed that males (92.1% in EG1, 92% in EG2 and 96.3% in CG) and females (94.6% in EG1, 89.3% in EG2 and 95% in CG) in the three arms completed the exercise at follow-up respectively. At 12th week follow-up from all exercise groups, males' and females' measurements for waist-hip-ratio, waist-height-ratio, systolic BP (SBP), heart rate and pulse pressure showed significant drops from baseline, while diastolic BP (DBP) and body mass index (BMI) reported mixed results for males and females from the various treatments. Both treatments demonstrated favourable outcomes. However, differences in the change between baseline and endpoint yielded mixed outcomes (SBP; p<0.05 for both males and females, DBP; p<0.05 for males and females, waist-height-ratio; p = 0.01 and <0.05 for males and females respectively, waist-hip-ratio; P = 0.01 and >0.05 for males and females respectively, BMI; p>0.05 for both males and females, heart rate; p<0.05 for males and females and pulse pressure; p = 0.01 and >0.05 for males and females respectively). The study design however could not test for superiority. The study demonstrated that the F-7.5m- MIE treatment programme and the WHO recommended 3-5 times weekly bouts of 30-60 minutes regime produced comparably similar favourable outcomes in adherence and BP reductions with improved body composition. Trial registration: Trial registered with Pan African Clinical Trial Registry (www.pactr.org): no. PACTR202107584701552. (S3 Text).

The Effect of Physical Exercise on Oxidation Capacity and Utero-Placental Circulation in Pregnancies with Gestational Diabetes Mellitus and Uncomplicated Pregnancies, a Pilot Study.

Background: Gestational diabetes mellitus (GDM) is associated with aggravated oxidation capacity and utero-placental circulation, while aerobic exercise could improve both. The study aims to assess oxidation capacity and utero-placental circulation before and after a bout of aerobic exercise in GDM and uncomplicated pregnancies.; Methods: In this cross-sectional study, women with GDM (GDMs) and women with uncomplicated pregnancies(controls), underwent 30 min of moderate intensity cycling. Total antioxidant capacity (TAC), catalase activity (CAT), reduced glutathione (GSH), Uterine Arteries (UtA PI) and Umbilical Artery (UmA PI) pulsatility indexes were estimated prior-to, immediately after and one hour after exercise; Results: In each group, 25 pregnant women were included. In both groups, between prior-to and immediately after exercise, TAC and CAT increased, while GSH decreased, (p < 0.001). In GDMs, CAT was lower than controls at any time point (p < 0.05), while in GDMs delta(Δ) CAT (prior-to and immediately after exercise) was lower than controls (p = 0.003). In GDMs, UtA PI centiles decreased between prior-to and either immediately or one hour after exercise, while they did not change in controls. In GDMs, pre-conceptional BMI and weight gain predicted negatively ΔTAC (prior-to to one hour after exercise); Conclusions: Moderate intensity exercise bout improves oxidation capacity in GDM and uncomplicated pregnancies, although at a lesser extent in the former. Exercise leads to decreased UtA arteries resistance in women with GDM.

Cognitive fatigue due to exercise under normobaric hypoxia is related to hypoxemia during exercise

We previously found that a 10-min bout of moderate-intensity exercise (50% maximal oxygen uptake) under normobaric and hypoxic conditions (fraction of inspired oxygen [{{text{F}}_text{IO}}_{_{2}}] = 0.135) reduced executive performance and neural activity in the left dorsolateral prefrontal cortex (DLPFC). To examine whether this cognitive fatigue is due to a decrease in SpO2 during exercise, we compared executive performance and related prefrontal activation between two experimental conditions, in which the participants inhaled normobaric hypoxic gas ({{text{F}}_text{IO}}_{_{2}}= 0.135) (hypoxic exercise [HE]) or hypoxic gas adjusted so that SpO2 during exercise remained at the resting level (milder hypoxic exercise [ME]). ME condition showed that reaction time in executive performance decreased (t[13] = 2.228, P < 0.05, d = 0.34, paired t-test) and left DLPFC activity increased (t[13] = -2.376, P < 0.05, d = 0.63, paired t-test) after exercise compared with HE condition. These results showed that the HE-induced reductions in the left DLPFC activity and executive performance were both suppressed in the ME condition, supporting the hypothesis that exercise-induced cognitive fatigue under hypoxic environment is due to hypoxemia during exercise. This may lead to the development of a method of coping with cognitive fatigue due to exercise that causes hypoxemia.

Statins effect on insulin resistance after a meal and exercise in hypercholesterolemic pre-diabetic individuals.

AimTo study if statins, a widely prescribed, inexpensive medication to prevent coronary artery diseases may cause insulin resistance (IR).MethodsFasted (HOMA‐IR) and post‐meal insulin resistance were assessed in 21 pre‐diabetic hypercholesterolemic individuals treated with statins (STA trial). Measurements were compared to another trial conducted 96 h after statin withdrawal using placebo pills (PLAC trial). Trials were duplicated 16–18 h after a bout of moderate‐intensity exercise (500 kcal of energy expenditure) to reduce IR and better appreciate statin effects (EXER+STA and EXER+PLAC trials).ResultsStatin withdrawal did not affect fasting (HOMA‐IR; 2.35 ± 1.05 vs. 2.18 ± 0.87 for STA vs. PLAC trials; p = 0.150) or post‐meal insulin resistance (i.e., Matsuda‐index, STA 6.23 ± 2.83 vs. PLAC 6.49 ± 3.74; p = 0.536). A bout of aerobic exercise lowered post‐meal IR (p = 0.043), but statin withdrawal did not add to the exercise actions (p = 0.564). Statin withdrawal increased post‐meal plasma free glycerol concentrations (0.136 ± 0.073 vs. 0.185 ± 0.090 mmol·L−1 for STA vs. PLAC trials; p < 0.001) but not plasma free fatty acids or fat oxidation (p = 0.981, and p = 0.621, respectively). Post‐meal fat oxidation was higher in the exercise trials (p = 0.002).ConclusionsWithdrawal of statin medication does not affect fasting or post‐meal insulin resistance in pre‐diabetic hypercholesterolemic individuals. Furthermore, statin use does not interfere with the beneficial effects of exercise on lowering IR.

Influence of exercise duration on respiratory function and systemic immunity among healthy, endurance-trained participants exercising in sub-zero conditions

BackgroundStrenuous endurance exercise in sub-zero temperatures can cause airway damage that may lead to EIB. Prolonged exercise can also elicit greater immune perturbations than short-duration exercise. However, the influence of exercise duration on lung function and systemic immunity in sub-zero temperatures has not been established. Additionally, it is currently unknown whether atopic disposition, which is risk factor for EIB, influences respiratory responses in a sub-zero climate. The aim of this study was to compare respiratory and systemic immune responses to two cold air running trials of short and long duration, as well as to examine whether the responses differed between atopic and non-atopic subjects.MethodsEighteen healthy, endurance-trained subjects (males/females: 14/4; age: 29.4 ± 5.9 years old; BMI: 23.1 ± 1.7; atopic/non-atopic: 10/8) completed two moderate-intensity climate chamber running trials at − 15 °C, lasting 30 and 90 min, in a randomized, cross-over design. Lung function (spirometry and impulse oscillometry), serum CC16, respiratory symptoms, and blood leukocyte counts were examined before and after the trials.ResultsLung function was not significantly affected by exercise or exercise duration. CC16 concentration increased after both trials (p = 0.027), but the response did not differ between trials. Respiratory symptom intensity was similar after each trial. There was a greater increase in neutrophils (p < 0.001), and a decrease in eosinophils (p < 0.001) after the 90-min bout. The 90-min protocol increased X5 compared to the 30-min protocol only in atopic subjects (p = 0.015) while atopy increased lower airway symptoms immediately after the 90-min session (p = 0.004).ConclusionsOur results suggest that a 90-min bout of moderate-intensity exercise at − 15 °C does not cause substantial lung function decrements, airway epithelial damage or respiratory symptoms compared to 30 min running in the same environment, despite a heightened redistribution of white blood cells. However, exercise at − 15 °C may cause airway injury and evoke respiratory symptoms, even at moderate intensity. Atopic status may lead to greater peripheral bronchodilation and higher frequency of respiratory symptoms after long-duration exercise in cold.Trial registration: 01/02/2022 ISRCTN13977758. This trial was retrospectively registered upon submission to satisfy journal guidelines. The authors had not initially registered the study, as the intervention was considered to be a controlled simulation of exercise in a naturally occurring environment (i.e. sub-zero air) for healthy volunteers.