Improve Exercise Performance Research Articles

Virtual Reality Could Improve Exercise Performance on a Stationary Bike

Virtual Reality Could Improve Exercise Performance on a Stationary Bike

КОРЕКЦІЯ РУХОВОГО СТЕРЕОТИПУ ЖІНОК З ЦУКРОВИМ ДІАБЕТОМ І ТИПУ, ЯКІ ПЕРЕНЕСЛИ КЕСАРІВ РОЗТИН, ЗАСОБАМИ ФІЗИЧНОЇ ТЕРАПІЇ

Abstract. The Purpose is to determine the effectiveness of the use of physical therapy for the correction of the motor stereotype of women with type I diabetes that underwent cesarean section in the postpartum period.
 Methods 35 women with type 1 diabetes who underwent abdominal delivery (caesarean section) 1 month before the initial examination took part in the study. The control group consisted of 17 women, who recovered in the postpartum period without rehabilitation interventions or according to self-selected methods. 18 women of the comparison group were engaged in a physical therapy program, the effectiveness of which is presented in this study, which lasted 1 month. Within its framework, kinesitherapy was performed with women (therapeutic exercises for the upper and lower limbs, back, abdomen, chest; functional training to correct the movements of habitual activities and those that take care of a child); manual massage (back, abdomen, lower limbs). Means of physical therapy were used to improve the physical qualities of women - flexibility, strength, endurance, dexterity, speed; normalization of psycho-emotional status, which can be changed due to the risk of postpartum depression; improvement of peripheral blood circulation, changed due to diabetic angiopathy; improvement of sensitivity of peripheral tissues and neuromuscular control, altered due to diabetic neuropathy; improvement of tissue sensitivity to insulin and normalization of glucose utilization by tissues.
 The effectiveness of physical status correction was performed according to the standard Functional Movement Screen technique.
 Results The movement capabilities of women with diabetes according to the Functional Movement Screen in the postpartum period were relatively low, which was due to a long period of reduced physical activity, changes in the biomechanics of the body, and postpartum reorganization of the body.
 During the re-examination, the improvement in exercise performance was (respectively in the control group and the comparison group): "deep squat" – 11.9% and 49.2%; "hurdle step" – 17.2% and 31.7%; "in-line lunge" – 35.4% and 86.8%; "shoulder mobility" – 14.0% and 50.3%; "active straight leg raise" – 24.1% and 47.0%; "trunk stability push-up" – 20.0% and 60.4%; "rotary stability" – 34.0% and 67.1%. This is evidenced by the results of FMS in women of the control group, which were statistically significantly better (p<0.05) compared to the original data, but the number of women with low scores was still significant. At the same time, the determination of FMS parameters in women of the comparison group during the repeated examination showed the feasibility of using physical therapy to improve the condition of women with diabetes in the postpartum period, since in this group the repeated results were better not only the initial levels, but also the corresponding indicators of the control group upon re-examination (p<0.05).
 Conclusions After the implementation of a physical therapy program with the use of therapeutic exercises of various orientations, functional training, a statistically significantly better result was found on all tests of the Functional Movement Screen compared to women with type I diabetes who recovered after cesarean section on their own. Therefore, it is advisable to prescribe physical therapy in the process of postpartum recovery of women with diabetes in order to improve their movement pattern and speed up recovery.

The Probiotic Streptococcus salivarius M18 Increases Plasma Nitrite but Does Not Alter Blood Pressure: A Pilot Randomised Controlled Trial

Some species of oral bacteria can reduce dietary nitrate to nitrite, which can later be converted to nitric oxide in the nitrate—nitrite—nitic oxide pathway. Increasing nitric oxide availability can reduce blood pressure (BP) and improve exercise performance. Streptococcus salivarius M18 (Streptococcus salivarius M18) is a bacteriocin-producing probiotic that is known to improve oral health by inhibiting pathogenic oral bacteria. However, it is presently unclear whether probiotic-induced alterations to the oral microbiome will influence circulating levels of nitric oxide metabolites and BP. Purpose: To determine the effects of Streptococcus salivarius M18 supplementation on plasma and salivary nitrate and nitrite levels and BP. Methods: Ten healthy males (age 32 ± 8 y, body mass 88.2 ± 15.1 kg) completed 2 × 14-day supplementation phases in a randomized order at least 14 days apart. In one phase, participants consumed Streptococcus salivarius M18 probiotic lozenges (2.5 billion colony-forming units/dose) once per day, and in the other, they ingested water (placebo). The abundance of bacteria on the tongue was assessed via Illumina 16S rRNA gene sequencing, unstimulated saliva, and venous blood samples were collected, and BP was measured pre and post each phase. Saliva and plasma were analysed for nitrate and nitrite using chemiluminescence, and pH was measured in saliva. The change in each outcome from pre- to post-supplementation was compared between phases using repeated measures ANOVA. Results: Plasma nitrite increased from baseline following probiotic supplementation (from 173 ± 39 to 223 ± 63 nM, p = 0.003, 95% CI 192–250 nM). In comparison, there was no change in the placebo phase or between baselines (all p > 0.05). The abundance of nitrite-producing bacteria was not altered, salivary nitric oxide metabolites and pH did not change, and the increase in plasma nitrite did not result in reductions in BP (all p > 0.05). Conclusions: Supplementation with Streptococcus salivarius M18 increased plasma nitrite, a key marker of NO availability. Despite this, Streptococcus salivarius M18 did not lower BP in these healthy normotensive participants. Additionally, the increase in plasma nitrite was not associated with abundance changes in bacteria thought important to NO generation. Further research is required to determine the mechanism behind the increase in plasma nitrite and the potential therapeutic and ergogenic benefits of Streptococcus salivarius M18 supplementation.

Exogenous lactate intake immediately after endurance exercise increases time to exhaustion in VO2max measurements in mice.

The purpose of the study was to investigate the effects of 4 weeks of lactate intake immediately after endurance exercise on maximal oxygen uptake (VO2max) in exercise performance. Seven-week-old mice from the Institute of Cancer Research (ICR) were randomly divided into four groups: vehicle intake (SE/CON), lactate intake (SE/LAC), endurance exercise with vehicle intake (EX/ CON), and lactate intake with endurance exercise (EX/ LAC). Mice were subjected to 60-70% VO2max endurance exercise with or without oral lactate intake 5 days/ week for 4 weeks. VO2max measurements (VO2max, time to exhaustion (TTE), respiratory exchange rate, fat oxidation, and carbohydrate oxidation) were recorded at the end of the study period. After 48 h of VO2max measurement, the mice were sacrificed, and three different abdominal fat samples (epididymal, perirenal, and mesenteric) were collected. Body weight and abdominal fat mass did not differ between the groups. When measuring VO2max, endurance exercise raised VO2max, and lactate intake after endurance exercise increased TTE. The change in energy substrate utilization during VO2max measurement demonstrated that although the respiratory exchange rate and fat oxidation were enhanced by lactate intake, there were no synergistic effects of lactate intake and endurance exercise. Lactate intake immediately after endurance exercises can improve exercise performance, indicating the benefit of long-term exogenous lactate intake as an exercise supplement.

Social Comparison in Healthy Adult Peloton Bikers: How Visual Display of Exercise Data Affects Performance

UniversityIn group exercise settings, individuals compare their performance against others, a process called social comparison. Although social comparison in laboratory-based exercise settings has been investigated, little is known about how exercising with others can boost motivation to perform in a non-laboratory group exercise setting with data display. Peloton bikers (N = 26) completed the same 30-minute cycling session in three conditions: group data display, individual data display, and no data display. Participants’ exercise performance (i.e., heart rate, calories burned, and distance cycled) was assessed for each condition. Ego orientation and social comparison were investigated as predictors of performance. Results indicated that in the group data condition, participants had higher heart rates (p = .02), calories burned (p = .03), and longer distance cycled (p < .001) compared to the no data condition. Positive correlations emerged between social comparison and calories burned (r = .52), social comparison and distance (r = .45), and calories burned and distance (r = .75). Additionally, there was a negative correlation between ego orientation and HR (r = -.45), and between task and ego orientations (r = -.47). Ego orientation explained 19% of the variance in HR, and social comparison accounted for 20% and 27% of the variance in distance and calories burned, respectively. These results suggest that social comparison, ego orientation, and visually displayed data can all improve exercise performance. This study is bridging the gap between research and practice by providing further evidence of the application of the motivational effect of visually displayed exercise data in a group exercise setting. Specifically, fitness professionals can utilize the visual presentation of exercise data to increase their participant’s engagement, while being cognizant of the risk of over-exertion.

PS10 Can an aerobic exercise intervention for patients with psoriasis improve health outcomes and support lifestyle behaviour change?

Abstract Patients with psoriasis do not exercise to the extent recommended for cardiovascular health, due to significant disease-specific barriers, which may augment their increased risk of CVD and metabolic syndrome. Therefore, we developed a bespoke, evidenced-based exercise programme for patients with psoriasis, hypothesizing that it may have utility in the management of psoriasis. Eight patients with psoriasis (32.5 ± 12.02 years old, BMI 26.7 ± 3.3 kg m-2) completed a 20-week physical activity intervention. The first 10 weeks of the intervention comprised two walking sessions per week. Each session was of 1h duration and led by a sports-scientist for small-groups of patients with psoriasis. The volume of exercise per session was calculated so that participants would incrementally progress to heart-healthy levels of exercise over the programme. During weeks 10–20 of the programme, participants engaged in independent activities. Warm-ups, pre-exercise stretching, and cool-downs were incorporated into each of the sports-scientist led sessions. Step counts were recorded using a Newfeel Onwalk 900 pedometer throughout the study. Measurements at pre-, mid-, and post-intervention endpoints (week 0, 10 and 20) included assessment of (i) psoriasis: Psoriasis Area and Severity (PASI); Physicians Global Assessment (PGA); (ii) quality of life: Dermatology Life Quality Index (DLQI), Short Form 36 (SF-36); and (iii) cardiometabolic disease/risk – pulse wave velocity (PWV); blood pressure (BP); body weight and BMI. In addition, cardiorespiratory fitness (CRF) was assessed by: 30-s sit-to-stand (30STS); timed up and go (TUG); single leg balance (SLB); static body-weight wall-squat (SBWS); and step count. Recruitment to the study is ongoing. We observed a significant reduction in both Psoriasis Area and Severity Index and systolic BP at the weeks 10 and 20 timepoints (P < 0.05). We also observed a statistically significant improvement in the SF-36 mental health domain between the weeks 10 and 20 timepoints (P = 0.035). The CRF statistically significantly improved across the duration of the study, with a statistically significant improvement in exercise performance, as evidenced by 30STS, TUG and pedometer step counts at week 10 (P < 0.05), SLB between baseline and week 20 (P = 0.043) and SBWS performance across all timepoints. Exercise induces health benefits, including reduced skin inflammation and systolic BP, and increased CRF, and may improve some aspects of quality of life in those with psoriasis. The impact of lifestyle on psoriasis warrants further investigation. Our data suggest that exercise could represent an adjuvant therapy in the future management of psoriasis.

Arctigenin derivatives improve exercise performance in mice: synthesis and biological evaluation.

Arctigenin (ARG) has potent antifatigue activity, but its clinical application has been restricted for its poor water solubility. In this study, seven ARG derivatives containing different amino acids coupled via an ethoxy linker were synthesized, and tested for their solubility, as well as activities to improve exercise performance in mice. All of the derivatives showed improved solubility compared to that of ARG. Derivative Z-A-6 exhibited the highest activity, showing that the mice ran a 4.88-fold greater distance in the running wheel test and swam a 2.86-fold greater time in the swimming test than those in the blank control group. Z-A-6 treatment increased the plasma superoxide dismutase and catalase concentrations as well as reduced lactic acid and blood urea nitrogen accumulation during exercise. Z-A-6 treatment enhanced the phosphorylation of adenosine monophosphate-activated protein kinase, and no acute toxicity was observed. The results will contribute to the development of potential antifatigue agents.

Hematological, skeletal muscle fiber and exercise performance adaptations to heat training in elite female and male cyclists.

Heat exercise training may increase exercise performance in athletes. The underlying mechanisms remain partly unresolved, and it is unknown if female and male athletes may experience comparable gains. The aims were to investigate whether heat training (HEAT) increases hemoglobin mass (Hbmass), skeletal muscle fiber characteristics and thermoneutral exercise performance in elite female and male endurance athletes. Female (n=20; VO2max = 58.2 ± 6.7 ml.min.kg) and male (n=27; VO2max = 76.4 ± 7.8 ml.min.kg) cyclists were studied before and after five weeks of randomized control or HEAT training consisting of five weekly sessions each of 50 min duration which were included in their normal training regimes. Overall, the observed relative responses to HEAT were largely similar in female and male study participants. HEAT increased (P<0.05) Hbmass in female from 650 ± 77 to 675 ± 76 g (4.0 ± 1.6%) and from 1008 ± 155 to 1041 ± 147 g (3.5 ± 2.3%) in male. In contrast, skeletal muscle citrate synthase activity, fiber type distribution and capillary density remained unchanged with HEAT. Lactate threshold, VO2max and mean power output during 15 min all out testing were all enhanced (P<0.05) following HEAT in female and male study participants. In conclusion, five weeks of HEAT increases Hbmass in female and male elite cyclists and improves exercise performance in a thermoneutral environment. Based on this, heat training may be recommended to elite female and male athletes aiming to perform in a thermoneutral environment.

Effect of the beta-alanine supplementation in sports: an umbrella review of systematic reviews and meta-analyses

INTRODUCTION: Nutritional supplements, in addition to the athlete’s diet, are crucial for improving sports performance and the management of training and recovery. Supplements may provide a convenient source of energy and macronutrients and help prevent micronutrient deficiencies. Beta-alanine (BA) is a popular supplement thought to improve exercise performance in a variety of sports. The purpose of this umbrella review was to explore the evidence for the effect of BA supplementation on exercise performance.EVIDENCE ACQUISITION: A systematic literature search was conducted in the following databases: PubMed®, Web of Science®, and Scopus®, for studies published until 6th October 2022 and the searches were limited to systematic reviews or meta-analyses.EVIDENCE SYNTHESIS: Eight articles met the criteria for inclusion in this review. Except for one study, which included only athletes, all studies included a mixed population of athletes and non-athletes. Five of these studies examined exercise performance, while the other two focused on fatigue resistance and body composition. The daily BA dosages in the research ranged from 1.2 to 7.0 g, while the intervention length varied from 4 days to 13 weeks. Apart from the body composition study, all of the other research included in this review suggested that BA supplementation had positive ergogenic effects. Exercise duration had a significant impact on the effect size of BA supplementation, with effects estimated to be greatest between 30 seconds to 10 minutes.CONCLUSIONS: BA supplementation had a positive effect on exercise performance in all systematic reviews/meta-analyses. It is effective for sports activities primarily in middle-distance events.

Repeated Inhalation of Peppermint Essential Oil Improves Exercise Performance in Endurance-Trained Rats.

Peppermint essential oil, being natural and safe, with antioxidant and anti-inflammatory properties, has long been a research interest in relieving fatigue and improving exercise performance. However, the related studies report controversial results, and the mechanisms remain unclear. Here we found that inhalation of peppermint essential oil significantly extended the exhaustion time in rats subjected to 2-week weight-bearing swimming training. Sprague-Dawley rats were subjected to a 2-week weight-loaded forced swimming regimen. Prior to each swimming session, the rats were administered peppermint essential oil via inhalation. An exhaustive swimming test was performed at the end of the protocol. Rats treated with essential oil had significantly extended time to exhaustion compared with exercised rats without essential oil treatment. In addition, treated rats also showed reduced oxidative damage induced by endurance exercise. Notably, the rats receiving two-week essential oil inhalation while not subjected to swimming training did not show improved exercise performance. The findings demonstrate that repeated inhalation of peppermint essential oil enhances the effects of endurance training and improves exercise performance partially by preventing oxidative damage.

Effect of Probiotic Yogurt Supplementation(Bifidobacterium animalis ssp. lactis BB-12) on Gut Microbiota of Female Taekwondo Athletes and Its Relationship with Exercise-Related Psychological Fatigue.

The gut microbiota plays a critical role in regulating human health and athletic performance. Probiotic supplementation has been shown to modulate gut microbiota composition and improve exercise performance. This study aimed to investigate the effect of probiotic yogurt supplementation on gut microbiota and its relationship with exercise-related psychological fatigue in female taekwondo athletes. Twenty female taekwondo athletes were randomly assigned to either a dietary intervention group (DK) or a control group (CK). The athletes' exercise-related psychological fatigue was measured using the Athlete Burnout Questionnaire (ABQ) before and after an 8-week intervention. High-throughput sequencing was used to profile the gut microbiota, and functional prediction of the microbial community was performed. The effect of the dietary intervention on the athletes' exercise-related psychological fatigue clearance rate and its relationship with the gut microbiota were explored. (1) The probiotic supplementation of Bifidobacterium animalis ssp. lactis BB-12 for 8 weeks significantly increased the ABQ scores of the DK group compared to the CK group (p < 0.05). (2) The abundances of Bifidobacterium, Bacteroides, Lachnospiraceae, family _Lactobacillaceae, and genus _Lactobacillus were significantly higher in the DK group than in the CK group after probiotic supplementation, while Escherichia coli was significantly lower in the DK group than in the CK group. (3) The ABQa scores were positively correlated with Proteus; ABQb scores were positively correlated with Streptococcus and Enterococcus; and ABQc scores were positively correlated with Klebsiella, Bacteroides, and Streptomyces. (4) The DK group had significantly higher levels of L-arginine biosynthesis I (via L-ornithine), fatty acid biosynthesis and oxidation, and L-isoleucine biosynthesis III pathways compared to the CK group. Tyrosine degradation I (via 2,3-dihydroxyphenylpropionate) was significantly lower in the DK group than in the CK group. Probiotic yogurt supplementation of Bifidobacterium animalis ssp. lactis can promote the clearance of exercise-related psychological fatigue in female taekwondo athletes by upregulating beneficial gut microbiota, inhibiting harmful gut microbiota, and regulating relevant metabolic pathways.

Effects of Stroop task duration on subsequent cognitive and physical performance

The strength model of self-control purports to explain why brief cognitive response inhibition tasks impair subsequent isometric handgrip endurance. According to the model, ego depleting tasks requiring self-control resources impair performance on subsequent tasks that also require self-control resources. However, several lines of evidence challenge this model, including evidence of improved exercise performance following longer cognitive tasks. Our study investigated the effects of cognitive task duration on (1) subsequent physical endurance performance, (2) concurrent cognitive task performance, and (3) subsequent novel cognitive task performance. Adopting an experimental design, with Stroop task type (incongruent, congruent) and duration (5, 10, 20 min) as between-participant factors, participants (N = 180) completed a color word Stroop task, an isometric handgrip to exhaustion task, and a novel 5-min incongruent number word Stroop task. In the handgrip task, endurance performance was worse following incongruent word Stroop than congruent word Stroop for 10-min tasks but not 5-min and 20-min tasks. In the word Stroop task, accuracy was lower and speed was slower following incongruent word Stroop than congruent word Stroop. Importantly, reaction times improved with longer task durations. In the novel number Stroop task, accuracy was higher following incongruent word Stroop than congruent word Stroop. In conclusion, the finding that the ego depletion effect was moderated by cognitive task duration is better explained by the expected value of control model than the strength model.

The association between ischemic preconditioning and exercise performance: a systematic review and meta-analysis

Purpose: The present work was performed to provide an updated and comprehensive systematic review and meta-analysis on the potential ergogenic effects associated with ischemic preconditioning (IPC). In this context, this systematic review and meta-analysis aimed to determine the magnitude of the potential ergogenic effect of IPC and the influence of descriptive factors that contribute to the variability of its potential ergogenic effect. We hypothesized that IPC would be associated with improved exercise performance, and putative factors would modulate this association. Methods: On October 17, 2022, a systematic search of three databases (PubMed, Scopus, and Web of Science) was performed. The electronic search yielded 2,876 unique records, of which 79 were included in analyses after abstract and full-text screening. Eligible study designs included within subjects cross-over, sham controlled study, with a randomized or counter balanced study design. Prespecified analyses aimed to determine whether the ergogenic effect of IPC is influenced by: 1) exercise parameters (type of exercise, fraction of inspired oxygen, and muscle group(s) involved in exercise) and 2) IPC parameters (dosage, duration, and timing before onset of exercise). Results: The meta-analysis model demonstrated that exercise performance was improved with IPC compared to the sham control (pooled standard paired difference (SPD), 0.156; 95% confidence interval (CI), 0.084 to 0.227; Z = 4.258; P &lt; 0.001; n = 105). Both remote IPC (pooled SPD, 0.219; 95% CI, 0.071 to 0.368; Z = 2.894; P = 0.004) and local IPC (pooled SPD, 0.159; 95% CI, 0.088 to 0.231; Z = 4.386; P &lt; 0.001) demonstrated ergogenic effects on performance. Subgroup analyses based on the fraction of inspired oxygen level revealed improved exercise performance in normoxic (pooled SPD, 0.169; 95% CI, 0.100 to 0.237; Z = 4.805; P &lt; 0.001) but not hypoxic (pooled SPD, 0.160; 95% CI, -0.029 to 0.349; Z = 1.659; P = 0.097) conditions. The most notable improvement in exercise performance following IPC was demonstrated during cycling (pooled SPD, 0.116; 95% CI, 0.023 to 0.209; Z = 2.454; P = 0.014), running (pooled SPD, 0.180; 95% CI, 0.056 to 0.303; Z = 2.847; P = 0.004), and leg press (pooled SPD, 0.421; 95% CI, 0.034 to 0.808; Z = 2.131; P = 0.033) performance tests. Conclusion: Overall, IPC demonstrated a clear ergogenic effect on exercise performance across various exercise modalities under normoxic environmental conditions. The enhanced exercise performance following IPC was most pronounced in aerobic tests of performance which predominantly recruited large muscle groups in the lower extremities: cycling, running, and leg press. This is the full abstract presented at the American Physiology Summit 2023 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 comparison of passive heat treatment-induced vascular adaptations relative to exercise training

Epidemiological data indicate that repeated heat stress improves cardiovascular health, making passive heat therapy (PHT) a potential alternative for those unable to exercise. Few studies to date have examined the potential exercise mimetic effects in humans, and it is unclear how adaptations compare in magnitude to exercise training. OBJECTIVE: To examine the effects of 6 weeks of localized, muscle-focused PHT on resistance artery vascular function, exercise hemodynamics, and exercise performance relative to the adaptations observed following high-intensity aerobic exercise training focused on the same muscles. HYPOTHESIS: 6 weeks of PHT, applied through pulsed shortwave diathermy (2 hr, 3 days/week), would increase resistance artery function, improve exercise hemodynamics, and enhance exercise performance more than a sham treatment, but less than single-leg knee extension (KE) exercise training (EX; 40 min, 3 days/week). We also hypothesized that these functional adaptations would be accompanied by increased skeletal muscle capillarity. METHODS: We randomized 34 sedentary but otherwise healthy, young adults (ages 18–36; n = 17 female, 17 male) to receive PHT, EX, or sham heating sessions (SHAM; 2 hr, 3 days/week) over 6 weeks. Vascular function was determined through the blood flow response during both a passive leg movement (PLM) assessment and a knee extension graded exercise test (GXTmax). Muscle biopsies were taken from the vastus lateralis at baseline and after 6 weeks of intervention. RESULTS: Peak muscle treatment temperature was significantly different between all groups with PHT exhibiting a higher peak temperature (~40.80°C) than those in the EX (~37.75°C, P&lt;0.001) and SHAM groups (~36.10°C, P&lt;0.001). Peak blood flow during PLM increased to the same extent (P=0.625) in both the EX (~10.5% increase, P=0.009) and PHT groups (~8.5% increase, P=0.044); but tended to decrease in the SHAM group (P=0.087). KE peak flow increased in EX (~19%, P=0.005), but did not change in PHT (P=0.523) and decreased in SHAM (~7%, P=0.020). Peak vascular conductance during KE significantly increased by ~25% in EX (P=0.030) and PHT (P=0.012). KE peak power increased in EX by ~27% (P=0.001) but did not significantly change in PHT(P=0.175) and SHAM groups (P=0.111). EX, but not PHT or SHAM increased muscle capillary-to-fiber ratio (P = 0.0003), capillary density (P = 0.0428), and the Capillary to Fiber Perimeter Exchange Index (P = 0.0089). CONCLUSIONS: 6 weeks of localized PHT, when applied to young healthy individuals, improved resistance artery function at rest and during exercise to the same extent as exercise training. However, PHT did not lead to increased KE peak flow, microvascular remodeling, or improved exercise performance. Therefore, PHT mimics many, but not all the vascular benefits of exercise training. Further research is necessary to determine the mechanism by which 6 weeks of PHT led to improved vascular function at rest and during exercise. This is the full abstract presented at the American Physiology Summit 2023 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.

Defecation enhances cerebral perfusion and delays fatigue in elite triathletes.

Rectal distension increases regulatory burden to autonomic nervous system in the brain. To determine the effect of rectal defecation on endurance performance and blood supply to the prefrontal brain and sub-navel regions of elite triathletes. Thirteen elite triathletes completed a cycling time trial (80% VO2max) under defecated and non-defecated conditions, using a counterbalanced crossover design. Oxygenation and blood distribution in prefrontal brain and sub-navel regions were monitored by near-infrared spectroscopy (NIRS) during cycling. Defecation moderately decreased systolic blood pressure (-4 mmHg, p < 0.05, d = 0.71), suggesting an alleviation of autonomic nervous activity. During the exercise trials, fatigue (cycling time to exhaustion) occurred when cerebral oxygenation decreased to ~ 5 % below baseline regardless of treatment conditions, suggesting a critical deoxygenation point for sustaining voluntary exertions. Cerebral blood (estimated by total hemoglobin) increased progressively throughout the entire exercise period. Defecation decreased sub-navel oxygenation levels below the non-defecated level, suggesting an increased sub-navel oxygen consumption. Exercise also decreased sub-navel blood distribution, with minimal difference between non-defecated and defecated conditions. Defecation improved blood pooling in the prefrontal brain during exercise (p < 0.05) and enhanced cycling performance in triathletes (Non-defecated: 1624 ± 138 s vs. defecated: 1902 ± 163 s, d = 0.51, p < 0.05). Our results suggest that improved exercise performance after defecation is associated with greater blood availability to compensate deoxygenation in the prefrontal brain region during exercise. Further investigation is needed to examine the role of increasing sub-navel oxygen consumption in the performance improvement after defecation.

Two weeks of arm cycling sprint interval training enhances spinal excitability to the biceps brachii.

The present study aimed to investigate whether a 2-wk arm cycling sprint interval training (SIT) program modulated corticospinal pathway excitability in healthy, neurologically intact participants. We employed a pre-post study design with two groups: 1) an experimental SIT group and 2) a nonexercising control group. Transcranial magnetic stimulation (TMS) of the motor cortex and transmastoid electrical stimulation (TMES) of corticospinal axons were used at baseline and post-training to provide indices of corticospinal and spinal excitability, respectively. Stimulus-response curves (SRCs) recorded from the biceps brachii were elicited for each stimulation type during two submaximal arm cycling conditions [25 watts (W) and 30% peak power output (PPO)]. All stimulations were delivered during the mid-elbow flexion phase of cycling. Compared with baseline, performance on the time-to-exhaustion (TTE) test at post-testing was improved for members of the SIT group but was not altered for controls, suggesting that SIT improved exercise performance. There were no changes in the area under the curve (AUC) for TMS-elicited SRCs for either group. However, the AUC for TMES-elicited cervicomedullary motor-evoked potential SRCs were significantly larger at post-testing in the SIT group only (25 W: P = 0.012, d = 0.870; 30% PPO: P = 0.016, d = 0.825). This data shows that overall corticospinal excitability is unchanged following SIT, whereas spinal excitability is enhanced. Although the precise mechanisms underlying these findings during arm cycling at post-SIT are unknown, it is suggested that the enhanced spinal excitability may represent a neural adaptation to training.NEW & NOTEWORTHY Two weeks of arm cycling sprint interval training (SIT) improves subsequent aerobic exercise performance and induces changes within the descending corticospinal pathway. Specifically, spinal excitability is enhanced following training, whereas overall corticospinal excitability does not change. These results suggest that the enhanced spinal excitability may represent a neural adaptation to training. Future work is required to discern the precise neurophysiological mechanisms underlying these observations.

Caffeine Modifies the Immune and Anti-inflammatory Responses to Short Incremental Cycling Exercise Until Exhaustion in Humans: A Pilot Study

Exercise has well-documented effects on immune function with both positive and negative sequelae dependent on intensity, volume, and duration. The immunosuppressive effects of exercise are mediated, in part, by the complex interaction of cytokines, catecholamines, and nutrition. Caffeine has been reported to modulate immune function; however, the interaction with brief exhaustive exercise is not well characterized. It was hypothesized that caffeine would upregulate the cytokine response to intense exercise. Seven male students volunteered to participate in a randomized, double-blinded crossover study where they ingested either caffeine (6 mg/kg) or a maltodextrin placebo (6 mg/kg) 1 h prior to a cycling exercise. The exercise protocol started at 100 W and the intensity was increased by 50 W every two minutes until exhaustion. Serum samples were collected pre-, post-, and 1-h post-exercise and analyzed for IL-4, IL-10, and TGF-β1. Caffeine ingestion increased time to exhaustion (P = 0.005; Effect Size [ES] = 1.33), IL-4 (P = 0.004; ES = 2.34), IL-10 (P = 0.047; ES = 0.41 ± 0.57), and TGF-β1 (P = 0.013; ES = 0.76). The accentuated response of the cytokines may have important ramifications due to their potent anti-inflammatory and immunoregulatory properties. Specifically, the 6 mg/kg caffeine dose not only improved exercise performance but the cytokine data is indicative of an upregulated inflammatory response and an enhancement of the anti-inflammatory benefits of exercise.

Aspirin Precooling Improves Exercise Performance in Multiple Sclerosis: Results of a double-blind randomized controlled trial (P8-3.008)

Aspirin Precooling Improves Exercise Performance in Multiple Sclerosis: Results of a double-blind randomized controlled trial (P8-3.008)

高強度間欠的運動トレーニングが30秒程度で疲労困憊に至る超最大運動時の代謝・循環指標および運動持続時間に及ぼす影響

Present study aimed to examine the effects of high-intensity intermittent training on metabolic or circulatory parameters and exercise time during 30s-lasting exhaustive exercise. Six healthy males (22 ± 1yrs) had an intermittent training four days a week for four weeks. The intermittent training consisted of 8 or more sets of 20s exercise bout at an intensity of 170%VO2 max separated by 10-s recovery. Before and after training period, VO2 max and maximal accumulated O2 deficit (MAOD) were determined as indices of metabolic capacity. During 30s-lasting exhaustive exercise, VO2, O2 deficit, and circulatory parameters, such as heart rate, stroke volume, and cardiac output, were also determined every 10s. After the training, VO2 max and MAOD were significantly increased. During 30s-lasting exhaustive exercise, exercise time, stroke volume, and cardiac output were also significantly enhanced. However, no significant differences were observed in VO2 and O2 deficit every 10s during 30s-lasting exhaustive exercise. Therefore, these findings suggest that high-intensity intermittent training enhances exercise time during 30s-lasting exhaustive exercise and that the improvement of exercise performance is closely related to an increase in anaerobic capacity.

Synthetic ERRα/β/γ Agonist Induces an ERRα-Dependent Acute Aerobic Exercise Response and Enhances Exercise Capacity.

Repetitive physical exercise induces physiological adaptations in skeletal muscle that improves exercise performance and is effective for the prevention and treatment of several diseases. Genetic evidence indicates that the orphan nuclear receptors estrogen receptor-related receptors (ERRs) play an important role in skeletal muscle exercise capacity. Three ERR subtypes exist (ERRα, β, and γ), and although ERRβ/γ agonists have been designed, there have been significant difficulties in designing compounds with ERRα agonist activity. Additionally, there are limited synthetic agonists that can be used to target ERRs in vivo. Here, we report the identification of a synthetic ERR pan agonist, SLU-PP-332, that targets all three ERRs but has the highest potency for ERRα. Additionally, SLU-PP-332 has sufficient pharmacokinetic properties to be used as an in vivo chemical tool. SLU-PP-332 increases mitochondrial function and cellular respiration in a skeletal muscle cell line. When administered to mice, SLU-PP-332 increased the type IIa oxidative skeletal muscle fibers and enhanced exercise endurance. We also observed that SLU-PP-332 induced an ERRα-specific acute aerobic exercise genetic program, and the ERRα activation was critical for enhancing exercise endurance in mice. These data indicate the feasibility of targeting ERRα for the development of compounds that act as exercise mimetics that may be effective in the treatment of numerous metabolic disorders and to improve muscle function in the aging.