VO2max Research Articles

The Effect of Heart Rate Variability Biofeedback on Recovery After Aerobic Exercise.

Recovery is a critical factor in athletic performance, and accelerating this process is essential to enable athletes to perform more effectively in both training load and competitive performance. After exercise, immediate recovery is potentially helpful for investigating autonomic activity levels, as they are definable with heart rate variability (HRV). The purpose of this study was to examine the effect of ten sessions of HRV-Biofeedback (HRV-BF) training on recovery process parameters after the aerobic performance. In this study, twenty-four soccer players aged 18-24 volunteered to participate. The athletes who met the research criteria were divided into an experimental group (n = 12) and a control group (n = 12). Each participant's height, weight, BMI, body fat percentage, and aerobic capacity were measured before and after the 10-session intervention. The experimental group participated in a 10-session HRV-BF training and soccer training program, while the control group only participated in a 10-session soccer training program. Aerobic capacity tests were then applied again to experimental and control group participants. The effect of biofeedback on the three HRV parameters during the 5-minute acute recovery period after the test was investigated. The results showed that regularly applied HRV-BF training can significantly shorten the HRV recovery parameter after exercise. Specifically, the athletes who performed HRV-BF training demonstrated faster cardiovascular recovery after aerobic exercise. This suggests that implementing HRV-BF training for athletes can significantly accelerate their recovery processes during and after competitions. Given recent technological advancements, it is promising to consider adding HRV-BF training to stress management interventions, particularly in relation to physiological stress indicators.

Skeletal and respiratory muscle blood flow redistribution during submaximal exercise in pulmonary hypertensive rats.

Pulmonary hypertension (PH) is a chronic, progressive disease characterized by pulmonary vascular remodelling, dyspnoea and exercise intolerance. Key facets of dyspnoea and exercise intolerance include skeletal and respiratory muscle contractile and metabolic disturbances; however, muscle perfusion during exercise has not been investigated. We hypothesized that diaphragm blood flow ( ) would be increased and locomotory muscle would be decreased during submaximal treadmill running in PH rats compared to healthy controls. Female Sprague-Dawley rats were injected (i.p.) with monocrotaline to induce PH (n=16), or a vehicle control (n=15). Disease progression was monitored via echocardiography. When moderate disease severity was confirmed, maximal oxygen uptake ( ) tests were performed. Rats were given >24h to recover, and then fluorescent microspheres were infused during treadmill running (20m/min, 10% grade; ∼40-50% maximal speed attained during the test) to determine tissue . In PH rats compared with healthy controls, was lower (84 (7) vs. 67 (11) ml/min/kg; P<0.001), exercising diaphragm was 35% higher and soleus was 28% lower. Diaphragm was negatively correlated with soleus and in PH rats. Furthermore, there was regional redistribution in the diaphragm in PH compared to healthy rats, which may represent or underlie diaphragmatic weakness in PH. These findings suggest the presence of a pathological respiratory muscle blood flow steal phenomenon in PH and that this may contribute to the exercise intolerance reported in patients. KEY POINTS: Pulmonary hypertension (PH) impairs exercise tolerance, which is associated with skeletal and respiratory muscle dysfunction. Increased work of breathing in PH may augment diaphragm blood flow and lower locomotory muscle blood flow during exercise, hindering exercise tolerance. Our findings demonstrate that respiratory muscle blood flow is increased while the locomotory muscle is decreased in PH compared to healthy rats during exercise, suggesting that blood flow is preferentially redistributed to sustain ventilatory demand. Furthermore, blood flow is regionally redistributed within the diaphragm in PH, which may underlie diaphragm dysfunction. Greater respiratory muscle work at a given workload in PH commands higher respiratory muscle blood flow, impairing locomotory muscle oxygen delivery and compromising exercise tolerance, which may be improved by therapeutics which target the diaphragm vasculature.

Optimising Physical Training in DanceSport by Using HIIT Training and Smart Devices for Monitoring Physical Activity

&lt;p dir="ltr"&gt;&lt;span&gt;This study investigates the effectiveness of High-Intensity Interval Training (HIIT), specifically for Tabata, combined with smart monitoring devices on adult dancesport practitioners' physical fitness and performance. The primary objective was to assess the impact of these interventions on key physical parameters and overall performance. Forty participants were divided into two groups: an experimental group (n=20) that engaged in Tabata training three times a week while using smart devices to monitor their activity, and a control group (n=20) that continued with their regular training routines. The experimental group showed significant improvements in aerobic and anaerobic capacity, agility, and overall motor performance throughout the study. These enhancements were measured using standardized physical assessments and the Mann-Whitney non-parametric test, confirming statistically significant progress in the experimental group compared to the control group. Integrating smart devices was crucial in maintaining and enhancing participant motivation, providing real-time feedback, facilitating goal-setting, and allowing for progress tracking, contributing to increased responsibility and engagement in physical activity. Participant feedback highlighted the motivational benefits of smart technology, consistent with existing literature. The immediate performance data and synchronization with fitness apps enhanced the training experience, promoting continuous improvement and long-term commitment. The findings indicate that combining Tabata training with smart monitoring devices effectively improves the physical and technical performance of adult dancesport practitioners. This dual approach enhances physical conditioning and also ensures training relevance to the specific demands of dancesport, maintaining both aesthetic and functional performance aspects. In conclusion, using HIIT, specifically Tabata, alongside smart devices, offers a powerful methodology for optimizing dancers' physical preparation. Future research should investigate the long-term impacts of these training programs, integrate different forms of HIIT, and include a broader participant demographic to validate and expand these findings.&lt;/span&gt;&lt;/p&gt;&lt;div&gt;&lt;span&gt;&lt;br /&gt;&lt;/span&gt;&lt;/div&gt;

Skeletal Muscle mRNA Splicing Variants Association With Four Different Fitness and Energetic Measures in the GESTALT Study

ABSTRACTBackgroundPhysical activity is essential for maintaining muscle mitochondrial function and aerobic capacity. The molecular mechanisms underlying such protective effects are incompletely understood, in part because it is difficult to separate the effects of disease status and physical activity. We explored the association of human skeletal muscle transcriptomic with four measures of energetics and mitochondria oxidative capacity in healthy individuals.MethodsUsing RNA sequencing of vastus lateralis muscle biopsies from 82 GESTALT participants (52 males, aged 22–89 years), we explored gene and splicing variant expression profiles associated with self‐reported physical activity, peak oxygen consumption (VO2 peak), muscle oxidative capacity (kPCr) and mitochondrial respiration (Mit‐O2 flux). The effect of aging on gene expression was examined in participants with low and high VO2 peak.ResultsThe four measures of energetics were negative correlated with age and generally intercorrelated. We identified protein‐coding genes associated with four energetic measures adjusting for age, muscle fiber‐ratio, sex and batch effect. Mitochondrial pathways were overrepresented across all energetic variables, albeit with little overlap at the gene level. Alternative spliced transcript isoforms associated with energetics were primarily enriched for cytoplasmic ribonucleoprotein granules. The splicing pathway was up‐regulated with aging in low but not in high fitness participants, and transcript isoforms detected in the low fitness group pertain to processes such as cell cycle regulation, RNA/protein localization, nuclear transport and catabolism.ConclusionsA consistent mitochondrial signature emerged across all energetic measures. Alternative splicing was enhanced in older, low fitness participants supporting the energy‐splicing axis hypothesis. The identified splicing variants were enriched in pathways involving the accumulation of ribonucleoproteins in cytoplasmic granules, whose function remains unclear. Further research is needed to understand the function of these proteoforms in promoting adaptation to low energy availability.

Association Between Metabolic Syndrome and Physical Fitness in Firefighters in Cape Town, South Africa.

To assess the relationship between metabolic syndrome (MetS) and physical fitness in firefighters. Firefighters (n = 309) were systematically recruited to participate in this study. A questionnaire and physical measures were used to collect data on firefighters' cardiometabolic health and physical fitness levels. Data were analyzed using binary and multinomial logistic regressions. The prevalence of MetS was 23.0%, which was most prevalent in station and platoon commanders. Multivariable analysis showed that age (P < 0.001), lean body mass (P < 0.001), absolute aerobic capacity (P < 0.001), and leg strength (P < 0.001) was significantly associated with MetS. In addition, relative aerobic capacity (P < 0.001), push-ups (P = 0.016), and sit-ups (P < 0.001) were inversely associated with MetS. Firefighters with MetS had a higher absolute aerobic capacity and strength, and healthier fighters had a higher relative aerobic capacity, muscular endurance capacity, and flexibility.

"Do probiotics mitigate GI-induced inflammation and perceived fatigue in athletes? A systematic review".

Fatigue and gastrointestinal (GI) distress are common among athletes with an estimated 30-90% of athletes participating in marathons, triathlons, or similar events experiencing GI complaints. Intense exercise can lead to increased intestinal permeability, potentially allowing members of the gut microbiota to permeate into the bloodstream, resulting in an inflammatory response and cascade of performance-limiting outcomes. Probiotics, through their capacity to regulate the composition of the gut microbiota, may act as an adjunctive therapy by enhancing GI and immune function while mitigating inflammatory responses. This review investigates the effectiveness of probiotic supplementation on fatigue, inflammatory markers, and exercise performance based on randomized controlled trials (RCTs). This review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines and PICOS (Population, Intervention, Comparison, Outcome, Study design) framework. A comprehensive search was conducted in Sportdiscus, PubMed, and Scopus databases, and the screening of titles, abstracts, and full articles was performed based on pre-defined eligibility criteria. Of the 3505 records identified, 1884 were screened using titles and abstracts, of which 450 studies were selected for full-text screening. After final screening, 13 studies met the eligibility criteria and were included for review. The studies contained 513 participants, consisting of 351 males and 115 females, however, two studies failed to mention the sex of the participants. Among the participants, 246 were defined as athletes, while the remaining participants were classified as recreationally active (n = 267). All trials were fully described and employed a double- or triple-blind placebo-controlled intervention using either a single probiotic strain or a multi-strain synbiotic (containing both pro- and pre-biotics). This review assesses the effects of daily probiotic supplementation, ranging from 13 to 90 days, on physical performance and physiological markers in various exercise protocols. Ten studies reported improvements in various parameters, such as, enhanced endurance performance, improved anxiety and stress levels, decreased GI symptoms, and reduced upper respiratory tract infections (URTI). Moreover, despite no improvements in maximal oxygen uptake (VO2), several studies demonstrated that probiotic supplementation led to amelioration in lactate, creatine kinase (CK), and ammonia concentrations, suggesting beneficial effects on mitigating exercise-induced muscular stress and damage. Probiotic supplementation, specifically at a minimum dosage of 15 billion CFUs daily for a duration of at least 28 days, may contribute to the reduction of perceived or actual fatigue.

Association of vitamin D deficiency with post-exercise hypotension and arterial stiffness following prolonged endurance exercise in healthy young men.

Vitamin D is associated with vascular function; however, the impact of different vitamin D levels on vascular elasticity following prolonged exercise remains uncertain. The primary objective of this study was to investigate the association of vitamin D levels with changes in peripheral pulse wave velocity (pPWV) and the magnitude of acute post-exercise hypotension (PEH) following prolonged endurance exercise in healthy young men. All the participants were divided into two groups: the 25-hydroxyvitamin D (25(OH)D) sufficiency group (25(OH)D ≧50 nmol/L) and the deficiency group (25(OH)D < 50 nmol/L). A cardiopulmonary exercise test for maximal oxygen uptake (O2max) was performed on the graded cycling. The prolonged exercise was set at 60% O2max for 120min of continuous riding on a stationary bicycle. The pPWV and blood pressure were measured at baseline and 0, 15, 30, 45, 60 min after prolonged endurance exercise. Post hoc analysis revealed that the vitamin D sufficient group had a greater magnitude of PEH than the deficiency group at post-45 min. Multiple linear regression analyses showed a significant correlation between 25(OH)D and both pPWV (p = 0.036) and PEH (p = 0.007), after adjusting for O2max, weight, height, and physical activity. In addition, the 25(OH)D deficiency group also had higher pPWV at post-15 min (5.41 ± 0.93 vs 4.84 ± 0.75 m/s), post-30 min (5.30 ± 0.77 vs 4.87 ± 0.50 m/s), post-45 min (5.56 ± 0.93 vs 5.05 ± 0.68 m/s) than the sufficiency group. There was a positive correlation between 25(OH)D levels and systolic PEH following prolonged endurance exercise. Individuals with sufficient 25(OH)D status may have better vascular elasticity and more efficient blood pressure regulation during exercise.

Mitochondrial pathways and sarcopenia in the geroscience era

Sarcopenia is associated with structural, ultrastructural, and molecular abnormalities of skeletal muscle. Mitochondrial dysfunction is a pivotal factor involved in muscle aging and sarcopenia. Mitochondrial bioenergetics are significantly reduced in muscles of older adults which is associated with whole-body aerobic capacity, muscle strength, and physical performance. Transcriptional profiling of muscle samples from older adults also revealed inverse correlations between gene expression patterns of autophagy and mitophagy and muscle volume and physical performance. This is in line with the proposition that mitochondrial quality control (MQC) processes are key to organellar and tissue health. MQC encompasses mitochondrial biogenesis, dynamics, and mitophagy. The latter has recently been included among the hallmarks of aging and alterations in MQC have been associated with chronic sterile inflammation as well as muscle atrophy and dysfunction. Several biomarkers spanning MQC, inflammation, metabolism, intercellular communication, and gut microbiota have been linked to sarcopenia. Findings from these initial studies hold promise to inform geroscience-based research in the field of sarcopenia by offering a plausible biological framework for developing gerotherapeutics and monitoring their effects.

ANÁLISE DA COMPOSIÇÃO CORPORAL E APTIDÃO FÍSICA DE ATLETAS PARALÍMPICOS DE RIO BRANCO ACRE

Introduction: Sports training techniques have sparked interest in detailing the physical and physiological characteristics of athletes to prescribe training specifically tailored to their goals. Objective: This study aimed to analyze body composition and its relationship with physical fitness in Paralympic athletes from Rio Branco, Acre. Method: The sample consisted of 33 athletes from the Paralympic Reference Center of Rio Branco, aged between 11 and 54 years, including 20 with intellectual disabilities, 11 with physical disabilities, and 2 with visual disabilities. Measurements included body mass, height, circumferences, and skinfold thickness. Physical performance was evaluated through handgrip strength (using a hydraulic hand dynamometer in kilograms), speed (30-meter test), upper limb power (medicine ball throw test), and maximum oxygen consumption (beep test). Results: Statistical analysis included Pearson’s correlation coefficient and the Kruskal-Wallis test, with significance set at p&lt;0.05, using SPSS software (version 29.0). Body mass index (BMI) and body mass were significantly different between athletes with physical and intellectual disabilities. A negative correlation was observed between aerobic performance (VO2max) and variables such as age (r= -0.441, p= 0.010), BMI (r= -0.590, p&lt;0.001), body mass (r= -0.376, p= 0.031), and body fat index (BFI) (r= -0.688, p&lt;0.001). Additionally, BFI showed a positive correlation with speed performance (r= 0.603, p= 0.001). Conclusion: Body composition significantly influences physical performance variables, indicating that factors such as BMI, body mass, and BFI impact the sports performance of Paralympic athletes.

Maximal oxygen uptake, pulmonary function and walking economy are not impaired in patients diagnosed with long COVID.

SARS-CoV-2 may result in the development of new symptoms, known aslong COVID, a few months after the original infection. It is elusive to what extent physical capacity in patients diagnosed with long COVID is impacted. We compared maximal oxygen uptake (V̇O2max), one of the single most important factors for cardiovascular health and mortality, expired lung volumes and air flow, oxygen cost of walking and 6-min-walking-test (6MWT), in 20 patients diagnosed with long COVID (11 males and 9 females; 44 ± 16years (SD); 26.7 ± 3.8BMI, duration of acute phase 1.7 ± 1.2weeks, tested 4 ± 3months after long COVID diagnosis) with 20 healthy age and sex matched controls (11males and 9females; 44 ± 16years; 25.9 ± 4.0BMI). Long COVID patients had a V̇O2max of 41.4 ± 16.2mL∙kg-1∙min-1(men) and 38.2 ± 7.5 (women) and this was not different from controls. Similarly, mean spirometry measures in the patient group (VC; FVC; FEV1; FEV1/FVC) were also not different (85-106%) from predicted healthy values. Finally, inclined treadmill (5%, 4km∙h-1) walking economy was not different between the groups (long COVID: 15.2 ± 1.1mL∙kg-1∙min-1; controls: 15.2 ± 1.2mL∙kg-1∙min-1), while the 6MWT revealed a difference (long COVID: 606 ± 118m; controls: 685 ± 85m; p = 0.036). V̇O2max, oxygen cost of walking, and spirometry measurements did not appear to be impaired in patients diagnosed with long COVID with a prior mild to moderate SARS-CoV-2 infection. The typical outcomes in these essential factors for health and longevity implies that while long COVID can present with a range of symptoms, caution should be made when attributing these symptoms directly to compromised pulmonary function or V̇O2max.

The Effect of Variable Continuous Training Compared To HIIT On VO2 Max In Athletes: A Systematic Review

The Effect of Variable Continuous Training Compared To HIIT On VO2 Max In Athletes: A Systematic Review

The dual timescales of gait adaptation: initial stability adjustments followed by subsequent energetic cost adjustments.

Gait adaptation during bipedal walking allows people to adjust their walking patterns to maintain balance, avoid obstacles and avoid injury. Adaptation involves complex processes that function to maintain stability and reduce energy expenditure. However, the processes that influence walking patterns during different points in the adaptation period remain to be investigated. We assessed split-belt adaptation in 17 young adults aged 19-35. We also assessed individual aerobic capacity to understand how aerobic capacity influences adaptation. We analyzed step lengths, step length asymmetry (SLA), mediolateral margins of stability, positive, negative and net mechanical work rates, as well as metabolic rate during adaptation. Dual-rate exponential mixed-effects regressions estimated the adaptation of each measure over two timescales; results indicate that mediolateral stability adapts over a single timescale in under 1 min, whereas mechanical work rates, metabolic rate, step lengths and SLA adapt over two distinct timescales (3.5-11.2 min). We then regressed mediolateral margins of stability, net mechanical work rate and metabolic rate on SLA during early and late adaptation phases to determine whether stability drives early adaptation and energetic cost drives late adaptation. Stability predicted SLA during the initial rapid onset of adaptation, and mechanical work rate predicted SLA during the latter part of adaptation. Findings suggest that stability optimization may contribute to early gait changes and that mechanical work contributes to later changes during adaptation. A final sub-analysis showed that aerobic capacity levels <36 and >43 ml kg-1min-1 resulted in greater SLA adaptation, underscoring the metabolic influences on gait adaptation. This study illuminates the complex interplay between biomechanical and metabolic factors in gait adaptation, shedding light on fundamental mechanisms underlying human locomotion.

Genotypic Influences on Actuators of Aerobic Performance in Tactical Athletes

Background: This study examines genetic variations in the systemic oxygen transport cascade during exhaustive exercise in physically trained tactical athletes. Research goal: To update the information on the distribution of influence of eleven polymorphisms in ten genes, namely ACE (rs1799752), AGT (rs699), MCT1 (rs1049434), HIF1A (rs11549465), COMT (rs4680), CKM (rs8111989), TNC (rs2104772), PTK2 (rs7460 and rs7843014), ACTN3 (rs1815739), and MSTN (rs1805086)—on the connected steps of oxygen transport during aerobic muscle work. Methods: 251 young, healthy tactical athletes (including 12 females) with a systematic physical training history underwent exercise tests, including standardized endurance running with a 12.6 kg vest. Key endurance performance metrics were assessed using ergospirometry, blood sampling, and near-infrared spectroscopy of knee and ankle extensor muscles. The influence of gene polymorphisms on the above performance metrics was analyzed using Bayesian analysis of variance. Results: Subjects exhibited good aerobic fitness (maximal oxygen uptake (VO2max): 4.3 ± 0.6 L min−1, peak aerobic power: 3.6 W ± 0.7 W kg−1). Energy supply-related gene polymorphisms rs1799752, rs4680, rs1049434, rs7843014, rs11549465, and rs8111989 did not follow the Hardy–Weinberg equilibrium. Polymorphisms in genes that regulate metabolic and contractile features were strongly associated with variability in oxygen transport and metabolism, such as body mass-related VO2 (rs7843014, rs2104772), cardiac output (rs7460), total muscle hemoglobin content (rs7460, rs4680), oxygen saturation in exercised muscle (rs1049434), and respiration exchange ratio (rs7843014, rs11549465) at first or secondary ventilatory thresholds or VO2max. Moderate influences were found for mass-related power output. Conclusions: The posterior distribution of effects from genetic modulators of aerobic metabolism and muscle contractility mostly confirmed prior opinions in the direction of association. The observed genetic effects of rs4680 and rs1049434 indicate a crucial role of dopamine- and lactate-modulated muscle perfusion and oxygen metabolism during running, suggesting self-selection in Swiss tactical athletes.

Moderate-Duration Dynamic Stretching During Warm-up Improves Running Economy and Running Performance in Recreational Distance Runners.

The purpose of this study was to investigate, in distance runners, the acute effects of moderate durations (60s per leg) of static (SS) and dynamic stretching (DS) on running economy (RE) and performance. Twelve recreational runners completed a randomized crossover design. Initially, the second ventilatory threshold (VT2) and the speed associated with the maximal oxygen uptake (VO2max) (vVO2max) were determined through an incremental test. Then, participants completed submaximal continuous-running (75%VT2 and 85%VT2) and running-until-exhaustion (vVO2max) tests preceded by 3 warm-ups: running plus SS or DS (SS or DS conditions) and running without stretching (NS condition). TheSS and DS conditions consisted of 5minutes of running plus 10minutes of SS or DS, respectively, and theNS condition consisted of 15minutes of running without stretching. RE at 75%VT2 and 85%VT2, time to exhaustion, and total running distance were evaluated. Rating of perceived exertion was also assessed. Running economy at75%VT2 resulted significantly better in the DS than in theNS (P < .001) and in the SS (P < .05). Time to exhaustion and total running distance were significantly improved in DS compared with NS (P < .001) and SS (P < .01). No differences in rating of perceived exertion among conditions were found. Our results showed that, in recreational distance runners, a preexercise moderate-duration bout of DS improved RE and enhanced total running distance and time to exhaustion, whereas 60seconds of SS did not induce significant improvements. Overall, our study demonstrates the effectiveness of moderate DS durations in optimizing RE and performance parameters, showing that such effects depend on the stretching modality used.

Comparison between VO2 max and serum lactate levels of male body builders and non-body builders in Pakistan

ABSTRACT BACKGROUND AND OBJECTIVE: Volume oxygen maximum (VO2max) is a measure of physical fitness and athletic performance. Lactate accumulation during exercise occurs when anaerobic metabolism predominates. There is a difference of opinion among researchers on the intensity of exercise needed to cause this release and whether lactate levels play a role in it. The study aims to determine the effect of VO2max on the circulatory lactate levels and assess the comparison between the two parameters in male bodybuilders steroid non-users. METHODOLOGY: This study was conducted at the exercise physiology laboratory at the Postgraduate medical institute (PGMI) Lahore, Pakistan. The study involved 20 healthy male subjects within the age range of 20 to 35 years recruited through convenient non-probability sampling. Group I: non-bodybuilders, Group II: bodybuilders not using anabolic steroids. All participants underwent a graded exercise test on cardiopulmonary exercise testing (CPET) equipment up till exhaustion for VO2max assessment. Blood sampling was done pre and post-exercise (80% of VO2max) to measure blood lactate levels. Data was analyzed by SPSS version 23. Mean ± SD was calculated for quantitative variables. Paired t-test was used for comparison for pre- and post-exercise test variables. p-value &lt;0.05 taken as statistically significant. RESULTS: Bodybuilders achieved a significantly higher VO2max as compared to non-bodybuilders (p &lt;0.001). Blood lactate levels increased significantly in all the study groups at an exercise intensity of 80% of VO2max (p &lt;0.001). CONCLUSION: Exercise intensity of 80% of VO2max is sufficient for the significant increase in blood lactate levels.

Yoga for Psychophysiological Wellbeing during Menstrual Phases in Eumenorrheic Females.

Hormonal shifts during the menstrual cycle (MC) cause autonomic imbalances and psycho-physiological distress in eumenorrheic females. This present study reveals that yoga proactively improves the overall psychophysiological health and wellness in eumenorrheic female college students during different phases of MC. Healthy eumenorrheic female college students (Mage= 20.11 ± 5.39 years, n = 82) were randomized to a control and yoga group (n = 41). A well-conceptualized yoga module (CYM) for 5 days/week for 3 months (1h daily in the morning) was practiced by the yoga group volunteers. Intra and intergroup comparisons were performed for the estimation of mindfulness awareness scale (MAAS), menstrual distress questionnaire (MDQ), cardiometabolic risk factors, heart rate variability (HRV), and endurance fitness during the luteal (LP) and follicular (FP) phases. Psychophysiological discomforts before CYM practice were mostly observed during LP compared to FP due to significant changes in mindfulness, pain, concentration, autonomic reactivity, negative affect, double product (DoP), rate pressure product (RPP), and HRV values. CYM practice influenced HRV parameters for an increase in parasympathetic activity and a decrease in sympathetic balance for better cardiac-autonomic functioning, with significant improvement in maximal oxygen consumption (VO2max) and physical work capacity (PWC170). Accordingly, MAAS and MDQ scores also improved significantly after yogic practice. The intra-group and inter-group significant improvements in psychophysiological parameters through CYM practice are relevant in eumenorrheic females to perform effectively throughout their MC period, by improving MC distress and sympathovagal (LF/HF) balance.

Effectiveness of exercise-based rehabilitation on functionality and quality of life in breast cancer survivors undergoing chemo-radiotherapy: A systematic review and meta-analysis

Abstract Breast cancer survivors often face physical and psychological complications post-chemoradiotherapy, including fatigue, muscle weakness, pain, and reduced quality of life (QoL). This systematic review and meta-analysis, conducted according to PRISMA guidelines, aimed to evaluate the effectiveness of exercise-based rehabilitation in improving functionality and QoL in breast cancer survivors. Databases such as MEDLINE, PEDro, Cochrane Library, and CINAHL Complete were searched for studies published between January 2014 and August 2024. The methodological quality was assessed using the PEDro scale, and bias was evaluated with the Cochrane RoB 2.0 tool. Evidence certainty was determined via the GRADE framework. The intervention significantly reduced fatigue (standardized mean difference [SMD] = −0.50, 95% confidence interval [CI]: −0.60 to −0.40, P &lt; 0.00001). However, no significant effect was observed for aerobic capacity (VO2 max) (SMD = −0.06, 95% CI: −0.58–0.46; P = 0.83), though long-term interventions showed slight improvements. Muscle strength significantly increased (SMD = 1.02, 95% CI: 0.17–1.87, P = 0.02), with gains in both upper and lower limbs. Pain outcomes were mixed, with long-term interventions showing a small but significant reduction (SMD = −0.35, 95% CI: −0.69 to −0.02, P = 0.05). QoL significantly improved (SMD = 0.94, 95% CI: 0.42–1.46, P = 0.0004), with long-term interventions showing greater effects (SMD = 1.25, 95% CI: 0.34–2.15, P = 0.007). In conclusion, exercise-based rehabilitation reduces fatigue, improves muscle strength, and enhances QoL. Standardized protocols are needed to generalize benefits across broader populations. that these benefits can be generalized across broader populations. Further research should focus on developing tailored and standardized exercise regimens to maximize patient outcomes.

Physical Demand Assessment of Volunteer Firefighters During Wildland Firefighting

Wildland firefighting is physically and mentally demanding. The aerobic capacity of firefighters is important due to the demands of the activity and the associated occupational risks. The main objectives of this study were to identify and characterise the physically demanding tasks undertaken by volunteer firefighters during wildland fires (real work conditions). A total of 125 firefighters replied to a survey about sociodemographic, biometric data, and work fitness assessment. A group of 23 was evaluated in a physical stress test using a VO2peak protocol to determine maximum oxygen consumption and ventilatory thresholds. The physical demands and physiological responses were collected during the operations at the firefront (n = 21). The results revealed that wildland firefighting entails physical demands that exceed established reference values, with maximum oxygen uptake exceeding 40%. The cardiovascular strain is particularly notable in tasks performed near the firefront, reflecting fatigue. The physical and cardiac demands associated with forest fire fighting have been demonstrated to contribute to occupational illnesses with prolonged exposure. This study underscores the imperative for interventions to enhance the identification and real-time monitoring of physiological parameters to enhance firefighters’ overall health and well-being.

The Implication of NT-proBNP in the Assessment of the Clinical Phenotype of Patients with Type 2 Diabetes Mellitus, Without Established Cardiovascular Disease

Background: Natriuretic peptide (NP) levels have been proposed for characterization and risk stratification of heart failure (HF) among patients with cardiovascular disease (CVD). However, their role in patients with diabetes mellitus type 2 (T2DM) has not been well studied and understood. The aim of this study was to assess phenotypical, functional characteristics and imaging parameters in relation to N-terminal pro b-type natriuretic peptide (NT-proBNP) values in T2DM patients without known CVD that may predispose to overt HF. Methods: This was a cross-sectional study of 100 consecutive T2DM patients (mean overall age of 67 ± 9 years, 40% women and 60% men) who were enrolled from the outpatient diabetic clinic. Patients underwent a cardiopulmonary exercise test (CPET), and echocardiographic and cardiac magnetic resonance imaging (CMR); serum NT-proBNP was also measured. Results: The mean (standard deviation) NT-proBNP was 149 (±186) pg/mL. Patients in the highest tertile of NT-proBNP values (&gt;107 pg/mL) had lower values of predicted maximum oxygen consumption compared to the lowest quartile (&lt;55 pg/mL) (84% vs. 92%, p = 0.018) in the CPET and higher ratio of early diastolic mitral inflow velocity to early diastolic mitral annulus velocity (E/e′) (9.0 vs. 7.2, p = 0.05) in echocardiography. Finally, there was a negative correlation between right ventricle end diastolic volume in CMR and predicted maximum oxygen consumption (b = −0.225 ± 0.11, p = 0.046). Conclusions: NT-proBNP levels seemed to be a useful marker in people with T2DM, as elevated levels reflected ongoing appearance of HF with preserved ejection fraction and were related to CPET and echocardiographic indices of impaired left ventricular diastolic and right ventricular systolic function.

Effects of Hyperthermia and Acidosis on Mitochondrial Oxidative Phosphorylation.

The intracellular environment of skeletal muscle can develop pronounced hyperthermia and acidosis during strenuous exercise, and these alterations in the typical intracellular conditions have been shown to alter mitochondrial respiration. However, the impact of these conditions on ATP synthesis is poorly understood. We used Thoroughbred racehorses to test the hypothesis that both hyperthermia and acidosis decrease the rate of ATP synthesis, but that athletic conditioning mitigates this loss of phosphorylation capacity. Isolated mitochondria were harvested from skeletal muscle before and after a 9-week racetrack conditioning program that increased whole-body aerobic capacity by 19%, and oxidative phosphorylation capacity was tested ex vivo under normothermic and hyperthermic conditions, as well as normal pH and acidic pH created by the addition of lactic acid. In unfit horses, hyperthermia caused a 30-55% decrease in the rate of ATP synthesis and loss of phosphorylation efficiency (P/O ratio decreased from 4.2 to 1.7 during maximal oxidative phosphorylation). Aerobic conditioning resulted in increased phosphorylation efficiency under hyperthermic conditions. Lactic acidosis had a small negative effect on ATP synthesis in unfit horses, but aerobic conditioning increased the sensitivity of isolated mitochondria to the deleterious effects of lactic acidosis. These data support a prominent role of hyperthermia in skeletal muscle fatigue during exercise, particularly in unfit subjects. However, acidosis may be a more important cause of failure of ATP synthesis in fit subjects.