VO2max Research Articles

From surgery to functional capacity: muscle strength modifications in women post sleeve gastrectomy.

Severe obesity is characterized by excessive accumulation of fat generating a general health decline. Multidisciplinary treatment of obesity leads to significant weight loss in a few patients; therefore, many incur bariatric surgery. The main purpose of the study is to evaluate changes in functional capacity of people with obesity undergoing bariatric surgery and, in parallel, to correlate pre-surgery functional capacity with weight loss to improve exercise prescription during pre-operatory stage. sixty women with diagnosed obesity were included. Maximal oxygen consumption, upper and lower limb strength and level of physical activity were recorded 1 month before and 6 months after sleeve gastrectomy. significant reduction on body weight (-30.1kg) and Body Mass Index (-11.4kg/m2) were highlighted after surgery. Absolute grip strength decreased significantly (-1.1kg), while body weight normalized grip and lower limb strength increased significantly. The level of physical activity increased especially in leisure time (+ 593 METs/week) and active transport (+ 189.3 METs/week). Pre-surgery BMI and age predicted the amount of weight loss after surgery. Sleeve gastrectomy induces a reduction of muscle strength despite the increase of time spent in physical activity. Further research is necessary to integrate these results with data on body composition, and objective evaluation of physical activity level to define useful information for exercise prescription in terms of surgery pre-habilitation. Padova University Hospital Board (protocol n. 2027 dated January 12, 2017).

Physiological and Locomotor Profiling Enables to Differentiate Between Sprinters, 400-m Runners, and Middle-Distance Runners.

Thron, M, Woll, A, Doller, L, Quittmann, OJ, Härtel, S, Ruf, L, and Altmann, S. Physiological and locomotor profiling enables to differentiate between sprinters, 400-m runners, and middle-distance runners. J Strength Cond Res XX(X): 000-000, 2024-Different approaches exist for characterizing athletes, e.g., physiological and locomotor profiling. The aims of this study were to generate and compare physiological and locomotor profiles of male and female runners and to evaluate relationships between the different approaches. Thirty-four highly trained adolescent and young adult female and male athletes (n = 11 sprinters; n = 11,400-m runners; n = 12 middle-distance runners) performed two 100-m sprints on a running track to determine maximal sprinting speed (MSS) and maximal lactate accumulation rate (ċLamax). A cardiopulmonary exercise test was performed on a treadmill to determine maximal aerobic speed (MAS) and maximal oxygen uptake (V̇o2max). Anaerobic speed reserve (ASR) was calculated as the difference between MSS and MAS. Group comparisons were conducted with a 2-way ANOVA (discipline × sex; p < 0.05) and Bonferroni post hoc tests and Cohen's d as effect size. Parameters were correlated by Pearson's correlation coefficients. Maximal aerobic speed and V̇o2max were higher in 400-m and middle-distance runners compared with sprinters (p ≤ 0.02; -2.24 ≤ d ≤ -1.29). Maximal sprinting speed and ċLamax were higher in sprinters and 400-m runners compared with middle-distance runners (0.03 ≤ p ≤ 0.28; 0.73 ≤ d ≤ 1.23). Anaerobic speed reserve was highest in sprinters and lowest in middle-distance runners (p ≤ 0.03; 1.24 ≤ d ≤ 2.79). High correlations were found between ASR and MAS, MSS, and ċLamax (p < 0.01; -0.55 ≤ r ≤ 0.91) and between ċLamax and MSS (p < 0.01; r = 0.74). Our results indicate that athletes of different sprinting and running disciplines show differing physiological and locomotor profiles, and that the parameters of these approaches are related to each other. This can be of interest for assessing strengths and weaknesses (e.g., for talent identification) or training prescription in these disciplines.

Possibilities of backward walking application in the rehabilitation of patients with gonarthrosis: review

INTRODUCTION. Osteoarthritis of the knee joint or gonarthrosis (GA) is one of the most common joint pathologies. The medical and social significance of GA is associated with its high prevalence and a significant percentage of premature disability and a significant deterioration in the quality of life due to persistent pain syndrome. Modern treatment of patients with GA includes a combination of pharmacological and non-pharmacological methods; physical therapy is the leading method of non-drug therapy. By now, a number of studies have been conducted to research the effectiveness of backward walking (BW) in people with GA. AIM. Analysis of scientific data on the possibilities of using BW in the rehabilitation of patients with GA. MATERIALS AND METHODS. A systematic search of literary sources by keywords was carried out: “backward walking”, “gonarthrosis”, “knee osteoarthritis”, “knee joint”, “rehabilitation”, “physical therapy”. DISCUSSION. Recently, backward locomotion is increasingly used in medicine. Kinetic and kinematic analysis during BW showed a number of advantages over the usual method of movement, which can be successfully used for rehabilitation of patients with GA. BW is associated with less overload on knee joints. It is also one of the few natural ways of strengthening the quadriceps. It prevents excessive stretching of the anterior cruciate ligament and improves the stability of the knee joint. BW leads to a more cardiovascular and respiratory load and a more significant aerobic and anaerobic capacity of the organism compared with forward walking at similar parameters of physical activity. CONCLUSION. There is evidence that adding BW to conventional physiotherapy treatment may further reduce pain, functional disability and improve the strength of the quadriceps muscles.

Cardiovascular crossroads - exploring the impact of atrial fibrillation on mitral valve regurgitation and MitraClip treatment

Abstract Introduction The use of the MitraClip technique is becoming increasingly popular as a treatment option for patients suffering from mitral valve regurgitation who are not suitable for surgery. It is unclear how pre-existing atrial fibrillation impacts patients during the procedure. Purpose The question arises: What is the underlying cause of atrial fibrillation in patients with significant mitral valve involvement and why do some patients remain unaffected? This study aims to compare and identify differences in cohorts of patients with and without atrial fibrillation before the MitraClip procedure. Methods We analyzed a register of 279 patients who underwent MitraClip treatment. The study classified the patients according to the presence (n=140, 50%) or absence (n=139, 50%) of atrial fibrillation prior to the procedure. We utilized univariate analysis to compare demographic, clinical, and echocardiographic parameters. Multivariate logistic regression was also performed to determine significant predictors. Results Both cohorts were of similar size, but there were significant differences in certain parameters. Women were more frequent in the group without atrial fibrillation (45% compared to 34%, p=0.045). The group with atrial fibrillation was slightly older (73 years compared to 70 years, p&amp;lt;0.001) and had a lager body surface area (1.95 compared to 1.87, p=0.005). Parameters such as Euroscore II, NT-proBNP and creatinine levels were not significantly different. Nevertheless, it is important to note that the group with atrial fibrillation had a greater transverse dimension of the left atrium (55 compared to 50, p&amp;lt;0.001). Additionally, the atrial fibrillation group exhibited a higher degree of tricuspid regurgitation (2.9 vs 2.0, p=0.007) and a slightly lower baseline VO2 max (11.63 vs 12.59, p&amp;lt;0.001). Multivariate logistic regression revealed that baseline tricuspid regurgitation is a significant predictor of atrial fibrillation, with and odds ratio of 2.066 (95% CI: 1.041-4.097, p=0.038). Conclusion During the MitraClip procedure, patients with atrial fibrillation demonstrate certain specific characteristics, including older age, increased body surface area, larger left atrial size, and higher grade of tricuspid regurgitation. The significant association of tricuspid regurgitation with atrial fibrillation emphasizes its potential role in clinical evaluation and subsequent treatment.

Assessing Maximal Oxygen Uptake: Influence of Leg Length in the Harvard Step Test and Queen’s College Step Test

Maximal oxygen uptake (VO2max) indicates cardiovascular endurance in evaluating overall health and physical performance. The CPX method is accurate, but accessibility is lower due to issues related to cost and complexity. For this reason, the Harvard Step Test and Queen's College Step Test are drawing interest. Step-based tests are influenced by factors such as leg length, requiring an investigation into the correlation between leg length and VO₂max estimation using these methods. This study investigates the influence of leg length on predicted VO₂max (pVO2max) determined through both the Harvard Step Test and the Queen's College Step Test. The assessment of VO2max was carried out using CPX on a treadmill. Measurements were obtained through the Harvard Step Test and Queen's College Step Test on steps. The participants were informed about the experimental procedure, and the experiment was conducted 24 hours later. The experiment maintained controlled conditions, and each measurement was conducted as a single trial, repeated three times for accuracy. The study found a significant positive correlation (r = 0.595, P &lt; 0.05) between CPX VO2max and lower leg length. Lower leg length was found to significantly influence exercise intensity as determined by both the Harvard Step Test pVO2max (explaining 35.4% of the variance, P &lt; 0.05) and the Queen's College Step Test pVO2max (explaining 30% of the variance, P &lt; 0.05). It is recommended to adjust the step height to the individual's body size when estimating exercise difficulty or pVO2max using step-based exercises.

EFFECTS OF FACE MASKS ON CARDIORESPIRATORY PARAMETERS DURING EXERCISE VELOERGOMETRY TEST

The COVID-19 pandemic has sparked ongoing scientific discussions about the adverse effects of wearing face masks on cardiorespiratory indicators, and the subjective response to exertion. Many researchers have investigated the impact of wearing face masks on different physiological factors through various exercise routines, such as a progressive cycling test, the 6-minute walk test, and treadmill walking at a constant pace, yielding inconsistent findings. This study aimed to examine the physiological and perceptual responses of wearing surgical face masks during and after the veloegometry test. Fifteen healthy young adults (mean age, 26.8±4.4 years, 5 males and 10 females) conducted the Astrand-Rhyming veloegometry protocol twice (with and without masks). Physiological outcomes (heart rate, maximal oxygen uptake, and oxygen saturation level), perceived exertion, and discomfort feeling by modified Borg scale were assessed. No significant differences were observed in physiological outcomes with or without masks during increasing load intensities (p &gt; 0.05) except for the last minute of testing and the minute after testing (p ≤ 0.005). Participants wearing masks reported the tendency of higher exertion level (3.8±1.08 vs 4.4±0.9) but statistical analysis can't definitively confirm it. While exercising with a face mask may not adversely affect cardiorespiratory factors, it can elevate perceived exertion levels and discomfort, particularly when exercise intensity exceeds a certain threshold.

Exercise capacity after COVID-related multisystem inflammatory syndrome in children-A cross-sectional study

BackgroundAfter recovery from COVID-19 associated multisystem inflammatory syndrome in children (MISC), exercise restrictions were advised for 6 months. Studies done to assess exercise capacity at 3–6 months post recovery from MISC, prior to withdrawal of exercise restrictions, yielded varying information. Whether their exercise capacity was on par with their peers at/beyond 1-year post-recovery needed to be assessed. ObjectivesPrimary: To compare the exercise capacity between children with a history of MISC and unaffected childrenSecondary: To compare the exercise capacity between a) children with a history of MISC and children with a history of COVID but not MISC b) children with a history of COVID but not MISC and unaffected children. MethodsChildren (aged ≥8 years) who had recovered from MISC >1-year ago (n = 21) were compared with unaffected children (n = 42) and children who had COVID but not MISC (n = 21) respectively using cardiopulmonary exercise testing (CPET). Comparisons were made between 1. Post-MISC vs unaffected 2. Post-MISC vs post-COVID 3. Post-COVID vs unaffected. ResultsCompared with unaffected children, post-MISC and post-COVID groups had similar peak oxygen uptake (VO2 max) but significantly lesser exercise duration. Children who were very sick during their hospitalization for MISC had an exercise capacity comparable to others in the post-MISC group. Overweight/obese children in post-MISC group had a significantly lesser exercise capacity. But, the numbers of overweight/obese children and very sick children were not adequate to run a separate sub-group analysis. ConclusionsAt/beyond 1 year post-recovery from MISC, exercise capacity was comparable to healthy children and children who had COVID but not MISC, but exercise duration was significantly less. Overweight/obese children need to be followed up longer with emphasis on regular exercises. Children who were very sick during MISC hospitalization had recovered their exercise capacity.

Optimizing cardiopulmonary rehabilitation duration for long COVID patients: an exercise physiology monitoring approach.

The presence of prolonged symptoms after COVID infection worsens the workability and quality of life. 200 adults with long COVID syndrome were enrolled after medical, physical, and mental screening, and were divided into two groups based on their performance. The intervention group (n = 100) received supervised rehabilitation at Department of Pulmonology, Semmelweis University with the registration number 160/2021 between 01/APR/2021-31/DEC/2022, while an age-matched control group (n = 100) received a single check-up. To evaluate the long-term effects of the rehabilitation, the intervention group was involved in a 2- and 3-month follow-up, carrying out cardiopulmonary exercise test. Our study contributes understanding long COVID rehabilitation, emphasizing the potential benefits of structured cardiopulmonary rehabilitation in enhancing patient outcomes and well-being. Significant difference was found between intervention group and control group at baseline visit in pulmonary parameters, as forced vital capacity, forced expiratory volume, forced expiratory volume, transfer factor for carbon monoxide, transfer coefficient for carbon monoxide, and oxygen saturation (all p < 0.05). Our follow-up study proved that a 2-week long, patient-centered pulmonary rehabilitation program has a positive long-term effect on people with symptomatic long COVID syndrome. Our data showed significant improvement between two and three months in maximal oxygen consumption (p < 0.05). Multidisciplinary, individualized approach may be a key element of a successful cardiopulmonary rehabilitation in long COVID conditions, which improves workload, quality of life, respiratory function, and status of patients with long COVID syndrome.

Kinematics but not kinetics alterations to single-leg drop jump movements following a subject-tailored fatiguing protocol suggest an increased risk of ACL injury.

Neuromuscular fatigue causes a transient reduction of muscle force, and alters the mechanisms of motor control. Whether these alterations increase the risk of anterior cruciate ligament (ACL) injury is still debated. Here we compare the biomechanics of single-leg drop jumps before and after the execution of a fatiguing exercise, evaluating whether this exercise causes biomechanical alterations typically associated with an increased risk of ACL lesion. The intensity of the fatiguing protocol was tailored to the aerobic capacity of each participant, minimizing potential differential effects due to inter-individual variability in fitness. Twenty-four healthy male volunteers performed single leg drop jumps, before and after a single-set fatiguing session on a cycle ergometer until exhaustion (cadence: 65-70 revolutions per minute). For each participant, the intensity of the fatiguing exercise was set to 110% of the power achieved at their anaerobic threshold, previously identified by means of a cardiopulmonary exercise test. Joint angles and moments, as well as ground reaction forces (GRF) before and after the fatiguing exercise were compared for both the dominant and the non-dominant leg. Following the fatiguing exercise, the hip joint was more extended (landing: Δ=-2.17°, p = 0.005; propulsion: Δ=-1.83°, p = 0.032) and more abducted (landing: Δ=-0.72°, p = 0.01; propulsion: Δ=-1.12°, p = 0.009). Similarly, the knee joint was more extended at landing (non-dominant leg: Δ=-2.67°, p < 0.001; dominant: Δ=-1.4°, p = 0.023), and more abducted at propulsion (both legs: Δ=-0.99°, p < 0.001) and stabilization (both legs: Δ=-1.71°, p < 0.001) hence increasing knee valgus. Fatigue also caused a significant reduction of vertical GRF upon landing (Δ=-0.21 N/kg, p = 0.003), but not during propulsion. Fatigue did not affect joint moments significantly. The increased hip and knee extension, as well as the increased knee abduction we observed after the execution of the fatiguing exercise have been previously identified as risk factors for ACL injury. These results therefore suggest an increased risk of ACL injury after the execution of the participant-tailored fatiguing protocol proposed here. However, the reduced vertical GRF upon landing and the preservation of joint moments are intriguing, as they may suggest the adoption of protective strategies in the fatigued condition to be evaluated in future studied.

Role of Mediterranean Diet and Physical Activity in the Prevention and Treatment of Depression

The Mediterranean diet, characterized by an abundance of whole grains, plant foods, olive oil and moderate intake of fish has been associated with a variety of disease outcomes. The Mediterranean diet is recognised as a healthful dietary pattern and has been extensively associated with chronic disease risk reduction. Consumption of food groups in the Mediterranean-based diet has anti-inflammatory and antioxidant properties which improves endothelial function and neuronal membrane composition. Engagement in physical activity, on the other hand, has anti-inflammatory and neuro-chemical effects that sustains cerebral blood flow, improves aerobic capacity and cerebral nutrient supply, and improves secretion of enkephalins and endorphins secreted during exercise.

Effect of supervised nordic walking on glycemic control and maximal aerobic capacity in patients with type 2 diabetes mellitus: a randomized controlled trial

Purpose Amidst the global diabetes crisis, Europe faces mortality and prevalence rates of 10-12%, as reported by the World Health Organisation. The COVID-19 pandemic worsened metabolic concerns, particularly in India. This study delves into the unexplored impact of type 2 diabetes on individuals with a normal BMI, examining the efficacy of supervised nordic walking in improving glycemic control and aerobic capacity compared to standard activity and diet control. Materials and Methods A parallel arm superiority randomised controlled trial enrolled 70 participants (aged 40–65) with type 2 diabetes and BMI <25 kg/m2. The intervention group (n = 35) received 4 weeks of Nordic walking alongside conventional treatment, while the control group (n = 35) received only conventional treatment. Key outcomes included glycated haemoglobin levels, maximum oxygen uptake, and rate of perceived exertion. Results The intervention group exhibited a substantial decrease in glycated haemoglobin (mean difference: 0.58, p < 0.001) compared to the control group, which showed minimal changes (mean difference: 0.09, p > 0.05). Additionally, the intervention group demonstrated significant enhancements in maximal oxygen uptake (p < 0.001) and distance walked (mean difference: 56.74, p < 0.001), whereas the control group experienced minimal alterations. Rate of perceived exertion showed no significant changes in either group. Conclusion Supervised Nordic walking demonstrated notable enhancements in glycemic control and aerobic capacity in individuals with type 2 diabetes and a normal BMI.

Возрастные особенности аэробных возможностей организма у спортсменов с разной направленностью физических нагрузок

The purpose of this study was to identify age-related features of aerobic capacity in athletes working on their endurance or speed-strength qualities. Materials and methods. The research involved 103 male athletes, who were divided into groups according to the type of physical activity (endurance (n = 58) and strength-speed (n = 45)) and age (12–15, 16–18 and 19–26 years). Their aerobic capacity was determined using cardiorespiratory exercise testing. Results. It was shown that the increase in relative peak oxygen consumption (VO2peak) was influenced not so much by age as by the type of physical activity (ANOVA: F = 18.1, p = 0.00004). At the same time, respiratory coefficient (F = 5.6, p = 0.007), heart rate at anaerobic threshold (F = 4.9, p = 0.009), tidal volume (F = 7.5, p = 0.01) and minute ventilation (F = 6.6, p = 0.002) were influenced mainly by age. In athletes aged 12–15 years, factor analysis established a negative correlation of type of physical activity with oxygen pulse, while physical working capacity was positively correlated with breathing parameters. Subjects aged 16–18 years showed no significant correlations between the variables and type of physical activity; at the same time, the number of correlations between ergometry parameters and physical working capacity factor increased with age. In athletes aged 19–26, the variables correlated strongly with the type of physical activity; the contribution of VO2peak to the physical working capacity factor is clearly demonstrated. The development of aerobic capacity is mainly influenced by the type of physical activity. However, in athletes aged 12–15 years, aerobic loads do not lead to a significant increase in VO2peak. The greatest increase in VO2peak is observed in 16–18-year-olds, while after 18 years of age, its growth halts.

Adjunctive hiking bouts during 8weeks regular sailing training improves cardiorespiratory and muscular responses during hiking emulation in highly trained sailors.

To investigate the effects of 8-week hiking bench training on cardiorespiratory and muscular responses of highly trained sailors during hiking emulation. Twenty-four sailors were assigned into two groups: the hiking bench training group (HTG, n=12) and the control group (CG, n=12). Both groups maintained their regular training with the HTG performed two additional hiking bench training sessions per week for 8weeks, while the CG performed an equivalent duration of on-water sailing training. Physiological responses were assessed by performing four successive 3-min hiking bouts on a sailing emulation ergometer before and after the 8-week training period. Comparing the pretest, both groups exhibited a significant decrease (p<0.05) in the percentage of maximal oxygen uptake (%VO2max) and maximal heart rate (%HRmax); the HTG experienced a greater decrease in %VO2max in bouts 2 and 3. The root mean square (RMS) of rectus femoris (RF), vastus lateralis (VL), rectus abdominis (RA), and external oblique decreased significantly (p<0.05), whereas the mean power frequency (MPF) of RF, VL, and RA exhibited an increasing trend. The RMS of RF and RA in HTG were lower than those in CG in the initial three bouts; VL and EA in HTG were lower than those in CG in bouts 1 and 2 (p<0.05). The MPF of RA in HTG was significantly increased in bouts 2, 3, and 4 (p<0.05). Eight-week hiking bench training could improve hiking economy and the activation of lower limb and trunk muscles delaying the onset of fatigue in sailors.

Reliability and validity of the modified shuttle test-paeds to measure cardiorespiratory fitness in children

BackgroundThe Modified Shuttle Test-Paeds (Paeds), a recently developed 10-meter Shuttle run test for aerobic capacity in children. This study aims to investigate the construct validity (known-group and convergent validity) and test-retest reliability of the recently developed test for cardiorespiratory fitness, the Modified Shuttle Test-Paeds (Paeds).MethodsA total of 144 participants (6–12 y) were tested on the Paeds test, and 84 children were tested on the 20-meter Shuttle Run test (20 m-SRT) to assess construct validity. To evaluate test-retest reliability, 46 children were tested twice on the Paeds.ResultsNo sex differences were found, but there was an age effect. A strong correlation was found between Paeds and the 20 m-SRT (rs=0.78, p < 0.001). The test-retest reliability was good (ICC 0.84; 95% CI 0.74–0.91).ConclusionPaeds appears to be a reliable and valid tool for estimating cardiorespiratory fitness in typically developing children aged 6–12 years and has the advantages of being shorter, needing less space, not requiring pacing and being self-motivational. More studies are needed to assess whether children reach an aerobic steady state in three minutes and how much of the results of the Paeds test can be explained by the agility component of the task (turning and grasping or aiming a bean bag). For clinical use, psychometric properties should be studied in various patient groups (e.g., ADHD, DCD, and children with intellectual disabilities).

Unlocking Strength: The Powerful Impact of Ashwagandha (Withania somnifera) Supplementation on Resistance Training

Withania somnifera, commonly known as ashwagandha, has gained popularity in recent years among individuals interested in healthy lifestyles, natural medicine, and sports. This review aims to summarize the current knowledge regarding the effects of ashwagandha supplementation on various aspects of physical performance, particularly in the context of resistance training. Studies have shown that ashwagandha can positively impact muscle strength, with significant increase of muscle force and power output. Additionally, it has demonstrated potential in modulating body composition, with reduction of body fat percentage noted in certain populations. However, results of studies on ashwagandha’s effect on muscle size remain inconclusive and may depend on various factors such as training status and individual responses. In terms of endurance, ashwagandha supplementation has been associated with improvement in maximal oxygen uptake, indicating enhanced aerobic capacity and delayed exhaustion during endurance activities. Furthermore, ashwagandha was shown to aid muscle recovery by reducing exercise-induced muscle damage and inflammatory response, potentially accelerating the muscle regeneration process. Ashwagandha may also influence hormone levels, such as testosterone and cortisol, with potential implications for muscle growth and recovery. However, further research is needed to fully understand the mechanisms underlying these effects. Overall, ashwagandha supplementation appears to hold promise for enhancing physical performance and overall well-being. Further research is needed to elucidate optimal dosages, long-term safety, and potential interactions with other supplements or medications.

The Impact of Exercise Training on Muscle Sympathetic Nerve Activity: A Systematic Review and Meta-Analysis.

The purpose of this systematic review and meta-analysis was to examine the effects of exercise training on muscle sympathetic nerve activity (MSNA) in humans. Studies included exercise interventions (randomized controlled trials [RCTs], non-randomized controlled trials [non-RCTs] or pre-to-post intervention) that reported on adults (>18 years) where MSNA was directly assessed using microneurography, and relevant outcomes were assessed (MSNA [total activity, burst frequency, burst incidence, amplitude], heart rate, blood pressure [systolic blood pressure, diastolic blood pressure, or mean blood pressure], and aerobic capacity [maximal or peak oxygen consumption]). 40 intervention studies (n=1,253 individuals) were included. RCTs of exercise compared to no exercise illustrated that those randomized to the exercise intervention had a significant reduction in MSNA burst frequency and incidence compared to controls. This reduction in burst frequency was not different between individuals with cardiovascular disease compared to those without. However, the reduction in burst incidence was greater in those with cardiovascular disease (9 RCTs studies, n = 234, MD -21.08 bursts/100 hbs; 95% CI -16.51, -25.66; I2 = 63%) compared to those without (6 RCTs, n = 192, MD -10.92 bursts/100 hbs; 95% CI -4.12, -17.73; I2 = 76%). Meta-regression analyses demonstrated a dose-response relationship where individuals with higher burst frequency and incidence pre-intervention had a greater reduction in values post-intervention. These findings suggest that exercise training reduces muscle sympathetic nerve activity, which may be valuable for improving cardiovascular health.

Six-minute walk test in healthy British service personnel

IntroductionThe 6 min walk test (6MWT) is a widely used, safe and effective submaximal exercise test. The primary outcome is the distance walked, but additional physiological and patient-reported metrics can...

Respiratory and Metabolic Responses of CD4 + T Cells to Acute Exercise and their Association with Cardiorespiratory Fitness.

The study aimed to investigate to what extent acute endurance exercise, especially eccentric exercise and cardiorespiratory fitness affect the metabolic profile of CD4 + cells. 15 male, healthy adults aged between 20 and 33 years with a maximal oxygen uptake (VO 2max ) between 44 and 63 ml/kg/min performed a downhill run (DR) and a level run (LR) for 45 minutes at 70% of their VO 2max on a treadmill in a cross-over design. Blood samples were taken before (T0), directly after (T1), 3 hours after (T3), and 24 hours (T24) after each exercise for analyzing leukocyte numbers and cytokine levels. Isolated CD4 + cells were incubated for 4 hours in autologous resting versus 3 hours after exercise serum (T3 DR and T3 LR), and subsequently, cellular respiration, transcriptomic, and metabolomics profiles were measured. The systemic immune inflammation index increased significantly after DR and LR at T1 and T3 (p < .001). In contrast, the transcriptomic and metabolic profile of CD4 + cells showed no significant alterations after incubation in T3 exercise serum. However, cardiorespiratory fitness positively correlated with the maximal mitochondrial respiration in CD4 + cells after incubation with T3 LR serum (r = .617, p = .033) and with gene expression of oxidative phosphorylation and levels of different metabolites. Similarly, VO 2max was associated with an anti-inflammatory profile on RNA level. Lower lactate, methylmalonic acid, and D-gluconic acid levels were found in CD4 + cells of participants with a high VO 2max (p < .001). Acute exercise leads to a mild pro-inflammatory milieu with only small changes in the metabolic homeostasis of CD4 + cells. High cardiorespiratory fitness is associated with a metabolic shift to oxidative phosphorylation in CD4 + cells. Functional relevance of this metabolic shift needs to be further investigated.

Impact of MCT Oil and Caffeine on Substrate Metabolism during Submaximal Exercise

Introduction: Recent research has suggested that medium-chain triglyceride (MCT) supplementation may increase fat oxidation (FatOx) during aerobic exercise, sparing muscle glycogen and, perhaps, enhancing performance. As both MCT and caffeine (CAF) are theorized to elicit these effects, this pilot study’s purpose was to compare the physiological responses of their combined supplementation during submaximal cycling exercise. Methods: Eight aerobically trained males (mean±SD; age 23.6±4.4 years; body mass 82.3±15.8 kg; height 180.9±8.7 cm) completed one aerobic capacity (VO2peak) test and three 45-min exercise trials at 60% VO2peak. Blinded and counterbalanced, one-hour prior to each trial, participants consumed: MCT+CAF (20 mL + 100 mg), long-chain triglycerides (LCT)+CAF (40 mL + 100 mg), or CAF (100 mg). Oxygen consumption (VO2), carbon dioxide output (VCO2), and minute ventilation (VE) were measured, subsequently calculating respiratory exchange ratio (RER), energy expenditure (EE), carbohydrate oxidation (CarbOx), and FatOx. Results: No significant differences between conditions were observed for average VO2 (p=0.474; η2=0.101), VE (p=0.323; η2=0.149), (RER (p=0.323; η2=0.149), EE (p=0.474; η2=0.101), CarbOx (p=0.274; η2=0.169), or FatOx (p=0.478; η2=0.100) or for total EE (p=0.474; η2=0.101), CarbOx (p=0.274; η2=0.169), or FatOx (p=0.478; η2=0.100). Conclusions: Co-ingestion of MCT+CAF didn’t produce any significantly different physiological responses compared to co-ingestion of LCT+CAF or the CAF control.

Longitudinal changes in anthropometric, physiological, and physical qualities of international women's rugby league players.

This is the first study to assess longitudinal changes in anthropometric, physiological, and physical qualities of international women's rugby league players. Thirteen forwards and 11 backs were tested three times over a 10-month period. Assessments included: standing height and body mass, body composition measured by dual x-ray absorptiometry (DXA), a blood panel, resting metabolic rate (RMR) assessed by indirect calorimetry, aerobic capacity (i.e.,[Formula: see text]) evaluated by an incremental treadmill test, and isometric force production measured by a force plate. During the pre-season phase, lean mass increased significantly by ~2% for backs (testing point 1: 47 kg; testing point 2: 48 kg) and forwards (testing point 1: 50 kg; testing point 2: 51 kg) (p = ≤ 0.05). Backs significantly increased their [Formula: see text] by 22% from testing point 1 (40 ml kg-1 min-1) to testing point 3 (49 ml kg-1 min-1) (p = ≤ 0.04). The [Formula: see text] of forwards increased by 10% from testing point 1 (41 ml kg-1 min-1) to testing point 3 (45 ml kg-1 min-1), however this change was not significant (p = ≥ 0.05). Body mass (values represent the range of means across the three testing points) (backs: 68 kg; forwards: 77-78 kg), fat mass percentage (backs: 25-26%; forwards: 30-31%), resting metabolic rate (backs: 7 MJ day-1; forwards: 7 MJ day-1), isometric mid-thigh pull (backs: 2106-2180 N; forwards: 2155-2241 N), isometric bench press (backs: 799-822 N; forwards: 999-1024 N), isometric prone row (backs: 625-628 N; forwards: 667-678 N) and bloods (backs: ferritin 21-29 ug/L, haemoglobin 137-140 g/L, iron 17-21 umol/L, transferrin 3 g/L, transferring saturation 23-28%; forwards: ferritin 31-33 ug/L, haemoglobin 141-145 g/L, iron 20-23 umol/L, transferrin 3 g/L, transferrin saturation 26-31%) did not change (p = ≥ 0.05). This study provides novel longitudinal data which can be used to better prepare women rugby league players for the unique demands of their sport, underpinning female athlete health.