Dose-response relationship between 15 weeks of running and aerobic fitness: a retrospective analysis based on the fun running program.

BACKGROUND: Students' physical fitness, particularly aerobic fitness, has seriously declined during the COVID-19 epidemic. However, in the post-epidemic era, there are few studies on the methods of improving aerobic fitness. Understanding the dose-response relationship between physical activity and aerobic fitness is crucial for developing effective exercise prescriptions. METHOD: This retrospective study reviewed the Fun Running program at Wannan Medical College in China. We conducted a pre-post study design to analyze the impact of 15 weeks of Fun Running training on aerobic fitness. Middle and long-distance running pace (MLDR-P) was used as the primary indicator of aerobic fitness. A paired sample T-test was used to analyze the differences between the two MLDR-Ps. Pearson's correlation was used to examine the correlation between variables. Multiple linear regression was used to determine the extent to which Fun Running components explain the variance in MLDR-P. RESULTS: A total of 3244 college students participated in this study. 15 weeks of Fun Running training can significantly improve the MLDR-P in both females (P < 0.001, ES = 0.68) and males (P < 0.001, ES = 0.72). The MLDR-P was significantly correlated with Fun Running (R2 = 0.95, p < 0.05, for females; R2 = 0.96, p < 0.05, for males). The component that had the greatest impact on MLDR-P was pace (ß = 1.39, for females; ß = 1.09, for males), followed by distance (ß = 0.49, for females; ß = 0.15, for males), and last frequency (ß = -0.03, for all). CONCLUSION: This study fills the gap in research on the dose-response relationship between running and aerobic fitness among college students in the post-epidemic era. The results show that 15 weeks of Fun Running training can significantly improve aerobic fitness. Examination of the dose-response relationship between Fun Running and MLDR-P provides practitioners with valuable insights into prescribing aerobic fitness training, allowing them to develop more effective training programs. Future research should focus on how to implement a hierarchical Fun Running program effectively.

Near-InfraRed Spectroscopy Provides a Reproducible Estimate of Muscle Aerobic Capacity, but Not Whole-Body Aerobic Power.

Near-infrared spectroscopy (NIRS) during repeated limb occlusions is a noninvasive tool for assessing muscle oxidative capacity. However, the method's reliability and validity remain under investigation. This study aimed to determine the reliability of the NIRS-derived mitochondrial power of the musculus vastus lateralis and its correlation with whole-body (cycling) aerobic power (V̇O2 peak). Eleven healthy active men (28 ± 10 y) twice (2 days apart) underwent repeated arterial occlusions to induce changes in muscle oxygen delivery after 15 s of electrical muscle stimulation. The muscle oxygen consumption (mV̇O2) recovery time and rate (k) constants were calculated from the NIRS O2Hb signal. We assessed the reliability (coefficient of variation and intraclass coefficient of correlation [ICC]) and equivalency (t-test) between visits. The results showed high reproducibility for the mV̇O2 recovery time constant (ICC = 0.859) and moderate reproducibility for the k value (ICC = 0.674), with no significant differences between visits (p > 0.05). NIRS-derived k did not correlate with the V̇O2 peak relative to body mass (r = 0.441, p = 0.17) or the absolute V̇O2 peak (r = 0.366, p = 0.26). In conclusion, NIRS provides a reproducible estimate of muscle mitochondrial power, which, however, was not correlated with whole-body aerobic capacity in the current study, suggesting that even if somewhat overlapping, not the same set of factors underpin these distinct indices of aerobic capacity at the different (peripheral and whole-body systemic) levels.

The effects of telerehabilitation in adults with complex biventricular congenital heart conditions: protocol for a multi-centre, randomised controlled trial-CH-FIT.

BACKGROUND: Accumulated evidence suggests that exercise training exerts beneficial effects on people with congenital heart conditions. These findings are predominantly derived from small, single-centre exercise trials conducted in outpatient rehabilitation facilities. In recent years, the delivery of exercise interventions remotely has increased through digital communications technology (telerehabilitation). However, very little research to date has been conducted into the efficacy of telerehabilitation in people with a congenital heart condition. AIMS: To evaluate the effects of a telehealth-delivered exercise intervention in people with a history of a surgical biventricular repair due to a congenital heart condition. METHODS: One hundred eligible adolescent (≥ 16 years) and adult participants living with a complex biventricular congenital heart condition will be recruited from four Australian sites and randomised to either (1) a 16-week telehealth-delivered combined (aerobic and resistance) exercise training programme of moderate-to-vigorous intensity or (2) usual care (control group), in a 1:1 allocation, with an 8-month follow-up. OUTCOMES OF INTEREST: The primary outcome will be the change in aerobic capacity expressed as peak oxygen uptake (VO2peak). Secondary outcomes will include changes in vascular function, muscle oxygenation, metabolic profile, body composition and musculoskeletal fitness, neurohormonal activation, neurocognitive function, physical activity levels, dietary and nutritional status, and quality of life. Outcomes will be assessed at baseline, 16 weeks, and 12 months (to determine longer-term maintenance potential). DISCUSSION: If found to be efficacious, telerehabilitation may be an alternative option for delivering exercise, improving health outcomes, and increasing accessibility to exercise programmes. Efficacy data is required to quantify the clinical significance of this delivery mode of exercise. TRIAL REGISTRATION: ACTRN12622000050752 Trial registration date: 17 January 2022 Trial registration URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=382635&showOriginal=true&isReview=true Trial registry name: Australian and New Zealand Clinical Trials Registry.

Aerobic fitness as a moderator of acute aerobic exercise effects on executive function.

This study aimed to investigate the moderating role of aerobic fitness on the effect of acute exercise on improving executive function from both behavioral and cerebral aspects. Thirty-four young individuals with motor skills were divided into high- and low-fitness groups based on their maximal oxygen uptake. Both groups completed 30 min of moderate-intensity aerobic exercise on a power bike. Executive function tests (Flanker, N-back, More-odd-shifting) were performed before and after exercise and functional near-infrared spectroscopy was used to monitor prefrontal cerebral blood flow changes during the tasks. The results indicated significant differences between the two groups regarding executive function. Participants with lower aerobic fitness performed better than their higher fitness counterparts in inhibitory control and working memory, but not in cognitive flexibility. This finding suggests that the aerobic fitness may moderate the extent of cognitive benefits gained from acute aerobic exercise. Furthermore, the neuroimaging data indicated negative activation in the frontopolar area and dorsolateral prefrontal cortex in response to three complex tasks. These findings underscore the importance of considering individual aerobic fitness when assessing the cognitive benefits of exercise and could have significant implications for tailoring fitness programs to enhance cognitive performance.

Immediate effect of physical activity on the autonomic nervous system in individuals with autism spectrum disorders of different age groups: a randomised trial.

Background: Autism spectrum disorder (ASD) is one of the most complex neurodevelopmental disorders. It affects almost all human physiological systems. Individuals with ASD often display dysregulation in their autonomic nervous system (ANS), which may elicit differing effects across age groups. Also, studying the ANS missed several important parameters related to ANS. Studying the ANS is crucial in developing adaptive behavioural strategies and maintaining communication abilities and social behaviours. Thus, this study compared the immediate effect of physical activity on the ANS in individuals with ASD in different age groups. Methods: 200 participants (106 males and 94 females) took part in a double-blinded randomised design. All participants were divided into four groups according to their age (4-7, 7-10, 10-13 and 14-18 years old). Participants performed a 60 min treadmill walk. The main outcome measurements were heart rate (HR), saturation of peripheral oxygen (SpO2), respiratory rate (RR) and end-tidal carbon dioxide (etCO2). Results: Before the study, there were non-significant differences between groups in their physical characteristics (body mass index, Childhood Autism Rating Scale, physical activity level, both parents' existence, aerobic capacity and gender) (p>0.05). At baseline measurements, there were non-significant differences between all groups for all outcome measurements (p>0.05). Immediately after physical activity, there was significant difference between group 1 and other groups (p<0.05), while all other differences were non-significant (p>0.05). At the follow-up (after 15 min of rest), group 1 maintained significant differences with the other groups for all outcome measurements (p<0.05), while there were non-significant differences between the other three groups (p>0.05). Conclusion: This study revealed that the SpO2 significantly decreased immediately after the physical activity, while HR, RR and etCO2 significantly increased immediately after physical activity in comparison to the baseline measurements. Contrary to other ANS parameters (SpO2, RR and etCO2), HR in early ages (4-7 years old) was higher after physical activity and remained elevated longer than other ages. The early ages (4-7 years old) take more time to return to the normal status of ANS parameters including SpO2, HR, RR and etCO2. Trial registration number: NCT05725733.

Functional electrical stimulation combined with voluntary cycling accentuates VO2 response in people with severe multiple sclerosis: A pilot study.

BACKGROUND: Lower limb muscle weakness and reduced balance due to disease progression in multiple sclerosis (MS) may make robust aerobic exercise difficult. Functional electrical stimulation (FES) cycling combined with voluntary cycling may allow people with severe MS to enhance the intensity of aerobic exercise. The aim of this study was to investigate the cardiorespiratory, power, and participant-reported perceptions during acute bouts of FES cycling, voluntary cycling, and FES cycling combined with voluntary cycling (FES assist cycling). METHODS: Participants with severe MS (Expanded Disability Status Scale [EDSS] ≥ 6.0) undertook three exercise trials on a leg cycle ergometer. Trial 1 involved 30 min of FES cycling; Trial 2 involved two 10-minute bouts of voluntary cycling separated by 10 min rest; and Trial 3 was a combination of trials 1 and 2 (FES assist cycling). Outcome measures included VO2 (volume of oxygen consumption), cycle power output, heart rate, RPE, and post-exercise perceptions of pain and fatigue. RESULTS: Ten people with severe MS participated (9 female; age 52.4 ± 9.98 y; EDSS 7.1 ± 0.6). The average VO2 during the 30-minute trials was significantly higher for FES assist cycling compared to voluntary cycling (429.7 ± 111.0 vs 388.5 ± 101.0 mL/min, 95% CI 23.4 to 113.0 mL/min, p = 0.01), with a large effect size (Hedges' g = 1.04). Participants reported similar rates of perceived exertion at the end of FES cycling (13 ± 2), voluntary cycling (14 ± 2), and FES assist cycling (15 ± 1); p = 0.14. Self-reported pain was higher during both FES cycling (5.4 vs 0.3; 95% CI 3.4 to 6.7, p = 0.01, Hedges' g = 2.07) and FES assist cycling (4.2 vs. 0.3; 95% CI 2.3 to 5.5, p = 0.01, Hedges' g = 1.71) than voluntary cycling, both with large effect sizes. There was no difference in self-reported fatigue at the end of each trial (p = 0.21). CONCLUSION: This study found FES assist cycling produced significantly higher VO2 values than voluntary cycling, although the clinical significance of these differences is unknown. Participants performed FES assist cycling at a self-reported RPE consistent with moderate to vigorous intensity, however it was considered light-intensity exercise when expressed by METS. FES assist cycling was no more fatiguing post-exercise than the other modes.

Cardiorespiratory and Muscular Fitness in Children and Adolescents with Obesity.

PURPOSE OF REVIEW: Examine the current state of literature related to the impact of obesity in children and adolescents on health-related physical fitness and the resultant cardiometabolic disease risk. RECENT FINDINGS: Cardiorespiratory fitness of children and adolescents has declined over the past few decades which corresponds with an increase in obesity rates. Children with obesity are more likely to have low cardiorespiratory fitness which is associated with higher cardiometabolic disease risk and poorer mental health. The impact of obesity on muscular fitness in children and adolescents is more difficult to ascertain, but in general measures of physical function are lower in children with obesity which has also been associated with higher cardiometabolic disease risk. Components of health-related physical fitness are trending negatively in children and adolescents and appear to be related to the increase in prevalence of obesity. The resultant cardiometabolic disease risk has also risen which suggests a greater disease burden in the future. These disparaging findings highlight the need for aggressive interventions to improve physical fitness in children and adolescents.

Relationships between training load and body composition and physical fitness changes in sedentary individuals: A 4-month small-sided soccer games intervention.

Purpose: This study aimed to: (i) analyze the changes in physical fitness and body composition following a 4-month intervention of small-sided games (SSG) training; and (ii) analyze the association between internal and external training loads and the observed changes in physical fitness and body composition among sedentary young adults. Methods: Sixty sedentary individuals (males: 30; females: 30) participated in this randomized controlled trial study. Physical fitness and body composition parameters were assessed at the 1st, 8th weeks, and 16th weeks after a SSG intervention. Results: Significant main effects of time and gender on overall physical fitness parameters, with a notable time-group interaction were observed. For body composition measures, we found significant main effects of time, group, and gender. Furthermore, we identified significant correlations between shuttle run, handgrip, and vertical jump performance, and the time spent at VO2max (TVO2max) during SSG (r = -0.779, p = 0.001; r = -0.788, p = 0.001; r = 0.692, p = 0.004, respectively). Handgrip strength exhibited significant correlations with heat exhaustion (HE) and total distance (TD) during SSG (r = -0.616, p = 0.014; r = -0.629, p = 0.012). Similarly, we observed significant correlations between hip perimeter (HP), skinfolds (SF), waist-to-hip ratio (W:H), and TVO2max (r = 0.624, p = 0.013; r = 0.663, p = 0.007; r = 0.535, p = 0.040, respectively). Conclusion: This study indicates that the intensity achieved during SSG plays a crucial role in fostering positive adaptations in aerobic capacity, maximal strength, and jumping performance in recreational soccer. Therefore, practitioners should ensure that SSG formats generate the required stimulus to sustain prolonged periods within VO2max zones.

Effects of short-term exercise and endurance training on skeletal muscle mitochondria damage induced by particular matter, atmospherically relevant artificial PM2.5.

Introduction: This study aimed to investigate the potential of short-term aerobic exercise to mitigate skeletal muscle mitochondrial damage following ambient PM2.5 exposure, and how 12 weeks of endurance training can enhance aerobic fitness to protect against such damage. Methods: Twenty-four male C57BL/6 J mice were split into sedentary (SED, n = 12) and endurance training (ETR, n = 12) groups. The ETR group underwent 12 weeks of training (10-15 m/min, 60 min/day, 4 times/week), confirmed by an Endurance Exercise Capacity (EEC) test. Post-initial training, the SED group was further divided into SSED (SED and sedentary, n = 6) and SPE (SED and PM2.5 + Exercise, n = 6). Similarly, the ETR group was divided into EEX (ETR and Exercise, n = 6) and EPE (ETR and PM2.5 + Exercise, n = 6). These groups underwent 1 week of atmospherically relevant artificial PM2.5 exposure and treadmill running (3 times/week). Following treatments, an EEC test was conducted, and mice were sacrificed for blood and skeletal muscle extraction. Blood samples were analyzed for oxidative stress indicators, while skeletal muscles were assessed for mitochondrial oxidative metabolism, antioxidant capacity, and mitochondrial damage using western blot and transmission electron microscopy (TEM). Results: After 12 weeks of endurance training, the EEC significantly increased (p < 0.000) in the ETR group compared to the SED group. Following a one-week comparison among the four groups with atmospherically relevant artificial PM2.5 exposure and exercise treatment post-endurance training, the EEX group showed improvements in EEC, oxidative metabolism, mitochondrial dynamics, and antioxidant functions. Conversely, these factors decreased in the EPE group compared to the EEX. Additionally, within the SPE group, exercise effects were evident in HK2, LDH, SOD2, and GPX4, while no impact of short-term exercise was observed in all other factors. TEM images revealed no evidence of mitochondrial damage in both the SED and EEX groups, while the majority of mitochondria were damaged in the SPE group. The EPE group also exhibited damaged mitochondria, although significantly less than the SPE group. Conclusion: Atmospherically relevant artificial PM2.5 exposure can elevate oxidative stress, potentially disrupting the benefits of short-term endurance exercise and leading to mitochondrial damage. Nonetheless, increased aerobic fitness through endurance training can mitigate PM2.5-induced mitochondrial damage.

High-Intensity Interval Versus Moderate-Intensity Continuous Exercise Training on Glycemic Control, Beta Cell Function, and Aerobic Fitness in Women with Type 2 Diabetes.

Objective: This study aimed to compare the effects of High-Intensity Interval Training (HIIT) and Moderate-Intensity Continuous Training (MICT) on glycemic control, beta-cell function, and aerobic fitness in women with Type 2 Diabetes Mellitus (T2DM). Methods: Thirty-six women with T2DM were assigned equally to HIIT, MICT, and control (CON) groups. Participants in the exercise cohorts underwent a 12-week training regimen (three sessions per week), while the CON group maintained an inactive lifestyle. Glycaemia variables, beta-cell function, maximal oxygen uptake (VO2max), lipid profiles, and body composition were assessed at baseline and post-intervention. Results: Both HIIT and MICT interventions led to significant improvements in glucose, insulin, HbA1c, and insulin resistance index. Moreover, visceral adiposity index (VAI), lipid accumulation product (LAP), total cholesterol (TC), and low-density lipoprotein (LDL) levels significantly decreased in the HIIT and MICT groups after 12 weeks. Triglyceride (TG) levels decreased only after MICT, while high-density lipoprotein (HDL) levels increased after both interventions. Maximal oxygen uptake (VO2max), body mass, body mass index (BMI), and waist circumference (WC) significantly improved in all exercise groups. Notably, the HIIT group showed greater reductions in body mass compared to MICT. Nevertheless, beta-cell function remained unaltered after these two exercise regimens. Conclusion: Both HIIT and MICT interventions effectively managed T2DM in women, regardless of exercise intensity. The HIIT regimen can be considered for time-efficient lifestyle interventions in people with T2DM.

Clinimetric Properties of the Steep Ramp Test to Assess Cardiorespiratory Fitness, Its Underlying Physiological Responses, and Its Current Applications: A Scoping Review.

OBJECTIVE: Providing an overview of the clinimetric properties of the steep ramp test (SRT)-a short-term maximal exercise test-to assess cardiorespiratory fitness (CRF), describing its underlying physiological responses, and summarizing its applications in current clinical and research practice. DATA SOURCES: MEDLINE (through PubMed), CINAHL Complete, Cochrane Library, EMBASE, and PsycINFO were searched for studies published up to July 2023, using keywords for SRT and CRF. STUDY SELECTION: Eligible studies involved the SRT as research subject or measurement instrument and were available as full text articles in English or Dutch. DATA EXTRACTION: Two independent assessors performed data extraction. Data addressing clinimetric properties, physiological responses, and applications of the SRT were tabulated. DATA SYNTHESIS: In total, 370 studies were found, of which 39 were included in this study. In several healthy and patient populations, correlation coefficients between the work rate at peak exercise (WRpeak) attained at the SRT and oxygen uptake at peak exercise during cardiopulmonary exercise testing (CPET) ranged from .771-.958 (criterion validity). Repeated measurements showed intraclass correlation coefficients ranging from .908-.996 for WRpeak attained with the first and second SRT (test-retest reliability). Physiological parameters, like heart rate and minute ventilation at peak exercise, indicated that the SRT puts a lower burden on the cardiopulmonary system compared to CPET. The SRT is mostly used to assess CRF, among others as part of preoperative risk assessment, and to personalize interval training intensity. CONCLUSIONS: The SRT is a practical short-term maximal exercise test that is valid for CRF assessment and to monitor changes in CRF over time in various healthy and patient populations. Its clinimetric properties and potential applications make the SRT of interest for a widespread implementation of CRF assessment in clinical and research practice and for personalizing training intensity and monitoring longitudinal changes in CRF.

Preoperative aerobic fitness and perioperative outcomes in patients undergoing cystectomy before and after implementation of a national lockdown.

Background: Lower fitness is a predictor of adverse outcomes after radical cystectomy. Lockdown measures during the COVID-19 pandemic affected daily physical activity. We hypothesised that lockdown during the pandemic was associated with a reduction in preoperative aerobic fitness and an increase in postoperative complications in patients undergoing radical cystectomy. Methods: We reviewed routine preoperative cardiopulmonary exercise testing (CPET) data collected prior to the pandemic (September 2018 to March 2020) and after lockdown (March 2020 to July 2021) in patients undergoing radical cystectomy. Differences in CPET variables, Postoperative Morbidity Survey (POMS) data, and length of hospital stay were compared. Results: We identified 267 patients (85 pre-lockdown and 83 during lockdown) who underwent CPET and radical cystectomy. Patients undergoing radical cystectomy throughout lockdown had lower ventilatory anaerobic threshold (9.0 [7.9-10.9] vs 10.3 [9.1-12.3] ml kg-1 min-1; P=0.0002), peak oxygen uptake (15.5 [12.9-19.1] vs 17.5 [14.4-21.0] ml kg-1 min-1; P=0.015), and higher ventilatory equivalents for carbon dioxide (34.7 [31.4-38.5] vs 33.4 [30.5-36.5]; P=0.030) compared with pre-lockdown. Changes were more pronounced in males and those aged >65 yr. Patients undergoing radical cystectomy throughout lockdown had a higher proportion of day 5 POMS-defined morbidity (89% vs 75%, odds ratio [OR] 2.698, 95% confidence interval [CI] 1.143-6.653; P=0.019), specifically related to pulmonary complications (30% vs 13%, OR 2.900, 95% CI 1.368-6.194; P=0.007) and pain (27% vs 9%, OR 3.471, 95% CI 1.427-7.960; P=0.004), compared with pre-lockdown on univariate analysis. Conclusions: Lockdown measures in response to the COVID-19 pandemic were associated with a reduction in fitness and an increase in postoperative morbidity among patients undergoing radical cystectomy.

Uniform Homeostatic Stress Through Individualized Interval Training Facilitates Homogeneous Adaptations Across Rowers With Different Profiles.

PURPOSE: This study compared the effects of individualizing supramaximal interval rowing interventions using anaerobic power reserve (APR [high-intensity interval training (HIIT) prescribed according to individual APR (HIITAPR)]) and power associated with maximal oxygen uptake (WV˙O2max [HIIT prescribed based on the individual WV˙O2max (HIITW)]) on the homogeneity of physiological and performance adaptations. METHODS: Twenty-four well-trained rowers (age 24.8 [4.3] y, stature 182.5 [3] cm, body mass 86.1 [4.3]) were randomized into interventions consisting of 4 × 30-second intervals at 130%APR (WV˙O2max + 0.3 × maximal sprint power) with weekly progression by increasing the number of repetitions per set (5, 6, 7, 8, 9, and 10, from first to sixth session) and the same sets and repetitions with the intensity described as 130% WV˙O2max. The work-to-recovery ratio was 1:1 for repetitions and 3 minutes between sets. Responses of aerobic fitness indices, power output, cardiac hemodynamics, locomotor abilities, and time-trial performance were examined. RESULTS: Both HIITAPR and HIITW interventions significantly improved V˙O2max, lactate threshold, cardiac hemodynamics, and 2000-m performance, with no between-groups difference in changes over time. However, HIITAPR resulted in a lower interindividual variability in adaptations in V˙O2max and related physiological parameters, but this is not the case for athletic performance, which can depend on a multitude of factors beyond physiological parameters. CONCLUSIONS: Results demonstrated that expressing supramaximal interval intensity as a proportion of APR facilitates imposing the same degrees of homeostatic stress and leads to more homogeneous physiological adaptations in maximal variables when compared to prescribing a supramaximal HIIT intervention using WV˙O2max. However, lower interindividual variability would be seen in submaximal variables if HIIT interventions were prescribed using WV˙O2max.

Validation of the maximal cardiopulmonary exercise test in adolescents with major depressive disorder and comparison of cardiorespiratory fitness with sex- and age-related control values.

Endurance training has been shown to be effective in treating adolescents with major depressive disorder (MDD). To integrate endurance training into the therapeutic setting and the adolescents' daily lives, the current performance status of the adolescents should be accurately assessed. This study aims to examine adolescents with MDD concerning exhaustion criteria during a cardiopulmonary exercise test (CPET), as well as to compare the values obtained thereon with sex- and age-related control values. The study included a retrospective examination of exhaustion criteria ((i) oxygen consumption (V̇O2) plateau, (ii) peak respiratory exchange ratio (RERpeak) > 1.0, (iii) peak heart rate (HRpeak) ≥ 95% of the age-predicted maximal HR, and (iv) peak blood lactate concentration (BLCpeak) > 8.0 mmol⋅L-1) during a graded CPET on a cycle ergometer in adolescents with MDD (n = 57). Subsequently, maximal V̇O2, peak minute ventilation, V̇O2 at the first ventilatory threshold, and peak work rate of participants who met at least two of four criteria were compared with published control values using an independent-sample t-test. Thirty-three percent of the total population achieved a V̇O2 plateau and 75% a RERpeak > 1.0. The HR and BLC criteria were met by 19% and 22%, respectively. T-test results revealed significant differences between adolescents with MDD and control values for all outcomes. Adolescents with MDD achieved between 56% and 83% of control values.   Conclusions: The study shows that compared with control values, fewer adolescents with MDD achieve the exhaustion criteria on a CPET and adolescents with MDD have significantly lower cardiorespiratory fitness.   Clinical trial registration: No. U1111-1145-1854. What is Known: • It is already known that endurance training has a positive effect on depressive symptoms. What is New: • A relevant proportion of adolescents with major depressive disorder do not achieve their V̇O2max during a graded cardiopulmonary exercise test. • Adolescents with major depressive disorder have significantly lower cardiorespiratory fitness compared to sex- and age-related control values.

Cardiorespiratory fitness (V̇O2peak) across the adult lifespan in persons with multiple sclerosis and matched healthy controls.

OBJECTIVES: Cardiorespiratory fitness (measured as peak oxygen uptake; V̇O2peak) is a well-established health predictor in the general population and in persons with multiple sclerosis (pwMS). We aimed to investigate differences in V̇O2peak between age groups and the prevalence of V̇O2peak impairments across the adult lifespan in pwMS compared to age- and sex-matched healthy controls (HC). DESIGN: Cross-sectional study. METHODS: Data from 469 pwMS (EDSS range 1.0-7.0), who carried out graded cardiopulmonary exercise testing during their rehabilitation stay at the Valens clinic from 07/2010 to 10/2022, were retrospectively analyzed. Data from 21,063 HC were extracted from previously published studies containing normative reference values. RESULTS: With advanced age (i.e., across age groups), a continuous deterioration of V̇O2peak was observed in both pwMS and HC. Within all age groups, V̇O2peak was reduced in pwMS compared to HC with deficits ranging from 29 % to 40 % for females (p < .05), and from 30 % to 41 % for males (p < .05). However, no age ∗ group interaction was observed in neither males (p = .626) nor females (p = .557). With V̇O2peak impairments defined as values below the 5th percentile of HC, a high prevalence was observed in pwMS, with values ranging from 48 % to 100 % across age groups. CONCLUSIONS: The present data provide evidence for a parallel deterioration of V̇O2peak in pwMS and matched controls with advancing age, coinciding with a high prevalence of impairments in V̇O2peak already present in young adulthood in pwMS. Understanding the extent of impairments as well as the age trajectories of cardiorespiratory fitness in pwMS is crucial for designing optimal rehabilitative and preventive interventions.

Acute oral antioxidant consumption does not alter brachial artery flow mediated dilation in young adults independent of exercise training status.

Endothelium-dependent vasodilation can be tested using a variety of shear stress paradigms, some of which may involve the production of reactive oxygen species. The purpose of this study was to compare different methods for assessing endothelial function and their specific involvement of reactive oxygen species and influence of aerobic training status. Twenty-nine (10 F) young and healthy participants (VO2max: 34-74 mL·kg-1·min-1) consumed either an antioxidant cocktail (AOC; vitamin C, vitamin E, α-lipoic acid) or placebo (PLA) on each of two randomized visits. Endothelial function was measured via three different brachial artery flow-mediated dilation (FMD) tests: reactive hyperemia (RH-FMD: 5 min cuff occlusion and release), sustained shear (SS-FMD: 6 min rhythmic handgrip), and progressive sustained shear (P-SS-FMD: three intensities of 3 min of rhythmic handgrip). Baseline artery diameter decreased (all tests: 3.8 ± 0.5 to 3.7 ± 0.6 mm, p = 0.004), and shear rate stimulus increased (during RH-FMD test, p = 0.021; during SS-FMD test, p = 0.36; during P-SS-FMD test, p = 0.046) following antioxidant consumption. However, there was no difference in FMD following AOC consumption (RH-FMD, PLA: 8.1 ± 2.6%, AOC: 8.2 ± 3.5%, p = 0.92; SS-FMD, PLA: 6.9 ± 3.9%, AOC: 7.8 ± 5.2%, p = 0.15) or FMD per shear rate slope (P-SS-FMD: PLA: 0.0039 ± 0.0035 mm·s-1, AOC: 0.0032 ± 0.0017 mm·s-1, p = 0.28) and this was not influenced by training status/fitness (all p > 0.60). Allometric scaling did not alter these outcomes (all p > 0.40). Reactive oxygen species may not be integral to endothelium-dependent vasodilation tested using reactive, sustained, or progressive shear protocols in young males and females, regardless of fitness level.

Frailty is associated with worse executive function and higher cerebral blood velocity in cognitively healthy older adults: a cross-sectional study.

Frailty is characterized by an increased vulnerability to adverse health events. Executive function impairment is an early sign of progression towards cognitive impairments. Whether frailty is associated with executive function and the associated mechanisms are unclear. We test the hypothesis that higher frailty is associated with worse executive function (Trail Making Test) and if aerobic fitness, prefrontal cortex oxygenation (ΔO2Hb), or middle-cerebral artery velocity (MCAv) impact this association. Forty-one (38 females) cognitively health older adults (70.1 ± 6.3 years) completed a Trail task and 6-min walk test. Prefrontal cortex oxygenation was measured during the Trail task (via functional near-infrared spectroscopy) and MCAv in a sub-sample (n=26, via transcranial Doppler). A 35-item frailty index was used. Frailty was independently, non-linearly related to trail B performance (Frailty2: ß=1927 [95% CI: 321-3533], p = 0.02), with the model explaining 22% of the variance of trail B time (p = 0.02). Aerobic fitness was an independent predictor of trail B (ß=-0.05 [95% CI: -0.10-0.004], p = 0.04), but age and ΔO2Hb were not (both, p > 0.78). Frailty was positively associated with the difference between trails B and A (ß=105 [95% CI: 24-186], p = 0.01). Frailty was also associated with a higher peak MCAv (ρ = 0.40, p = 0.04), but lower ΔO2Hb-peakMCAv ratio (ρ = -0.44, p = 0.02). Higher frailty levels are associated to worse Trail times after controlling for age, aerobic fitness, and prefrontal oxygenation. High frailty level may disproportionately predispose older adults to challenges performing executive function tasks that may manifest early as a compensatory higher MCAv despite worse executive function, and indicate a greater risk of progressing to cognitive impairment.

Cardiorespiratory fitness and circadian rhythms in adolescents: a pilot study.

Although cardiorespiratory fitness (CRF), an important marker of youth health, is associated with earlier sleep/wake schedule, its relationship with circadian rhythms is unclear. This study examined the associations between CRF and rhythm variables in adolescents. Eighteen healthy adolescents (10 females and 8 males; Mage = 14.6 ± 2.3 yr) completed two study visits on weekdays bracketing an ambulatory assessment during summer vacation. Visit 1 included in-laboratory CRF assessment (peak V̇o2) using a ramp-type progressive cycle ergometry protocol and gas exchange measurement, which was followed by 7-14 days of actigraphy to assess sleep/wake patterns and 24-h activity rhythms. During Visit 2, chronotype, social jetlag (i.e., the difference in midsleep time between weekdays and weekends), and phase preference were assessed using a questionnaire, and hourly saliva samples were collected to determine the dim light melatonin onset (DLMO) phase. All analyses were adjusted for sex, pubertal status, and physical activity. Greater peak V̇o2 was associated with earlier sleep/wake times and circadian phase measures, including acrophase, UP time, DOWN time, last activity peak (LAP) time, and chronotype (all P < 0.05). Peak V̇o2 was negatively associated with social jetlag (P = 0.02). In addition, the mixed-model analysis revealed a significant interaction effect between peak V̇o2 and actigraphy-estimated hour-by-hour activity patterns (P < 0.001), with the strongest effects observed at around the time of waking (0600-1000). In healthy adolescents, better CRF was associated with an earlier circadian phase and increased activity levels notably during the morning. Future studies are needed to investigate the longitudinal effects of the interactions between CRF and advanced rhythms on health outcomes.NEW & NOTEWORTHY In healthy adolescents, better cardiorespiratory fitness, as assessed by the gold standard measure [laboratory-based assessment of peak oxygen consumption (V̇o2)], was associated with earlier circadian timing of sleep/wake patterns, rest-activity rhythms and chronotype, and less social jetlag. These findings highlight the close interrelationships between fitness and rhythms and raise the possibility that maintaining higher cardiorespiratory fitness levels alongside earlier sleep/wake schedule and activity rhythms may be important behavioral intervention targets to promote health in adolescents.

Introduction of an applicant Job-Related Task Assessment (JTA) and the effects on the health and fitness of police recruits.

BACKGROUND: In 2020, a police department in the south-eastern USA introduced a Job-Related Task Assessment (JTA). The JTA included running, climbing, crawling, balance, direction changes, stair climbing, dragging, pushing, and simulated controlling of a struggling subject and needed to be completed by applicants in 6 : 57 min:s. It is not known whether introducing the JTA in the hiring process affected the health and fitness of hired recruits. OBJECTIVE: To compare the health and fitness of recruits hired prior to, and following, the JTA introduction. METHODS: Analysis was conducted on recruit data split into academy training year: 2016 (n = 91), 2017 (n = 129), 2018 (n = 167), 2019 (n = 242), and 2020 (n = 37). The 2020 group was hired after the JTA introduction and included one academy class. The following were recorded for all recruits: age, height, body mass, and body mass index; systolic and diastolic blood pressure (BP); sit-and-reach; grip strength; push-ups; sit-ups; 2.4-km run; and a physical ability test (PAT). A univariate ANOVA, with sex and age as covariates and Bonferroni post hoc, determined between-year differences. RESULTS: The recruits from 2020 were significantly lighter than 2018 recruits (p < 0.031), had higher systolic and diastolic BP than recruits from 2016-2018 (p≤0.006), completed the 2.4-km run faster than recruits from all years (p < 0.001), and completed the PAT faster than the 2016 and 2019 (p = 0.006-0.007) recruits. CONCLUSION: The JTA introduction led to the selection of recruits with lower body mass, and better aerobic (2.4-km run) and job-specific fitness (PAT). However, 2020 recruits also had higher BP which should be monitored.

Physical fitness test performance in firefighter trainees: Differences between graduated and released trainees and predicting academy graduation.

BACKGROUND: Fitness tests have been previously used to predict academy graduation and highlight specific capacities to be targeted in applicants/trainees to optimise their potential for academy success. OBJECTIVE: To compare the fitness of graduated and released (did not complete academy requirements) firefighter trainees and explore using decision tree analysis to predict academy graduation via fitness tests. METHODS: Retrospective analysis was conducted on 686 trainees who completed an occupational physical ability test (OPAT): Illinois agility test; push-ups; pull-ups; leg tucks; estimated maximal aerobic capacity (VO2max); backwards overhead 4.54-kg medicine ball throw; 10-repetition maximum deadlift; and 91.44-m farmer's carry. Data were recorded in raw and scaled scores (tests scored from 0-100; maximum OPAT score was 800). Trainees were split into 'graduated' (GRAD; n = 576) or 'released' (REL; n = 110) groups. Mann-Whitney U-tests compared between-group OPAT scores. A decision tree analysis using Chi-square automatic interaction detection was conducted, with raw and scaled scores entered into the analysis. A separate analysis was conducted with only the raw scores. RESULTS: GRAD trainees outperformed REL trainees in all OPAT events (p < 0.001). OPAT total score was the best predictor of academy graduation (p < 0.001), followed by the deadlift score (p = 0.003). Estimated VO2max was the only significant raw score predictor (p < 0.001). CONCLUSIONS: GRAD trainees were fitter than the REL trainees. Fitness could predict trainees who graduated from the academy. Overall fitness (OPAT total score), muscular strength (deadlift) and aerobic capacity were important graduation predictors. Training staff could develop these fitness qualities in their trainees to potentially improve fire academy graduation rates.