Maximal Cycle Ergometer Test Research Articles

Oxygen uptake efficiency slope in 8- to 12-year-old boys and girls.

Oxygen uptake efficiency slope (OUES) is an objective physiological measure that can be obtained from a standard graded exercise test. However, there is conflicting evidence regarding sex differences in OUES values in children. Therefore, this study investigated potential sex differences in absolute, ratio-scaled, and allometrically scaled OUES in 8.0- to 12.0-year-old children. Retrospective and prospective data of 18 boys and 22 girls were utilized. All participants had undergone familiarization before performing a maximal cycle ergometer test to determine OUES. These values were also ratio-scaled and allometrically scaled to mass and body surface area (BSA). Group differences were tested via independent sample t-tests (or Mann-Whitney U if not normally distributed). Absolute OUES values (VO<inf>2</inf> mL∙min-1/log<inf>10</inf>VE L∙min-1) were significantly higher in boys compared to girls (1860.8±359.3 vs. 1514.3±212.6). When scaled to mass (VO<inf>2</inf> mL∙kg-1∙min-1/log<inf>10</inf>VE L∙kg-1∙min-1), OUES was no longer significantly different between groups, but when scaled to BSA (VO<inf>2</inf> mL∙m-2∙min-1/log<inf>10</inf>VE L∙m-2∙min-1), OUES was significantly higher in the boys than the girls (1414.4±204.2 vs. 1268.9±134.6). When allometry was applied for mass (OUES/mass0.444) boys had significantly higher value than girls (350.8±46.7 vs. 305.0±31.5). The present study demonstrated that boys had greater OUES values scaled to BSA and allometrically scaled to body mass. These findings provide further evidence of sex differences with OUES values in preadolescent children and implies the need for sex-specific reference values prior to using OUES for the assessment of cardiorespiratory pathology in children.

Adolescent mental health and cardiorespiratory fitness: A comparison of two cohorts 12 years apart.

The aim of the study was to compare the mental health and cardiorespiratory fitness (CRF) of adolescents in two cross-sectional cohorts, one measured in 2003 and the other in 2015, both at age 15 and across sexes. The study also sought to estimate the association between mental health and CRF in the two cohorts and examine the relationship between the level of CRF and mental health in each cohort overall and by sex. Data from 443 participants born in 1988 (228 males, 215 females) and 303 participants born in 1999 (126 males, 177 females) were analyzed. Mental health was assessed using self-reports of body image, self-esteem, and symptoms of depression and anxiety. CRF was estimated using a maximal cycle ergometer test. From 2003 to 2015, body image scores improved (p = .043), self-esteem remained stable, and CRF declined significantly (p < .001). No self-esteem differences were observed between sexes in any cohort. Males had higher CRF and body image scores than females in both cohorts (p < .001 for all comparisons). Higher CRF correlated with fewer depressive symptoms across sexes and cohorts. Specifically, higher CRF was associated with anxiety in females and improved body image in males (2003) and both sexes (2015). Increased CRF was linked to higher self-esteem in females but not in males. Overall, higher CRF levels were associated with better mental health outcomes for both sexes. These results highlight the potential of improving adolescent mental health through increased physical fitness.

Physical fitness in male adolescents and atherosclerosis in middle age: a population-based cohort study

ObjectivesTo examine the associations between physical fitness in male adolescents and coronary and carotid atherosclerosis in middle age.MethodsThis population-based cohort study linked physical fitness data from the Swedish Military Conscription...

Longitudinal development and tracking of cardiorespiratory fitness from childhood to adolescence.

Cardiorespiratory fitness (CRF) is an important indicator of health in childhood and adolescence but longitudinal studies on the development and tracking of CRF from childhood to adolescence are scarce. The objectives of this study were (1) to assess longitudinal development and track CRF over 10 years from childhood to adolescence, and (2) to examine potential sex differences in the development and tracking of CRF during this period. Participants were Icelandic children born in 1999, measured at the age of 7 (n = 190, 106 girls), 9 (n = 163, 95 girls), 15 (n = 239, 134 girls), and 17 (n = 202, 119 girls). CRF was assessed with a maximal cycle ergometer test and expressed as maximal power output (Max W) and maximal power output relative to lean mass (W/kgLM). Multilevel regression models were used to study the longitudinal development of CRF, and tracking was assessed with Spearman's rank correlation, logistic regression, and the percentage of participants remaining in low, moderate, or high CRF categories between measurements. Max W and W/kgLM increased for both boys and girls up to age 15. Max W plateaued for both boys and girls while W/kgLM plateaued for girls but declined for boys from age 15 to 17. Boys had higher Max W than girls from age 15 and higher W/kgLM from age 9. CRF tracked at low to moderate levels from childhood to adolescence and at high levels in adolescence, with higher values observed for boys than girls. Age 15 was a critical time point in the development of CRF, with values starting to plateau for girls and decline for boys. The results support early intervention for improved CRF in later years, with interventions targeting all children, regardless of their CRF level.

Effects of reduced sedentary time on resting, exercise and post-exercise blood pressure in inactive adults with metabolic syndrome – a six-month exploratory RCT

Evidence on the long-term effects of reducing sedentary behaviour (SB) on blood pressure (BP) is scarce. Therefore, we performed a sub-analysis of the BP effects of a six-month intervention that aimed at reducing SB by 1 h/day and replacing it with non-exercise activities. Sixty-four physically inactive and sedentary adults with metabolic syndrome (58% female, 58 [SD 7] years, BP 143/88 [16/9] mmHg, SB 10 [1] h/day) were randomised into intervention (INT, n = 33) and control (CON, n = 31) groups. Resting BP and BP at each stage during and after a graded maximal bicycle ergometer test were measured before and after the intervention. SB, standing, moderate-to-vigorous physical activity (MVPA), and light physical activity (LPA) were measured in six-second intervals at baseline and during the whole six-month intervention using hip-worn accelerometers. The analyses were adjusted for BP medication status. The intervention resulted in a 40 min/day reduction in SB and concomitant 20 min/day increase in MVPA. Resting systolic BP was lower in the CON group before and after the intervention. No group x time interactions were observed in resting BP or BP during exercise at submaximal or maximal intensities, or during recovery. The changes in LPA and MVPA were inversely correlated with the changes in BP during light-to-moderate intensity exercise. An intervention that resulted in a 40 min/day reduction in SB for six months was not sufficient at influencing BP at rest, during or after exercise in adults with metabolic syndrome. However, successfully increasing LPA or MVPA might lower BP during light-to-moderate-intensity activities.

Exercise systolic blood pressure response during cycle ergometry is associated with future hypertension in normotensive individuals.

We aimed to investigate the association between the exercise systolic blood pressure (SBP) response and future hypertension (HTN) in normotensive individuals referred for cycle ergometry, with special regard to reference exercise SBP values and exercise capacity. In this longitudinal cohort study, data from 14 428 exercise tests were cross-linked with Swedish national registries on diagnoses and medications. We excluded individuals with a baseline diagnosis of cardiovascular disease or HTN. The peak exercise SBP (SBPpeak) was recorded and compared with the upper limit of normal (ULN) derived from SBPpeak reference equations incorporating age, sex, resting SBP, and exercise capacity. To evaluate the impact of exercise capacity, three SBP to work rate slopes (SBP/W-slopes) were calculated, relative to either supine or seated SBP at rest or to the first exercise SBP. Adjusted hazard ratios [HRadjusted (95% confidence interval, CI)] for incident HTN during follow-up, in relation to SBP response metrics, were calculated. We included 3895 normotensive individuals (49 ± 14 years, 45% females) with maximal cycle ergometer tests. During follow-up (median 7.5 years), 22% developed HTN. Higher SBPpeak and SBPpeak > ULN were associated with incident HTN [HRadjusted 1.19 (1.14-1.23) per 10 mmHg, and 1.95 (1.54-2.47), respectively]. All three SBP/W-slopes were positively associated with incident HTN, particularly the SBP/W-slope calculated as supine-to-peak SBP [HRadjusted 1.25 (1.19-1.31) per 1 mmHg/10 W]. Both SBPpeak > ULN based on reference values and high SBP/W-slopes were associated with incident HTN in normotensive individuals and should be considered in the evaluation of the cycle ergometry SBP response.

Response of cardiorespiratory system during maximal exercise cycle ergometer test in women cross-country skiers with different skills levels

Objective: to estimate the functional features of the cardiorespiratory system of female cross-country skiers with different skills levels at the maximal bicycle ergometer test.Material and methods: 70 female cross-country skiers were divided into three groups. The first group included 21 cross-country skiers with first adult sporting rank, the second — 25 candidates in master of sports, the third group — 24 sport masters in cross-country skiing. Maximal exercise tests were used to determine cardiorespiratory fitness via spiroergometric system «Oxycon Pro» (Jaeger, Hoechberg, Germany).Results: The most notable differences were observed between the first-class and the masters of the sports groups. In the first-class group the heart rate during the maximal exercise test was, on average, 11 beats/min higher than in the master of sports group (p&lt;0.05), and the oxygen consumption at the anaerobic threshold was, on average, lower by 7.7 ml/min/kg (p &lt; 0.05) when comparing the same groups.Conclusion: The influence of skills levels on physiological parameters at maximal bicycle ergometer test was shown. The capacity in the first group occurs due to cardiovascular system tension, and the same in the group high qualification skiers happen due to the mechanisms of oxygen transport development.

Exercise-induced B-lines for the diagnosis of heart failure with preserved ejection fraction: a two-centre study.

Diagnosis of heart failure with preserved ejection fraction (HFpEF) remains challenging despite the use of scores/algorithms. This study intended to assess the diagnostic value of exercise lung ultrasound (LUS) for HFpEF diagnosis. We studied two independent case-control studies of HFpEF patients and control subjects undergoing different exercise protocols: (i) submaximal exercise stress echocardiography (ESE) with LUS performed by expert cardiologists (N = 116, HFpEF = 65.5%), and (ii) maximal cycle ergometer test (CET) (N = 54, HFpEF = 50%) with LUS performed by unexperienced physicians shortly trained for the study. B-line kinetics (i.e. peak values and their changes from rest) were assessed. In the ESE cohort, the C-index (95% CI) of peak B-lines for HFpEF diagnosis was 0.985 (0.968-1.000), whereas the C-index of rest and exercise HFA-PEFF scores (i.e. including stress echo findings) were < 0.90 (CI 0.823-0.949), and that of H2FPEF score was < 0.70 (CI 0.558-0.764). The C-index increase of peak B-lines on top of the above-mentioned scores was significant (C-index increase > 0.090 and P-value < 0.001 for all). Similar results were observed for change B-lines. Peak B-lines > 5 (sensitivity = 93.4%, specificity = 97.5%) and change B-lines > 3 (sensitivity = 94.7%, specificity = 87.5%) were the best cutoffs for HFpEF diagnosis. Adding peak or change B-lines on top of HFpEF scores and BNP significantly improved diagnostic accuracy. Peak B-lines showed a good diagnostic accuracy in the LUS beginner-led CET cohort (C-index = 0.713, 0.588-0.838). Exercise LUS showed excellent diagnostic value for HFpEF diagnosis regardless of different exercise protocols/level of expertise, with additive diagnostic accuracy on top of available scores and natriuretic peptides.

Cardiorespiratory Fitness in Young Adult Women With a History of Premature Adrenarche.

Premature adrenarche (PA) may predispose to some adverse long-term health outcomes. Cardiorespiratory fitness (CRF) is one of the strongest factors known to predict overall health, but no data exist on the CRF of women with a history of PA. To study if hyperandrogenism in childhood resulting from PA leads to a measurable difference in CRF between young adult PA and control women. A total of 25 women with PA and 36 age-matched controls were followed from prepubertal age until adulthood. Anthropometric measurements, body composition, biochemical, and lifestyle factors were assessed. The main outcome measure was maximal cycle ergometer test result at the mean age of 18.5 years. We also assessed prepubertal predicting factors for CRF with different linear regression models. Though prepubertal children with PA were taller and heavier than their non-PA peers, there were no significant differences in height, body mass index, body composition, or physical activity in young adulthood. We observed no significant differences in any of the parameters of the maximal cycle ergometer test, including maximal load (P = .194) or peak oxygen consumption (P = .340). Hemodynamic responses of the groups were similar. None of the examined models or prepubertal factors significantly predicted CRF at adult age. This study suggests that hyperandrogenism in childhood/adolescence resulting from PA does not have a significant impact on adulthood CRF.

Cross-sectional associations between physical fitness and biomarkers of inflammation in children-The PANIC study.

Systemic low-grade inflammation has been proposed as an underlying pathophysiological mechanism for cardiometabolic diseases. We investigated the associations of physical fitness with a systemic low-grade inflammatory state in a population sample of children. Altogether 391 children aged 6-9 years were examined. Cardiorespiratory fitness (maximal power output, Wmax ) was assessed by a maximal cycle ergometer test and neuromuscular fitness by hand grip strength, sit-up, standing long jump, 50-meter shuttle run, static balance, sit-and-reach, and box and block tests. Body fat percentage (BF%) and lean mass (LM) were assessed by dual-energy X-ray absorptiometry (DXA). High sensitivity C-reactive protein (hs-CRP), leptin, leptin receptor, high molecular weight adiponectin (HMW-adiponectin), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and glycoprotein acetyls (GlycA) were assessed from fasting blood samples. The modified inflammatory score (IS) was calculated using the population-specific z-scores and formula (z hs-CRP + z leptin + z IL-6 + z TNF-α + z GlycA)-z leptin receptor-z HMW-adiponectin. The data were analyzed using linear regression analyses. Higher Wmax /kg of body mass (β=-0.416, 95% CI=-0.514 to -0.318), higher number of completed sit-ups (β=-0.147, 95% CI=-0.244 to -0.049), a longer distance jumped in the standing long jump test (β=-0.270, 95% CI=-0.371 to -0.169), and a shorter time in the 50-meter shuttle run test (β=0.123, 95% CI=0.022 to 0.223) were associated with lower IS. None of these associations remained statistically significant after adjustment for BF%. Higher physical fitness is associated with a more favorable inflammatory biomarker profile in children. However, the associations were explained by BF%.

Early adulthood exercise capacity, but not muscle strength, associates with subclinical atherosclerosis 40 years later in Swedish men.

Poor exercise capacity and muscle strength in early adulthood are risk factors for cardiovascular disease (CVD). However, it is unclear how these factors relate to subclinical atherosclerosis due to a lack of longitudinal studies. This study investigated whether early adulthood exercise capacity and muscle strength associated with later adulthood subclinical atherosclerosis. This study included Swedish men (n = 797) who were eligible for military conscription (at ∼18-years of age) and who participated in the baseline assessment of the visualization of asymptomatic atherosclerotic disease for optimum cardiovascular prevention trial between 2013 and 2016 (at 60 years of age). At conscription, isometric muscle strength (dynamometer) and maximum exercise capacity (maximal load cycle ergometer test) were measured. During later adulthood (at 60 years old), the presence of carotid plaques and intima media thickness were measured by using high-resolution ultrasound. At follow-up, plaques were present in 62% (n = 493) of men. Exercise capacity in early adulthood associated with 19% lower odds of plaques [odds ratio (OR) 0.81, 95% confidence interval (CI) 0.68-0.96], independent of muscle strength. This association was not mediated by any single CVD risk factor. However, the total indirect effect of later, but not early, adulthood CVD risk factors was significant, while the direct effect was non-significant (OR 0.85, 95% CI 0.71-1.02). Associations between muscle strength and subclinical atherosclerosis were non-significant. Higher exercise capacity during early adulthood, but not muscle strength, may protect against carotid plaque development during adulthood mediated by the combination rather than a single later adulthood CVD risk factors.

Perspectives on exercise intensity, volume, step characteristics and health outcomes in walking for transport.

Quantification of movement intensity and energy utilization, together with frequency of trips, duration, distance, step counts and cadence, is essential for interpreting the character of habitual walking for transport, and its potential support of health. The purpose of the study is to illuminate this with valid methods and novel perspectives, and to thereby provide a new basis for characterizing and interpreting walking in relation to health outcomes. Habitual middle-aged commuting pedestrians (males = 10, females = 10) were investigated in the laboratory at rest and with maximal treadmill and cycle ergometer tests. Thereafter, levels of oxygen uptake, energy expenditure, ventilation, heart rate, blood lactate, rated perceived exertion, cadence, number of steps, duration, distance, and speed were recorded during the normal walking commute of each participant in Greater Stockholm, Sweden. The number of commutes per week over the year was self-reported. Walking in the field demanded about 30% more energy per km compared to level treadmill walking. For both sexes, the walking intensity in field was about 46% of maximal oxygen uptake, and energy expenditure amounted to 0.96 kcal · kg- 1 · km- 1. The MET values (males: 6.2; females: 6.5) mirrored similar levels of walking speed (males: 5.7; females: 5.9 km · h- 1) and levels of oxygen uptake (males: 18.6; females: 19.5 mL · kg- 1 · min- 1). The average number of MET-hours per week in a typical month was 22 for males and 20 for females. This resulted in a total weekly energy expenditure of ~1,570 and 1,040 kcal for males and females, respectively. Over the year, the number of walking commutes and their accumulated distance was ~385 trips and 800 km for both sexes. Walking in naturalistic field settings demands its own studies. When males and females walk to work, their relative aerobic intensities and absolute energy demands for a given distance are similar. It is equivalent to the lower part of the moderate relative intensity domain. The combination of oxygen uptake, trip duration and frequency leads to high and sustained levels of MET-hours as well as energy expenditure per week over the year, with a clear health enhancing potential. Based on this study we recommend 6000 transport steps per day, or equivalent, during five weekdays, over the year, in order to reach optimal health gains.

The Effect Of Sex And Exercise Intensity On Hunger Ratings In Adults: A Pilot Study

Acute exercise transiently suppresses appetite, oftentimes in an intensity dependent manner. However, the majority of prior work only included young adult males, and did not explore the effects of sex on exercise-induced appetite measures. PURPOSE: To determine the effect of exercise intensity and sex on appetite responses in middle-age adult males and females. METHODS: Untrained males (n = 5; age: 46.8 ± 5.8 y; BMI; 22.5 ± 0.84 kg/m2 VO2peak: 34.7 ± 6.7 mL/kg/min) and females (n = 4; age: 43.8 ± 5.4 y; BMI 22.2 ± 0.94 kg/m2;VO2peak: 28.15 ± 2.3 mL/kg/min) completed 3 conditions in a randomized, crossover design: control (C), moderate intensity exercise (at the lactate threshold (LT); MOD), or high intensity (75% of the difference between LT and VO2 peak; HI) exercise. Exercise intensity was determined from a maximal incremental cycle ergometer test. Venous blood was sampled at the end of each 3-min stage and analyzed for lactate. Visits occurred in the morning after an overnight fast. All exercise sessions were calorically matched within subjects. Subjective appetite parameters were assessed via visual analogue scales (VAS) during each condition at: 0 minutes, 60 minutes, 90 minutes, 120 minutes. Area-under-the curve values were calculated using the trapezoidal method for each VAS component. RESULTS: Preliminary inspection of data suggest perception of hunger (units = mm*120 min-1; males: C: 491.1 ± 291.7 MOD: 355.8 ± 107.8, HI: 351.6 ± 129.2;females: C: 539.6 ± 69.5, MOD: 419.6 ± 106.9, HI: 409.5 ± 67.5) satisfaction (males: C: 420.6 ± 174.9, MOD: 293.7 ± 187.65, HI: 395.3 ± 197.05; females: C: 279.0 ± 239.7 MOD: 342.4 ± 159.6, HI: 382.0 ± 146.4), fullness (males: C: 393.6 ± 154.3, MOD: 266.1 ± 163.8, HI: 398.6 ± 176.5; females: C: 247.5 ± 241.2, MOD: 264.4 ± 215.5, HI: 411.5 ± 159.9), and how much you think you can eat (males: C: 653.7 ± 225.9, M: 573.9 ± 239.2, HI: 460.2 ± 248.9; females: CON: 684.4 ± 192.1, MOD: 545.6 ± 107.4, HIGH: 731.0 ± 150.2), are affected in an intensity dependent manner with differing responses between middle aged males and females. CONCLUSIONS: Both exercise intensity and sex may impact subjective ratings of appetite. Supported by The University of Virginia School of Education and Human Development, and National Institute of Diabetes and Digestive and Kidney Diseases (1R01DK12950-01)

Rapid Onset Vasodilation: Impact of Cardiorespiratory Fitness

IntroductionHigher cardiorespiratory fitness is associated with greater vascular function that leads to improved regulation of skeletal muscle blood flow during exercise. Rapid onset vasodilation (ROV) describes the immediate increase in blood flow following a single contraction, which is integral to support greater blood flow during exercise. As such, blood flow regulation during exercise hyperemia is important. However, it is unclear if cardiorespiratory fitness plays a role in ROV of small muscle mass in young, healthy individuals.PurposeTo investigate the relationship of cardiorespiratory fitness on ROV following a single handgrip (HG) contraction in young, healthy adults.MethodsCardiorespiratory fitness (VO2peak) was assessed during a maximal cycle ergometer test in 14 volunteers (M/F, 6/8; 28 ± 5yrs; 24.8 ± 4.1kg/m2). Brachial velocity and diameter were measured using duplex Doppler ultrasound for 10 cardiac cycles prior to and 20 cardiac cycles following the first cardiac cycle after a single 30% of maximal voluntary handgrip contraction. Brachial artery blood flow (FBF) was calculated for each cardiac cycle: (diameter2/2)*π*velocity*60. Peak forearm (brachial) blood flow (FBFpeak) was determined as the maximal FBF from baseline following the first cardiac cycle after the single HG contraction. Time to peak blood flow response was determined as the time to reach FBFpeak and heart rate was measured using a three‐lead ECG. The relationship between FBFpeak and time to peak blood flow was tested using a multivariate regression analysis with cardiorespiratory fitness and sex as independent variables.ResultsCardiorespiratory fitness (VO2peak: 30.6 ± 8.0mL/kg/min); β for VO2peak= 0.162 [0.003, 0.327]) was the only predictor of time to peak blood flow response, F(1,12)= 4.602, p= 0.05, R2= 0.217, r= 0.526, while sex (β for time to peak= ‐106.5 [‐156.9, ‐56.2]) was the only predictor of FBFpeak, F(1,12)= 21.245, p&lt;0.001, R2= 0.609, r= 0.799, indicating that females had a lower FBFpeakoverall.ConclusionOur data suggests blood flow responsiveness (e.g., time to peak) is positively associated with cardiorespiratory fitness and these data contribute to our understanding of potential mechanisms between improved blood flow regulation commonly associated with greater cardiorespiratory fitness. More research is necessary to fully elucidate the role biological sex has on these relationships, but our data suggest there may be sex differences in certain blood flow responses.

Comparison of Predicted Exercise Capacity Equations in Adult Korean Subjects.

BackgroundMaximal oxygen uptake (VO2 max) is a useful index to assess exercise capacity. However, there is no reference value for Koreans. This study aimed to compare actual VO2 max and predicted VO2 max using exercise capacity equations in Korean subjects.MethodsThis retrospective study enrolled 383 patients who underwent cardiopulmonary exercise test (CPET) with incremental maximal cycle ergometer test at Asan Medical Center from January 2020 to May 2021. Stage 1 and 2 lung cancer patients with normal lung function and healthy persons of 50 subjects who had maximal CPET were analyzed.ResultsThe subjects were aged 65 ± 13 years and predominantly male (74%). CPET results were as follows: absolute VO2 max, 1.2 ± 0.3 L/min; body weight referenced VO2 max, 20 ± 3.9 mL/kg/min; peak work rate, 94 ± 24 watts; peak heart rate, 142 ± 21 bpm; peak O2 pulse, 10 ± 3 mL/beat; minute ventilation, 59 ± 14 L/min; peak respiratory rate, 34 ± 6 breaths per minute; and peak breathing reserve, 41 ± 18%. There was significant discordance between the measured and predicted absolute VO2 max using the Jones, Hansen, and Wasserman prediction equations developed for Caucasian population (P < 0.001). Agreement using Bland-Altman test between true and predicted absolute VO2 max was the best in Chinese equation (−0.03, 2SD = 0.55) compared to Jones (0.42, 2SD = 1.07), Hansen (0.44, 2SD = 0.86), and Wasserman (0.42, 2SD = 0.86) equations.ConclusionThe reference value and prediction equation from studies including primarily Caucasians may not be appropriate for Koreans. Since the mean difference is the lowest in Chinese equation, the Chinese equation might be used for the Korean adult population.

Closure of outpatient cardiac rehabilitation during the first COVID-19 lockdown in Austria in spring 2020 resulted in deteriorating physical exercise capacity: a mixed-methods study

BackgroundGroup-based cardiac rehabilitation (CR) has inevitably been disrupted by COVID-19-related public health measures, increasing the risk of deterioration in modifiable risk factors for patients with cardiovascular disease (CVD).PurposeTo examine the impact of CR closure during the first COVID-19-related national lockdown in Austria in spring 2020 on patients' maintenance of physical activity, physical fitness levels, and cardiovascular risk profile; and to describe the patient experience of lack of group-based CR training due to COVID-19.MethodsThis mixed-methods study recruited patients from an outpatient CR centre in Austria during summer 2020. Eligibility criteria were regular attendance at weekly group-based exercise training at the centre until the COVID-19-related lockdown in March 2020; pre-lockdown completion of a maximal cycle ergometer test; no contraindications for maximal exercise testing; and no new complaints limiting exercise performance. Participants underwent post-lockdown quantitative assessment of physical fitness (maximal cycle ergometer testing, submaximal cycle ergometer training session at individual pre-lockdown settings) and cardiovascular risk status. These were compared with pre-lockdown data from medical records. Participants gave qualitative interviews about their experience of maintaining exercise during lockdown. Interviews were audio-recorded, transcribed, coded, and interpreted using framework analysis.ResultsTwenty-eight (57%) of 49 eligible patients were recruited, 1 withdrew, and 27 completed all study procedures. Two participants were excluded from analysis of physical fitness data, due to subsequent diagnosis of new complaints limiting exercise performance. Mean (SD) age was 69 (7.4) years. Six (22%) were female. Median (IQR) time since first CVD event was 8 (5.5, 9) years. In maximal ergometer testing, 14 (56%) had deteriorated, 10 (40%) were unchanged, and 1 (4%) had improved post-lockdown. At group level, power was significantly reduced (maximal ergometer testing, submaximal ergometer training), whereas CVD risk factors remained unchanged from pre- to post-lockdown (table 1). Qualitative analysis corroborated the negative impact of the closure of CR classes (table 2).ConclusionsThis patient cohort was heterogeneous with respect to physical activity levels and exercise capacity, yet overall motivated and experienced in exercise training, having regularly attended training sessions at the centre before the lockdown. Despite individually seeking out alternative exercise options during lockdown, group average exercise capacity deteriorated even in this motivated and exercise-conscious group. This highlights the importance of providing group-based opportunities for supervised high intensity training for patients who engage well in such a setting, and the detrimental impact of disruption to this type of CR service.Funding AcknowledgementType of funding sources: Public grant(s) – National budget only. Main funding source(s): Ludwig Boltzmann Gesellschaft COVID-19 Support Measure: Open Innovation in Science (OIS) Research Enrichment Fund

Cardiorespiratory and metabolic demand of the 6-minute pegboard and ring test in healthy young adults

ObjectiveTo determine the cardiorespiratory and metabolic demand of the Six-Minute Pegboard and Ring Test (6PBRT) in healthy young adults and its association with maximal arm cycle ergometer test (arm CET). MethodsVolunteers were randomized to performed the 6PBRT test or arm CET. The second test was performed after 48 h. Oxygen consumption (VO2), heart rate (HR), dyspnea and upper limb fatigue were assessed during the tests. Demographic data, body composition, level of physical activity, arm strength and endurance were also evaluated. ResultsDuring 6PBRT, VO2 values increased from 5.8 to 11.1 mL kg−1.min−1 (p < 0.001). VO2peak, HR Mean and HRmax at 6PBRT were 47.2% and close to 65% respectively of those achieved during the arm CET. There was a positive correlation between the score on 6PBRT and VO2mean and VO2peak achieved at arm CET (r = 0.268; p = 0.003 and r = 0.247; p = 0.046 respectively). No correlation was found between the HRmean, HRpeak, level of physical activity or strength with 6PBRT (p > 0.05). Handgrip endurance had a positive correlation with score on 6PBRT (r = 0.237; p = 0.054). Body Mass Index, body fat and fat mass were negatively correlated with the score on 6PBRT (r = 0.301; p = 0.014, 0.329; p = 0.007 and r = 0.427; p = 0.001). ConclusionsThe 6PBRT test showed a moderate cardiorespiratory and metabolic demand in healthy individuals in comparison of arm CET. BMI, body fat and fat mass correlated with the score on 6PBRT.

Association Between Self-Recorded Heart Rate Variability Profiles And Actigraphy-Derived Physical Activity In Young Healthy Adults

Mobile devices facilitate daily heart rate variability (HRV) tracking and serve as a potential behavior modification tool for cardiovascular health. It is currently unclear whether serial self-recorded HRV measures are influenced by physical activity (PA) levels. PURPOSE: To evaluate the association between self-recorded HRV profiles and actigraphy-derived PA levels in young, apparently healthy adults. METHODS: Men (n = 21, 24.4 ± 4.9 years) and women (n = 20, 21.4 ± 2.7 years) self-recorded post-waking HRV for 60 s in supine and standing positions using a heart rate chest strap and mobile application over one week. The week average of the natural logarithm of the root-mean square of successive R-R interval differences (LnRMSSDavg, a vagal HRV index) and the coefficient of variation (LnRMSSDcv, a marker of day-to-day fluctuation) were assessed. Throughout the observation period, subjects wore a validated wrist-based activity monitor to determine average sedentary time; light, moderate, moderate-vigorous (MV), and vigorous (V) PA; and total steps. Aerobic capacity (VO2max) was obtained via a maximal cycle ergometer test post-observation. RESULTS: In men, no associations were observed between any HRV and PA variables (P > 0.05). In women, sedentary time (606 ± 108 min) was associated (r = 0.59) with supine LnRMSSDcv (9.8 ± 5.2%), MVPA (259 ± 74 min) was associated with standing (13.0 ± 4.4%) and supine LnRMSSDcv (r = -0.45 and -0.51, respectively), VPA (152 ± 54 min) was associated with supine LnRMSSDcv (r = -0.53), and total step count (13,209 ± 2,560) was associated (r = 0.45) with supine LnRMSSDavg (4.1 ± 0.5) (all P < 0.05). VO2max was associated with the same PA variables in women (P < 0.05), but none of the PA variables in men (P > 0.05). After adjusting for VO2max (28.1 ± 5.9 mL·kg·min-1), all associations between HRV and PA variables in women became non-significant (P > 0.05). CONCLUSIONS: Significant associations between self-recorded HRV profiles and actigraphy-derived PA levels that were only observed in women appear to be explained by fitness. Thus, PA tailored to the enhancement of aerobic capacity will likely yield the greatest HRV improvements, reflected in higher average values with less day-to-day fluctuation. Supported by Georgia Southern University Faculty Research Committee Seed Funding Award.

Organized Sport Participation, Physical Activity, Sleep and Screen Time in 16-Year-Old Adolescents.

This study aimed to examine the association of different frequencies of organized sport participation (OSP) with physical activity, cardiorespiratory fitness, body composition, sleep, and screen time among adolescents. A cross-sectional study involving 315 16-year-old adolescents was conducted. OSP was self-reported, being categorized as 0 times a week, less than three times a week, 4–5 times a week, and 6–7 times a week, on average. Screen time was also self-reported but physical activity and sleep duration were objectively measured. Cardiorespiratory fitness and body composition were measured using a maximal cycle ergometer test and a dual-energy X-ray absorptiometry (DXA) scan, respectively. An analysis of covariance revealed a significant association between OSP and physical activity (F (3, 286) = 14.53, p < 0.01), cardiorespiratory fitness (F (3, 236) = 17.64, p < 0.01), screen time (F (3, 294) = 8.14, p < 0.01), body fat percentage (F (3, 292) = 11.84, p < 0.01), and fat free mass (F (3, 290) = 5.76, p < 0.01. No significant association was found between OSP and sleep duration. Post hoc analyses showed that OSP at least four times a week was beneficial to favorable physical activity levels, cardiorespiratory fitness, screen time, and body composition and may therefore serve as a valuable tool in battling unhealthy lifestyle behaviors among adolescents.

Plasma irisin and its associations with oxidative stress in athletes suffering from overtraining syndrome.

Irisin is a novel exercise-induced myokine that may be involved in regulating energy metabolism. We determined whether overtraining syndrome (OTS) and its biochemical markers are associated with plasma irisin levels in athletes. Seven severely overtrained athletes (OA) and 10 healthy control athletes (CA) were recruited and examined at the time of diagnosis (baseline) and after 6- and 12-months follow-up. Training volume and intensity were initially restricted but progressively increased in OA as OTS symptoms alleviated; CA continued their normal training routine. A maximal cycle ergometer test was performed with irisin analyzed before and after the test. Before the exercise test, irisin levels tended to be lower in OA than in CA at baseline (154.5 ± 28.5 vs. 171.7 ± 58.7 ng/mL). In both groups, at rest irisin levels changed only marginally during follow-up and were not affected by maximal exercise, nor were they associated with physical performance or body fat percentage. Irisin concentration at rest correlated positively with an oxidative stress marker, malondialdehyde (MDA) and negatively with an antioxidant protection marker, oxygen radical absorbance capacity (ORAC) in response to the exercise test in OA at baseline. Our findings help to clarify the possible contribution of irisin and its association with oxidative stress in the pathophysiology of OTS.