Submaximal Test Research Articles

Exercise based assessment of cardiac autonomic function in type 1 versus type 2 diabetes mellitus.

BackgroundCardiac autonomic neuropathy (CAN) is a complication of diabetes mellitus (DM) that is associated with increased mortality. Exercise-based assessment of autonomic function has identified diminished parasympathetic reactivation after exercise in type 2 DM. It is postulated herein, that this would be more prominent among those with type 1 DM.MethodsSixteen subjects with type 1 DM (age 32.9 ± 10.1 years), 18 subjects with type 2 DM (55.4 ± 8.0 years) and 30 controls (44.0 ± 11.6 years) underwent exercise-based assessment of autonomic function. Two 16-min submaximal bicycle tests were performed followed by 45 min of recovery. On the second test, atropine (0.04 mg/kg) was administered near end-exercise so that all of the recovery occurred under parasympathetic blockade. Plasma epinephrine and norepinephrine levels were measured at rest, during exercise, and during recovery.ResultsThere were no differences in resting or end-exercise heart rates in the three groups. Parasympathetic effect on RR-intervals during recovery (p < 0.03) and heart rate recovery (p = 0.02) were blunted in type 2 DM. Type 1 DM had higher baseline epinephrine and norepinephrine levels (p < 0.03), and exhibited persistent sympathoexcitation during recovery.ConclusionsDespite a longer duration of DM in the study patients with type 1 versus type 2 DM, diminished parasympathetic reactivation was not noted in type 1 DM. Instead, elevation in resting plasma catecholamines was noted compared to type 2 DM and controls. The variable pathophysiology for exercise-induced autonomic abnormalities in type 1 versus type 2 DM may impact prognosis.

Metabolic Flexibility and Mechanical Efficiency in Women Over-60.

Purpose: Aging deteriorates metabolic flexibility (MF). Moreover, recent studies show that glycolysis is barely increased despite impoverished lipid metabolism, in addition to increased relevance of muscle power in older adults. This study aims to analyze MF, i.e., fat and carbohydrates oxidation rates (FATox and CHOox), and the point of maximal fat oxidation (MFO), in a group of active women over-60. It also aims to delve into the role of power production and mechanical efficiency regarding MF. This will help to decipher their metabolic behavior in response to increasing intensity. Methods: Twenty-nine women (66.13 ± 5.62 years) performed a submaximal graded cycling test, increasing 10 W each 3-min15-s, from 30 W to the second ventilatory threshold (VT2). Muscle power was adjusted with a Saris-H3 roller, together with a continuous gas analysis by indirect calorimetry (Cosmed K4b2). Pre and post-test blood lactate (BLa) samples were included. Frayn’s equations, MFO and CHOoxpeak (mg/min/kg FFM) were considered for MF analysis (accounting for average VO2 and VCO2 in each last 60-s), whilst delta and gross efficiencies (DE%, GE%), and exercise economy (EC), were added for Mechanical Efficiency. Mean comparisons regarding intensities 60, 80 and 100% at VT2, completed the study together with correlation analysis among the main variables. Results: MFO and CHOoxpeak were small (6.35 ± 3.59 and 72.79 ± 34.76 g/min/kgFFM respectively) for a reduced muscle power (78.21 ± 15.84 W). Notwithstanding, GE% and EC increased significantly (p < 0.01) with exercise intensity. Importantly, coefficients of variation were very large confirming heterogeneity. Whilst muscle power outcomes correlated significantly (p < 0.01) with MFO (r = 0.66) and age (r = −0.62), these latter failed to be associated. Only GE% correlated to CHOoxpeak (r = −0.61, p < 0.01) regarding mechanical efficiency. Conclusions: Despite being active, women over-60 confirmed impaired substrates switching in response to exercise, from both FAT and CHO pathways. This limits their power production affecting exercise capacity. Our data suggest that decreased power with age has a key role above age per se in this metabolic inflexibility. Vice versa, increasing power seems to protect from mitochondrial dysfunction with aging. New studies will confirm if this higher efficiency when coming close to VT2, where GE is the more informative variable, might be a protective compensatory mechanism.

Association of Physical Activity With Maximal and Submaximal Tests of Exercise Capacity in Middle- and Older-Aged Adults.

Although physical activity (PA) is an important determinant of exercise capacity, the association between these constructs is modest. The authors investigated the associations of self-reported and objectively measured PA with maximal and submaximal tests of exercise capacity. Participants aged ≥40years (N = 413; 49.6% female) completed a PA questionnaire, wore a uniaxial accelerometer (5.2 ± 1.1 days), and performed maximal (cardiopulmonary exercise test [CPET]) and submaximal (long-distance corridor walk) tests with indirect calorimetry (oxygen consumption, V˙O2). Linear regression models were fitted to assess the variation in exercise capacity explained (partial eta squared, η2) by PA variables. Accelerometer-measured vigorous (η2 = 22% female; η2 = 16% male) and total PA (η2 = 17% female; η2 = 13% male) explained the most variance in CPET V˙O2 (p < .001). All η2 values were lower for long-distance corridor walk V˙O2 (η2 ≤ 11%). Age contributed more to CPET V˙O2 than any PA variable in males (η2 = 32%), but not in females (η2 = 19%). Vigorous and total PA play important roles in CPET V˙O2 in mid to late life.

Associations between objectively measured physical activity, sedentary time, and cardiorespiratory fitness with inflammatory and oxidative stress markers and heart rate variability.

To assess the associations between physical activity (PA) and sedentary time (SEDT) with inflammatory and oxidative stress markers, heart rate variability (HRV) and post-exercise recovery (HRR) controlling for cardiorespiratory fitness (CRF) and potential confounders. The following data was collected from 44 participants during 2019 (age = 49.5 ± 6.4 years, 66% women): Plasma levels of C-reactive protein (CRP) and cytokines (IL-1β, INF-γ, TNF-α, MCP-1, IL-6, IL-8, IL-10, IL-18, IL-23); catalase (CAT) and glutathione peroxidase (GPX) activities; resting heart (HR) rate for HRV analysis, anthropometric measures, a submaximal cycling test to evaluate CRF with active recovery to assess and HRR (absolute and ΔHR), and 7-day accelerometry. Women spent significantly more SEDT (p = 0.035), had higher inflammatory markers (IL-6 and TNF) and lower HRV indices [SDNN, LF/HF, SD2 (p > 0.05)]. Significant associations were found between SEDT and markers of inflammation [CRP, B = 0.006, p = 0.001; MCP-1, B = 0.003, p = 0.038]. HRV indices were significantly associated with inflammatory/oxidative stress markers [IL-10 (p = 0.04), GPX (p = 0.014), ln-IL 23 (p = 0.036), CAT (p = 0.026)] while HRR was positively associated with light PA [Δ3 (B = 0.051, p = 0.043), Δ4 (B = 0.062, p = 0.021)] and inversely related to catalase [Δ3 (B = -54.7, p = 0.042), Δ4 (B = -54.1, p = 0.021] and CRP [Δ5 (B = -19.8, p = 0.033)]. Higher CRF showed lower values for TNF-α (p = 0.02) and IL-10 (p = 0.003) and better HRV/HRR indices [RMSSD, PNS, SampEn, SD1 (p < 0.05)]. SEDT had a higher impact on inflammation and autonomic balance, independently of PA levels with differences by sex and CRF. PA appears to be more important for a better HRR. Lower HRV and HRR could be indicative of inflammatory status.

Workplace exercise program in a hospital environment: an effective strategy for the promotion of employees physical and mental health. A randomized controlled study.

The demanding and exhausting working hours, as well as the bad and unsuitable working conditions that prevail in several hospitals, affect employees' physical and mental health. The purpose of this study was to examine the effectiveness of a daily 6-week supervised workplace exercise program on health indices, functional capacity, overall fitness, subjective vitality, and life satisfaction in health professionals. A randomized controlled study was used. 50 health professionals (40-55years), working in a hospital environment, were divided into two groups: exercise (EG) and control group (CG). EG performed a 6-week supervised concurrent chair-based exercise program (stretching, strength, balance exercises, aerobic dance; 5days/week, 30-40min/day, 2 workouts/day lasted 15-20min) in the hospital. Health indices (body composition, blood pressure, respiratory function), functional capacity (flexibility, balance), physical fitness (strength, cardiorespiratory fitness), subjective vitality, and life satisfaction were measured before and after the completion of the program. Additionally, after the completion of the program, EG participants' enjoyment was assessed. EG significantly increased (p < 0.001) lean body mass and respiratory function (range of mean increase 3.5-4.5%, depending on the variable), functional capacity (range of mean increase 18-40%, depending on the variable), lower and upper libs maximal strength (range of mean increase 10-25%, depending on the variable), subjective vitality (41.3%) and life satisfaction (21.5%); while significantly decreased (p < 0.001) heart rate during submaximal test (-14%), body fat and blood pressure (range of mean decrease -3.5% to -5.5%, depending on the variable). In CG, all the above variables did not change. Furthermore, a great percentage of employees (95%) reported high levels of enjoyment. A workplace exercise program may be safely used for the promotion of employees' physical and mental health.

Near infrared spectroscopy to evaluate the effect of a hybrid exercise programme on peripheral muscle metabolism in patients with intermittent claudication: an exploratory PROSECO-IC sub study

ABSTRACT Intermittent claudication (IC) is characterized by decreased blood flow and oxygen delivery to the lower-limb muscles, resulting in pain and impaired functional capacity. This study evaluated the effects of a 12-week hybrid walking intervention on muscle oxygenation and functional capacity in 38 patients with IC (Rutherford I–III). Functional capacity was evaluated by means of two different treadmill test protocols and a six-minute walk test (6MWT). Muscle oxygenation was assessed during the treadmill tests using near-infrared spectroscopy. After the intervention, maximal walking distance was significantly increased (p < 0.001) during the progressive maximal treadmill test (mean (SD): +155 (SD 177) metres) and 6MWT (+18 (SD 29) metres) metres, with concomitant improvements in muscle oxygenation measures. Deoxygenation was slower during the progressive maximal test (p < 0.001) and reoxygenation was faster during recovery (p = 0.045). During the more submaximal test, oxygenated haemoglobin was better preserved (p = 0.040). Slower deoxygenation was more pronounced in the high responders of the progressive maximal treadmill test (p = 0.002). The findings suggest that preserved oxygen availability and slower deoxygenation during exercise could partly explain the improvements in functional capacity.

Sub Maximal Ergospirometry Parameters in Untrained Non-Frail Octogenarian Subjects.

Background and Objectives: The prevalence of chronic diseases increases with age, and in octogenarian elderly, a cardiorespiratory test with gas analysis is more effective in determining the risk of mortality than applying the conventional risk factors. Materials and Methods: 25 untrained non-frail octogenarian subjects (four men) performed a submaximal test with gas analysis, which was stopped after the second ventilatory threshold (VT2) was reached. The variables analyzed were oxygen consumption at the first threshold (VO2 VT1); ventilatory class (VE/VCO2); oxygen uptake efficiency slope (OUES); cardiorespiratory optimal point (COP); oxygen pulse difference between VT2 and VT1 (diff. VO2/HR VT2-VT1). Results: the variables were classified categorically based on cut-off points present in the literature, where the variable with the highest percentage of altered cases was dif. VO2/HR VT2-VT1 at 48%; followed by VO2 VT1 at 40%, OUES at 36%, COP at 32%, and VE/VCO2 at 24%. Chi-square analysis between the measured parameters defined that normal and altered variables were related to each other, except for the variable VE/VCO2 and OUES. Conclusions: it was found that the main altered variable was the oxygen pulse and the least altered variable was VCO2/VCO2; there was only a statistically significant difference in a pair of OUES vs. VE/VCO2 variables.

Association between match physical activity and neuromuscular characteristics in youth football.

The aim of this study was to examine the associations between maximal and submaximal neuromuscular field tests, match physical activity levels and biological maturation in youth football players. Sixty-four football players from under 14 to under 17 age groups were assessed. Players performed a repeated-sprint ability test, counter movement jump, 10-m, and 30-m sprint test, as well as an assessment of peripheral muscle function following a multi-stage incremental (i.e., four intensity levels) change of direction test (COD). Knee extensors peak-torque (PTmax) and the decrement of torque values (dec) were considered as COD outcomes. Physical match activities were tracked by GPS technology, while rate of perceived exertion (RPE) was assessed using the CR10 Börg Scale. Pearson's correlations (90% confidence interval) were used to examine the relationships. Small associations were found between field tests and match activities. The relationships increased from small to moderate for some tests when match data with RPE>5 were considered. The largest associations were found between distance covered <-2.5m·s-2 and both COD PTmax and dec when RPE>5. The results of the present study provide further evidence of a small-to-moderate association between muscular performance and match work-rate in young football players. Although physical and physiological evaluations fail to precisely estimate the quantity of physical activities performed during matches, it is suggested that they can be utilized to monitor the training effect over time in young football players.

Implementation of supervised exercise therapy in a veteran population with symptomatic claudication.

Real-world implementation of supervised exercise therapy (SET) referral for symptomatic intermittent claudication has been limited by poor provider awareness around reimbursement and low patient adherence owing to factors including limited center availability and long travel distances to sites. In this study, 76 of 77 consecutive male veteran patients with intermittent claudication managed at a single-center vascular specialty clinic were referred to SET prior to revascularization. Pre- and post-SET submaximal exercise treadmill testing was performed for assessment of exercise capacity in metabolic equivalents (METs). In the 48.7% of subjects who completed 36 sessions of SET (n = 37), the average improvement in METs was 60.3%, reflecting improvement from baseline average of 3.4 METs to 5.5 METs after SET. Another 14 patients pursued self-guided exercise therapy and 25 patients declined any participation in exercise therapy. Reasons for declining participation in SET included inadequate transportation, cost of copayment, and interference with full-time work schedules. There was a nonsignificant numeric trend toward improved change in ankle-brachial index in the combined SET and self-guided exercise groups compared to those that declined exercise therapy (0.011 ± 0.124 vs -0.040 ± 0.105, p = 0.156). High acceptance of referral to SET is possible, despite the limitations to implementation. Incorporation of novel pre- and post-SET submaximal exercise treadmill testing allows for assessment of change in exercise capacity and aids in risk stratification and management of intermittent claudication symptoms.

Dietary Nitrate Supplementation Does Not Alter Exercise Efficiency at High Altitude - Further Results From the Xtreme Alps Study.

IntroductionNitrate supplementation in the form of beetroot juice (BRJ) ingestion has been shown to improve exercise tolerance during acute hypoxia, but its effect on exercise physiology remains unstudied during sustained terrestrial high altitude exposure. We hypothesized that performing exercise at high altitude would lower circulating nitrate and nitrite levels and that BRJ ingestion would reverse this phenomenon while concomitantly improving key determinants of aerobic exercise performance.MethodsTwenty seven healthy volunteers (21 male) underwent a series of exercise tests at sea level (SL, London, 75 m) and again after 5–8 days at high altitude (HA, Capanna Regina Margherita or “Margherita Hut,” 4,559 m). Using a double-blind protocol, participants were randomized to consume a beetroot/fruit juice beverage (three doses per day) with high levels of nitrate (∼0.18 mmol/kg/day) or a nitrate-depleted placebo (∼11.5 μmoles/kg/day) control drink, from 3 days prior to the exercise trials until completion. Submaximal constant work rate cycle tests were performed to determine exercise efficiency and a maximal incremental ramp exercise test was undertaken to measure aerobic capacity, using breath-by-breath pulmonary gas exchange measurements throughout. Concentrations of nitrate, nitrite and nitrosation products were quantified in plasma samples collected at 5 timepoints during the constant work rate tests. Linear mixed modeling was used to analyze data.ResultsAt both SL and HA, plasma nitrate concentrations were elevated in the nitrate supplementation group compared to placebo (P < 0.001) but did not change throughout increasing exercise work rate. Delta exercise efficiency was not altered by altitude exposure (P = 0.072) or nitrate supplementation (P = 0.836). V̇O2peak decreased by 24% at high altitude (P < 0.001) and was lower in the nitrate-supplemented group at both sea level and high altitude compared to placebo (P = 0.041). Dietary nitrate supplementation did not alter other peak exercise variables or oxygen consumption at anaerobic threshold. Circulating nitrite and S-nitrosothiol levels unexpectedly rose in a few individuals right after cessation of exercise at high altitude.ConclusionWhilst regularly consumed during an 8 days expedition to terrestrial high altitude, nitrate supplementation did not alter exercise efficiency and other exercise physiological variables, except decreasing V̇O2peak. These results and those of others question the practical utility of BRJ consumption during prolonged altitude exposure.

Aerobic exercise training in older men and women-Cerebrovascular responses to submaximal exercise: Results from the Brain in Motion study.

Physical inactivity is a leading modifiable risk factor for cardiovascular and cerebrovascular disease, cognitive dysfunction, and global mortality. Regular exercise might mitigate age‐related declines in cardiovascular and cerebrovascular function. In this study, we hypothesize that a 6‐month aerobic exercise intervention will lead to a decrease in cerebrovascular resistance index (CVRi) and to an increase in cerebral blood flow (CBF) and cerebrovascular conductance index (CVCi) during two submaximal exercise workloads (40% VO2max and 65 W), intensities that have been shown to be comparable to activities of daily life. Two hundred three low‐active healthy men and women enrolled in the Brain in Motion study, completed a 6‐month exercise intervention and underwent submaximal and maximal tests pre‐/post‐intervention. The intervention improved the gas exchange threshold and maximal oxygen consumption (VO2max), with no change in heart rate at VO2max, during the treadmill VO2max test. Heart rate and CVRi decreased from pre‐intervention values during both relative (40% VO2max) and absolute (65 W) submaximal exercise tests. Blood flow velocity in the middle cerebral artery and CVCi increased post‐intervention during 40% VO2max and 65 W. Changes in mean arterial pressure were found only during the absolute component (65 W). Our study demonstrates that aerobic exercise improves not only cardiorespiratory indices but also cerebrovascular function at submaximal workloads which may help to mitigate age‐related declines in everyday life. Investigation of the mechanisms underlying the decline in cardiovascular and cerebrovascular capacity with aging has important implications for the maintenance of health and continued independence of older adults.

Autonomic support of central hemodynamics and physical working capacity in female swimmers and runners in a one-year training cycle

The aim of the work is to assess dynamic changes in heart rate variability (HRV), central hemodynamics and physical performance in female swimmers at a distance of 50–200 meters and female runners at a distance of 400 meters in the preparatory and competitive periods of the training process. Materials and methods. At the beginning of the preparatory period and at the end of the competitive period, 11 female swimmers were examined, including 1 athlete – Master of Sports of Ukraine (MSU), 7 athletes – Candidate Masters of Sports (CMS), 1 – first-class athlete, 2 – second-class athletes, and 22 female runners, including 1 athlete – Master of Sports of Ukraine of International Class (MSUIC), 3 athletes – Candidate Masters of Sports, 7 first-class athletes, 8 – second-class athletes and 3 – third-class athletes. Time- and frequency domain methods of HRV analysis were used to assess the mechanisms of heart neurohumoral regulation. Central hemodynamic parameters were examined by an automated tetrapolar rheography according to W. Kubiček et al. (1970) modified by Yu. T. Pushkar et al. (1970). Physical working capacity (PWC) was measured using a submaximal PWC170 test. The functional state index (FSI) was calculated according to the formula that we had proposed and patented. Results. Analysis of HRV indices in female swimmers revealed the prevalence of parasympathetic influences in the competitive period. There was a central hemodynamics-related significant decrease in cardiac index (CI) in the competitive period, although its value corresponded to the eukinetic circulatory type (CT). The ratio of CTs was 18.2 %: 81.8 %: 0.0 %, hypokinetic, eukinetic and hyperkinetic CT, respectively, indicating a tendency towards eukinetic CT prevalence over hypokinetic one (P = 0.075) and the absence of athletes with physiologically unfavorable hyperkinetic CT. The PWC170/kg value increased by an average of 12.44 %, from 12.860 ± 0.732 kgm·min-1·kg-1 to 14.460 ± 0.823 kgm·min-1·kg-1 (P = 0.002), and FSI – of 22.21 % (P = 0.0005) and corresponding to “below average” score. In the competitive period, 2 CMS female athletes qualified for MSU, 1 first-class athlete qualified for CMS, and 2 second-class athletes achieved the first-class sport qualification. Conclusions. Female swimmers demonstrated the significant prevalence of parasympathetic effects of the ANS, the tendency towards the eukinetic CT predominance and the absence of hyperkinetic CT, significantly increased PWC170/kg value by 12.44 % and FSI – by 22.21 % in the competitive period as compared with the preparatory period. The correlation analysis to assess both periods revealed the important relationship between heart rate (HR) and autonomic rhythm index (ARI), HR and indicator of the adequacy of regulation processes (IARP), indicating that training-induced bradycardia shifted the autonomic balance towards the predominance of the parasympathetic arm of the ANS. Decreased ARI caused the decrease in СI, resulting in the transformation of hyperkinetic CT into eukinetic one and the absence of physiologically unfavorable hyperkinetic CT in the athletes. The increased functional state of female swimmers in the competitive period helped to achieve improvements in their athletic performance.

Test-Retest Reliability of the Microvascular Oxygenation Recovery Response Subsequent to Submaximal Cycling Exercise

Introduction: The purpose was to quantify the within-session and between-session reliability of halftime (HT) and monoexponential curve fitting (EXP) analyses, when assessing the microvascular tissue oxygenation (StO2) recovery response via near-infrared spectroscopy (NIRS). Methods: Seventeen subjects completed a submaximal cycling test and 6-minute cool-down on three occasions. The protocol was completed twice during session 1 and once during session 2. StO2 were collected via NIRS from a randomized vastus lateralis. StO2 response from the last minute of exercise and the entire cool-down was analyzed using HT and EXP. Within-session and between-session reliability were examined by mixed, absolute agreement intraclass correlation coefficients (ICC) and standard error of the measurement (SEM). Results: HT resulted in higher within-session reliability compared to EXP for exercising StO2 (ICCHT=0.920, ICCEXP=0.865, SEMHT=4.9 ∆BSL, SEMEXP=6.2 ∆BSL) and StO2 recovery time (ICCHT=0.772, ICCEXP=0.720, SEMHT=7 sec, SEMEXP=9 sec). Similar between-session reliability for exercising StO2 was observed (ICCHT=0.895, ICCEXP=0.879, SEMHT=5.2 ∆BSL, SEMEXP=5.4 ∆BSL), however HT elicited higher between-session reliability for StO2 recovery time (ICCHT=0.583, ICCEXP=-0.211, SEMHT=7 sec, SEMEXP=15 sec). Conclusions: Due to the better within-session (exercising StO2, StO2 recovery time) and between-session (StO2 recovery time) reliability, practitioners are encouraged to use HT when assessing exercising StO2 and StO2 recovery time.

Effects of Face Masks on Physical Performance and Physiological Response during a Submaximal Bicycle Ergometer Test.

The ongoing COVID-19 pandemic requires wearing face masks in many areas of our daily life; hence, the potential side effects of mask use are discussed. Therefore, the present study explores whether wearing a medical face mask (MedMask) affects physical working capacity (PWC). Secondary, the influence of a filtering facepiece mask with exhalation valve class 2 (FFP2exhal) and a cotton fabric mask (community mask) on PWC was also investigated. Furthermore, corresponding physiological and subjective responses when wearing face masks as well as a potential moderating role of subjects’ individual cardiorespiratory fitness and sex on face mask effects were analyzed. Thirty-nine subjects (20 males, 19 females) with different cardiorespiratory fitness levels participated in a standardized submaximal bicycle ergometer protocol using either a MedMask, FFP2exhal, community mask, or no mask (control) on four days, in randomized order. PWC130 and PWC150 as the mechanical load at the heart rates of 130 and 150 beats per minute were measured as well as transcutaneous carbon dioxide partial pressure, saturation of peripheral capillary oxygen, breathing frequency, blood pressure, perceived respiratory effort, and physical exhaustion. Using the MedMask did not lead to changes in PWC or physiological response compared to control. Neither appeared changes exceeding normal ranges when the FFP2exhal or community mask was worn. Perceived respiratory effort was up to one point higher (zero-to-ten Likert scale) when using face masks (p < 0.05) compared to control. Sex and cardiorespiratory fitness were not factors influencing the effects of the masks. The results of the present study provide reason to believe that wearing face masks for infection prevention during the COVID-19 pandemic does not pose relevant additional physical demands on the user although some more respiratory effort is required.

The reliability, validity and sensitivity of an individualised sub-maximal fitness test in elite rugby league athletes

ABSTRACT We aimed to examine the reliability, validity and sensitivity of an individualised sub-maximal fitness test (SMFTIFT60). Nineteen elite rugby league players performed a one-week test-retest of SMFTIFT60. Typical Errors and ICCs were: small (<3.5%) and extremely high (>0.90) for accelerometer-derived variables; moderate (<2.5% points) and moderate to very high (0.71–0.89) for exercise and recovery heart rate (HRex and HRR, respectively). Convergent validity correlations with the 10-week pre-season change in 30–15 Intermittent Fitness Test performance were large for changes in SMFTIFT60 HRex (r = −0.57) and HRR (0.60), and very large for changes in accelerometer measures (range: −0.71 to −0.79). For sensitivity, within-player dose–response relationships between SMFTIFT60 HRex and prior 3-day training loads were negative and ranged from moderate (session ratings of perceived exertion [sRPE-TL], r = −0.34), to large (high-speed running distance, −0.51; acceleration load, −0.73) and very large (heart rate Training Impulse [TRIMP], −0.83). All other relationships were unclear or trivial to small. Physiological and accelerometer-derived measures from the SMFTIFT60 are reliable and valid for the assessment of fitness in rugby league players. Only HRex appears sensitive to acute changes in training load. The SMFTIFT60 could be a useful monitoring tool in team sports

Oxygen uptake efficiency slope in community-dwelling ambulant stroke survivors during walking and stair climbing: a cross-sectional study

ABSTRACT Background Oxygen uptake efficiency slope during submaximal tests has been proposed as a more appropriate measure of aerobic capacity after suffering a stroke, since some individuals cannot tolerate maximal exercise testing. However, it has not yet been investigated whether the oxygen uptake efficiency slope is able to differentiate between healthy individuals and those who have suffered a stroke. Objectives To compare the oxygen uptake efficiency slope during walking and stair climbing between stroke survivors and age- and sex-matched healthy controls. Methods This is a cross-sectional study in which 18 individuals who had suffered a stroke (stroke survivors) and 18 healthy controls matched for sex and age were included. Oxygen consumption and minute ventilation were collected breath-by-breath during walking (6-min Walk Test) and stair climbing. The oxygen uptake efficiency slope was estimated by the slope of the line obtained through linear regression. Results The stroke survivors had a lower oxygen uptake efficiency slope during the 6-min Walk Test than the healthy controls (MD 498, 95% CI 122 to 873, p = .01). The between-group difference for the Stair Test was smaller and not statistically significant (MD 349, 95%CI −73 to 772, p = .10). Conclusions Stroke survivors had lower oxygen uptake efficiency slope during the performance of the 6-min Walk Test when compared to sex- and age-matched healthy controls. This suggests that stroke survivors have worse cardiopulmonary capacity.

Population and Age-Based Cardiorespiratory Fitness Level Investigation and Automatic Prediction.

Maximal oxygen consumption (VO2max) reflects aerobic capacity and is crucial for assessing cardiorespiratory fitness and physical activity level. The purpose of this study was to classify and predict the population-based cardiorespiratory fitness based on anthropometric parameters, workload, and steady-state heart rate (HR) of the submaximal exercise test. Five hundred and seventeen participants were recruited into this study. This study initially classified aerobic capacity followed by VO2max predicted using an ordinary least squares regression model with measured VO2max from a submaximal cycle test as ground truth. Furthermore, we predicted VO2max in the age ranges 21–40 and above 40. For the support vector classification model, the test accuracy was 75%. The ordinary least squares regression model showed the coefficient of determination (R2) between measured and predicted VO2max was 0.83, mean absolute error (MAE) and root mean square error (RMSE) were 3.12 and 4.24 ml/kg/min, respectively. R2 in the age 21–40 and above 40 groups were 0.85 and 0.75, respectively. In conclusion, this study provides a practical protocol for estimating cardiorespiratory fitness of an individual in large populations. An applicable submaximal test for population-based cohorts could evaluate physical activity levels and provide exercise recommendations.

Normative Data of Maximal Oxygen Consumption (VO2 Max) among Healthy Young Adults: A Cross-sectional Study

Introduction: Maximal oxygen uptake (VO2 max) is the maximum quantity of oxygen a person can consume, and it remains constant over time despite increased exertion. The amount of oxygen consumed by the working muscles is measured by maximal oxygen consumption. The maximal oxygen uptake can be measured using maximal or submaximal tests, by gas analyser or field methods. The estimated VO2 max can be used to study people’s fitness and raise awareness about physical activity and lifestyle changes. Aim: To determine the VO2 max values using a direct method and provide normative data of VO2 max for healthy young adults in the age group of 18-25 years in both sexes. Materials and Methods: This cross-sectional study was approved by the Institutional Ethical Committee of RUHS College of Medical Sciences, Jaipur, Rajasthan, India. A total of 419 healthy young adults (male and female students) were recruited from RUHSCollege of Medical Sciences and MNIT College, Jaipur, Rajasthan, India from January 2019 to March 2020. Anthropometric data included age, height, weight according to the National Health and Nutrition Examination Survey (NHANES) and followed by measurement of VO2 max using a gas analyser of AD-Instrument (model-ML206). Collected data was entered in Microsoft excel. Paired t-test was used to compare mean and Standard Deviation (SD) of variables between male and female participants. The p-value of &lt;0.05 was considered as significant. Results: The study was conducted on 419 apparently healthy college students (275 male and 144 female). The mean VO2 max value for males was 45.30±7.35 mL/kg/min and for females it was 35.71±5.29 mL/kg/min, which was found to be significantly higher in males than in females. The mean VO2 max among the largest proportion of the males (27.63%) falls in the ‘Good’ category of cardiorespiratory fitness scale and the largest proportion of the females (32.63%) falls in the ‘Fair’ category of cardiorespiratory fitness scale. Conclusion: The value of VO2 max was lower in the Indian population than in the western population, when value obtained from this study was compared with the standard normative value of cardiorespiratory fitness. Therefore, the values obtained in this study could serve as a normative for the Indian population.

Cardiopulmonary exercise test in patients with refractory angina: functional and ischemic evaluation

ObjectivesRefractory angina (RA) is a chronic condition clinically characterized by low effort tolerance; therefore, physical stress testing is not usually requested for these patients. Cardiopulmonary exercise testing (CPET) is considered a gold standard examination for functional capacity evaluation, even in submaximal tests, and it has gained great prominence in detecting ischemia. The authors aimed to determine cardiorespiratory capacity by using the oxygen consumption efficiency slope (OUES) in patients with refractory angina. The authors also studied the O2 pulse response by CPET and the association of ischemic changes with contractile modifications by exercise stress echocardiography (ESE). MethodsThirty-one patients of both sexes, aged 45 to 75 years, with symptomatic (Canadian Cardiovascular Society class II to IV) angina who underwent CPET on a treadmill and exercise stress echocardiography on a lower limb cycle ergometer were studied. ClinicalTrials.gov: NCT03218891. ResultsThe patients had low cardiorespiratory capacity (OUES of 1.74 ± 0.4 L/min; 63.9±14.7% of predicted), and 77% of patients had a flattening or drop in O2 pulse response. There was a direct association between Heart Rate (HR) at the onset of myocardial ischemia detected by ESE and HR at the onset of flattening or drop in oxygen pulse response detected by CPET (R = 0.48; p = 0.019). ConclusionPatients with refractory angina demonstrate low cardiorespiratory capacity. CPET shows good sensitivity for detecting abnormal cardiovascular response in these patients with a significant relationship between flattening O2 pulse response during CEPT and contractile alterations detected by exercise stress echocardiography.

2664-2069.2022.19DETERMINATION OF PHYSICAL PERFORMANCE IN SPORTS: POWER-ERGOMETRY METHOD (FROM THE AUTHOR'S MANY YEARS OF EXPERIENC)

Introduction. One of the factors of highly effective competitive activity of athletes is their achievement of a high level of special ability to work. The latter (ability to work) is determined by the results of testing in sports activities ("field conditions"), which involve the use of specific loads in the selected sport. There is a large arsenal of samples (tests) conducted in these conditions. One of such tests is our proposed method of power-ergometry (submaximal power-ergometry test PWC170) in determining anaerobic-aerobic performance of a forceful nature. The results of multi-year-research by author are considered in the article. Recommendations are given on the possibilities of using power-ergometry test in the practice of sports medicine, sports, "invasport", strength fitness, etc. Aim is to analyze and summarize the research data of the author of the article, which relate to the application of the method of power-ergometry in determining the physical performance of athletes. Material and methods: 1) analysis of scientific and scientific-methodical literature on the problems of physical performance research, 2) pedagogical experiment: functional research (determination of physical performance by submaximal test PWC170), 3) pedagogical observation of pupils and students, 4) statistical methods. Results: the patented method of power-ergometry on determination of PWC170 has no analogues in the countries of near and far abroad; no such studies have been conducted in Ukraine; instrumental (hardware) and non-apparatus methods of ergometric research have been considered. Conclusions: the perspectives of using the mentioned method in the practice of sports, sports medicine, as well as in the educational process of students of the faculties of health, physical education and sports of medical and pedagogical universities of Ukraine have been shown.