scholarly journals Quantification and Verification of Cardiorespiratory Fitness in Adults with Prehypertension

Sports ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Dharini M. Bhammar ◽  
Lung-Chang Chien
Keyword(s):  
Cardiorespiratory Fitness ◽  
Statistical Difference ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Test Results ◽  
Incremental Test ◽  
Incremental Exercise Test ◽  
Increased Risk ◽  
Verification Test

Background: Low cardiorespiratory fitness is associated with increased risk of hypertension and atherosclerosis in adults with prehypertension. The purpose of this study was to quantify cardiorespiratory fitness and to examine the utility of supramaximal constant-load verification testing for validating maximal oxygen uptake (VO2max) attainment in adults with prehypertension. Methods: Eleven adults (four women) with prehypertension (22.5 ± 2.9 y; body mass index (BMI): 24.6 ± 3.2 kg·m2) underwent an incremental exercise test followed 15 min later by a verification test at 105% of maximal work rate on a cycle ergometer. Results: There was no statistical difference in VO2 between the incremental (2.23 ± 0.54 L·min−1) and verification tests (2.28 ± 0.54 L·min−1; p = 0.180). Only three out of eleven participants had a higher VO2 during the verification when compared with the incremental test. If the verification test had not been conducted, one participant would have been incorrectly classified as having low cardiorespiratory fitness based on incremental test results alone. Conclusions: Verification testing validates the attainment of VO2max and can potentially reduce the over-diagnosis of functional impairment (i.e., deconditioning) in adults with prehypertension.

scholarly journals Confinement, partial sleep deprivation and defined physical activity–influence on cardiorespiratory regulation and capacity

2021 ◽  
Author(s):  
Jessica Koschate ◽  
Uwe Drescher ◽  
Uwe Hoffmann
Keyword(s):  
Physical Activity ◽  
Cardiorespiratory Fitness ◽  
Space Mission ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Binary Sequences ◽  
Kinetics Parameters ◽  
Slow Heart Rate ◽  
Partial Sleep Deprivation ◽  
Sleep Schedule

Abstract Introduction Adequate cardiorespiratory fitness is of utmost importance during spaceflight and should be assessable via moderate work rate intensities, e.g., using kinetics parameters. The combination of restricted sleep, and defined physical exercise during a 45-day simulated space mission is expected to slow heart rate (HR) kinetics without changes in oxygen uptake ($${\dot{\text{V}}\text{O}}_{{2}}$$ V ˙ O 2 ) kinetics. Methods Overall, 14 crew members (9 males, 5 females, 37 ± 7 yrs, 23.4 ± 3.5 kg m−2) simulated a 45-d-mission to an asteroid. During the mission, the sleep schedule included 5 nights of 5 h and 2 nights of 8 h sleep. The crew members were tested on a cycle ergometer, using pseudo-random binary sequences, changing between 30 and 80 W on day 8 before (MD-8), day 22 (MD22) and 42 (MD42) after the beginning and day 4 (MD + 4) following the end of the mission. Kinetics information was assessed using the maxima of cross-correlation functions (CCFmax). Higher CCFmax indicates faster responses. Results CCFmax(HR) was significantly (p = 0.008) slower at MD-8 (0.30 ± 0.06) compared with MD22 (0.36 ± 0.06), MD42 (0.38 ± 0.06) and MD + 4 (0.35 ± 0.06). Mean HR values during the different work rate steps were higher at MD-8 and MD + 4 compared to MD22 and MD42 (p < 0.001). Discussion The physical training during the mission accelerated HR kinetics, but had no impact on mean HR values post mission. Thus, HR kinetics seem to be sensitive to changes in cardiorespiratory fitness and may be a valuable parameter to monitor fitness. Kinetics and capacities adapt independently in response to confinement in combination with defined physical activity and sleep.

scholarly journals Prior exercise impairs subsequent performance in an intensity- and duration-dependent manner

2021 ◽  
Author(s):  
Madison M Fullerton ◽  
Louis Passfield ◽  
Martin J. MacInnis ◽  
Danilo Iannetta ◽  
Juan M Murias
Keyword(s):  
Lactate Threshold ◽  
Peak Power ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Dependent Manner ◽  
Incremental Test ◽  
Subsequent Performance ◽  
Prior Exercise ◽  
Subsequent Time ◽  
Constant Load Exercise

Prior constant-load exercise performed for 30-min at or above maximal lactate steady state (MLSSp) significantly impairs subsequent time-to-task failure (TTF) compared with TTF performed without prior exercise. We tested the hypothesis that TTF would decrease in relation to the intensity and the duration of prior exercise compared to a baseline TTF trial. Eleven individuals (6 men, 5 women, 28 ± 8 yrs) completed the following tests on a cycle ergometer (randomly assigned after MLSSp was determined): i) a ramp-incremental test, ii) a baseline TTF trial performed at 80% of peak power (TTFb), iii) five 30-min constant-PO rides at 5% below lactate threshold (LT-5%), halfway between LT and MLSSp (Delta50), 5% below MLSSp (MLSS-5%), MLSSp, and 5% above MLSSp (MLSS+5%), and iv) 15- and 45-min rides at MLSSp (MLSS15 and MLSS45, respectively). Each condition was immediately followed by a TTF trial at 80% of peak power. Compared to TTFb (330 ± 52s), there was 8.0 ± 24.1, 23.6 ± 20.2, 41.0 ± 14.8, 52.2 ± 18.9, and 75.4 ± 7.4% reduction in TTF following LT-5%, Delta50, MLSS-5%, MLSSp, and MLSS+5%, respectively. Following MLSS15 and MLSS45 there were 29.0 ± 20.1 and 69.4 ± 19.6% reductions in TTF, respectively (P <0.05). It is concluded that TTF is reduced following prior exercise of varying duration at MLSSp and at submaximal intensities below MLSS. Novelty: •Prior constant-PO exercise, performed at intensities below MLSSp, reduces subsequent TTF performance. •Subsequent TTF performance is reduced in a linear fashion following an increase in the duration of constant-PO exercise at MLSSp.

O2 uptake kinetics after acetazolamide administration during moderate- and heavy-intensity exercise

1998 ◽  
Vol 85 (4) ◽  
pp. 1384-1393 ◽  
Author(s):  
Barry W. Scheuermann ◽  
John M. Kowalchuk ◽  
Donald H. Paterson ◽  
David A. Cunningham
Keyword(s):  
Energy Demand ◽  
Ventilatory Threshold ◽  
Venous Blood ◽  
Lactate Concentration ◽  
Exponential Model ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Ergometer Exercise ◽  
Single Response

Inhibition of carbonic anhydrase (CA) is associated with a lower plasma lactate concentration ([La−]pl) during fatiguing exercise. We hypothesized that a lower [La−]plmay be associated with faster O2uptake (V˙o 2) kinetics during constant-load exercise. Seven men performed cycle ergometer exercise during control (Con) and acute CA inhibition with acetazolamide (Acz, 10 mg/kg body wt iv). On 6 separate days, each subject performed 6-min step transitions in work rate from 0 to 100 W (below ventilatory threshold, <V˙eT) or to a V˙o 2 corresponding to ∼50% of the difference between the work rate atV˙eT and peakV˙o 2(>V˙eT). Gas exchange was measured breath by breath. Trials were interpolated at 1-s intervals and ensemble averaged to yield a single response. The mean response time (MRT, i.e., time to 63% of total exponential increase) for on- and off-transients was determined using a two- (<V˙eT) or a three-component exponential model (>V˙eT). Arterialized venous blood was sampled from a dorsal hand vein and analyzed for [La−]pl. MRT was similar during Con (31.2 ± 2.6 and 32.7 ± 1.2 s for on and off, respectively) and Acz (30.9 ± 3.0 and 31.4 ± 1.5 s for on and off, respectively) for work rates <V˙eT. At work rates >V˙eT, MRT was similar between Con (69.1 ± 6.1 and 50.4 ± 3.5 s for on and off, respectively) and Acz (69.7 ± 5.9 and 53.8 ± 3.8 s for on and off, respectively). On- and off-MRTs were slower for >V˙eT than for <V˙eT exercise. [La−]plincreased above 0-W cycling values during <V˙eT and >V˙eT exercise but was lower at the end of the transition during Acz (1.4 ± 0.2 and 7.1 ± 0.5 mmol/l for <V˙eT and >V˙eT, respectively) than during Con (2.0 ± 0.2 and 9.8 ± 0.9 mmol/l for <V˙eT and >V˙eT, respectively). CA inhibition does not affect O2 utilization at the onset of <V˙eT or >V˙eT exercise, suggesting that the contribution of oxidative phosphorylation to the energy demand is not affected by acute CA inhibition with Acz.

Dependence of the Nature of the Pedaling Activity on Maximal Aerobic Power in Cycling

2017 ◽  
Vol 12 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Anthony Bouillod ◽  
Julien Pinot ◽  
Flavien Soenen ◽  
Theo Ouvrard ◽  
Frederic Grappe
Keyword(s):  
Exercise Test ◽  
Environmental Conditions ◽  
Power Output ◽  
Aerobic Power ◽  
Cycle Ergometer ◽  
Maximal Aerobic Power ◽  
Limits Of Agreement ◽  
Incremental Test ◽  
Incremental Exercise Test ◽  
Adaptation To Training

Purpose:To analyze the effect of the pedaling activity in different 4-min time trials (TT4s) (laboratory and field conditions) and compare TT4 and maximal aerobic power (MAP) determined from the classical incremental exercise test in laboratory. It was hypothesized that the exercises performed on the field would determine higher physical (power output [PO]) and mental involvements due to different environmental conditions.Methods:Sixteen male cyclists underwent an incremental test to exhaustion and 3 TT4s under different conditions: cycle ergometer (CE), level ground (LG), and uphill (UP).Results:Correlation was observed for PO with a trivial effect size and narrow limits of agreement between MAP and CE TT4 (r = .96, P < .001). The comparison between the CE, LG, and UP tests indicates that PO was significantly higher in UP than in CE (+8.0%, P < .001) and LG (+11.0%, P < .001).Conclusions:The results suggest that PO depends on the nature of the pedaling activity. Moreover, PO under CE TT4 is a relevant predictor of MAP. It seems important to measure MAP by taking into account the cycling conditions, considering that coaches and scientists use this parameter to assess the aerobic potential of athletes and determine the exercise intensities useful for monitoring adaptation to training.

Intensity-dependent tolerance to exercise after attaining V̇o2 max in humans

2003 ◽  
Vol 95 (2) ◽  
pp. 483-490 ◽  
Author(s):  
Edward M. Coats ◽  
Harry B. Rossiter ◽  
James R. Day ◽  
Akira Miura ◽  
Yoshiyuki Fukuba ◽  
...  
Keyword(s):  
High Intensity ◽  
Critical Power ◽  
Load Cycle ◽  
Constant Load ◽  
Cycle Ergometer ◽  
Work Rate ◽  
Hyperbolic Function ◽  
Exercise Tests ◽  
Ergometer Exercise

The tolerable duration of high-intensity, constant-load cycle ergometry is a hyperbolic function of power, with an asymptote termed critical power (CP) and a curvature constant (W′) with units of work. It has been suggested that continued exercise after exhaustion may only be performed below CP, where predominantly aerobic energy transfer can occur and W′ can be partially replenished. To test this hypothesis, six volunteers each performed cycle-ergometer exercise with breath-by-breath determination of ventilatory and pulmonary gas exchange variables. Initially, four exercise tests to exhaustion were made: 1) a ramp-incremental and 2) three high-intensity constant-load bouts at different work rates, to estimate lactate (θ̂L) and CP thresholds, W′, and maximum oxygen uptake (V̇o2 max). Subsequently, subjects cycled to the limit of tolerance (for ∼360 s) on three occasions, each followed by a work rate reduction to 1) 110% CP, 2) 90% CP, and 3) 80% θ̂L for a 20-min target. W′ averaged 20.9 ± 2.35 kJ or 246 ± 30 J/kg. After initial fatigue, 110% CP was tolerated for only 30 ± 12 s. Each subject completed 20 min at 80% θ̂L, but only two sustained 20 min at 90% CP; the remaining four subjects fatigued at 577 ± 306 s, with oxygen consumption at 89 ± 8% V̇o2 max. The results support the suggestion that replenishing W′ after fatigue necessitates a sub-CP work rate. The variation in subjects' responses during 90% CP was unexpected but consistent with mechanisms such as reduced CP consequent to prior high-intensity exercise, variation in lactate handling, and/or regional depletion of energy substrates, e.g., muscle glycogen.

scholarly journals Accuracy of Non-Exercise Estimated Cardiorespiratory Fitness in Japanese Adults

2021 ◽  
Vol 18 (23) ◽  
pp. 12288
Author(s):  
Robert A. Sloan ◽  
Marco V. Scarzanella ◽  
Yuko Gando ◽  
Susumu S. Sawada
Keyword(s):  
Cardiorespiratory Fitness ◽  
Cycle Ergometer ◽  
Test Results ◽  
Lower Tertile ◽  
Healthcare Settings ◽  
Japanese Adults ◽  
Activity Measures ◽  
Cross Classification ◽  
Using Data

Cardiorespiratory fitness (CRF) is an independent predictor of morbidity and mortality. In Japan, annual physical exams are mandatory in workplace settings, and most healthcare settings have electronic medical records (EMRs). However, in both settings, CRF is not usually determined, thereby limiting the potential for epidemiological investigations using EMR data. PURPOSE: To estimate CRF (mL/kg/min) using variables commonly recorded in EMRs. METHODS: Participants were 5293 Japanese adults (11.7% women) who completed an annual physical exam at a large gas company in Tokyo, Japan, in 2004. The mean age was 48.3 ± 8.0 years. Estimated CRF (eCRF) was based on age, measured body mass index, resting heart rate, systolic and diastolic blood pressure, and smoking. Measured CRF was determined by a submaximal cycle ergometer graded exercise test. RESULTS: Regression models were used for males and females to calculate Pearson’s correlation and regression coefficients. Cross-classification of measured CRF and eCRF was conducted using the lowest quintile, quartile, and tertile as the unfit categories. R’s for eCRF were 0.61 (MD 4.41) for men and 0.64 (MD 4.22) for women. The overall accuracy level was reasonable and consistent across models, yet the unfit lower tertile model provided the best overall model when considering the positive predictive value and sensitivity. CONCLUSION: eCRF may provide a useful method for conducting investigations using data derived from EMRs or datasets devoid of CRF or physical activity measures.

scholarly journals Real Assessment of Maximum Oxygen Uptake as a Verification After an Incremental Test Versus Without a Test

2021 ◽  
Vol 12 ◽  
Author(s):  
Paulina Hebisz ◽  
Agnieszka Danuta Jastrzębska ◽  
Rafał Hebisz
Keyword(s):  
Oxygen Uptake ◽  
Peak Oxygen Uptake ◽  
Cycle Ergometer ◽  
Activity Analysis ◽  
Additional Benefit ◽  
Repeated Measurements ◽  
Maximum Oxygen Uptake ◽  
Altman Analysis ◽  
Incremental Test ◽  
Verification Test

The study was conducted to compare peak oxygen uptake (VO2peak) measured with the incremental graded test (GXT) (VO2peak) and two tests to verify maximum oxygen uptake, performed 15 min after the incremental test (VO2peak1) and on a separate day (VO2peak2). The aim was to determine which of the verification tests is more accurate and, more generally, to validate the VO2max obtained in the incremental graded test on cycle ergometer. The study involved 23 participants with varying levels of physical activity. Analysis of variance showed no statistically significant differences for repeated measurements (F = 2.28, p = 0.118, η2 = 0.12). Bland–Altman analysis revealed a small bias of the VO2peak1 results compared to the VO2peak (0.4 ml⋅min–1⋅kg–1) and VO2peak2 results compared to the VO2peak (−0.76 ml⋅min–1⋅kg–1). In isolated cases, it was observed that VO2peak1 and VO2peak2 differed by more than 5% from VO2peak. Considering the above, it can be stated that among young people, there are no statistically significant differences between the values of VO2peak measured in the following tests. However, in individual cases, the need to verify the maximum oxygen uptake is stated, but performing a second verification test on a separate day has no additional benefit.

scholarly journals Haemostatic and thrombo-embolic complications in pregnant women with COVID-19: a systematic review and critical analysis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juliette Servante ◽  
Gill Swallow ◽  
Jim G. Thornton ◽  
Bethan Myers ◽  
Sandhya Munireddy ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Pregnant Women ◽  
Clinical Evidence ◽  
Case Reports ◽  
Standard Form ◽  
Test Results ◽  
Maternal Deaths ◽  
High Clinical Suspicion ◽  
Increased Risk ◽  
Definition Of

Abstract Background As pregnancy is a physiological prothrombotic state, pregnant women may be at increased risk of developing coagulopathic and/or thromboembolic complications associated with COVID-19. Methods Two biomedical databases were searched between September 2019 and June 2020 for case reports and series of pregnant women with a diagnosis of COVID-19 based either on a positive swab or high clinical suspicion where no swab had been performed. Additional registry cases known to the authors were included. Steps were taken to minimise duplicate patients. Information on coagulopathy based on abnormal coagulation test results or clinical evidence of disseminated intravascular coagulation (DIC), and on arterial or venous thrombosis, were extracted using a standard form. If available, detailed laboratory results and information on maternal outcomes were analysed. Results One thousand sixty-three women met the inclusion criteria, of which three (0.28, 95% CI 0.0 to 0.6) had arterial and/or venous thrombosis, seven (0.66, 95% CI 0.17 to 1.1) had DIC, and a further three (0.28, 95% CI 0.0 to 0.6) had coagulopathy without meeting the definition of DIC. Five hundred and thirty-seven women (56%) had been reported as having given birth and 426 (40%) as having an ongoing pregnancy. There were 17 (1.6, 95% CI 0.85 to 2.3) maternal deaths in which DIC was reported as a factor in two. Conclusions Our data suggests that coagulopathy and thromboembolism are both increased in pregnancies affected by COVID-19. Detection of the former may be useful in the identification of women at risk of deterioration.

scholarly journals Greater cardiorespiratory fitness reduces incidence of atrial fibrillation: a meta-analysis

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
C Verdicchio ◽  
A Elliott ◽  
R Mahajan ◽  
D Linz ◽  
D Lau ◽  
...  
Keyword(s):  
Risk Factors ◽  
Atrial Fibrillation ◽  
Risk Factor ◽  
Cardiorespiratory Fitness ◽  
Meta Analysis ◽  
Exercise Stress ◽  
Inverse Association ◽  
Exercise Interventions ◽  
Increased Risk ◽  
Statistical Heterogeneity

Abstract Funding Acknowledgements Type of funding sources: None. Introduction  Atrial Fibrillation (AF) is the most common sustained cardiac arrhythmia affecting 1-2% of the global population, with the prevalence of AF increasing dramatically over the past two decades. Although low levels of cardiorespiratory fitness (CRF) and physical activity are predictive of cardiovascular disease onset and mortality, only recently has this emerged as a potential risk factor for AF. Purpose The aim of this meta-analysis was therefore to quantify the relationship between CRF, measured by a symptom limited exercise stress test, and incident AF. We hypothesised that there would be an inverse relationship between CRF and the incidence of AF. Methods The systematic literature review was conducted using PUBMED, MEDLINE and EMBASE databases, with seven studies meeting the inclusion criteria. A random-effects meta-analysis was then used to compare the multivariate risk estimates of the lowest CRF group from each cohort with the group of the highest CRF. Results Data from 206,925 individuals (55.8% males) was used for analysis with a mean age of 55 ± 2.5 years and a mean follow-up period of 10.3 ± 5 years. The total number of AF events across the studies was 19,913. The overall pooled risk of AF in the high-CRF group versus the low-CRF group showed a significant lower risk of incident AF in those with high-CRF (OR: 0.52, 95% CI, 0.44-0.605, p &lt; 0.001). There was evidence of statistical heterogeneity between the studies (I2 = 81%, p &lt; 0.001). AF incidence rates demonstrated an overall decline in rates across the CRF quartiles from low to high. The mean incidence rate for low-CRF was 21 ± 13.4 compared to 6.9 ± 0.7 per 1000 person-years for the high CRF group (p = 0.03). Conclusion There is an inverse association between a lower CRF and an increased risk of AF, with a higher level of CRF protective against AF. This study highlights that low-CRF may be an additional risk factor for AF along with already other established lifestyle-based risk factors such as obesity and hypertension. Exercise interventions should be promoted as a primary prevention strategy in those at risk of developing AF with known risk factors. Future studies are warranted to identify the mechanism(s) through which improved CRF confers a reduction in AF incidence. Abstract Figure. AF risk between high and low-CRF

scholarly journals Physical Activity, Sedentary Behavior, and Cardiorespiratory Fitness in Hazardous and Non-Hazardous Alcohol Consumers

2021 ◽  
pp. 089011712098583
Author(s):  
Mats Hallgren ◽  
Davy Vancampfort ◽  
Thi-Thuy-Dung Nguyen ◽  
Elin Ekblom-Bak ◽  
Peter Wallin ◽  
...  
Keyword(s):  
Physical Activity ◽  
Sedentary Behavior ◽  
Cardiorespiratory Fitness ◽  
Leisure Time ◽  
Health Assessment ◽  
Cross Sectional Study ◽  
Cycle Ergometer ◽  
Cross Sectional ◽  
Physically Active ◽  
Alcohol Abstainers

Purpose: To describe physical activity habits, sedentary behavior, and cardiorespiratory fitness levels among alcohol abstainers, hazardous and non-hazardous drinkers. Design: Cross-sectional study with data collected between 2017-19. Setting: Sweden. Subjects: Adults aged 18-65 years (n = 47,559; 59.4% male). Measures: During a routine health assessment, participants answered validated single-item questions regarding: habitual physical activity, structured exercise, and the percentage of time spent sedentary during leisure-time (past 30 days), and completed a 6-minute cycle ergometer test (V02max) to determine cardiorespiratory fitness (CRF). Participants were categorized as alcohol abstainers, non-hazardous drinkers or hazardous drinkers (low/high) based on the Alcohol Use Disorders Identification Test (AUDIT-C) cut-points for men and women. Analysis: Logistic regression models stratified by sex and age. Results: Compared to non-hazardous drinkers, the heaviest drinkers were less physically active (males: OR = 1.38, CI = 1.13-1.67, p = .001; females: OR = 1.41, CI = 1.01-1.97, p = .040) and more sedentary during leisure time (males: OR = 1.94, CI = 1.62-2.32, p = .000; females: OR = 1.62, CI = 1.21-2.16, p = .001). Apart from young females, the heaviest drinkers also did less structured exercise than non-hazardous drinkers (males: OR = 1.22, CI = 1.15-1.51, p = .000; females: OR = 1.43, CI = 1.15-1.78, p = .001). The strongest associations were seen among adults aged 40-65 years (shown here). High-hazardous drinking was associated with low CRF among older males only (OR = 1.19, CI = 1.00-1.41). Conclusion: Middle-aged adults with AUDIT-C scores of ≥6 (women) and ≥7 (men) were less physically active and more sedentary during leisure time and may be appropriate targets for physical activity interventions.

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