Low Cardiorespiratory Fitness Research Articles

Associations of cardiorespiratory fitness, screen time and mental health among Chinese school children

To assess the independent and joint associations between cardiorespiratory fitness (CRF), screen time and mental health among Chinese school-aged children, a cross-sectional study was conducted in 3 primary schools in Wuhan city, China. Children self-reported ST, and their height, weight and CRF were measured. Mental health (anxiety, depressive symptom, and self-esteem) was assessed by self-administered questionnaires. A total of 805 children aged 9.1 ± 0.6 years participated in this study. High ST was associated with significantly increased risk for anxiety and low self-esteem, while high CRF was associated with a decreased risk of low self-esteem. In the joint model, children with low ST and high CRF showed the lowest risk for anxiety (OR: 0.42, 95%CI: 0.20-0.89) and low self-esteem (OR:0.44, 95%CI: 0.24-0.82). High ST and low CRF were negatively associated with mental health in Chinese schoolchildren. Health care and interventions on limiting ST and improving CRF level are warranted to promote the mental health in this population.

Relationships of Metabolic Syndrome and Cardiorespiratory Fitness with Cognitive Impairment in older adults

PURPOSE: This study aimed to examine the independent and combined association of metabolic syndrome (MetS) and cardiorespiratory fitness (CRF) levels with cognitive decline risk in older Korean adults.METHODS: This study included 509 community-dwelling older adults aged 60–89 years (81.7% women). CRF was assessed using the safe and easily administered submaximal exercise 6-min walking test (6MWT) on an outdoor track. Cognitive impairment was assessed using the Korean version of the MMSE for Dementia Screening (MMSE-DS). A multivariate logistic regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for cognitive impairment according to MetS- and CRF-based subgroups.RESULTS: Compared to subjects with no MetS/normal CRF (OR, 1), the risk of cognitive impairment was significantly higher among subjects with MetS/normal CRF (OR, 1.747; 95% CI, 1.044-2.923; <i>p</i>=.043) or no MetS/low CRF (OR, 2.246; 95% CI, 1.146–4.402; <i>p</i>=.018). The OR increased to 3.066 (95% CI, 1.711–5.492; <i>p</i><.001) for those with both MetS and low CRF.CONCLUSIONS: The early identification and treatment of individuals with MetS or low CRF may significantly reduce the risk of cognitive decline. Furthermore, promoting physical activity may play an important role in preventing MetS and improving CRF among older adults.

Abstract 15787: Depending on Chain Length Plasma Ceramides Are Associated With Higher or Lower Cardiorespiratory Fitness in the General Population

Introduction: Ceramides are promising new predictive biomarkers for cardiovascular diseases (CVD), but their main mode of action is still unknown. As low cardiorespiratory fitness (CRF) is also linked with CVD, we investigated the association of three of the most abundant blood plasma ceramides and their respective ratios with CRF in a large population-based study. Hypothesis: Plasma long-chain ceramide levels are positively associated with higher CRF in the general population, while higher short-chain ceramide levels are associated with lower CRF. Methods: Levels of C16:0, C22:0, and C24:0 ceramide were quantified by a liquid chromatography-mass spectrometry and CRF was measured by a cardiopulmonary exercise test in the first follow-up of the Study of Health in Pomerania (SHIP-START-1; n = 1,105; mean age 50.3 years). Multivariable linear regression models were used to assess the association between ceramides and CRF. Results: Higher C24:0 levels as well as C24:0/C16:0 ratio were significantly associated with higher CRF, while higher levels of C22:0 or C22:0/C16:0 ratio were associated with lower CRF. Furthermore, we found that body mass index (BMI) interacts with these associations, whereas neither, sex, beta blockers nor lipid-lowering medication had any effect modifying influence. Conclusions: This study showed that ceramides are associated with CRF, one of the most important risk factors of CVD. Ceramide C24:0 as well as C24:0/C16:0 ratio might be beneficial regarding CRF, whereas C22:0 and C22:0/C16:0 ratio might be detrimental. Our study results were independent of many cardiovascular risk factors, which highlights ceramides as potential predictive biomarkers. Future studies with larger numbers of subjects are needed to verify these results, and to evaluate whether the observed interaction with BMI could limit the use to specific BMI subgroups.

Abstract 13330: Cardiorespiratory Fitness is Associated With Decreased Platelet Reactivity

Introduction: Platelets are key mediators in atherosclerotic cardiovascular disease (CVD). Low cardiorespiratory fitness (CRF) is a major risk factor for atherosclerosis. However, little is known about the effects of CRF on platelet function. Methods: Platelet assays and cardiopulmonary exercise testing were conducted in the Framingham Heart Study (n= 3001). A linear mixed effects model was used to analyze associations between CRF (assessed by peak oxygen uptake [VO 2 ] in participants achieving a respiratory exchange ratio >= 1), and platelet reactivity traits from multiple platelet function assays: whole blood Multiplate impedance aggregometry (MP), Total-Thrombus Formation Analysis System (T-TAS), and light transmission aggregometry (LTA). Statistical models adjusted for relatedness, age, sex, and anti-platelet medications. Bonferroni correction for multiple statistical testing resulted in a significance threshold of p<7.35E-04. Results: Of 68 platelet traits analyzed, 31 traits passed the significance threshold, all with a direction of effect indicating higher CRF associated with decreased platelet reactivity. Significant traits spanned multiple platelet agonists. Our strongest associations were seen with MP after TRAP-6 (velocity, p=1.57E-26; AUC, p=2.33E-21; aggregation, p=5.30E-16) and ADP stimulation (velocity, p=1.63E-19; AUC, p=7.64E-17; aggregation, p=1.00E-11), and LTA after ristocetin stimulation (max aggregation, p=5.33E-11; AUC, p=1.11E-10). Conclusion: Our research adds to past work that shows CRF to be associated with reduced CVD by suggesting that decreased platelet reactivity may be involved mechanistically. We found significant associations with multiple platelet agonists, indicating higher CRF globally inhibits platelets; however, given the multiple strong associations after TRAP-6 and ADP stimulation, PAR-1 and purinergic signaling, respectively, may be most heavily involved. This is notable since each of these receptor pathways is directly or indirectly tied to anti-coagulant or anti-platelet therapies. Ultimately, our results suggest that CRF may be important for additional consideration in tailoring anti-platelet strategies.

Prognostic value of right ventricular strain and peak oxygen consumption in heart failure with reduced ejection fraction.

Our purpose is to evaluate the combined predictive value of cardiopulmonary exercise testing (CPET) and echocardiographic evidence of left ventricular (LV) and right ventricular (RV) strain in predicting mortality and heart transplant (HTx) in a series of outpatients with heart failure with reduced ejection fraction (HFrEF). A retrospective cohort study of 66 patients with HFrEF (median age, 57years; 51% women) who underwent CPET and echocardiography (up to 90days apart) to assess prognosis. The primary outcome was a composite of death and need for HTx. At a median follow-up of 27 [20-39] months, 19 patients (29%) experienced the primary outcome. In unadjusted analysis, most echocardiographic and CPET parameters were associated with the primary outcome, including percentage of predicted peak oxygen consumption (ppVO2), VE/VCO2 slope, LV ejection fraction, and LV and RV longitudinal strain. After adjusting for other clinical, echocardiographic and CPET variables, RV free wall longitudinal strain and ppVO2 remained significantly associated with the primary outcome. Kaplan-Meier survival curves for death and HTx, based on the best cutoff values, showed lower survival rates in patients with impairment in both ppVO2 and RV FW-LS than in those with one or neither parameter impaired (p < 0.001). RV dysfunction and low cardiorespiratory fitness were independent markers of death and need for HTx. Impairment of both ppVO2 and RV FW-LS had a strong additive impact on prognostic assessment in this cohort of patients with HFrEF.

Is low cardiorespiratory fitness a feature of metabolic syndrome in children and adults?

Cardiorespiratory fitness has been inversely associated with risk of cardiometabolic diseases. However, there are no studies comparing the independent associations of cardiorespiratory fitness scaled by body size and composition using different approaches with cardiometabolic risk factors between children and adults. We therefore investigated these associations in children and adults using same measures for cardiorespiratory fitness and cardiometabolic risk factors. Cross-sectional. A total of 352 children (47.2 % girls) and 572 men were included in the study. Peak oxygen uptake (V̇O2peak) was measured during a maximal exercise test on a cycle ergometer and was scaled by total body mass, total fat free mass, and allometrically modelled body mass, fat free mass, and stature. Insulin, glucose, triglycerides, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol were assessed from fasting blood samples and systolic blood pressure and diastolic blood pressure were measured. Homeostatic model assessment for insulin resistance and continuous metabolic risk score were computed. V̇O2peak scaled by body mass was inversely associated with insulin, homeostatic model assessment for insulin resistance, triglycerides, diastolic blood pressure, the cardiometabolic risk score and the number of cardiometabolic risk factors in children and adults. However, these associations attenuated remarkably when V̇O2peak was scaled by total fat free mass or allometrically modelled body mass, fat free mass, or stature. V̇O2peak was consistently and positively associated with high-density lipoprotein cholesterol in children and adults irrespective of the scaling approach. The inverse associations of cardiorespiratory fitness with cardiometabolic risk factors among children and adults attenuated remarkably when body size and composition were appropriately controlled for. However, the positive association between cardiorespiratory fitness and high-density lipoprotein cholesterol was consistent irrespective of the scaling approach.

Calibrating a Comprehensive Immune Age Metric to Analyze the Cross Sectional Age-Related Decline in Cardiorespiratory Fitness.

Cardiorespiratory fitness (CRF) is essential for sustained work ability in good health, but declines with aging, as does the functionality of the immune system, the latter process commonly referred to as immunosenescence. This study aimed to compare the capacity of immunosenescence biomarkers with chronological age for predicting low CRF in a cross-sectional sample recruited from the regional working population. CRF was determined by submaximal bicycle ergometer testing in a cross-sectional sample of 597 volunteers aged 20-70 years from the 'Dortmund Vital Study' (DVS, ClinicalTrials.gov Identifier: NCT05155397). Low CRF was scored if the ergometer test was not completed due to medical reasons or if the power output projected to a heart rate of 130 bpm divided by body mass was below sex-specific reference values of 1.25 W/kg for females and 1.5 W/kg for males, respectively. In addition to established biomarkers of immunosenescence, we calibrated a comprehensive metric of immune age to our data and compared its predictive capacity for low CRF to chronological age, while adjusting our analysis for the influence of sex, obesity, and the level of regular physical activity, by applying univariate and multiple logistic regression. While obesity, low physical activity, chronological and immune age were all associated with increased probability for low CRF in univariate analyses, multiple logistic regression revealed that obesity and physical activity together with immune age, but not chronological age, were statistically significant predictors of low CRF outcome. Sex was non-significant due to the applied sex-specific reference values. These results demonstrate that biological age assessed by our immunological metric can outperform chronological age as a predictor for CRF and indicate a potential role for immunosenescence in explaining the inter-individual variability of the age-related decline in cardiorespiratory fitness.

Association between the empirical dietary inflammatory index and cardiorespiratory fitness in Tehranian adults in 2017-2018.

BackgroundInflammatory-related chronic diseases are increasing in Iran with high consumption of a diet containing pro-inflammatory potential and a sedentary lifestyle. The empirical dietary inflammatory index (EDII) was developed as a tool to assess dietary effects on systemic inflammation. We examined the hypothesis that specific dietary patterns reflecting systemic inflammation are associated with cardiorespiratory fitness (CRF) in Tehranian adults.MethodsThis cross-sectional study was carried out on 270 adults who are residents of Tehran. Dietary intake was assessed using a 168-item valid and reliable food frequency questionnaire. The EDII score was developed according to participant dietary intakes of 21-item pre-defined food groups. CRF was assessed by using a graded exercise treadmill test. Anthropometric measurements were assessed using standard methods. To discover the association between CRF and EDII, we used multivariable logistic regression analysis.ResultsThose who were in the third tertile of the EDII had 57% lower odds of having better VO2Max (ml/kg/min) than those in the first tertile (OR: 0.43; 95% CI: 0.16, 1.12, p = 0.01). There were no significant differences between tertiles of the EDII score in terms of VO2 (L·min) and VO2 (LBM) before and after adjusting for confounders. There was a significant decrease in VO2Max (ml/kg/min) across tertiles of the EDII after controlling for covariates (p-value = 0.04). There was a significant inverse association between the EDII score and VO2Max (ml/kg/min) (β = −0.35, p = 0.001).ConclusionsOur finding demonstrated that a higher EDII might be associated with lower CRF in Tehranian adults. Prospective studies are needed to shed light on the causal link between the EDII and CRF.

Sex-specific associations of cardiorespiratory fitness and galectin-3 in the general population.

Low cardiorespiratory fitness (CRF) is associated with greater mortality and morbidity. Galectin-3 (Gal-3) is a prognostic biomarker for fibrosis and heart failure. Gal-3 is also associated with a greater risk for cardiovascular mortality. Whether CRF is related with Gal-3 is unclear. The objective of this study was to assess the sex-specific associations of CRF and Gal-3 levels in the general population. Gal-3 concentrations were determined using a sandwich enzyme immunoassay in the population-based Study of Health in Pomerania (SHIP-TREND-0). Sex-stratified linear regression models adjusted for age, current smoking status, and renal function were used. Individuals with left ventricular ejection fraction (LVEF) <40%, previous myocardial infarction, atrial fibrillation, chronic lung disease, severe renal disease (estimated glomerular filtration rate <30mL/min/mm2 ), a history of cancer, and extreme values for Gal-3 (<1st percentile; >99th percentile) were excluded. A total of n=1515 participants with a median age of 49 (IQR: 39-60years, 48% males) were included. In men, a 1L/min greater VO2 peak was significantly related to 0.50ng/mL (95% CI -0.8068 to -0.1938, P<0.01) less Gal-3. In males, a 1mL/min/kg higher VO2 peak adjusted for body weight was associated with -0.0286ng/mL (95% CI -0.0052 to -0.0005, P=0.02) less Gal-3. When VO2 peak was adjusted for lean mass 1mL/kg/min more was correlated with a -0.0022ng/mL (95% CI -0.0043 to -0.0007, P=0.04) less Gal-3. In women, VO2 peak (β -0.2046 95% CI -0.6541 to 0.2449, P=0.37) and VO2 peak adjusted for lean mass (β -0.0019 95% CI -0.0421 to -0.0050, P=0.12) were not related with Gal-3, whereas a 1mL/min/kg higher VO2 peak adjusted for body weight was significantly associated with a -0.0064ng/mL lower Gal-3 (95% CI -0.0092 to -0.0035, P<0.01). There were no differences between pre-menopausal and post-menopausal women. VO2 peak was associated with Gal-3 only in men, but VO2 peak adjusted for body weight in women and men. Our results suggest that the adverse consequences of low CRF may be mediated by Gal-3. Further research is needed to understand the sex-specific association between CRF and Gal-3 and whether they are clinically relevant.

Effectiveness of cardiopulmonary rehabilitation after COVID-19 in Poland.

Patients with a history of COVID‑19 are characterized by a deteriorated level of cardiorespiratory fitness (CRF). The COVID‑19 rehabilitation program of the National Health Fund (NHF) was developed and financed by the public insurer in Poland to help convalescents return to full health. We aimed to evaluate the effectiveness of cardiopulmonary rehabilitation (CR) after COVID‑19, carried out under the NHF program. The study included 553 convalescents at a mean age of 63.5 years (SD, 10.26; 316 women [57.1%]), hospitalized at the Cardiac Rehabilitation Department of the Ustroń Health Resort, Poland, after a median of 23.10 weeks (interquartile range [IQR], 16.25-29.00) following COVID‑19. The mean duration of CR was 21 days (IQR, 21-28). The effectiveness of CR was assessed based on the improvement in spirometry and clinical parameters, as well as indicators of CRF and exercise tolerance. The mean baseline CRF level, as assessed by the 6‑minute walk test (6MWT), was reduced to 76.32% of the predicted value (SD, 15.87) in men and 85.83% of the predicted value (SD, 15.60) in women, while the mean values of the spirometry parameters were normal. During CR, there was an improvement in the median 6MWT distance by 42.5 m (95% CI, 37.50-45.00; P <0.001), and in the median exercise tolerance assessed on the Borg scale (fatigue, by -1 point; 95% CI, -1.0 to -1.0; P <0.001; dyspnea, by -1.5 points; 95% CI, -1.5 to -1.0; P <0.001). We observed a decrease in the mean resting blood pressure by 8.57 mm Hg (95% CI, -11.30 to -5.84; P <0.001) for systolic and by 3.38 mm Hg (95% CI, -4.53 to -2.23; P <0.001) for diastolic values. The most pronounced improvement was seen in the patients with low CRF level at baseline, who were eligible for lower‑intensity rehabilitation models. The CR effectiveness was not dependent on the severity of COVID‑19 or the time from the disease onset to the commencement of rehabilitation. CR is a safe and effective intervention that can accelerate recovery from COVID‑19, including an increase in exercise capacity and exercise tolerance.

Validation, Recalibration, and Predictive Accuracy of Published V̇O 2max Prediction Equations for Adults Ages 50-96 Yr.

Maximal oxygen uptake ( ) is the criterion measure of cardiorespiratory fitness. Lower cardiorespiratory fitness is a strong predictor of poor health outcomes, including all-cause mortality. Because testing is resource intensive, several non-exercise-based V˙O 2max prediction equations have been published. We assess these equations' ability to predict measured V˙O 2max , recalibrate these equations, and quantify the association of measured and predicted V˙O 2max with all-cause mortality. Baltimore Longitudinal Study of Aging participants with valid V˙O 2max tests were included ( n = 1080). Using published V˙O 2max prediction equations, we calculated predicted V˙O 2max and present performance metrics before and after recalibration (deriving new regression estimates by regressing measured V˙O 2max on Baltimore Longitudinal Study of Aging covariates). Cox proportional hazards models were fit to quantify associations of measured, predicted, and recalibration-predicted values of V˙O 2max with mortality. Mean age and V˙O 2max were 69.0 ± 10.4 yr and 21.6 ± 5.9 mL·kg -1 ·min -1 , respectively. The prediction equations yielded root mean square error values ranging from 4.2 to 20.4 mL·kg -1 ·min -1 . After recalibration, these values decreased to 3.9-4.2 mL·kg -1 ·min -1 . Adjusting for all covariates, all-cause mortality risk was 66% lower for the highest quartile of measured V˙O 2max relative to the lowest. Predicted V˙O 2max variables yielded similar estimates in unadjusted models but were not robust to adjustment. Measured V˙O 2max is an extremely strong predictor of all-cause mortality. Several published V˙O 2max prediction equations yielded the following: 1) reasonable performance metrics relative to measured V˙O 2max especially when recalibrated, and 2) all-cause mortality hazard ratios similar to those of measured V˙O 2max , especially when recalibrated, yet 3) were not robust to adjustment for basic demographic covariates likely because these were used in the equation for predicted V˙O 2max .

Relationships Of Metabolic Syndrome And Cardiorespiratory Fitness With Cognitive Impairment In Korean Older Adults

Metabolic syndrome (Mets), which refers to a clustering of central obesity, increased resting blood pressure, increased fasting glucose, increased triglycerides and decreased high-density lipoprotein cholesterol, is associated with an increased risk for cardiovascular diseases and mental health conditions including cognitive decline. Poor cardiorespiratory fitness (CRF) is another-established risk factor for the health conditions. PURPOSE: The purpose of this study was to examine the relationships of MetS and CRF with cognitive impairments in Korean older adults. METHODS: Study participants were community dwelling Korean older adults (n = 509/82% women) aged 60-89 years. Mets was defined according to the Asian waist circumference criteria based on the National Cholesterol Education Program Adult Treatment Panel III criteria. CRF was measured using a submaximal exercise 6-minute walking test. Cognitive impairment was assessed with the Mini-Mental State Examination for Dementia Screening of Korean version (MMSE-KC). Cognitive impairment was defined as an MMSE-KC score of <1.5 standard deviations from the age-, sex-, and education-adjusted norm for older Koreans. Multivariate logistic regression analysis was used to assess the relationships of Mets and CRF with cognitive impairment at p = 0.05 with the SPSS-PC software (version 27.0). RESULTS: The prevalence of cognitive impairment was 23.4% in total, with 14.0% in men and 25.5% in women. Compared to no Mets plus normal CRF, the risk for cognitive impairment was incremental from Mets only (OR (95% CI) = 1.747 (1.044-2.923), p = 0.043) to low CRF only (OR (95% CI) = 2.246 (1.146-4.402), p = 0.018) and Mets plus low CRF (OR (95% CI) = 3.066 (1.711-5.492), p < 0.001). CONCLUSIONS: The current findings of the study suggest an individual and synergistic effects of Mets and low CRF on cognitive impairments in Korean older adults. Supported by the National ResearchFoundation funded by the Korea Government (NRF-2018R1D1A1B07048210 & 2020S1A5B5A16084067).

Weight History Association With Current Cardiorespiratory And Muscular Fitness

High cardiorespiratory and muscular fitness are often associated with lower body fat mass. Age-associated increases in body mass might be attenuated by maintaining a higher level of fitness into middle-age. PURPOSE: This study aimed to compare the cardiorespiratory and muscular fitness of individuals who have maintained body mass during adulthood to those who have had substantial increases and/or decreases in body mass in adulthood. METHODS: Obese, overweight, and non-obese adults were recruited to participate. Long-term health and weight history was collected retrospectively on 79 individuals. Total body composition, maximal oxygen consumption, grip strength, and maximal isometric knee extension strength were measured. Participants were subsequently categorized based on short term and long-term weight loss history, cardiorespiratory fitness, and muscle function for further analysis. RESULTS: Participants (31 Male, 45 female, aged 41.0 ± 12.3 years) were 29.2 ± 10.1% body fat having gained 9.3 ± 11.7 kg since 20 years of age. Current cardiorespiratory fitness as indicated by relative maximal oxygen consumption was 36.6 ± 12.0 ml*kg-1*min-1. No significant relationship existed between weight gain since age 20 and current cardiorespiratory fitness (r = -0.12). No differences in weight history were observed after classification of participants into high vs. low cardiorespiratory fitness nor high vs. low muscular fitness. CONCLUSIONS: Current cardiorespiratory and muscular fitness are independent of past body weight history. Despite the limitations of retrospective analysis of weight history and inability to determine previous levels of fitness, these results imply that high fitness might not be protective against age-associated body mass increases, but also that low fitness might not destine an individual to larger than normal gains in body mass

High-intensity Training And A Low-caloric-diet Improves Maximal Oxygen Consumption And Body Composition In Overweight Adults

Obesity and low cardiorespiratory fitness are global challenges causing a massive burden on the health care system worldwide. Thus, efficient exercise and nutritional interventions are warranted. PURPOSE: We investigate the effect of high-intensity training executed as full body circuit training and a calorie-restricted diet plan on cardiorespiratory fitness and body composition in overweight sedentary adults. METHODS: Sedentary overweight men (n = 34) and women (n = 46) were recruited. The selection criteria were a sedentary lifestyle for the last five years, an age range of 25-55 yrs and a body mass index >25. The study was a randomized controlled trial, where participants were randomized gender-specifically into a high-intensity training group (HIT; age 38 ± 9 (25-54) yrs; height 174 ± 10 cm; weight 96.1 ± 19.3 kg; n = 40) and control group (CON; age 39 ± 7 (27-52) yrs, height 168 ± 8 cm, weight 89.9 ± 17.2 kg; n = 40). HIT completed full-body high-intensity circuit training with 2-4 weekly sessions combined with a calorie-restricted dietary plan for 8 wks. CON had no training or lifestyle changes in the same interval. VO2max-tests and body composition assessments were performed at baseline and post-intervention. RESULTS: VO2max was 2.3 ± 0.6 and 2.1 ± 0.5 L⸱min-1 at baseline in HIT and CON respectively and did not change during the intervention period. However, VO2max adjusted for body weight improved (P < 0.05) by ~7% in HIT (24.5 ± 5.1 vs 25.7 ± 5.5 ml⸱min-1⸱kg-1) during the intervention period with greater (P < 0.05) change score than CON where a reduction (P < 0.05) of ~5% (24.1 ± 5.1 vs 22.6 ± 4.6 ml⸱min-1⸱kg-1) was observed. Body weight decreased (P < 0.05) by 5.9 ± 3.2 kg post-intervention in HIT with higher (P < 0.05) change score than CON (+0.3 ± 1.6 kg). Also, BMI declined (P < 0.05) from 31.8 ± 5.5 to 29.9 ± 4.4 kg/m2 in HIT only. Body fat content was also lowered (P < 0.05) from 32.0 ± 9.5% at baseline to 30.9 ± 9.3% post-intervention in HIT with a greater change score compared to CON. No change was observed in skeletal muscle mass in neither HIT nor CON. CONCLUSION: High-intensity training performed as full body circuit training combined with a caloric-restricted diet over an eight-week period moderately improved body weight adjusted VO2max, but induced a marked weight loss and reduction in body fat content in overweight sedentary adults.

A Systematic Review of Cardiorespiratory Fitness Testing in Major Depression

ABSTRACTBackgroundDepression is associated with physical inactivity, low cardiorespiratory fitness (CRF), and poor physical health compared with the general population. Various protocols are employed to determine CRF studies of people experiencing depression, but standardized methods are absent from the literature. Thus, the aim of the present review is to systematically examine the protocols reported to determine CRF in patients with major depressive disorder (MDD).MethodsReplicating a previously published search strategy, the present review sourced relevant studies from PubMed, PsycInfo, Embase, CINAHL, MEDLINE, Psychology and Behavioural Sciences Collection, and SPORTDiscus from August 2015 to February 2021. Details of CRF testing protocols were extracted into a preprepared form for analysis.ResultsTwenty-three studies met the inclusion criteria, including those from a previous review of CRF in people with MDD. Twelve included studies employed maximal testing protocols, while 11 studies reported using submaximal testing protocols. Cycle ergometry was the most used protocol, followed by treadmill and walk tests. Notably, complete descriptions of the test protocols to facilitate test replication were frequently absent.ConclusionsCycle ergometry is commonly used to assess CRF in people with MDD, but protocol details are lacking, making replication difficult. Efforts to standardize protocol descriptions are warranted.

Upper-body Rowing Increases Cardiorespiratory Fitness But Not Flow-mediated Dilation In Individuals With Spinal Cord Injury

Spinal cord injury (SCI) is often associated with low cardiorespiratory fitness (VO2peak). Traditional upper-body exercise training for individuals with SCI (e.g. arm crank exercise and wheelchair propulsion) elicits positive effects on VO2peak, while the effects on vascular health are less clear. Upper-body rowing may prove to be an effective exercise modality for improving VO2peak and vascular health, as it involves repeated contractions of a relatively large muscle mass. PURPOSE: To determine the effects of exercise training performed on a rowing ergometer modified for wheelchair users on VO2peak, resting diameter of brachial artery and flow-mediated dilation (FMD). METHODS: Fifteen participants with SCI (8 males, 7 females; level of injury: C4-L3; ASIA Impairment Scale (AIS): A-C) were randomized to a control (CON, n = 7) or exercise (EXR, n = 8) group. VO2peak, resting brachial artery lumen diameter (mm) and FMD (%) were assessed before, and after six (6 W) and 12 weeks (12 W) of three weekly sessions of moderate-to-vigorous intensity exercise. VO2peak (ml/kg/min) was determined using an incremental arm crank test until exhaustion. FMD (%) was calculated as the relative increase in brachial artery diameter (determined by high-resolution ultrasound) after five minutes of cuff occlusion. Changes in diameter were analyzed off-line using semi-automated edge-detecting software. Main effects of group and time and group-by-time interactions were examined using linear-mixed models. RESULTS: There was an interaction effect for VO2peak and resting brachial artery diameter (p < .001 and p = .016, respectively). VO2peak increased from baseline (15.1 ± 5.0 ml/kg/min) to 6 W (16.6 ± 5.3 ml/kg/min, p = .007) and 12 W (17.8 ± 6.1 ml/kg/min, p < .001) in EXR, but not in CON. Resting brachial artery diameter increased from baseline (4.8 ± 0.7 mm) to 12 W (5.1 ± 0.9 mm, p = .005) in EXR, with no changes at 6 W (5.0 ± 0.9 mm), and no changes in CON. There were no main effects or interaction effect observed for FMD. CONCLUSION: These data indicate that rowing is efficient for improving VO2peak in individuals with SCI. While resting lumen diameter increases with training, 12 weeks of rowing does not increase brachial artery endothelial function.

Cardiorespiratory Fitness Level Alters Blood Pressure Responses Induced By Histamine H1- And H2-receptor Blockade During Dynamic Exercise

INTRODUCTION: Epidemiological studies have reported that greater cardiorespiratory fitness (CRF) is associated with lower blood pressure (BP). Histamine receptor-mediated peripheral vasodilation contributes to post-exercise hypotension and lowing exercising BP responses. Previously, our laboratory found that overactive BP responses to exercise were induced by the inability of histamine receptors in individuals with prehypertension. However, it is still unknown that CRF can impact BP responses elicited by the inability of the receptors. PURPOSE: This study was to assess whether aerobic fitness is effective in lowering excessive BP responses induced by the blockade of histamine receptors METHODS: In twelve male and female subjects (6 high CRF and 6 low CRF), we examined the effects of histamine H1- and H2- receptor blockades on heart rate (HR), stroke volume (SV), cardiac output (CO), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and total peripheral resistance (TPR) at workloads corresponding to 40% and 60% workloads of VO2peak during cycling exercise. RESULTS: Our study indicated that compared to the high CRF group, changes in MAP from the baselines were higher in the low CRF group before the blockade at each workload (40%: D14±2 vs. 8±1 mmHg; 60%: D21±3 vs. 15±2 mmHg). The changes in MAP in response to the blockade during exercise were substantially lower in the high CRF group (40%: D18±2 vs. 11±1 mmHg; 60%: D29±3 vs. 19±2 mmHg). CONCLUSIONS: Our study suggests that an improvement in CRF likely reduces exaggerated BP responses elicited due to the inability of histamine receptors in pathological conditions such as prehypertension and hypertension.

S08-4 In terms of individual fitness, people with low cardiorespiratory fitness are physically the most active

Abstract Background Depending on cardiorespiratory fitness (CRF), people may perceive differently the exertion of incident physical activity (PA). It has been proposed to use thresholds relative to individual fitness in PA monitoring when it is feasible. Methods 1952 adults (803 men, 1149 women), aged 20-69 years participated in the FinFit2017 (EUPASMOS) -study. Their VO2max was predicted with 6 min walking test and they had accelerometer wear time at least four days with minimum of 24 h/day during seven consecutive days of measurement period. The participants were divided into CRF thirds by age groups and sex. Acceleration data was analyzed in 6s epochs and intensity in MET (metabolic equivalent) values was calculated for each epoch. MET values were smoothed with 1min exponential moving average. The epoch activity was classified into moderate-to-vigorous PA (MVPA) using both absolute (3.0MET) and individual (40% of the oxygen uptake reserve) thresholds. The accumulated MVPA time was calculated for bouts at least 0.1, 1.5, 3.0, 5.0, 10.0, 15.0, 20.0, 30.0 and 60.0 minutes. Population-weighted average of accumulated PA times in CRF-thirds and partial Spearman correlations controlled by age and sex between bout lengths and VO2max were calculated for both absolute and relative thresholds. Results Participants in the lowest CRF-third accumulated the most (p &amp;gt; 0.05) MVPA time with relative threshold (22min (low); 15min (middle); 12min (high)) and the highest third (40min (low); 50min (middle); 56min (high)) with absolute threshold. The correlations were negative with individual thresholds, if short bouts were counted into accumulated time, and significant positive correlation (r = 0.048) was achieved only with at least 60.0min bouts. The correlations were significantly positive for all bout lengths with absolute thresholds and the highest correlation was achieved with at least 0.1min bouts (r = 0.295). Conclusions The lowest fitness third was the most active when the PA intensity was analyzed using relative thresholds. Their PA was mostly accumulated from short, few minute bouts. Thus, they had to utilize more of their aerobic capacity on daily basis just to keep up with their daily routines and the peers.

P05-01 Change in cardiorespiratory fitness in midlife and incident hypertension

BackgroundLow cardiorespiratory fitness (CRF) is associated with higher blood pressure and risk of incident hypertension. However, existing literature has mainly investigated CRF at baseline. For HEPA initiatives, it is important to know how change in CRF in midlife associate with incident hypertension, and whether this varies between sexes, age and baseline CRF.Methods91,728 individuals (20-79 years, 48% women, free from hypertension at baseline) from the Swedish workforce who had completed two health profile assessments in a nationwide occupational health service screening between 1986 and 2019 were included. CRF (assessed as VO2max) was estimated using a submaximal cycle test. Change in CRF between the two tests was expressed as % change in absolute CRF (L·min-1) per year and categorized as “maintainers” (-1% to 1% change/year), “decreases” (≥-1% change/year) or “increasers” (≥1% change/year). Incident hypertension was defined as having a blood pressure >140/90 mmHg or diagnosed with hypertension at the second test. Binary logistic regression was used to assess OR (95% CI) for hypertension at the second test between maintainers, decreases and increasers. All analyses were adjusted for sex, age, heart medication, time between tests, education, and change in other lifestyle variables between the two tests (stress, diet, exercise, smoking).ResultsCompared to maintainers (set as reference), OR for decreases was 1.27 (1.18-1.38) and increasers OR 0.99 (0.89-1.09). Isolating midlife participants (40-60 years), OR for decreasers was 1.47 (1.30-1.66) and increasers OR 0.75 (0.64-0.86). Looking at sex differences, male decreasers had OR 1.24 (1.12-1.36) and female decreasers OR 1.36 (1.20-1.56), compared to maintainers, while OR for male and female increasers was 0.93 (0.83-1.03) and 0.97 (0.83-1.13). For participants with low CRF at baseline (<32·kg-1·min-1), OR for decreasers was 1.70 (1.51-1.92) and increasers 1.32 (1.18-1.49). Corresponding ORs in those with high CRF at baseline were 0.90 (0.80-1.02) and 0.43 (0.26-0.71).ConclusionsDecrease in CRF with >1% per year associated with significant higher risk for incident hypertension, while maintaining or increasing CRF had similar risk associations. This was seen in both men and women, different age-groups and baseline level of CRF. Health enhancing promotion strategies to maintain or increase CRF level is highly clinically relevant.

O5-6 The relation between domain-specific physical behavior and cardiorespiratory fitness: a compositional data analysis on the physical activity health paradox using accelerometer-assessed data

BackgroundIn contrast to leisure time physical activity (LTPA), occupational physical activity (OPA) does not have similar beneficial health effects. These differential health effects, also known as the physical activity health paradox, might be explained by dissimilar effects of LTPA and OPA on cardiorespiratory fitness (CRF). This study aims to investigate the association between device-worn measures of physical behaviors during both work and leisure time and CRF among workers with high level of OPA.MethodsOur results are based on a sample of 309 workers employed within the service and production sector from the cross-sectional FEPA (Flemish Employees' Physical Activity) study. OPA and LTPA were measured using two Axivity AX3 accelerometers, worn on the back and right thigh for 2 to 4 consecutive working days. CRF levels were obtained by the Harvard step test. Compositional multiple linear regression analyses were used to analyze the relations, adjusted for age, sex, education, smoking, BMI, moderate-to vigorous physical activity (MVPA), and physical work demands.ResultsDuring work time, more sedentary behavior (SB) was associated with higher CRF when compared relatively to time spent on other work behaviors, while more SB during leisure time was associated with lower CRF when compared to other leisure time behaviors. Reallocating more time to MVPA from the other behaviors within leisure time was positively associated with CRF, which was not the case for MVPA during work.ConclusionOur results emphasize the need for taking the domain-specific nature of physical activity into account to understand its relation to CRF. Guidelines usually do not differentiate between OPA and LTPA in their recommendation to participate in at least 150 min of physical activity per week, regardless of the OPA level. Workers already meeting this recommendations through OPA might therefore mistakenly think that they already meet the recommendations on physical activity and think they can spend their leisure time in a sedentary fashion. In reality, these types of workers might benefit from recommendations to take more sitting breaks during their work and to participate in leisure time MVPA to maintain or improve their CRF in order ‘to be fit for the job'.