Validity and Reliability of Firefighting Simulation Test Performance.

Steep ramp test protocol for preoperative risk assessment and short-term high-intensity interval training to evaluate, improve, and monitor cardiorespiratory fitness in surgical oncology.

The Aerobics Center Longitudinal Study (ACLS) provides the opportunity to evaluate associations between measures of physical activity and mental health in a large and well-characterized population of men and women. Participants were 5451 men and 1277 women (20-88 yr) who completed a maximal fitness treadmill test and self-report measures of habitual physical activity, depressive symptoms (Center for Epidemiological Studies Scale for Depression; CES-D) and emotional well-being (General Well-Being Schedule; GWB). To evaluate the dose-response gradient of the association, we classified the sample, separately for men and women, into three levels of relative cardiorespiratory (CR) fitness (low, moderate, high) on the maximal treadmill test, and four levels on a physical activity index of weekly walking, jogging, and running. In both men and women, there was a significant inverse graded dose-response relationship between maximal CR fitness and the CES-D score (P < 0.0001), and a significant positive graded dose-response relationship between CR fitness and the GWB score (P < 0.0001). We also observed dose-response associations between the level of physical activity and both CES-D and GWB scores (P < 0.0001) that peaked at 11-19 miles per week. Among men and women in the ACLS, relative increases in maximal CR fitness and habitual physical activity are cross-sectionally associated with lower depressive symptomatology and greater emotional well-being. Prospective epidemiological studies and controlled clinical trials are needed to identify the minimal and optimal levels of physical activity and CR fitness associated with various mental health benefits in different segments of the general population.

Poor cardiorespiratory fitness (CRF) increases morbidity and mortality risks. Routine CRF assessment in clinical practice has thus been advocated, but little is known about the effect. In this study, we investigated the effect of CRF assessment on CRF in a preventive health check programme. We used a randomised design, in which we invited 4153 middle-aged adults and included 2201 participants who received a preventive health check with CRF assessment (intervention) or without CRF assessment (control). After 1 year, participants were examined. The primary outcomes were adjusted absolute (l/min), relative (ml/kg/min), and poor (%) CRF assessed by the Astrand-Ryhming test. We adjusted for baseline physical activity and intra-cluster correlation within general practices. A total of 901 attended the 1-year follow-up. In the intervention group, absolute CRF, relative CRF, and poor CRF were 2.7 l/min (95% confidence interval [CI]: 2.6; 2.8), 34.5 ml/kg/min (95% CI: 33.5; 35.4), and 31.0% (95% CI: 26.8; 35.2). In the control group, the corresponding figures were 2.8 l/min (95% CI: 2.7; 2.9), 35.2 ml/kg/min (95% CI: 34.2; 36.1), and 25.9% (95% CI: 21.8; 30.0). Adjusted absolute CRF was lower in the intervention group (-0.1 l/min [95% CI: -0.2; -0.01]). Adjusted relative CRF (-0.7 ml/kg/min [95% CI: -2.0; 0.6]) and poor CRF (5.0% [95% CI: -0.002; 10.1]) did not differ between groups. No differences were found when adjusting for potential confounding factors. Preventive health checks with CRF assessment did not provide higher CRF levels at 1-year follow-up than preventive health checks without CRF assessment.

Background: Cardio respiratory fitness in terms of maximum oxygen uptake (VO2 max) reflects the physical fitness of a person. VO2max determines the capacity of an individual to perform sustained exercise. The present study is to assess and compare the cardiorespiratory fitness in terms of VO2 max between trained and untrained subjects. Materials and Methods: This cross-sectional study was conducted on 30 young adult males undergoing physical training for more than 3 months to join British army and age-sex matched 30 non-trained controls. VO2max was estimated indirectly by following the protocol of Queen’s College Step Test (QCT) method. Results: VO₂ max was found significantly higher in the trained males as compared to non-trained group (68.91± 4.42 vs. 50.31±4.80; p=0.02). On comparison of VO₂ max of our subjects with the standard VO₂ max classification, our trained and non-trained groups fitted into the category of high and average on cardiorespiratory fitness scale respectively. Conclusion: Physical training improves cardio respiratory fitness by increasing VO₂ max.

Exercise and cardiorespiratory (CR) fitness may moderate age-related regional brain changes in nondemented (ND) older adults. The relationship of fitness to Alzheimer disease (AD)-related brain change is understudied, particularly in the hippocampus, which is disproportionately affected in early AD. The role of apolipoprotein E4 (apoE4) genotype in modulating this relationship is also unknown. ND (n=56) and early-stage AD patients (n=61) over the age of 65 years had magnetic resonance imaging and CR fitness assessments. Voxel-based morphometry techniques were used to identify AD-related atrophy. We analyzed the relationship of CR fitness with white and gray matter within groups, assessed fitness-related brain volume change in areas most affected by AD-related atrophy, and then analyzed differential fitness-brain relationships between apoE4 carriers. Atrophy was present in the medial temporal, temporal, and parietal cortices in patients with mild AD. There was a significant positive correlation of CR fitness with parietal and medial temporal volume in AD patients. ND patients did not have a significant relationship between brain volume and CR fitness in the global or small volume correction analyses. There was not a significant interaction for fitness x apoE4 genotype in either group. In early-stage AD, CR fitness is associated with regional brain volumes in the medial-temporal and parietal cortices suggesting that maintaining CR fitness may modify AD-related brain atrophy.

To explore the developmental origins of cardiorespiratory fitness. We examined the associations of birth size and duration of breast feeding with cardiorespiratory fitness assessed at the 9 year follow-up examination in 3612 participants of the Avon Longitudinal Study of Parents and Children (ALSPAC). We used physical work capacity at a heart rate of 170 beats per minute (PWC(170)) as our assessment of cardiorespiratory fitness. This was estimated using standard regression methods from parameters measured using an electronically braked cycle ergometer. Birth weight, length and ponderal index were all positively associated with cardiorespiratory fitness in both sexes, with no strong evidence of a difference in effect between girls and boys. Work capacity increased by 1.12 W (95% CI: 0.83, 1.40) on average per 1 standard deviation (SD) greater birth weight. This association was not affected by adjustment for socioeconomic position and maternal smoking during pregnancy; there was some attenuation with adjustment for both maternal and paternal height and body mass index and more marked attenuation with adjustment for the child's height and body mass index. In the fully adjusted model work capacity increased by 0.51 W (95% CI: 0.21, 0.81) per SD birth weight. Whether an individual had been breastfed and duration of breastfeeding were not associated with cardiorespiratory fitness in any models. Our results provide some support for a role of intrauterine factors in determining cardiorespiratory fitness in childhood.

Introduction: Unhealthy eating habits combined with low levels of physical activity and cardiorespiratory fitness pose a serious threat to the health of young people. The aim of this research was to determine the relationship between selected components of body composition, the occurrence of eating disorders, and cardiorespiratory fitness (CRF) and physical activity levels among university students. Material and Methods: This study was conducted among 254 students at a university in Poland. It included the measurements of body height, body composition analysis using bioelectrical impedance analysis (BIA), and assessment of cardiorespiratory fitness (CRF). This research also employed the My Eating Habits (MEH) questionnaire and the short version of the International Physical Activity Questionnaire (IPAQ-SF). Results: Based on body fat percentage (BF%), nearly one-fifth (19.69%) of participants were classified as obese. According to the body mass index (BMI), over one-third had excess body weight (overweight 24.02%, obesity 10.24%), while 6.7% were underweight. Eating disorders were significantly more prevalent in women (p = 0.0002). A significant relationship was observed between eating disorders and BMI, muscle mass (MM%), skeletal muscle mass (SMM%), body fat (BF%), and visceral fat (VFATL). Higher BMI, BF%, and VFATL were associated with a greater risk of developing eating disorders. Emotional overeating was significantly less common among individuals with normal body weight compared to those who were underweight or overweight. No statistically significant associations were found between students’ physical activity levels and eating habits. However, cardiorespiratory fitness (CRF) was significantly negatively correlated with the presence of eating disorders. Conclusions: Understanding the relationship between components of body composition, eating disorders, physical activity levels, and cardiorespiratory fitness is crucial for designing effective interventions that promote a healthier lifestyle and psychological well-being among university students.

Type 2 diabetes mellitus (T2DM) is associated with a higher risk for heart failure (HF). The impact of a lifestyle intervention and changes in cardiorespiratory fitness (CRF) and body mass index on risk for HF is not well established. Participants from the Look AHEAD trial (Action for Health in Diabetes) without prevalent HF were included. Time-to-event analyses were used to compare the risk of incident HF between the intensive lifestyle intervention and diabetes support and education groups. The associations of baseline measures of CRF estimated from a maximal treadmill test, body mass index, and longitudinal changes in these parameters with risk of HF were evaluated with multivariable adjusted Cox models. Among the 5109 trial participants, there was no significant difference in the risk of incident HF (n=257) between the intensive lifestyle intervention and the diabetes support and education groups (hazard ratio, 0.96 [95% CI, 0.75-1.23]) over a median follow-up of 12.4 years. In the most adjusted Cox models, the risk of HF was 39% and 62% lower among moderate fit (tertile 2: hazard ratio, 0.61 [95% CI, 0.44-0.83]) and high fit (tertile 3: hazard ratio, 0.38 [95% CI, 0.24-0.59]) groups, respectively (referent group: low fit, tertile 1). Among HF subtypes, after adjustment for traditional cardiovascular risk factors and interval incidence of myocardial infarction, baseline CRF was not significantly associated with risk of incident HF with reduced ejection fraction. In contrast, the risk of incident HF with preserved ejection fraction was 40% lower in the moderate fit group and 77% lower in the high fit group. Baseline body mass index also was not associated with risk of incident HF, HF with preserved ejection fraction, or HF with reduced ejection fraction after adjustment for CRF and traditional cardiovascular risk factors. Among participants with repeat CRF assessments (n=3902), improvements in CRF and weight loss over a 4-year follow-up were significantly associated with lower risk of HF (hazard ratio per 10% increase in CRF, 0.90 [95% CI, 0.82-0.99]; per 10% decrease in body mass index, 0.80 [95% CI, 0.69-0.94]). Among participants with type 2 diabetes mellitus in the Look AHEAD trial, the intensive lifestyle intervention did not appear to modify the risk of HF. Higher baseline CRF and sustained improvements in CRF and weight loss were associated with lower risk of HF. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00017953.

Cardiorespiratory fitness (CRF) declines with age, and greater declines increase the risk for adverse health outcomes. Understanding factors that attenuate age-related decreases in CRF can help extend healthy life. We sought to determine the longitudinal associations of aerobic physical activity, muscle-strengthening activity (MSA), and adiposity with CRF. Study participants were enrolled in the Cooper Center Longitudinal Study and had three or more preventive medical examinations at the Cooper Clinic (Dallas, Texas) during 1987-2019. Aerobic activity and MSA were self-reported, and three measures of adiposity were clinically assessed: body mass index (BMI), body fat percentage, and waist circumference. CRF, expressed as metabolic equivalents (METs), was estimated by a maximal treadmill test. The longitudinal associations of aerobic activity, MSA, and adiposity with CRF were estimated using multivariable mixed linear regression models. The study included 6105 participants who were followed for a median of 7.1 yr. Most participants were men (83.6%), and their average age at baseline was 47.0 (SD = 8.7) yr. Mean CRF at baseline was 12.2 (SD = 2.3) METs. Increasing aerobic activity (per 500 MET·min·wk -1 , β = 0.069, 95% confidence interval = 0.064-0.074 METs) or MSA (per days per week, β = 0.066, 95% confidence interval = 0.058-0.073 METs) was associated with increased CRF over time. Increasing BMI, body fat percentage, or waist circumference were each associated with decreased CRF over time. These data offer longitudinal evidence on how changes in aerobic activity, MSA, and various measures of adiposity (beyond BMI) independently correlate with CRF over time. Healthy lifestyle behaviors that include increasing aerobic and MSA and limiting adiposity may positively influence the retention of fitness with age and improve downstream health outcomes.

Cardiorespiratory fitness is a well-established independent predictor of cardiovascular health. However, the relevance of alternative exercise and non-exercise tests for cardiorespiratory fitness assessment in large cohorts has not been studied in detail. We aimed to evaluate the YMCA-step test and the Veterans Specific Activity Questionnaire (VSAQ) for the estimation of cardiorespiratory fitness in the general population. One hundred and five subjects answered the VSAQ, performed the YMCA-step test and a maximal cardiopulmonary exercise test (CPX) and gave BORG ratings for both exercise tests (BORGSTEP, BORGCPX). Correlations of peak oxygen uptake on a treadmill (VO2_PEAK) with VSAQ, BORGSTEP, one-minute, post-exercise heartbeat count, and peak oxygen uptake during the step test (VO2_STEP) were determined. Moreover, the incremental values of the questionnaire and the step test in addition to other fitness-related parameters were evaluated using block-wise hierarchical regression analysis. Eighty-six subjects completed the step test according to the protocol. For completers, correlations of VO2_PEAK with the age- and gender-adjusted VSAQ, heartbeat count and VO2_STEP were 0.67, 0.63 and 0.49, respectively. However, using hierarchical regression analysis, age, gender and body mass index already explained 68.8% of the variance of VO2_PEAK, while the additional benefit of VSAQ was rather low (3.4%). The inclusion of BORGSTEP, heartbeat count and VO2_STEP increased R(2) by a further 2.2%, 3.3% and 5.6%, respectively, yielding a total R(2) of 83.3%. Neither VSAQ nor the YMCA-step test contributes sufficiently to the assessment of cardiorespiratory fitness in population-based studies.

Relationship of Physical Activity, Fitness, and Fatness with Clustered Metabolic Risk in Children and Adolescents: The European Youth Heart Study

Association between neighborhood walkability, cardiorespiratory fitness and body-mass index

PURPOSE: The assessment of cardiorespiratory fitness using ratio scaling to total body mass (TBM) is confounded by fat mass in obese populations because fat tissue does not contribute to oxygen utilization during exercise. Our objective was to isolate the independent effects of obesity on fitness when normalized to total lean body mass (TLM) and leg lean mass (LLM). We tested the hypothesis that boys with obesity would have attenuated cardiorespiratory fitness compared to age-matched non-obese boys. METHODS: Values are expressed as means ±SD with significance set at P<0.05. Seventeen non-obese boys (10.6±0.9y, 141.8±6.5cm, 35.5±7.0kg, 24±5% body fat) and thirteen age-matched obese boys (10.6±1.4y, 146.3±10.6cm, 60.25±13.0kg, 44±2% body fat) completed a cardiorespiratory fitness test (VO2peak) and body composition scan (DXA). RESULTS: Utilizing a 2-tailed independent T-test, both groups had comparable VO2peak test times (9.1±1.4 min; P=0.80), and peak heart rates (187±12 bpm; P=0.50). Boys with obesity had a reduction in VO2peak when normalized to TBM (54% of age-matched boys without obesity); however, this effect was reduced less when compared to LBM (76%) and LLM (68%). Further, simple linear regression found that total body fat accounted for 69% variance for mL/kgTBM/min, 49% variance for mL/kgLBM/min, and 40% variance for mL/kgLLM/min. CONCLUSIONS: These data indicate that obesity in young boys impairs cardiovascular fitness which supports the concept that obesity in pediatrics reduces aerobic capacity, which may have later life consequences in regards to cardiorespiratory fitness and all-cause mortality. Lastly, we show that the normalization of VO2 to LBM and LLM can provide an independent measure of fitness.

Introduction: Prior studies demonstrate that poor CRF in early adulthood is associated with adverse cardiac structure and function in midlife. The purpose of this study is to examine if higher early adulthood CRF and retention of CRF through midlife are associated with lower subsequent risk of subclinical or clinical HF. Methods: CARDIA participants with available data on CRF at baseline (Year [Y] 0: 1985-86), follow-up (Y7 or Y20), and HF staging data by Y30 were included. CRF was estimated using treadmill duration from a maximal, symptom-limited graded exercise test via modified Balke protocol. An adjusted linear mixed model was used to estimate treadmill duration when CRF assessment was missing at Y7 or 20. HF stages were defined using AHA HF staging criteria, including Stage 0 (no HF risk factors). Clinical HF was adjudicated by committee. Adjusted multinomial models tested associations between Y0 CRF and percent CRF retained through Y20 with HF stages at Y30, with Stage 0 as the reference. Interactions by the four race-sex groups were examined. Results: Of 2,565 individuals (25.1±3.5 y, 43% Black, 55% female), 30% (n=778), 37% (n=952), 32% (n=813), and 1% (n=32) were classified as Stages 0, A, B, or C/D by Y30 exam, respectively. Compared with Stage 0, every 1-minute increment higher CRF in early-adulthood was associated with a lower adjusted odds ratio of HF [Stage A: 0.72 (95% CI 0.68, 0.76), Stage B: 0.80 (95% CI 0.75, 0.84), Stage C/D 0.86 (95% CI 0.71, 1.04)]. Compared with Stage 0, every 1-standard deviation of % CRF retained at Y20 (midlife) was also associated with a lower odds of Stage A, B, and C/D HF at Y30 (Figure). A race-sex interaction was not observed (p-interaction 0.42). Conclusion: Higher early adulthood CRF, and greater retention of CRF through midlife, were associated with lower risk of developing subclinical or clinical HF. Strategies to maintain optimal CRF across the young adulthood to midlife transition may be important in prevention of HF.

Low cardiorespiratory fitness and coronary artery calcification: Complementary cardiovascular risk predictors in asymptomatic type 2 diabetics.