Predictor Of Cardiorespiratory Fitness Research Articles

The Utilization of Body Composition to Predict Cardiorespiratory Fitness and Determine Association with CKD Stage in Individuals with Mid-Spectrum CKD: A Pilot Study

Body composition (BC), a measure of body fat mass (FM), lean body mass (LBM), and bone mineral content (BMC), can be used as a predictor of cardiorespiratory fitness (CRF). Prior studies have established a relationship between BC and VO2max in healthy individuals over 35 years of age. However, this relationship is poorly understood in chronic disease populations. The focus of the study was to assess the relationship between BC, cardiorespiratory fitness, and chronic kidney disease (CKD). A cross-sectional analysis was conducted among 24 (9 males and 15 females) individuals diagnosed with mid-spectrum CKD (stages G2–G3b) who completed a health screening, dual-energy X-ray absorptiometry (DEXA) scan, and underwent a VO2max exercise test. Normality tests, descriptive statistics, Pearson’s correlations, t-tests, and ANOVAs were conducted in SAS v.9.4. The average percent body fat (%BF) was 36.28 ± 8.47%, LBM was 109.4 ± 29.1 lb, BMC was 2308.7 ± 735.1 g, and VO2max was 20.13 ± 5.04 mL/kg/min−1. BC was able to predict CRF via VO2max (R2 = 0.721, p < 0.001) and CKD stage (R2 = 0.390, p < 0.017). Positive correlations were observed in LBM (r = 0.750, p < 0.0018) and BMC (r = 0.647, p < 0.001), and negative correlations were observed with FM (r = −0.384, p < 0.032) and %BF (r = −0.802, p < 0.0001). BC was able to predict both CRF and CKD stages, with significant associations observed between BC, VO2max, and CKD stage. The progression of the CKD stage was associated with lower LBM, BMC, and VO2max values, indicating a graded effect of BC on CRF and CKD stage.

Developing a New Curvilinear Allometric Model to Improve the Fit and Validity of the 20-m Shuttle Run Test as a Predictor of Cardiorespiratory Fitness in Adults and Youth.

Doubts have been raised concerning the validity of the 20-m shuttle-run test (20 mSRT) as a predictor of cardiorespiratory fitness (CRF) in youth based on Léger's equation/model. An alternative allometric model has been published recently that is thought to provide, not only a superior fit (criterion validity) but also a more biologically and physiologically interpretable model (construct validity). The purposes of this study were to explore whether allometry can provide a more valid predictor of CRF using 20 mSRT compared with Léger's equation/model. We fitted and compared Léger's original model and an alternative allometric model using two cross-sectional datasets (youth, n = 306; adult n = 105) that contained measurements of CRF ([Formula: see text]/[Formula: see text]) and 20 mSRT performance. Quality-of-fit was assessed using explained variance (R2) and Bland and Altman's limits of agreement. The allometric models provided superior fits for the youth (explained variance R2 = 71.9%) and adult (R2 = 77.7%) datasets compared with Léger's equation using their original fixed (R2 = 35.2%) or re-estimated parameter models (R2 = 65.9%), confirming that the allometric models demonstrate acceptable criterion validity. However, the allometric models also identified a non-linear "J-shaped" increase in energy cost ([Formula: see text]/[Formula: see text]) with faster final shuttle-run speeds (fitted speed exponent = 1.52; 95% CI 1.38-1.65). Not only do allometric models provide more accurate predictions of CRF ([Formula: see text]/[Formula: see text]; mlkg-1min-1) for both youth and adults (evidence of criterion validity), the "J-shaped" rise in energy demand with increasing final shuttle-run speed also provides the evidence of construct validity, resulting in a more plausible, physiologically sound, and interpretable model.

Relationship between Adherence to the Mediterranean Diet and Body Composition with Physical Fitness Parameters in a Young Active Population.

The current study aimed at analyzing the relationship between body composition, adherence to the Mediterranean diet (MD), and physical fitness (PF) in a young active population. A total of 1198 athletes (boys = 875; girls = 323) enrolled in different municipal sports schools participated in this study. Data on adherence to the MD (KIDMED questionnaire), anthropometric measurements, and PF (20 m shuttle run test, handgrip strength, vertical jump and forced spirometry) were collected. Results show that the pubertal boys had a higher score in the KIDMED test than the prepubertal ones (+0.38, p = 0.28). Moreover, boys with better adherence to the MD had significantly higher results in handgrip strength (+12.20 regarding low MD group and +9.13 regarding medium MD group, p < 0.05), as well as in forced vital capacity (FVC) (+0.66 regarding low MD group and 0.29 regarding medium MD group, p < 0.05). No differences were found in the girls. Finally, the result of the KIDMED test is a variable with a positive and significant relationship with cardiorespiratory fitness, along with the FVC, percentage of fat mass, and performance in the vertical jump (p < 0.05). It is concluded that adherence to the MD could show a relationship with various PF variables in boys and could be a predictor of cardiorespiratory fitness in both cases.

Depression, Socioeconomic Factors, and Ethnicity as Predictors of Cardiorespiratory Fitness Before and After Cardiac Rehabilitation.

To determine whether cardiac patients with psychosocial or socioeconomic problems have lower peak oxygen uptake ((Equation is included in full-text article.)O2peak) and whether these factors modify the effect of cardiac rehabilitation (CR). A retrospective cohort study of patients with ischemic heart disease, valvular heart disease, or heart failure referred for CR. (Equation is included in full-text article.)O2peak was assessed by a maximal cardiopulmonary exercise test. Pre-existing depression was defined by use of antidepressants and new-onset depression by a modified Primary Care Evaluation of Mental Disorders (PRIME-MD) questionnaire at CR intake. Socioeconomic status was defined by educational attainment and working status; ethnicity as Western European or non-Western European. Full data from baseline assessment were available on 1217 patients and follow-up on 861 patients. Mean ± SD (Equation is included in full-text article.)O2peak before CR was 21.8 ± 6.8 mL/kg/min. After multivariable adjustment, lower (Equation is included in full-text article.)O2peak was associated with lower educational attainment, not working, and non-Western ethnicity but not with depression. Mean improvement of (Equation is included in full-text article.)O2peak following CR was 2.4 ± 4.3 mL/kg/min. After multivariable adjustment educational attainment, employment status and ethnicity were significant predictors of improvement of (Equation is included in full-text article.)O2peak while depression was not. Education, attachment to the workforce, and ethnicity were all associated with lower (Equation is included in full-text article.)O2peak before CR, and the disparity was increased following CR. Having pre-existing depression and new-onset depression did not influence (Equation is included in full-text article.)O2peak either before or after CR. These results point to important subgroups in need of specially-tailored rehabilitation programs.

Comparison of Cardiorespiratory Fitness Prediction Models in Young Adults Running head: Comparison of VO2 max Prediction Models

to compare the predictive accuracy of regression models for a non-consecutive day VO2 max/Wingate testing protocol and a same day testing protocol. Participants (N=23) completed a treadmill GXT and Wingate cycle test. Participants (n=12) completed testing on non-consecutive days (NON) and (n=11) the same day (SAME). VO2 max (L/min) and peak power (PP) were collected. Linear regression analysis of NON revealed R2=0.808 and prediction equation Ŷ=1.499+0.004X and SAME showed R2=0.861 and prediction equation Ŷ=1.407+0.003X. NON standard error of estimate (SEE) and standard error of estimate percent (SEE %) were 0.62 L/min and 15.23%, respectively. SAME SEE and SEE% were 0.34 L/min and 10.98%, respectively. These results indicate PP obtained the same day of VO2max testing is a better predictor of cardiorespiratory fitness. Similarly, the SAME model is more accurate according to SEE and SEE%. This may be due to diminished effects of training adaptations that could occur 2-7 days between testing sessions during the NON testing protocol in healthy, active young adults.

Individual calibration of accelerometers in children and their health-related implications

ABSTRACTThis study compared children’s physical activity (PA) levels, the prevalence of children meeting current guidelines of ≥60 minutes of daily moderate to vigorous PA (MVPA), and PA-health associations using individually calibrated (IC) and empirical accelerometer cutpoints. Data from 75 (n = 32 boys) 10–12 year old children were included in this study. Clustered cardiometabolic (CM) risk, directly measured cardiorespiratory fitness (CRF), anthropometric and 7 day accelerometer data were included within analysis. PA data were classified using Froude anchored IC, Evenson et al. (Evenson, K. R., Catellier, D. J., Gill, K., Ondrak, K. S., & McMurray, R. G. (2008). Calibration of two objective measures of physical activity for children. Journal of Sports Sciences, 26(14), 1557–1565. doi:10.1080/02640410802334196) (Ev) and Mackintosh et al. (Mackintosh, K. A., Fairclough, S. J., Stratton, G., & Ridgers, N. D. (2012). A calibration protocol for population-specific accelerometer cutpoints in children. PLoS One, 7(5), e36919. doi:10.1371/journal.pone.0036919) (Mack) cutpoints. The proportion of the cohort meeting ≥60mins MVPA/day ranged from 37%-56% depending on the cutpoints used. Reported PA differed significantly across the cutpoint sets. IC LPA and MPA were predictors of CRF (LPA: standardised β = 0.32, p = 0.002, MPA: standardised β = 0.27 p = 0.013). IC MPA also predicted BMI Z-score (standardised β = −0.35, p = 0.004). Ev VPA was a predictor of BMI Z-score (standardised β = −0.33, p = 0.012). Cutpoint choice has a substantial impact on reported PA levels though no significant associations with CM risk were observed. Froude IC cutpoints represent a promising approach towards classifying children’s PA data.

The YMCA Submaximal Cycle Test and the 6-Minute Walk Test are Not Accurate Predictors of Cardiorespiratory Fitness During Mid-pregnancy

The YMCA Submaximal Cycle Test and the 6-Minute Walk Test are Not Accurate Predictors of Cardiorespiratory Fitness During Mid-pregnancy

Predictors of cardiorespiratory fitness in female and male adults with different body mass index: National Health and Nutrition Examination Survey 1999–2004 dataset

Background: The aim of this study was to explore factors affecting cardiorespiratory fitness in males and females with different body mass index (BMI).Methods: The National Health and Nutrition Examination Survey 1999–2004 data were used for this retrospective study. Estimated maximal oxygen uptake (VO2max) is surrogate for cardiorespiratory fitness (CRF). Univariate and multivariate linear regression analyses were performed to explore whether study variables were associated with estimated VO2max stratified by gender and BMI categories.Results: A total of 3292 subjects 20–49 years of age were included in the analysis. CRF significantly decreased as BMI increased in both females and males. Ethnic difference was found in normal BMI in both genders and obese females; homocysteine was significantly negatively associated with estimated VO2max, as was total cholesterol. Obese male subjects with diabetes had a lower estimated VO2max than those without diabetes, and C-reactive protein (CRP) level and vitamin B12 level were significantly negatively associated with CRF. Female subjects with diabetes had higher estimated VO2max than those without diabetes. Folate was significantly positively correlated with estimated VO2max, whereas CRP was negatively correlated in obese female.Conclusions: There are different predictors of CRF in males and females, and in individuals with different BMI.Key messagesDifferent BMI classes are associated with different predictors of cardiorespiratory fitness.Indicators of cardiorespiratory fitness differ between sexes.

Cardiorespiratory fitness estimation in free-living using wearable sensors.

In this paper we propose artificial intelligence methods to estimate cardiorespiratory fitness (CRF) in free-living using wearable sensor data. Our methods rely on a computational framework able to contextualize heart rate (HR) in free-living, and use context-specific HR as predictor of CRF without need for laboratory tests. In particular, we propose three estimation steps. Initially, we recognize activity primitives using accelerometer and location data. Using topic models, we group activity primitives and derive activities composites. We subsequently rank activity composites, and analyze the relation between ranked activity composites and CRF across individuals. Finally, HR data in specific activity primitives and composites is used as predictor in a hierarchical Bayesian regression model to estimate CRF level from the participant's habitual behavior in free-living. We show that by combining activity primitives and activity composites the proposed framework can adapt to the user and context, and outperforms other CRF estimation models, reducing estimation error between 10.3% and 22.6% on a study population of 46 participants. Our investigation showed that HR can be contextualized in free-living using activity primitives and activity composites and robust CRF estimation in free-living is feasible.

Correlates of Cardiorespiratory and Muscular Fitness among Brazilian Adolescents

To analyze socioeconomic indicators, physical activity (PA) opportunities, and behavioral correlates of cardiorespiratory and muscular fitness among Brazilian boys and girls. A sample of 1555 adolescents was randomly selected. Age- and sex-specific standard scores were calculated for each fitness component. Among boys, head of household's schooling, involvement in organized PA, meeting the PA recommendations, and computer/games use were associated with cardiorespiratory fitness. Involvement in organized PA and active time in Physical Education (PE) classes were predictors of muscular fitness. Among girls, active time in PE classes and TV watching were predictors of cardiorespiratory fitness. Meeting the PA recommendations was associated with muscular fitness. PA variables and sedentary behaviors should be independently considered for physical fitness promotion in youth.

Independence of physical activity and screen time as predictors of cardiorespiratory fitness in youth

Screen time (ST) is associated with physical activity (PA) levels. We aimed to investigate the relationship between ST and fitness. We assessed fitness and daily ST in 7,466 10-16-y-old schoolchildren from the east of England. The differences in fitness between ST groups, and the association between ST and fitness were assessed. ST was negatively associated with fitness in boys of all ages (P < 0.001) and girls in grades 6-9 (P < 0.005). Boys were less likely to be fit if they reported >2 h/d ST (odds ratio (OR): 0.70, 95% confidence interval (CI): 0.58-0.85) or >4 h/d (OR: 0.45, 95% CI: 0.35-0.57) ST, as were girls reporting >4 h/d ST (OR: 0.58, 95% CI: 0.43-0.78). Controlling for PA levels attenuated these odds in boys reporting >2 h/d ST (OR: 0.81, 95% CI: 0.66-0.91) or >4 h/d ST (OR: 0.65, 95% CI: 0.50-0.84) and in girls reporting >4 h/d ST (OR: 0.68, 95% CI: 0.50-0.93). These first data from English children show a negative association between ST and fitness in youth. Of note, very high levels of daily ST (>4 h) are associated with poor fitness. Some of the associations were mediated by PA levels. Our data support international recommendations to limit ST to <2 h/d; we believe such guidance should be issued in the United Kingdom.

Association of Leisure-Time Physical Activity With Cardiorespiratory Fitness in Indian Men

The relationship between leisure-time physical activity (LTPA) and cardiorespiratory fitness (CRF) is not clearly understood in Indian men. It is important to elucidate whether the duration or intensity of LTPA is responsible for increasing CRF. This will help in designing better physical activity intervention strategies for improving CRF in Indian men. Healthy nondiabetic urban Indian men with no history of coronary heart disease (CHD) were selected (n = 603; aged 22-64 years) and their energy intake and physical activity was determined using a questionnaire. Body fat (percent) was determined by leg-to-leg bioelectrical impedance analysis while CRF was measured on multistage, continuous treadmill test using Bruce protocol. Intensity of physical activity (METs) emerged as the best independent predictor of CRF (β = 0.217; P < .001). Using univariate General Linear Model, it was found that CRF is more a function of LTPA intensity than LTPA duration, since LTPA duration was not related to CRF when controlled for LTPA intensity. However, LTPA intensity remained significantly associated with CRF even after adjustment for LTPA duration. LTPA of preferably higher intensity should be incorporated in the lifestyle to improve CRF and prevent CHD in Indian men.

Determinants of cardiorespiratory fitness at 3, 6 and 12 months poststroke

Purpose: To better delineate intervention programs, knowledge of the factors that are associated with physical fitness in stroke survivors is crucial. This study aimed to predict cardiorespiratory fitness based on standardized measures along the several dimensions of the International Classification of Functioning, Disability and Health (ICF) model at several time intervals in the first year after stroke. Methods: Forty patients were assessed at 3, 6 and 12 months poststroke. A symptom-limited graded cycle ergometer test was used to assess cardiorespiratory fitness. Outcome variables were VO2 peak and the Oxygen Uptake Efficiency Slope (OUES). Impairments, activity limitations, participation restrictions, personal and environmental factors were assessed to determine predictive factors. Results: Explained variance at 3, 6 and 12 months poststroke was 39%, 55% and 91% for VO2 peak and 55%, 63% and 79% for OUES. A strong association between knee muscle strength and cardiorespiratory fitness was found at each measurement time, explaining up to 72 % of the variance in fitness. At 12 months poststroke, functional mobility, body mass index (BMI) and emotional status also contributed to explain variance. Conclusions: Knee muscle strength was found to be a very strong predictor of cardiorespiratory fitness during the first year after stroke and functional mobility became important at 12 months poststroke.Implications for RehabilitationKnee muscle strength was found to be a very strong predictor of cardiorespiratory fitness during the first year after stroke and functional mobility became important at 12 months post-stroke.Cardiorespiratory endurance training should be implemented with strength-developing exercises of both lower limbs, with emphasis on the weaker paretic side.

Correlates of aerobic fitness in urban and rural Portuguese adolescents

Background: Improving physical fitness is often an objective of programmes aimed at preventing obesity among youth.Aim: To evaluate the association between cardiorespiratory fitness (CRF) and area of residence controlling for several correlates in adolescents.Subjects and methods: CRF was assessed with the progressive aerobic cardiovascular endurance run (PACER) test in a cross-sectional sample of 362 Portuguese adolescents (165 males, 197 females) of 13–16 years of age. Youth were classified by area of residence as urban or rural. Gender, age, weight status, parental education, screen time (inactivity) and moderate-to-vigorous physical activity (MVPA) were statistically controlled. Logistic regression analysis was used.Results: Adolescents of both sexes from rural settings were 76% more likely to be classified as aerobically fit compared to those from urban areas. The odds ratio for CRF in the final model was similar in boys (OR = 0.24, 95% CI 0.06–0.99, p < 0.05) and girls (OR = 0.24, 95% CI 0.07–0.76, p < 0.05). MVPA and weight status were important predictors of CRF in Portuguese adolescents of 13–16 years of age. Maternal education was an additional predictor in girls.Conclusion: CRF and rural/urban settings were significantly related in this sample of Portuguese adolescents of both sexes.

Field estimation of Vo2 max in children eight years of age

The purpose of the investigation was to explore the validity of using timed distance runs as predictorr of cardiorespiratory fitness in young untrained children. Maximal oxygen consumption and performance in runs of 549, 1207, and 1609 meters (600 yards, 3/4 mile, and 1 mile) were compared in 38 children eight years of age. Males were found to exceed females on Vo2max and possessed significantly faster times in the 1207 and 1609 meter runs. The females exhibited greater six-site skinfold totals. The 1609 meter run proved to be the best predictor of Vo2max (ml/kg) in males. However, none of the three distances was acceptable for females.