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PubMed2005

The HPA axis response to stress in women: effects of aging and fitness.

This study tested the hypotheses that aging is associated with greater hypothalamic-pituitary-adrenal (HPA) axis reactivity to psychological stress, and whether aerobic fitness is associated with a lower HPA axis response to psychological stress. Three groups, consisting of young-unfit women (27.9+/-2.5 yr, n=10), older-unfit women (66.3+/-1.4 yr, n=14), and older-fit women (66.6+/-2.0 yr, n=12), underwent the Matt Stress Reactivity Protocol (MSRP). The MSRP is a stress test battery that combines mental challenges, a physical challenge, and a psychosocial stressor. Definition of fitness was based on maximal oxygen consumption (VO(2max)) where unfit was defined as having VO(2max)</=average for the respective age group and fit was defined as VO(2max)>average for the respective age group. The MSRP elicited increases in heart rate, blood pressure, ACTH, and cortisol (P<0.001). The older-unfit women had significantly greater cortisol responses to the challenge than both the young-unfit and the older-fit women (P<0.05), who did not differ from each other. ACTH levels were significantly higher in the older-unfit women at baseline and throughout the trial, compared to both young-unfit and the older-fit (P<0.01). The ACTH response was not different between any of the groups. The young-unfit women had greater heart rate responses than the older-unfit (P<0.01), while the latter had greater systolic blood pressure responses (P<0.01). There were no significant differences between the older-unfit and older-fit in terms of heart rate or blood pressure responses. Our result shows that among unfit women, aging is associated with greater HPA axis reactivity to psychological stress, and that higher aerobic fitness among older women can attenuate these age-related changes as indicated by a blunted cortisol response to psychological stress. These findings suggest that exercise training may be an effective way of modifying some of the neuroendocrine changes associated with aging.

Adrenocorticotropic Hormone↗
PubMed1998

Changes in physical fitness and changes in mortality.

BACKGROUND: Point estimates of physical fitness give important information on the risk of death in healthy people, but there is little information available on effects of sequential changes in physical fitness on mortality. We studied this latter aspect in healthy middle-aged men over a total follow-up period of 22 years. METHODS: 2014 healthy men aged 40-60 years had a bicycle exercise test and clinical examination, and completed a questionnaire in 1972-75 (survey 1). This was repeated for 1756 (91%) of 1932 men still alive by Dec 31, 1982 (survey 2). The exercise scores were adjusted for age. The change in exercise scores between surveys was divided into quartiles (Q1=least fit, Q4=fittest). An adjusted Cox's proportional hazards model was used to study the association between changes in physical fitness and mortality, with the Q1 men used as controls. FINDINGS: By Dec 31, 1994, 238 (17%) of the 1428 men had died, 120 from cardiovascular causes. There were 37 deaths in the Q4 group (19 cardiovascular); their relative risks of death were 0.45 (95% CI 0.29-0.69) for any cause and 0.47 (0.26-0.86) for cardiovascular causes. There was a graded, inverse relation between changes in physical fitness and mortality irrespective of physical fitness status at survey 1. INTERPRETATION: Change in physical fitness in healthy middle-aged men is a strong predictor of mortality. Even small improvements in physical fitness are associated with a significantly lowered risk of death. If confirmed, these findings should be used to influence public health policy.

Adult↗
PubMed1999

Seven-year changes in physical fitness, physical activity, and lipid profile in the CARDIA study. Coronary Artery Risk Development in Young Adults.

PURPOSE: To relate seven year changes in physical fitness and physical activity in the young adult population to changes in the plasma lipid profile and to examine the influence of weight change on those relationships. METHODS: The participants in this observational study were the 1777 black and white men and women, ages 18-30 at entry into the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, who completed a symptom-limited graded treadmill exercise test and had an overnight fasting blood draw at both the Baseline (1985-86) and Year 7 (1992-93) exams. CARDIA, a longitudinal study of the relationships of lifestyle and physiological variables to the development of coronary heart disease risk factors, consists of population-based cohorts in Birmingham, Alabama, Minneapolis, Minnesota and Chicago, Illinois and a cohort recruited from the membership of a large, pre-paid health care plan, broadly representative of the population, in Oakland, California. RESULTS: All race/gender groups experienced mean decreases in physical fitness and self-reported physical activity and increases in weight. Decreased fitness was associated with decreased high density lipoprotein-cholesterol (HDL-C), and conversely, increased fitness was associated with increased HDL-C. The correlation coefficients of change in fitness with change in HDL-C ranged from 0.17 in white men and black women to 0.24 in white women (P < 0.001 for all race/gender groups). Change in fitness was minimally correlated with change in low density lipoprotein-cholesterol (LDL-C) in all groups (r ranged from -0.09 in black women to -0.20 in white women), triglycerides (TG) in men and white women (r ranged from -0.10 to -0.15), and total cholesterol (TC) in white men and women (r = -0.11 and -0.15, respectively). The magnitude of these correlations was further reduced with adjustment for weight change. Correlations between change in activity and change in lipid and lipoprotein values were generally weak or nonexistent, except for the suggestion of a small, direct relationship with change in HDL-C in black and white women (r = 0.14 and r = 0.11, respectively). All of the weight change adjusted correlations were essentially unaffected by further adjustment for baseline fitness or activity and other covariates. CONCLUSIONS: Decreased fitness during young adulthood is associated with unfavorable changes in lipid profile, explained mostly by increased weight. Lack of association between change in activity and change in lipid profile observed in this study may be due, in part, to imprecision of activity measurement.

Adolescent↗
PubMed2005

Relationship of physical fitness to prevalence and incidence of overweight among schoolchildren.

OBJECTIVES: We examined the relationship between comprehensive fitness tests and overweight using a school surveillance system in a racially diverse city in the United States. RESEARCH METHODS AND PROCEDURES: Trained physical education teachers measured weight, height, and fitness annually from 2001 to 2003. We compiled data for a cross-sectional analysis (11,845 measurements on 6297 students, 5 to 14 years of age) and a 1-year prospective analysis (4215 measurements on 2927 students not overweight at baseline, 5 to 13 years of age). Overweight was defined as a BMI > or =95th percentile (Centers for Disease Control and Prevention 2000 growth charts), and underfit was defined as failing at least one of five fitness tests: endurance run, abdominal strength, flexibility, upper body strength, and agility (Amateur Athletic Union and Fitnessgram). Associations between fitness and overweight were examined using multivariate logistic regression models, adjusting for sociodemographic status and repeated measurements over time. RESULTS: The mean number of fitness tests passed was lower among students with a BMI above the 80th percentile. Overweight incidence over 1 year was 7% and 2% for underfit and fit girls, respectively (odds ratio, 3.3; 95% confidence interval, 2.0 to 5.6). Not passing either the endurance run or upper body strength test was associated with overweight incidence in both boys and girls. After adjusting for baseline BMI, the endurance run remained a significant predictor of incident overweight among girls (odds ratio, 2.0; 95% confidence interval, 1.1 to 3.5). DISCUSSION: Findings support a cross-sectional inverse relationship between physical fitness and overweight among school-aged children. The direction of causation between fitness and overweight is not clearly established and merits further study.

Adolescent↗
PubMed2006

Relationship between BMI, physical fitness, and motor skills in youth with mild intellectual disabilities.

INTRODUCTION: The negative impact of obesity on physical fitness and motor abilities has been documented in youth of various ages; however, this issue has not been explored in youth with mild intellectual disabilities (ID). Youth with ID are considered more overweight, less physically fit, and less motor proficient than peers without ID, so it is important to determine if these variables are associated in this population. The purpose of this study was to examine the relationship between body mass index (BMI), physical fitness, and motor skills in a large sample of youth with mild ID. METHOD: A systematic, stratified sampling method was used to select 444 youth with mild ID, aged 6-18 years, from eight special education schools in Hong Kong. Physical fitness was assessed using items from the national Hong Kong assessment: 6- (ages 6-8 years) or 9- (ages 9-18 years) minute run, sit-up, isometric push-up, sit and reach, and sum of skinfold. Functional motor skills were assessed in 244 youth from the fitness sample using the Test of Gross Motor Development-II. Subjects were categorized into normal or overweight/obese BMI groups based on international cutoff points. RESULTS: Approximately 20% of the sample was classified as overweight/obese (average BMI normal = 17.47+/-2.69; overweight/obese = 24.78+/-4.05). ANCOVA controlling for age and gender revealed group differences in the run (P = 0.001) and push-ups (P = 0.05), but not in the motor or other fitness variables. After controlling for age and gender, BMI was correlated with the run (r = -0.27, P < 0.001) and push ups (r = -0.18, P = 0.008). Age and gender were entered as the first block in hierarchical regression and accounted for most of the variance in all dependent variables, except sit and reach. The inclusion of BMI in the second block added to the model for run and push-ups only (deltaR2 run = 0.04, push-ups = 0.03, P<0.001). CONCLUSION: Overweight/obesity is minimally associated with aerobic fitness and muscular strength in youth with mild ID. BMI did not impact other fitness measures (sit-up, sit and reach) or motor skills in the sample. The undesirable level of overweight/obesity in this sample requires increased attention and immediate intervention.

Adolescent↗
PubMed1998

Changes in peak oxygen uptake and plasma volume in fit and unfit subjects following exposure to a simulation of microgravity.

To test the hypothesis that the magnitude of reduction in plasma volume and work capacity following exposure to simulated microgravity is dependent on the initial level of aerobic fitness, peak oxygen uptake (VO2peak) was measured in a group of physically fit subjects and compared with VO2peak in a group of relatively unfit subjects before and after 10 days of continuous 6 degrees head-down tilt (HDT). Ten fit subjects (40 +/- 2 year) with mean +/- SE VO2peak = 48.9 +/- 1.7 mL kg-1 min-1 were matched for age, height, and lean body weight with 10 unfit subjects (VO2peak = 37.7 +/- 1.6 mL kg-1 min-1). Before and after HDT, plasma, blood, and red cell volumes and body composition were measured and all subjects underwent a graded supine cycle ergometer test to determine VO2peak period needed. Reduced VO2peak in fit subjects (-16.2%) was greater than that of unfit subjects (-6.1%). Similarly, reductions in plasma (-18.3%) and blood volumes (-16.0%) in fit subjects were larger than those of unfit subjects (blood volume = -5.6%; plasma volume = -6.6%). Reduced plasma volume was associated with greater negative body fluid balance during the initial 24 h of HDT in the fit group (912 +/- 154 mL) compared with unfit subjects (453 +/- 200 mL). The percentage change for VO2peak correlated with percentage change in plasma volume (r = +0.79). Following exposure to simulated microgravity, fit subjects demonstrated larger reductions in VO2peak than unfit subjects which was associated with larger reductions in plasma and blood volume. These data suggest that the magnitude of physical deconditioning induced by exposure to microgravity without intervention of countermeasures was influenced by the initial fitness of the subjects.

Adult↗
PubMed1993

Physical fitness as a predictor of mortality among healthy, middle-aged Norwegian men.

BACKGROUND: Despite many studies suggesting that poor physical fitness is an independent risk factor for death from cardiovascular causes, the matter has remained controversial. We studied this question in a 16-year follow-up investigation of Norwegian men that began in 1972. METHODS: Our study included 1960 healthy men 40 to 59 years of age (84 percent of those invited to participate). Conventional coronary risk factors and physical fitness were assessed at base line, with physical fitness measured as the total work performed on a bicycle ergometer during a symptom-limited exercise-tolerance test. RESULTS: After an average follow-up time of 16 years, 271 men had died, 53 percent of them from cardiovascular disease. The relative risk of death from any cause in fitness quartile 4 (highest) as compared with quartile 1 (lowest) was 0.54 (95 percent confidence interval, 0.32 to 0.89; P = 0.015) after adjustment for age, smoking status, serum lipids, blood pressure, resting heart rate, vital capacity, body-mass index, level of physical activity, and glucose tolerance. Total mortality was similar among the subjects in fitness quartiles 1, 2, and 3 when the data were adjusted for these same variables. The adjusted relative risk of death from cardiovascular causes in fitness quartile 4 as compared with quartile 1 was 0.41 (95 percent confidence interval, 0.20 to 0.84; P = 0.013). The corresponding relative risks for quartiles 3 and 2 (as compared with quartile 1) were 0.45 (95 percent confidence interval, 0.22 to 0.92; P = 0.026) and 0.59 (95 percent confidence interval, 0.28 to 1.22; P = 0.15), respectively. CONCLUSIONS: Physical fitness appears to be a graded, independent, long-term predictor of mortality from cardiovascular causes in healthy, middle-aged men. A high level of fitness was also associated with lower mortality from any cause.

Adult↗
PubMed1994

The perception of physical fitness as a guide to its evaluation in firemen.

There is increasing interest in the acquisition and measurement of physical fitness in general populations (Bassey and Fentem 1981). Measuring fitness can be uncomfortable and exhausting for subjects and expensive and time-consuming for experimenters (Andersen et al. 1971). Various authors have described and/or evaluated methods for the prediction of VO2 max (Astrand and Rhyming 1954, Davies 1968, Fitchett 1985, Harrison et al. 1980, Jette 1979, Jette et al. 1982, Shephard 1975, Shephard et al. 1979). A valid, safe, socially-acceptable alternative for such measurements applicable to a population would be of benefit. Asking subjects how they perceive their own physical fitness might be such an alternative. The validity and reliability of the data contained from such a questionnaire could be tested against conventional measures of physical fitness. A study which incorporated questionnaire surveys as one method of determining physical fitness in a large population was undertaken on Fire Service personnel in England, Scotland, and Wales (Ellam et al. 1985); a subsample of the population were questioned in the same way but in addition their fitness was assessed by physiological measurements. This paper describes the characteristics of the physical fitness of an average fireman as revealed by responses to questionnaires and how firemen felt their fitness was related to their working duties; it further examines these in relation to objective measurements.

Adult↗
PubMedDate not supplied

The importance of considering biological maturity when assessing physical fitness measures in girls and boys aged 10 to 16 years.

It is widely considered that biological maturity influences physical fitness test performance, children can be advantaged/disadvantaged in physical fitness tests by being more or less mature than counterparts of the same chronological age. The current study sought to investigate the effect sexual maturity had upon performance in physical fitness tests. A cross-sectional study involving 161 girls and 152 boys was carried out. Each subject was assessed for stature, mass, self-assessment of sexual maturity, vertical jump, hand grip strength and the 20 m shuttle run test, all procedures were standardized. Spearman's rank correlation coefficients were developed to assess the relationship between maturity and physical fitness measures. ANCOVA inferential statistics were performed to investigate if performance in physical fitness tests differed between children of different sexual maturity stages irrespective of mass and stature. Significance was set at p < 0.05. Stage of sexual maturity was significantly correlated with all physical fitness measures (boys: r=0.56 to 0.73; girls: r=0.24 to 0.46). ANCOVA revealed that when stature and mass were taken into account significant differences were evident between sexual maturity stages in boys but not girls. This suggests that increases in mass and stature are primarily responsible for variation in girls' physical performance throughout maturation, whereas in boys there are some qualitative differences in performance due to other factors. It was concluded that sexual maturity has a large influence on physical fitness measures in boys but less effect in girls. Rating of physical fitness, particularly for boys should take into account biological maturity.

Adolescent↗
PubMed2005

Comparison of two adaptive procedures for fitting a multi-channel compression hearing aid.

We compared two adaptive procedures for fitting a multi-channel compression hearing aid. "Camadapt" uses judgements of the loudness of speech stimuli and the tonal quality of music stimuli. "Eartuner" uses judgements of the loudness and clarity of speech stimuli with differing spectral characteristics. Sixteen new users of hearing aids were fitted unilaterally, using each procedure. The fittings were assigned to Programs 1 and 2 in the aid, in a counter-balanced order. Subjects kept a diary of their experiences with each program in everyday life. Following 2-4 weeks of experience, they filled in the APHAB and other questionnaires and were re-fitted using both procedures. Camadapt generally led to higher low-level gains and lower high-level gains than Eartuner. Gains recommended by the procedures did not change following experience. Eight subjects preferred the Camadapt fitting and eight preferred the Eartuner fitting. Most subjects gave high overall satisfaction ratings for both procedures. Test-retest reliability was better for Eartuner than for Camadapt. Preference for the Camadapt fitting was associated with slightly better speech communication with Camadapt, while preference for the Eartuner fitting was associated with fewer problems with aversion for that procedure.

Acoustic Stimulation↗
PubMed2002

Fitness and fatness as predictors of mortality from all causes and from cardiovascular disease in men and women in the lipid research clinics study.

The relative size of the effects of fitness and fatness on longevity has been studied in only one cohort. The authors examined this issue using data from 2,506 women and 2,860 men in the Lipid Research Clinics Study. The mean age was 46.6 years in women and 45.1 years in men at baseline (1972-1976). Fitness was assessed using a treadmill test, and fatness was assessed as body mass index calculated from measured height and weight. Participants were followed for vital status through 1998. Hazard ratios were calculated using proportional hazard models that included covariates for age, education, smoking, alcohol intake, and the dietary Keys score. Fitness and fatness were both associated with mortality from all causes and from cardiovascular disease. For mortality from all causes, the adjusted hazard ratios were 1.32 among the fit-fat, 1.30 among the unfit-not fat, and 1.57 among the unfit-fat women compared with fit-not fat women. Among men the same hazard ratios were 1.25, 1.44, and 1.49 [corrected]. There were no significant interactions between fitness and fatness in either men or women. The authors conclude that both fitness and fatness are risk factors for mortality, and that being fit does not completely reverse the increased risk associated with excess adiposity.

Adult↗
PubMed2026

Competing subclones and fitness diversity shape tumor evolution across cancer types.

MOTIVATION: Intratumor heterogeneity arises from ongoing somatic evolution and complicates cancer diagnosis, prognosis, and treatment. Reconstructing evolutionary dynamics typically requires spatiotemporal samples, which are often unavailable in clinical settings. Computational approaches that can infer tumor evolutionary history from single-timepoint bulk sequencing data remain limited. RESULTS: We present estimating evolutionary events through single-timepoint sequencing (TEATIME), a novel computational framework that models tumors as mixtures of two competing cell populations: an ancestral clone with baseline fitness and a derived subclone with elevated fitness. Using cross-sectional bulk sequencing data, TEATIME estimates mutation rates, timing of subclone emergence, relative fitness, and number of generations of growth. To quantify intratumor fitness asymmetries, we introduce a novel metric-fitness diversity-which captures the imbalance between competing cell populations and serves as a measure of functional intratumor heterogeneity. Applying TEATIME to 33 tumor types from The Cancer Genome Atlas, we revealed divergent as well as convergent evolutionary patterns. Notably, we found that immune-hot microenvironments constraint subclonal expansion and limit fitness diversity. Moreover, we detected temporal dependencies in mutation acquisition, where early driver mutations in ancestral clones epistatically shape the fitness landscape, predisposing specific subclones to selective advantages. These findings underscore the importance of intratumor competition and tumor-microenvironment interactions in shaping evolutionary trajectories, driving intratumor heterogeneity. Lastly, we demonstrate that TEATIME-derived evolutionary parameters and fitness diversity offer novel prognostic insights across multiple cancer types. AVAILABILITY AND IMPLEMENTATION: R implementation of TEATIME is available on GitHub (https://github.com/liliulab/TEATIME) and Zenodo (https://zenodo.org/records/17422174).

Neoplasms↗
PubMed1989

The association between physical fitness and cardiovascular disease risk factors in children in a five-year follow-up study.

The relation between physical fitness and cardiovascular disease (CVD) risk factors was studied in 633 children selected from all fourth grades in 37 elementary schools in New York. They were participating in the control group of an intervention study to reduce CVD risk factors in children. Blood pressure, total and high-density lipoprotein (HDL) cholesterol and physical fitness were measured at baseline and at four subsequent examinations during five years of follow-up. Systolic blood pressure (SBP) at baseline was highest in children with poor physical fitness. The five-year change in physical fitness was inversely associated with the change in SBP, ie, children with the strongest decline in physical fitness showed the largest rise in SBP. HDL cholesterol at baseline was lowest in boys with poor physical fitness. The five-year change in physical fitness was positively related to the change in HDL cholesterol levels in boys; ie, boys with the largest decline in physical fitness had the largest decrease in HDL cholesterol level. These observations indicate that unfavourable long-term changes in physical condition in childhood may be related to unfavourable changes in blood pressure and serum lipids.

Blood Pressure↗
PubMed1983

Physical fitness of physical therapy students.

Physical fitness norms do not exist for physical therapists or physical therapy students. This lack, in part, reflects the complexity of physical fitness and the scarcity of data reported on physical fitness norms of other populations. This report describes the methods used and the results obtained for 16 physical fitness factors of 98 female and 13 male physical therapy upperclassmen and discusses the implications of physical fitness in the practice of physical therapy. Means, standard deviations, ranges, and percentile rankings are given by sex for each of the 16 fitness factors. The purpose of this study was to begin to establish physical fitness norms. As physical fitness norms are established, it will be possible to determine how norms of physical therapists and physical therapy students compare with established values.

Adult↗
PubMed1996

Fitting hearing aids to individual loudness-perception measures.

OBJECTIVE: The purpose of this study was to compare the prescribed gain, compression ratios, compression thresholds, and the relative predicted speech intelligibility (Speech Intelligibility Index [SII], American National Standards Institute 3.79, proposed) provided by four strategies proposed for selecting hearing aid parameters for low-threshold compression hearing instruments and by a traditional threshold-based hearing aid fitting procedure. The strategies used were Desired Sensation Level Input/Output (DSLTM[i/o]; Cornelisse, Seewald, & Jamieson, 1994), Visual Input-Output Locator Algorithm (VIOLA; Cox, 1994), FIG6 strategy (Killion, Reference Note 2), Ricketts and Bentler strategy (RAB), and a threshold-based hearing aid fitting procedure (National Acoustics Laboratories-Revised [NAL-R]; Byrne & Dillion, 1986). These new strategies have been suggested as alternatives to threshold-based strategies, which do not provide the varying amounts of target gain, as a function of input level, necessary to fit low-threshold compression hearing aids. DESIGN: The electroacoustic prescriptions and the predicted speech intelligibility were calculated across all five fitting strategies for 20 subjects. The threshold and loudness growth information used for each fitting was reported previously (Ricketts & Bentler, in press). RESULTS: Comparison across prescriptions revealed that the NAL-R strategy (due to the linear gain provided) prescribed the least gain for low-level inputs and the greatest gain for high-level inputs. Gain comparisons across fitting by loudness (FBL) strategies revealed a more shallow frequency response slope for strategies that require individual measures of loudness growth (RAB, VIOLA) in comparison with strategies that assumed average data (FIG6, DSLTM[i/o]). SII results revealed greater predicted speech intelligibility for the FIG6 and the DSLTM[i/o] compared with the NAL-R, RAB, and VIOLA. These differences were most apparent in noise backgrounds and least evident when loudness differences were minimized. CONCLUSIONS: It appears that differences in SII scores across the FBL fitting strategies are due, in part, to differences in the loudness of the output signal. It is assumed that differences in high-frequency shaping may also be a factor. These data do not appear to support the use of additional clinical time to obtain individual loudness growth measures. However, due to the fact that SII results are based on average performance, it is difficult to predict whether differences across these fitting strategies would be realized in actual measures of speech intelligibility or sound quality on an individual basis.

Correction of Hearing Impairment↗
PubMed1997

Physical fitness, lipids, and apolipoproteins in the Northern Ireland Health and Activity Survey.

The objective of this study was to investigate the relationship between physical fitness, lipids, and apolipoproteins in a cross-sectional study using a two-stage probability sample of the population of Northern Ireland. The main outcome measures were physical fitness using VO2max estimated by extrapolation from submaximal oxygen uptake while walking on a motor driven treadmill, and total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, HDL2 and HDL3, and Lp(a). There were no significant relationships with fitness, after adjustment for possible confounders, with the exception of a positive relationship with HDL2 in males (P < or = 0.01) and Lp(a) in females (P < or = 0.05). There was also a relationship between physical fitness and HDL:apo AI ratio in males and females after adjustment for possible confounders (P < or = 0.05). We concluded that there were few relationships between lipid parameters and physical fitness after adjustment for possible confounders. The relationship between physical fitness and Lp(a) in females suggests a benefit associated with physical fitness and the relationship between physical fitness and HDL:apo AI ratio was in keeping with improved HDL cholesterol transport.

Adult↗
PubMed1998

Physical activity and health-related fitness in youth: a multivariate analysis.

PURPOSE: To evaluate the relationship between indicators of physical activity and health-related fitness in youth 9-18 yr. METHODS: A cross-sectional sample of 356 boys and 284 girls 9-18 yr of age from phase I of the Quebec Family Study was studied. The sample was divided into three age groups by gender, 9-12, 13-15, and 16-18 yr of age. Physical activity variables included two estimates of activity, estimated daily energy expenditure (EE) and estimated moderate-to-vigorous physical activity (MVPA), and one estimate of inactivity, time spent watching television per day (TVTIME). Health-related fitness variables were the sum of six skin folds (SUM), number of sit-ups in 1 min (SITUP), physical work capacity at 150 beats x min(-1) (PWC150), and static strength of the leg (LMS). Partial canonical correlation was used to quantify the relationship between standardized (z-transformed) activity variables and health-related fitness items, controlling for age. RESULTS: There is a weak to moderate association between physical activity and fitness in youth. The first activity canonical variate is a function of positive loadings for EE and MVPA, with a smaller, negative loading for TVTIME. The first fitness variate generally includes positive loadings for PWC150 and SITUP, with a small negative loading for the SUM and a small positive loading for LMS. The first canonical correlations indicate that the variance shared by the fitness and activity variates ranges from 11 to 21%. CONCLUSION: There is a significant relationship between activity and health-related physical fitness, but a large part of the variability (80-90%) in fitness is not accounted for by physical activity as measured in this study.

Adolescent↗
PubMed2002

Cardiorespiratory fitness and stroke mortality in men.

PURPOSE: We examined the association between cardiorespiratory fitness and stroke mortality in men. METHODS: This is a prospective cohort study. We followed 16,878 men, ages 40-87 yr, who had a complete medical evaluation including a maximal treadmill exercise test and self-reported health habits. There were 32 stroke deaths during an average of 10 yr of follow-up (167,961 man-yr). RESULTS: After adjustment for age and examination year, there was an inverse association between cardiorespiratory fitness and stroke mortality (P = 0.005 for trend). This association remained after further adjustment for cigarette smoking, alcohol intake, body mass index, hypertension, diabetes mellitus, and parental history of coronary heart disease (P = 0.02 for trend). High-fit men (most fit 40%) had 68% (95% CI: 0.12, 0.82) and moderate-fit men had 63% (95% CI: 0.17, 0.83) lower risk of stroke mortality when compared with low-fit men (least fit 20%), respectively. CONCLUSIONS: Moderate and high levels of cardiorespiratory fitness were associated with lower risk of stroke mortality in men in the Aerobics Center Longitudinal study population.

Adult↗