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PubMed1994

Population evaluations of health related fitness from perceptions of physical activity and fitness.

The possibility of predicting health related fitness using questions on occupational and leisure activity was explored in 172 men and 178 women. ANOVA and multiple regression equations related questionnaire responses to objective fitness measures including body mass index, circumferences, skinfolds, body fat, blood glucose, uric acid, total cholesterol, HDL-cholesterol and triglycerides, PWC150, blood pressures, and resting heart rate. Reported occupational activities bore little relationship to health related fitness. Self-perceptions of moderately frequent and moderately intense leisure activity, plus at least average perceived fitness relative to age-matched peers, were associated with a favorable body fat content and lipid profile, whereas indicators of cardiovascular health (a low resting heart rate and a high PWC150) were linked with perceptions of frequent and intense activity, plus a perceived fitness level higher than that of a peer reference group. Based on these findings, a simple scoring of reported activity for use in fitness counseling is suggested.

Adult↗
PubMed2000

Cardiorespiratory fitness and coronary heart disease risk factors: the LDS Hospital Fitness Institute cohort.

BACKGROUND: Cardiorespiratory fitness is favorably associated with most modifiable coronary heart disease (CHD) risk factors. Findings are limited, however, by few data for women, persons with existing CHD, and low-risk populations. In the present study, we described cross-sectional associations between cardiorespiratory fitness and CHD risk factors in a large cohort of middle-aged men and women, of whom the majority were LDS Church members (Mormons), with and without existing CHD. METHODS AND RESULTS: Comprehensive health examinations were performed on 3232 men (age 45.9+/-10.8 years) and 1128 women (age 43.8+/-12.8 years) between 1975 and 1997. Maximal treadmill exercise testing was used to categorize those with (12% of the men and 10% of the women) and those without CHD into age- and sex-specific cardiorespiratory fitness quintiles. After adjustments for age, body fat, smoking status, and family history of CHD, favorable associations were observed between fitness and most CHD risk factors among men and women, regardless of CHD status. CONCLUSIONS: These data indicate that enhanced levels of cardiorespiratory fitness may confer resistance to elevations in CHD risk factors even in a low-risk sample of middle-aged men and women. Furthermore, these findings reinforce current public health recommendations that advocate increased national levels of physical activity and cardiorespiratory fitness for primary and secondary CHD prevention.

Cohort Studies↗
PubMed1992

Effects of time of posttest after two durations of exercise on speed and accuracy of addition and subtraction by fit and less-fit women.

18 adult female volunteers, ages 27 to 49 years, were divided into two groups based on their cardiorespiratory fitness to investigate speed and accuracy of addition and subtraction immediately, 5 min., and 15 min. postexercise. A 2 (fitness level) x 3 (exercise duration) x 3 (postexercise performance trials) repeated-measures analysis of variance indicated that, for the fit group, speed of problem solving was significantly faster after both 20-min. and 40-min. exercise sessions across all performance trials; for the less-fit group, speed of addition/subtraction was significantly faster only after the 20-min. exercise session across performance trials. No significant postexercise difference in accuracy was found for either fit or less-fit groups.

Adult↗
PubMedDate not supplied

Relation of physical activity and cardiovascular fitness to coronary heart disease, Part II: Cardiovascular fitness and the safety and efficacy of physical activity prescription.

BACKGROUND: This paper is the second of two reports that together review the scientific evidence regarding the inverse relation between physical activity and cardiovascular fitness and coronary heart disease (CHD). METHODS: Using a MEDLINE search with the key words exercise, physical fitness, coronary heart disease, and cardiovascular disease, more than 75 articles were reviewed, evaluating study design, measurement error, bias and confounding, the strength of associations, consistency of results, temporal and dose-response relation, and biologic plausibility. RESULTS: The relative risk in epidemiologic studies comparing the least to the most fit categories ranges from 1.2 to 4.8, which is greater than that for physical inactivity. The differences between cardiovascular fitness (an attribute) and physical activity (a behavior) are highlighted. The range of correlation (r = 0.02 to 0.44) between cardiovascular fitness and physical activity is discussed relative to measurement error and genetic and environmental factors. Studies reporting the safety of regular physical activity suggest an injury rate as high as 35 injuries per 100 persons per year. Efficacy studies limited to secondary prevention trials report a 66 percent compliance rate and 15 percent reduction in total mortality. CONCLUSIONS: The scientific evidence implying a causal relation between cardiovascular fitness and CHD is strongly positive, but the clinical and public health implications are unclear. Further research and clinical guidelines are suggested.

Cardiovascular Diseases↗
PubMed1988

EZ-FIT: a practical curve-fitting microcomputer program for the analysis of enzyme kinetic data on IBM-PC compatible computers.

EZ-FIT, an interactive microcomputer software package, has been developed for the analysis of enzyme kinetic and equilibrium binding data. EZ-FIT was designed as a user-friendly menu-driven package that has the facility for data entry, editing, and filing. Data input permits the conversion of cpm, dpm, or optical density to molar per minute per milligram protein. Data can be fit to any of 14 model equations including Michaelis-Menten, Hill, isoenzyme, inhibition, dual substrate, agonist, antagonist, and modified integrated Michaelis-Menten. The program uses the Nelder-Mead simplex and Marquardt nonlinear regression algorithms sequentially. A report of the results includes the parameter estimates with standard errors, a Student t test to determine the accuracy of the parameter values, a Runs statistic test of the residuals, identification of outlying data, an Akaike information criterion test for goodness-of-fit, and, when the experimental variance is included, a chi 2 statistic test for goodness-of-fit. Several different graphs can be displayed: an X-Y, a Scatchard, an Eadie-Hofstee, a Lineweaver-Burk, a semilogarithmic, and a residual plot. A data analysis report and graphs are designed to evaluate the goodness-of-fit of the data to a particular model.

Enzymes↗
PubMedDate not supplied

School fitness tests as predictors of adult health-related fitness.

Relationships between adolescent physical fitness and adult health-related fitness were investigated. Forty-five subjects (20 males, 25 females) participated in physical fitness tests in 1976 and again in 2001. The adolescent physical fitness tests were distance running (2,000 m for boys or 1,500 m for girls), 50 m run, pull-ups (boys) or flexed arm hangs (girls), shuttle run, a 30-sec sit-up test, standing broad jump, hand grip-test, and sit-and-reach test. The adult health-related physical fitness index (APFI), stratified by sex, was formed by summing the z-scores of a bicycle ergometer test, sit-up test, hand-grip test, and sit-and-reach test. Height- and weight-adjusted correlations between adolescence and adulthood for exactly similar tests for men and women were, respectively, 0.74 (95% CI, 0.44-0.89) and 0.53 (95% CI, 0.17-0.76) in sit-and-reach tests, 0.41 (95% CI, -0.04 to 0.72) and 0.55 (95% CI, 0.20-0.78) in sit-up tests, and 0.53 (95% CI, 0.11-0.44) and 0.44 (95% CI, 0.05-0.71) in hand-grip tests. When all adolescent tests were put in regression analysis together with BMI in 2001, the significant explanatory factors for APFI were distance running ability and the sit-and-reach test for men and sit-up test, flexed arm hang, and BMI in 2001 for women.

Adolescent↗
PubMed2005

Bilateral fitting of BAHAs and BAHA fitted in unilateral deaf persons: acoustical aspects.

The benefit of a bone-anchored hearing aid (BAHA) to a patient fitted bilaterally; and the benefit of a BAHA to a unilaterally deaf person was estimated by four acoustical measurements: directional sensitivity of a BAHA placed at the skull, vibration transmission in the skull, gain, and estimated transcranial attenuation of bone conducted sound. Provided a patient has a similar bone conduction hearing ability at both cochlea, it was found that a patient should, theoretically, benefit from bilateral fitting of BAHAs in terms of better hearing thresholds from the front, and better overall hearing ability from the surround. The data indicates further, that bilateral fitting facilitates extraction of interaural cues, which should lead to greater ability to determine the direction of a sound source, as well as better hearing in noise. However, due to the cross-hearing of bone conducted sound, the binaural processing for the patient fitted bilaterally with BAHAs is less than for normal binaural air conduction hearing. Finally, the data showed that the benefit of fitting a BAHA in a unilaterally deaf person, depends on that person's transcranial attenuation.

Acoustic Stimulation↗
PubMed2001

The fitness training unit in U.S. Army basic combat training: physical fitness, training outcomes, and injuries.

This study involved a retrospective examination of physical fitness, training outcomes, and injury rates among personnel in the Fitness Training Unit (FTU). Personnel were assigned to the FTU based on low performance on push-ups, sit-ups, and/or a 1-mile run (N = 44 men, 95 women) and received an augmented physical fitness program before basic combat training (BCT). They were compared with 712 men and 379 women who took the same test but were not assigned to the FTU and went directly to BCT. FTU and non-FTU personnel trained in the same battalions. Army Physical Fitness Test scores and BCT outcomes (discharged or completed BCT in 8 weeks) were obtained from unit training records. Injuries during BCT were documented from a review of the medical records. On entry to BCT, FTU women had similar 2-mile run times compared with non-FTU women (21.6 vs. 21.5 minutes, respectively; p = 0.86); FTU men were considerably slower on the 2-mile run than non-FTU men (20.3 vs. 17.3 minutes; p < 0.01). FTU women and non-FTU women had similar graduation success (60% vs. 68%, respectively; p = 0.14) and time-loss injury rates (1.3 vs. 1.4 people injured/100 person-days, respectively; p = 0.90). FTU men were less likely to graduate than non-FTU men (55% vs. 82%; p < 0.01) and more likely to suffer a time-loss injury (1.2 vs. 0.7 people injured/100 person-days; p < 0.01). Efforts should be directed toward providing a sufficient training stimulus to improve the aerobic fitness level of men (as well as women) in the FTU.

Analysis of Variance↗
PubMed1988

Physical fitness and chronic low back pain. An analysis of the relationships among fitness, functional limitations, and depression.

The purpose of this study was to describe the associations between physical fitness and important aspects of chronic low back pain problems, specifically, pain, depression, physical dysfunction, and psychologic dysfunction. Ninety-six persons with chronic low back pain were evaluated with a battery of physical and psychologic disability measures and basic physical fitness tests for aerobic capacity, strength, and flexibility. Greater overall physical fitness was significantly correlated with less physical dysfunction (R = -0.48) and fewer depressive symptoms (multiple R = -0.42), but not with psychologic dysfunction (R = -0.20) or pain (R = -0.20). Fitness accounted for 23% of the variance in physical dysfunction and 17% of the variance in depression in this mildly dysfunctional chronic back pain patient sample. Strength, as compared with aerobic capacity or flexibility, was the fitness variable contributing most to these observed associations.

Activities of Daily Living↗
PubMed1986

Curve-fitting in pharmacokinetics--a comparison between gamma- and biexponential fits.

Seven sets of plasma concentration-time data were fitted to both a conventional biexponential equation and a gamma equation. The values of clearance (CL) and mean residence time (MRT) were calculated from the fitted parameters and compared with the values calculated by the trapezoid rule. Both the biexponential and gamma equations provided adequate fits to the data. The values of CL and MRT calculated from the biexponential fits correlated very closely with the values calculated by the trapezoid rule, but there were large discrepancies between the values calculated from the gamma fits and the trapezoid rule. The biexponential model appears to be less sensitive to scatter in the data.

Heart Failure↗
PubMed2002

Application of nonlinear fitting and selection of the most fitted equation by AIC in stability test of pharmaceutical ingredients.

We proposed a method for objectively selecting the most fitted rate equation among candidate rate equations based on chemical kinetics by both nonlinear regression analysis and Akaike's information criterion (AIC), to express the decrease of pharmaceutical ingredient as an appropriate equation. Pseudo-zero, first, and second-order rate equations were prepared as candidates beforehand, and AIC was introduced for selecting the most fitted rate equation among the candidates. We compared the proposed method to the Weibull method that expressed any decrease patterns as a single equation. We quantified the contents of thiamine nitrate (VB1) and taurine after storage for one, three, and six months under 40 degrees C-75% relative humidity by high-pressure liquid chromatography. Decrease patterns of each sample were most fitted to one of the candidate rate equations, that is, pseudo-zero, first, and second-order rate equations, respectively, and the degree of fit in the most fitted equation was superior to that of the Weibull method, except for the pseudo-first-order rate equation. Moreover, we confirmed that the proposed method was considerably precise for estimating the stability of pharmaceuticals by comparing estimated residual rates and confidence intervals to experimental data.

Algorithms↗
PubMed2004

The bystander effect model of Brenner and Sachs fitted to lung cancer data in 11 cohorts of underground miners, and equivalence of fit of a linear relative risk model with adjustment for attained age and age at exposure.

Bystander effects following exposure to alpha-particles have been observed in many experimental systems, and imply that linearly extrapolating low dose risks from high dose data might materially underestimate risk. Brenner and Sachs (2002 Int. J. Radiat. Biol. 78 593-604; 2003 Health Phys. 85 103-8) have recently proposed a model of the bystander effect which they use to explain the inverse dose rate effect observed for lung cancer in underground miners exposed to radon daughters. In this paper we fit the model of the bystander effect proposed by Brenner and Sachs to 11 cohorts of underground miners, taking account of the covariance structure of the data and the period of latency between the development of the first pre-malignant cell and clinically overt cancer. We also fitted a simple linear relative risk model, with adjustment for age at exposure and attained age. The methods that we use for fitting both models are different from those used by Brenner and Sachs, in particular taking account of the covariance structure, which they did not, and omitting certain unjustifiable adjustments to the miner data. The fit of the original model of Brenner and Sachs (with 0 y period of latency) is generally poor, although it is much improved by assuming a 5 or 6 y period of latency from the first appearance of a pre-malignant cell to cancer. The fit of this latter model is equivalent to that of a linear relative risk model with adjustment for age at exposure and attained age. In particular, both models are capable of describing the observed inverse dose rate effect in this data set.

Air Pollutants, Radioactive↗
PubMed1977

Fitness effects of EMS-induced mutations on the X chromosome of Drosophila melanogaster. I. Viability effects and heterozygous fitness effects.

Drosophila melanogaster X chromosomes were mutagenized by feeding males sucrose solutions containing ethyl methanesulfonate (EMS); the concentrations of EMS in the food were 2.5 mM, 5.0 mM, and 10.0 mM. Chromosomes were exposed to the mutagen up to three times by treating males in succeeding generations. After treatment, the effective exposures were 2.5, 5.0, 7.5, 10.0, 15.0, and 30.0 mM EMS. X chromosomes treated in this manner were tested for effects on fitness in both hemizygous and heterozygous conditions, and for effects on viability in hemizygous and homozygous conditions. In addition, untreated X chromosomes were available for study. The viability and heterozygous fitness effects are presented in this paper, and the hemizygous fitness effects are discussed in the accompanying one (MITCHELL and SIMMONS 1977). Hemizygous and homozygous viability effects were measured by segregation tests in vial cultures. For hemizygous males, viability was reduced 0.5 percent per mM EMS treatment; for homozygous females, it was reduced 0.7% per mM treatment. The decline in viability appeared to be a linear function of EMS dose. The viabilities of males and females were strongly correlated. Heterozygous fitness effects were measured by monitoring changes in the frequencies of treated and untreated X chromosomes in discrete generation populations which, through the use of an X-Y translocation, maintained them only in heterozygous condition. Flies that were heterozygous for a treated chromosome were found to be 0.4% less fit per mM EMS than flies heterozygous for an untreated one.

Animals↗
PubMed1977

Fitness effects of EMS-induced mutations on the X chromosome of Drosophila melanogaster. II. Hemizygous fitness effects.

X chromosomes mutagenized with EMS were tested for their effects on the fitness of hemizygous carriers. The tests were carried out in populations in which treated and untreated X chromosomes segregated from matings between males and attached-X females; the populations were maintained for several generations, during which time changes in the frequencies of the treated and untreated chromosomes were observed. From the rates at which the frequencies changed, the fitness effects of the treated chromosomes were determined. It was found that flies hemizygous for a mutagenized chromosome were 1.7% less fit per mM EMS treatment than those hemizygous for an untreated chromosome. Since the same flies were only 0.5% per mM less viable than their untreated counterparts, the total fitness effect of an X chromosome carrying EMS-induced mutants is three to four times greater than its viability effect. By comparing the heterozygous effect of a mutagenized X chromosome on fitness with the corresponding hemizygous effect, the dominance value for the chromosome is estimated to be about 0.25.

Animals↗
PubMed2006

Automated ligand fitting by core-fragment fitting and extension into density.

A procedure for fitting of ligands to electron-density maps by first fitting a core fragment of the ligand to density and then extending the remainder of the ligand into density is presented. The approach was tested by fitting 9327 ligands over a wide range of resolutions (most are in the range 0.8-4.8 A) from the Protein Data Bank (PDB) into (Fo - Fc)exp(i phi(c)) difference density calculated using entries from the PDB without these ligands. The procedure was able to place 58% of these 9327 ligands within 2 A (r.m.s.d.) of the coordinates of the atoms in the original PDB entry for that ligand. The success of the fitting procedure was relatively insensitive to the size of the ligand in the range 10-100 non-H atoms and was only moderately sensitive to resolution, with the percentage of ligands placed near the coordinates of the original PDB entry for fits in the range 58-73% over all resolution ranges tested.

Algorithms↗
PubMed1994

The effect of pre-fitting counselling on the outcome of hearing aid fittings.

The effect of pre-fitting counselling on the outcome of fittings of NHS behind-the-ear hearing aids to adult first-time users was investigated. Questionnaires and diaries were sent both before and after fitting to 48 subjects who were given pre-fitting counselling and 47 control subjects, all of whom were fitted with standard NHS hearing aids in Southampton or Bath between September 1989 and July 1991. The test and control groups had similar distributions of age, sex and hearing loss. Analysis of the data showed that the counselling had no significant effect on levels of satisfaction, aid usage or benefit; these outcome measures also showed no significant correlation with any of the personal characteristics or attitude factors which were studied.

Aged↗