Evaluation of the MyWellness Key accelerometer.

OBJECTIVE: to examine the concurrent validity of the Technogym MyWellness Key accelerometer against objective and subjective physical activity (PA) measures. DESIGN: randomised, cross-sectional design with two phases. The laboratory phase compared the MyWellness Key with the ActiGraph GT1M and the Yamax SW200 Digiwalker pedometer during graded treadmill walking, increasing speed each minute. The free-living phase compared the MyWellness Key with the ActiGraph, Digiwalker, Bouchard Activity cord (BAR) and Global Physical Activity Questionnaire (GPAQ) for seven continuous days. Data were analysed using Spearman rank-order correlation coefficients for all comparisons. SETTING: laboratory and free-living phases. PARTICIPANTS: sixteen participants randomly stratified from 41 eligible respondents by sex (n=8 men; n=8 women) and PA levels (n=4 low, n=8 middle and n=4 high active). RESULTS: there was a strong association between the MyWellness Key and the ActiGraph accelerometer during controlled graded treadmill walking (r=0.91, p<0.01) and in free-living settings (r=0.73-0.76 for light to vigorous PA, respectively, p<0.01). No associations were observed between the MyWellness Key and the BAR and GPAQ (p>0.05). CONCLUSIONS: the MyWellness Key has a high concurrent validity with the ActiGraph accelerometer to detect PA in both controlled laboratory and free-living settings.

How do I measure physical activity in my patients? Questionnaires and objective methods.

How do healthcare providers know if their patients are getting enough physical activity to promote good health and to reduce their risks of chronic diseases and injury? The first step is to identify the patient's current level of physical activity using questionnaires and/or motion sensors. Questionnaires assess activity levels by having patients answer a set of questions about the types and amounts of activity performed at some time in the past. Motion sensors assess physical activity by patients wearing a small monitoring device that records their body movement as it occurs. If a provider is interested in determining a patient's caloric energy expenditure, he/she can apply statistical regression models to the questionnaire and motion sensor data to estimate kilocalories. If more precise measures of energy expenditure are desired, a provider can use the isotopic doubly labelled water method to estimate kilocalories; however, this method is costly and is impractical in non-research clinical settings.

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.

Moderate-intensity physical activity and fasting insulin levels in women: the Cross-Cultural Activity Participation Study.

OBJECTIVE: The purpose of this study was to determine the association between moderate-intensity physical activity (PA) and fasting insulin levels among African-American (n = 47), Native American (n = 46), and Caucasian women (n = 49), aged 40-83 years, enrolled in the Cross-Cultural Activity Participation Study. Associations by race/ethnicity, levels of central obesity, and cardiorespiratory fitness were also examined. RESEARCH DESIGN AND METHODS: Physical activity scores were obtained from detailed PA records that included all PA performed during two consecutive 4-day periods scheduled 1 month apart. Using MET intensity (the associated metabolic rate for a specific activity divided by a standard resting metabolic rate), PA was expressed as MET-min (the product of the minutes for each activity times the MET intensity level) per day of energy expended in moderate (3-6 METs) and moderate/vigorous (> or = 3 METs) PA. Fasting insulin levels were determined by radioimmunoassay. Data were analyzed by multiple linear regression analysis. RESULTS: After adjusting for race/ethnicity, age, educational attainment, and site, an increase of 30 min of moderate-intensity PA was associated with a 6.6% lower fasting insulin level (P < 0.05). The association was similar among races/ethnicities, centrally lean and centrally obese women, and women with low and high cardiorespiratory fitness levels. CONCLUSIONS: These findings lend support to the 1995 Centers for Disease Control and Prevention and American College of Sports Medicine recommendations for an accumulation of 30 min/day in moderate-intensity PA. They also contribute to the growing literature suggesting that moderate amounts of PA have a significant role in reducing the burden of hyperinsulinemia and diabetes among ethnic populations at highest risk for these conditions.

Intra-individual variation and estimates of usual physical activity.

PURPOSE: The magnitude of intra-individual variation, as determined by three methods of physical activity (PA) assessment, was estimated to determine the optimal number of repeated measures needed to reliably measure an individual's usual PA habits. METHODS: Data were obtained from 77 healthy adults enrolled in the Survey of Activity, Fitness, and Exercise (SAFE). PA was measured by: 1) Caltrac accelerometers worn 48-hours every 26 days for one year; 2) concurrent 48-hour PA records (PARs); and 3) a corresponding series of four-week PA histories (FWH). Repeated measures regression analyses were used to analyze the data. RESULTS: PA tended to be slightly higher in the summer months as compared with the winter months, but this seasonality explained little of the intra-individual variation. The intra-individual standard deviation (SD) estimated for the FWH (180 MET-min(d(-1))) was 39% of the mean annual MET-min(d(-1)), as compared with the Caltrac (163 MET-mind(d(-1)) or 9%) and PAR (259 MET-min(d(-1)) or 11%). Given the intra-individual variation, three repeated observations of the FWH, six Caltrac, or nine PAR over the course of the year were needed to achieve 80% reliability in estimation of mean annual PA. CONCLUSIONS: Intra-individual variation in PA is substantial and must be accounted for in estimates of usual PA.

Validation of the Stanford 7-day recall to assess habitual physical activity.

PURPOSE: The ability of the Stanford 7-Day Recall (7-DR), a well known instrument for surveying work and leisure-time physical activity (PA) in epidemiologic studies, to assess levels of habitual PA in men and women was evaluated. METHODS: The 7-DR was administered twice, one month apart. Its accuracy was studied in 77 men and women, aged 20-59 years, by its repeatability and comparison of both administrations of the 7-DR with: fourteen 48-hour physical activity records; fourteen 48-hour Caltrac accelerometer readings; peak oxygen uptake (VO(2) peak) determinations; and percent body fat. These criteria measures were obtained over a year's duration. RESULTS: One month repeatability correlation coefficients for 7-DR total activity were r = 0.60 and r = 0.36 for men and women, respectively. Comparison of corresponding indices of activity between the 7-DR and the PA record indicated: 1) a closer relationship in men for total (r = 0.58 for visit 10 7-DR and 0.66 for visit 11 7-DR, p < or = 0.01), and very hard (r = 0.44 and 0.60, p< or = 0.05) activity then in women (r = 0.32 and 0.33, p < or = 0.05, and r = 0.21, ns and 0.43, p< or = 0.01, respectively); and 2) in general, lower and less consistent associations for hard, moderate, and light activity. Total PA by the 7-DR was significantly associated with Caltrac readings in men only. 7-DR results were more consistently related to VO(2) peak in men than women, but were significantly related to percent body fat in women only. CONCLUSIONS: The ability of the 7-DR to assess habitual PA was greater for more vigorous than for lower intensity PA.

Accuracy of the College Alumnus Physical Activity Questionnaire.

The validity and reproducibility of the Physical Activity Index from the College Alumnus Questionnaire (PAI-CAQ) were determined in 78 men and women (21-59 yr) with a broad range of physical activity habits. The PAI-CAQ was computed as the sum of energy expended in stair climbing, walking, and sports and recreational physical activity recalled from the past week. Data were validated against measures of cardiorespiratory fitness, body fatness, motion detection, and physical activity records. All physical activity was recorded by participants for six 48-hour periods. Each day of the week, including weekends, were represented at least twice in the physical activity records. Age-adjusted correlation coefficients between like activities on the College Alumnus Questionnaire and physical activity records ranged from 0.25 to 0.65 in men and 0.28 to 0.86 in women. Correlations between the PAI-CAQ and validation criteria that reflected total and heavy-intensity physical activities were higher (r = 0.34-0.69, p < 0.05) than for lighter-intensity physical activities and motion detection expressed in MET-min.d-1 and kcal.d-1 (r < 0.35, p > 0.05). Test-retest reproducibility was higher over 1 month (r = 0.72) than over 8 and 9 months (r = 0.34 and 0.43) (p < 0.05). Energy expended in walking and stair climbing was underestimated on the College Alumnus Questionnaire, resulting in lower PAI-CAQ scores, as compared to the physical activity records.

Accuracy of recall of occupational physical activity by questionnaire.

The validity of the Tecumseh Occupational Activity Questionnaire (TOQ) and a modified Seven Day Recall (SDR) was measured in 46 healthy women, ages 20-60 years (mean +/- SD, 39.4 +/- 11.8). Occupational data were compared with direct (7-day occupational activity records and Caltrac accelerometer) and indirect (maximal oxygen uptake and percent body fat) measures of physical activity status. Physical activity survey and occupational record data were log transformed to normalize skewed distributions. Intraclass correlations ranged from r = 0.26 to 0.73 (P < 0.05) between similar activities on the TOQ and activity records for light intensity sitting, light-to-moderate intensity standing, and walking. Correlations between similar activities from the SDR and activity records ranged from r = 0.32 to 0.35 (P < 0.05) for light and moderate intensity activities. Correlations for total occupational activity between the surveys and activity records were r = 0.46 (P < 0.001) for the TOQ and r = 0.45 (P < 0.01) for the SDR. A modest correlation (r = 0.34, P < 0.10) was observed between the Caltrac scores and TOQ moderate intensity standing. Only the TOQ light-to-moderate intensity standing was related to maximal oxygen uptake (r = 0.32, P < 0.05). None of the measures were related to percent body fat (P > 0.05). These results suggest that the TOQ and SDR both provide reasonably accurate measurements of light and moderate intensity occupational physical activity.

Comprehensive evaluation of the Minnesota Leisure Time Physical Activity Questionnaire.

The accuracy of the Minnesota Leisure Time Physical Activity (LTPA) Questionnaire (a 1-year survey of non-occupational activity used in MRFIT) was studied in 78 men and women, age 20-59 years, by comparing survey results to the following measures obtained over a year's duration: six 48-hour physical activity records; fourteen 48-hour Caltrac accelerometer readings (Caltrac); 14 administrations of a 4-week version of the LTPA Questionnaire (FWH); 3 VO2peak determinations and percent body fat (% BF). The LTPA Questionnaire demonstrated: weak to moderate associations with % BF (r = -0.24) and with VO2peak (r = 0.47); a weak association with Caltrac readings expressed as MET.minutes.day-1 (r = 0.23); strong associations with corresponding activities reported on the FWH; and moderate associations with total and heavy activities reported in the physical activity record, but no associations with moderate and light activities. Furthermore, several types of LTPA were found to be either under-represented or not currently included in the Minnesota LTPA Questionnaire. It is concluded that although validation results were found to be quite good, several possible refinements were identified, which should improve the accuracy of the Minnesota LTPA Questionnaire in assessing habitual physical activity.

Physical activity and self-reported, physician-diagnosed osteoarthritis: is physical activity a risk factor?

This prospective study evaluated regular physical activity and self-reported physician-diagnosed osteoarthritis of the knee and/or hip joints among 16,961 people, ages 20-87, examined at the Cooper Clinic between 1970 and 1995. Among those aged 50 years and older, osteoarthritis incidence was higher among women (7.0 per 1000 person-years) than among men (4.9 per 1000 person-years, P = 0.001), while among those under 50 years of age, osteoarthritis incidence was similar between men (2.6) and women (2.7). High levels of physical activity (running 20 or more miles per week) were associated with osteoarthritis among men under age 50 after controlling for body mass index, smoking, and use of alcohol or caffeine (hazard ratio = 2.4, 95% CI: 1.5, 3.9), while no relationship was suggested among women or older men. These findings support the conclusion that high levels of physical activity may be a risk factor for symptomatic osteoarthritis among men under age 50.

Ability of the Atherosclerosis Risk in Communities (ARIC)/Baecke Questionnaire to assess leisure-time physical activity.

BACKGROUND: The Atherosclerosis Risk in Communities (ARIC)/Baecke Questionnaire is a general survey of both occupational and leisure (sport and exercise related and non-sport and exercise related) physical activity. METHODS: Its ability to assess leisure physical activity was studied in 78 men and women, age 20-59 years, by comparison to: six 48-hour physical activity records; 14 48-hour Caltrac accelerometer readings (Caltrac); three peak oxygen consumption (VO2 peak) determinations; and per cent body fat. These criteria measures were obtained over a year's duration. RESULTS: The following associations were evident in men and women respectively, between sport and exercise physical activity and: physical activity record heavy intensity activity (r = 0.73 and r = 0.63); VO2 peak (r = 0.67 and r = 0.45); and per cent body fat (r = -0.37, P = 0.08 and r = -0.44). Less concordance was evident (r = 0.39 for men and r = 0.23, NS, for women) between non-sport and exercise physical activity and physical activity record light intensity activity. Questionnaire and physical activity record indices of total leisure activity tended to be more closely related in men (r = 0.59) than women (r = 0.33). For both men and women, survey results were not closely associated with Caltrac readings. CONCLUSIONS: Although there are weaknesses, questionnaire strengths consistent for both men and women include: ease of administration, high reliability, and accurate assessment of heavy intensity activity as well as light intensity activities such as walking and bicycling.

Environmental influences, physical activity, and weight status in 8- to 16-year-olds.

OBJECTIVE: To assess the association between vigorous physical activity, participation on sport teams and in exercise programs, television watching, family environment, and weight status in youth. DESIGN: Cross-sectional data from the Third National Health and Nutrition Examination Survey. PARTICIPANTS: A group of 2791 youth between the ages of 8 and 16 years who were enrolled in the Third National Health and Nutrition Examination Survey. MAIN OUTCOME MEASURES: Overweight was defined using age- and sex-specific 85th percentile of body mass index using Center for Disease Control and Prevention growth charts. RESULTS: Both males and females who had an overweight mother and or father were more likely to be overweight compared with youth who did not have an overweight parent. Females who watched 4 or more hours of television were more likely to be overweight than those who watched less than 4 hours. Males and 14- to 16-year-old females who participated in sport team and exercise programs were less likely to be overweight than their counterparts who did not participate. Also, females with larger families and males from families with higher family incomes were less likely to be overweight. CONCLUSIONS: These results suggest that family environment is associated with overweight in youth and that sport and exercise program participants are less like to be overweight and that, for females, increased television watching is related to overweight.

Race/ethnicity, social class and their relation to physical inactivity during leisure time: results from the Third National Health and Nutrition Examination Survey, 1988-1994.

BACKGROUND: Physical inactivity is more prevalent among racial and ethnic minorities than among Caucasians. It is not known if differences in participation in leisure time physical activity are due to differences in social class. Thus, this paper provides estimates of the prevalence of physical inactivity during leisure time and its relationship to race/ethnicity and social class. METHODS: This was a national representative cross-sectional survey with an in-person interview and medical examination. Between 1988 and 1994, 18,885 adults aged 20 or older responded to the household adult and family questionnaires as part of the Third National Health and Nutrition Examination Survey . Mexican-Americans and African-Americans were over-sampled to produce reliable estimates for these groups. Multiple assessment of social class included education, family income, occupation, poverty status, employment status, and marital status. RESULTS: The age-adjusted prevalence (per 100) of adults reporting leisure time inactivity is lower among Caucasians (18%) than among African-Americans (35%) and Mexican-Americans (40%). African-American and Mexican-American men and women reported higher prevalence of leisure time inactivity than their Caucasian counterparts across almost every variable, including education, family income, occupation, employment, poverty and marital status. CONCLUSIONS: Current indicators of social class do not seem to explain the higher prevalence of physical inactivity during leisure time among African-American and Mexican-American. More research is needed to examine the effect of other constructs of social class such as acculturation, safety, social support and environmental barriers in promoting successful interventions to increase physical activity in these populations.

Active commuting to school: an overlooked source of childrens' physical activity?

The assessment and promotion of childrens' healthful physical activity is important: (i) to combat the international obesity epidemic that extends to childhood; and (ii) to establish an early habit of lifestyle physical activity that can be sustained into adolescence and adulthood. The primary focus of both assessment and promotion efforts has been on in-school physical education classes and, to a lesser extent, out-of-school structured exercise, sport and play. A potential source of continuous moderate activity, active commuting to school by means of walking or by bicycle, has been largely ignored in surveys of physical activity. Suggestive evidence of steep declines in the amount of childrens' destination walking can be gleaned from national transportation surveys. At the same time, there has been a dramatic increase in the reported use of motorised vehicles, including the use for chauffeuring children. There is very little evidence to support or refute active commuting to school as an important source of childrens' physical activity; however, this is largely because it has been overlooked in the stampede to assess time in more vigorous activities. The promotion of active commuting to school must be considered in the context of parents' real and perceived concerns for their children's personal and pedestrian safety. We certainly do not have a full understanding at this time of all the factors related to decisions about transportation mode, whether by child, parent, community, or school. Such information is necessary if successful and sustainable interventions can be implemented, important transport policy decisions can be made, and community and school designs can be modified. Practice rarely waits for research, however, and there are numerous examples of innovative programming, policies and environmental designs occurring internationally that can serve as natural experiments for enterprising researchers willing to push the envelope of our understanding of active commuting and childrens' physical activity. Since we know so little, there is much to learn.

The recall of physical activity: using a cognitive model of the question-answering process.

Issues related to the validity and reliability of self-reports of physical activity are an important consideration in assessing the relation between physical activity and various health outcomes that are of interest to epidemiologists. This paper examines the case for incorporating survey methods procedures into the development, refinement, and administration of instruments designed to obtain self-report information on physical activity. In doing so, we present a method of question analysis that enables researchers to identify potential cognitive difficulties with a question and then identify possible methods for improving data quality that have successfully improved the validity of survey instruments in other areas. In doing this, we review portions of the literature in cognitive psychology devoted to autobiographical memory and discuss methods that have emerged from this research that enhance the overall validity and reliability of the data obtained in a variety of health-related areas. We also illustrate ways in which these methods can be incorporated into existing physical activity surveys.

Quantifying energy expenditure and physical activity in the context of dose response.

PURPOSE: Methods for assessing physical activity (PA) and energy expenditure (EE) were reviewed to identify potential limitations to evaluating and interpreting dose-response relationships between PA and health-related outcomes and to suggest future research directions in this area. METHODS: Literature describing PA and EE assessment methodology was reviewed according to the reported validity, reliability, and feasibility of the measurement in epidemiologic studies. A summary of this review is presented for techniques applicable to studying PA or EE among free-living individuals. RESULTS: Several methods with varying degrees of precision and feasibility have been used to assess PA and EE in free-living populations. Lack of a gold standard field measure of PA may explain some of the variability in precision among these methods. The most accurate field measure of EE appears to be doubly labeled water; however, this approach has limited feasibility in terms of cost and use in studies of total EE only. Electronic motion sensors and physiologic measures related with EE are limited in their ability to discriminate specific types of PA and by inconvenient measurement procedures. Self-reported PA records and surveys are low-cost, relatively unobtrusive methods of assessing PA and EE in field settings and vary in terms of their format, mode of administration, and degree of detailing habitual PA levels. Disparity in the metric used to quantify PA and EE exists within the current literature, which limits the interpretation and comparison of observed dose-response relationships. CONCLUSIONS: Efforts to develop equated methods of assessing PA and EE in free-living populations are needed before a systematic evaluation and interpretation of dose-response characteristics between PA and specific health-related parameters can be undertaken.

Evaluation of the kaiser physical activity survey in women.

PURPOSE: The Kaiser Physical Activity Survey (KPAS) was evaluated for test-retest reliability and comparison with direct and indirect measures of physical activity (PA) in 50 women (ages 20-60 yr) with a broad range of physical activity (PA) habits. METHODS: The KPAS, an adaptation of the Baecke usual physical activity survey, was designed specifically to assess activity in women. It provides four summary activity indexes: housework/caregiving, active living habits, sports, and occupation. Summary indexes were compared against direct (Caltrac accelerometer and PA records) and indirect (cardiorespiratory fitness (VO2 peak) and percent body fat) criterion measures of PA. Participants kept detailed PA records for two, 7-d periods, separated by 1 month. Caltrac accelerometers were worn concurrently with the PA records. RESULTS: Intraclass correlations for 1-month test-retest reliability were high for all KPAS indexes (r = 0.79 to 0.91, P < 0.01). Age-adjusted Spearman rho correlations between the KPAS sports/exercise and active living habits indexes were of moderate magnitude for VO2 peak (r = 0.34 to 0.76, P < 0.01) and percent body fat (r = -.30 to -0.59, P < 0.05). KPAS caregiving and occupation indexes were related to Caltrac kcal x d(-1) (r = 0.30 to 0.44, P < 0.05). Correlations between similar activities from the KPAS and PA records ranged from r = 0.03 to 0.64. Daily, habitual activities from the KPAS and PA records had the highest correlations (r > 0.28). Correlations among infrequent activities were lower (r < 0.05). CONCLUSION: The KPAS demonstrated good reliability and was reasonably accurate in detecting regular housework/caregiving, occupation, sports/exercise, and active leisure activities among women with a broad range of physical activity habits.

Validity and reliability of self-reported physical activity status: the Lipid Research Clinics questionnaire.

We assessed the validity and reliability of the Lipid Research Clinics (LRC) physical activity (PA) questionnaire against measures of PA and physical fitness, and compared a new scoring system (four-point) with the method used in the LRC studies (two-point) in 28 men and 50 women. The two-point method classified participants as inactive or active based one question about regular, strenuous exercise habits. The four-point method classified participants as very low, low, moderate, and high active based on two questions; regular, strenuous exercise and self-rating of PA relative to peers. After adjusting for age and gender, the four-point method explained 17-29% of the variation in VO2max, percent body fat, and heavy-and light-intensity kcal.d-1 measured by the 4 wk history questionnaire (FWH). No association was found between the LRC ratings and Caltrac kcal and activity units and FWH total, moderate-intensity, and household PA kcal.d-1. Test-retest reliability was high (two-point, r = 0.85; four-point, r = 0.88). The LRC PA questionnaire is a relatively valid and reliable indicator of heavy PA in adults. The four-point method increases the ability to show graded associations between measures of cardiorespiratory fitness, body fatness, and leisure time PA.

Measurement of daily walking distance-questionnaire versus pedometer.

PURPOSE: This study compared measurements of daily walking distance on the College Alumnus questionnaire (CAQ) and a pedometer. METHODS: A total of 96 men and women (25-70 yr of age) with a wide range of physical activity habits were studied. Physical activity index was computed from the College Alumnus questionnaire (PAI-CAQ) as the sum of the energy expended in stair climbing, walking, and sports and recreational physical activity. Data on walking distance were compared with values obtained from the Yamax electronic pedometer (DW-500B). Participants wore the pedometer for 7 consecutive days, except when sleeping, showering, or performing sports and recreational activities. RESULTS: Subjects underestimated their daily walking distance on the CAQ, compared with the pedometer (1.43 +/- 1.01 vs 4.17 +/- 1.61 km x d(-1)). The energy expended in walking was correspondingly lower on the CAQ, compared with the pedometer-derived values (555 +/- 405 versus 1608 +/- 640 kcal x wk(-1)). CONCLUSIONS: These findings suggest that electronic pedometers are useful for examining questions about walking distance on physical activity questionnaires.

A simultaneous evaluation of 10 commonly used physical activity questionnaires.

Ten commonly used physical activity questionnaires were evaluated for reliability and validity in 78 men and women aged 20-59, with varying physical activity habits. One month reliability was found to be high for all questionnaires except those pertaining only to the last week or month. Longer term test-retest reliability tended to be lower. Validity was studied in relation to treadmill exercise performance, vital capacity, body fatness, the average of 14 4-wk physical activity histories and the average of 14 2-d accelerometer readings. No questionnaire measure was correlated with the accelerometer reading, and correlations with vital capacity were generally low. Only the Minnesota Leisure Time Physical Activity Questionnaire household chores measure was correlated with habitual performance of household chores. Most questionnaires, even very simple ones, were related to performance of heavy intensity physical activity and treadmill performance; these same questionnaires tended to be related to percent body fat. Fewer questionnaires related to performance of light or moderate activity. Occupational activity was unrelated to any of the validation measures. It is concluded that there are multiple, nonoverlapping dimensions of physical activity, reflected in multiple nonoverlapping validation realms. More important than the length or attention to detail of a questionnaire seems to be the logic of its questions. Important areas of physical activity that should be addressed in future questionnaires include sleep, light, moderate and heavy intensity leisure activities, household chores, and occupational activity. Recent versus habitual activity should also be considered.