Assessment of physical activity in older individuals: a doubly labeled water study

Calcium-fortified beverage supplementation on body composition in postmenopausal women

BACKGROUND

We investigated the effects of a calcium-fortified beverage supplemented over 12 months on body composition in postmenopausal women (n = 37, age = 48-75 y).

METHODS

Body composition (total-body percent fat, %FatTB; abdominal percent fat, %FatAB) was measured with dual energy x-ray absorptiometry. After baseline assessments, subjects were randomly assigned to a free-living control group (CTL) or the supplement group (1,125 mg Ca++/d, CAL). Dietary intake was assessed with 3-day diet records taken at baseline and 12 months (POST). Physical activity was measured using the Yale Physical Activity Survey.

RESULTS

At 12 months, the dietary calcium to protein ratio in the CAL group (32.3 +/- 15.6 mg/g) was greater than the CTL group (15.2 +/- 7.5 mg/g). There were no differences from baseline to POST between groups for changes in body weight (CAL = 0.1 +/- 3.0 kg; CTL = 0.0 +/- 2.9 kg), %FatTB (CAL = 0.0 +/- 2.4%; CTL = 0.5 +/- 5.4%), %FatAB (CAL = -0.4 +/- 8.7%; CTL = 0.6 +/- 8.7%), or fat mass (CAL = 1.3 +/- 2.6 kg; CTL = 1.3 +/- 2.7 kg).

CONCLUSION

These results indicate that increasing the calcium to protein ratio over two-fold by consuming a calcium-fortified beverage for 12 months did not decrease body weight, body fat, or abdominal fat composition in postmenopausal women.

HRT provides no additional beneficial effect on sarcopenia in physically active postmenopausal women: a cross-sectional, observational study

OBJECTIVES

Physical activity can prevent or retard the loss of muscle mass associated with aging. On the other hand, it has been suggested that HRT may also help prevent sarcopenia in postmenopausal women. We thus examined if HRT provides additional beneficial effect in physically active postmenopausal women.

METHODS

Forty postmenopausal women aged between 55 and 65 years old (normal weight, healthy and no medication) were recruited. Seventeen women were already taking HRT for at least one year whereas 23 were never submitted to HRT. Body composition was measured by DXA and physical activity metabolism was obtained by the use of accelerometry. Subjects were divided in tertile groups based on their daily physical activity energy expenditure (PAEE).

RESULTS

Physical activity groups were similar for age, HRT users distribution, BMI, trunk fat-free mass (FFM), and all fat mass (FM) components. The group of women who were the most physically active significantly displayed greater total FFM, appendicular FFM, and muscle mass index (MMI) compared to the group of less active women (P < 0.05) whereas HRT added no additional effect on any FFM components.

CONCLUSIONS

Our results suggest that in active postmenopausal women, HRT does not provide any additional beneficial effect on body composition.

Physical activity and its determinants in severe chronic obstructive pulmonary disease

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) have a limited exercise capacity. Surprisingly, little is known about their levels of physical activity practice. We assessed the levels and determinants of physical activity practice in severe COPD patients.

METHODS

A cross-sectional systematic sample of 346 COPD patients was recruited during 1 yr in four tertiary hospitals of the Barcelona area of Spain. Patients answered a questionnaire, which included physical activity assessment, and performed spirometric tests and blood gases.

RESULTS

Seventy-eight percent of patients walked daily whereas 17% did not practice any physical activity. Median energy expenditure in physical activity was 109 kcal x d(-1) (IQR 24-239). The following factors were independently associated with a lower physical activity level in a logistic regression analysis: female sex (OR 2.92, 95% CI 1.11-7.70), older age (1.04, 1.01-1.07 per year), higher socioeconomic status (2.23, 1.24-4.02), diabetes (2.66, 1.40-5.06), lower physical and mental quality of life (0.93, 0.90-0.96 and 0.96, 0.93-0.98, respectively, per unit), and long-term oxygen therapy (2.07, 1.19-3.60). Neither FEV1, previous COPD admissions, body mass index, nor other treatments were related to physical activity practice.

CONCLUSIONS

In conclusion, one third of severe COPD patients in our study reported a level of physical activity lower than the equivalent to walking less than 15 min x d(-1). Apart from sociodemographic variables, comorbidity, health-related quality of life, and long-term oxygen therapy were the only factors independently associated with a low level of physical activity.

A questionnaire-based assessment of daily physical activity in heart failure

Type and dose of daily energy expenditure (DEE) play a major role in modulations of health status and an increased knowledge of these dimensions of physical activity in congestive heart failure (CHF) patients would be valuable for clinical and epidemiological aims. We propose a new self-administered DEE questionnaire adapted to CHF patients and tested its validity. One hundred and five stable CHF participants, NYHA class I-IV, LVEF=33.2+/-6.1% performed an incremental symptom-limited Vo(2) (peak) test and filled in the questionnaire for DEE calculation. Reproducibility (n=24), sensitivity (n=21) of the questionnaire and inter-observer variability (n=105) were tested. Intensity levels were identified from DEE and their relationships to Vo(2)(peak), ventilatory and anthropometric characteristics were assessed by simple and multiple regression models. Reproducibility and sensitivity were high (r=0.98 and 0.88, respectively, P<0.0001) and inter-observer error reached 1.37%. DEE was highly correlated to physical activity energy expenditure (r=0.96, P<0.0001). Relationships between DEE, Vo(2)(peak), V(E)/Vo(2) and anthropometric characteristics were significant. An activity level above 3 MET was the best intensity criteria related to Vo(2)(peak) (r=0.62, P<0.0001) and DEE (r=0.80, P<0.0001). The questionnaire seems reproducible, sensible and valid for DEE estimation. Vo(2)(peak) appears related to DEE and especially to activities above 3 MET in CHF.

Validity of a multi-sensor armband in estimating rest and exercise energy expenditure

The SenseWear Armband (SWA; BodyMedia, Inc.), using multiple sensors, was designed to estimate energy expenditure (EE) in free-living individuals.

PURPOSE

To examine the reliability and validity of the SWA during rest and exercise compared with indirect calorimetry (IC).

METHODS

EE was assessed with SWA and IC in 13 males during two resting and one cycle ergometry (40 min at 60% VO2peak) sessions. In a second experiment, 20 adults walked on a treadmill for 30 min at three intensities (80.5 m x min, 0% grade; 107.3 m x min, 0% grade; 107.3 m x min, 5% grade) while IC and SWA measured EE.

RESULTS

At rest, no significant differences were found between EE measurements from the SWA (1.3 +/- 0.1 kcal x min) and IC (1.3 +/- 0.1 kcal x min), and the two methods were highly correlated (r = 0.76; P < 0.004). The SWA EE estimation was reliable when comparing the two resting visits (r = 0.93; P < 0.001). For the ergometer protocol, no significant differences were found between the SWA and IC measurements of EE early, mid, or late in exercise or for the total bout, although the measurements were poorly correlated (r = 0.03-0.12). The SWA EE estimate of walking increased with treadmill speed but not with incline. The SWA significantly overestimated (13-27%) the EE of walking with no grade (P < 0.02) and significantly underestimated (22%) EE on the 5% grade (P < 0.002). The SWA estimation of EE correlated moderately with IC (r = 0.47-0.69).

CONCLUSION

The SWA provided valid and reliable estimates of EE at rest and generated similar mean estimates of EE as IC on the ergometer; however, individual error was large. The SWA overestimated the EE of flat walking and underestimated inclined walking EE.

The Yale Physical Activity Survey for older adults: Predictions in the energy expenditure due to physical activity

OBJECTIVE

To evaluate the accuracy of the Yale Physical Activity Survey (YPAS) for older adults.

DESIGN

Fourteen-week strictly controlled diet study.

SUBJECTS/SETTING

Eleven men and 17 women, age range 55 to 78 years, spent 10 weeks in an outpatient setting and 4 weeks in an inpatient setting at the General Clinical Research Center, Noll Physiological Research Center, The Pennsylvania State University, University Park.

INTERVENTION

Subjects were provided dietary energy to maintain body weight within +/-0.5 kg of baseline weight. The daily menus contained 0.8 g protein per kilogram body weight and nonprotein energy as 60% carbohydrate and 40% fat.

MAIN OUTCOME MEASURES

Metabolizable energy intake (MEI) was measured at week 14 from the gross energy contents of food, urine, and feces, with corrections for any body composition changes during the last 6 weeks of weight maintenance. Resting energy expenditure (REE) was determined using indirect calorimetry. The thermic effect of feeding (TEF) was estimated to be 10% of the MEI. The energy expenditure due to physical activity (EEPA) was derived by the formula: EEPA=MEI-REE-TEF. This value was compared with the EEPA estimated from the YPAS. Statistical analyses performed Two-factor analysis of variance with repeated measures and paired t tests.

RESULTS

At week 14, after a minimum of 6 weeks of sustained weight stability, the derived EEPA was not different from that estimated using the YPAS for the men and the men and women combined, while the YPAS estimate was more than the measured mean value for the women (P<.05). There was wide variability in the accuracy of the EEPA prediction for individual subjects (range=-637 to 794 kcal).

APPLICATIONS/CONCLUSIONS

The YPAS may be used, with caution, to estimate the EEPA for groups of older individuals, and may provide inaccurate estimates of the EEPA in older individuals.

DAQIHF: Methodology and Validation of a Daily Activity Questionnaire in Heart Failure

PURPOSE

To assess the validity, reliability, and sensitivity of a new self-administered physical activity questionnaire estimating daily energy expenditure (DEE) in patients with congestive heart failure (CHF). There is a need to develop a low cost, practical, and accurate tool increasing the knowledge of the type and dose of physical activity in patients with CHF for clinical and epidemiological aims.

METHODS

One hundred five participants with stable CHF performed an incremental symptom-limited VO2(peak) test and completed the questionnaire. For DEE calculation, time spent in each activity was multiplied by its energy cost corrected for weight, age, sex, autonomy, and the total was calculated over 24 h. Reproducibility and sensitivity of the questionnaire as well as interrater reliability were tested. Concurrent validity was assessed against VO2(peak), anthropometric characteristics and data from the literature.

RESULTS

Test-retest correlation coefficients used to measure reproducibility ranged from 0.82 for activities ranging from 3 to 5 METs to 0.98 for DEE and a paired Student's t-test didn't reach statistical significance for any activity score studied. Interrater reliability was high with an error in DEE estimation of 1.37% (t value = -1.064; P = NS). Sensitivity (changes in VO2(peak) concurrent to changes in DEE) was high (r = 0.88, P < 0.0001). DEE was in line with the literature in patients with CHF and relationships between DEE and VO2(peak) (r = 0.71, P < 0.0001), and DEE and anthropometric characteristics (<0.0001) were significant. Activity level above 3 METs was the best intensity criteria related to VO2(peak) (r = 0.62, P < 0.0001) and DEE (r = 0.80, P < 0.0001).

CONCLUSION

The questionnaire seems reliable, sensitive and valid for the estimation of DEE. VO2(peak) appears related to global DEE and more particularly to activities above 3 METs in patients with CHF.

Adoption of Canada's Physical Activity Guide and Handbook for Older Adults: Impact on Functional Fitness and Energy Expenditure

This study investigated whether a behaviour change program, based on Canada's Physical Activity Guide and Handbook to Healthy Active Living for Older Adults (Health Canada, 1999a), would elicit greater benefits than adoption of the guide and handbook alone. Fifteen older adults received the guide and accompanying handbook and completed the 8-week behaviour change program (mean age 73.2 ± 5.2 yrs), while 14 others received only the guide and handbook (mean age 76.8 ± 10.0 yrs). Functional fitness (lower body strength/endurance, flexibility, agility/dynamic balance) (Rikli and Jones, 1999), and estimated energy expenditure (DiPietro et al., 1993) were measured at baseline and after 8 weeks. Lower body strength/endurance and agility/dynamic balance differed between groups at baseline, p <  0.05. All three functional fitness tests improved in both groups over time, p <  0.05. Estimated energy expended in physical activity increased in both groups over time, p <  0.05; however, there was a significantly greater increase in the behaviour-change group (Group × Time interaction, p <  0.05). Participant response to using the guide and handbook was positive. These results indicate that introduction to Canada's Physical Activity Guide and Handbook to Healthy Active Living for Older Adults leads to benefits, whether or not accompanied by program supports. The group receiving the behaviour change program had a greater increase in energy expenditure, which suggests that such an intervention may ultimately lead to greater health benefits. Key words: behaviour change, chair stand test, community residing, lifestyle activity

Assessment of physical activity by telephone interview versus objective monitoring

PURPOSE

To compare different methods of quantifying time in physical activity (PA).

METHODS

Twenty-five participants (12 male, 13 female) volunteered to be monitored for seven consecutive days, during which different PA patterns were measured by the simultaneous heart-rate motion sensor technique (HR+M). At the end of the 7th day, participants completed questions taken from the 2001 Behavioral Risk Factor Surveillance System (BRFSS) PA module telephone survey, in which they recalled the amount of time spent walking, and in moderate and vigorous activities. The results of the BRFSS PA module were then compared with those of the HR+M.

RESULTS

No significant group differences were found in the amount of time spent in moderate and vigorous activities between methods. However, individual differences were greater for time spent in moderate activities (SE +/- 7.36 min x d(-1); range -70 to 77 min x d(-1)) than for time spent in vigorous activities (SE +/- 3.57 min x d(-1); range -39 to 33 min x d(-1). Spearman correlation coefficients between the HR+M and the BRFSS were significant for vigorous activities (r = 0.54, P < 0.01). There was 80% agreement between the two methods of classifying individuals who either: (a) met the recommendations (through moderate and/or vigorous PA) or (b) did not meet the recommendations.

CONCLUSION

The BRFSS and HR+M methods yielded similar group estimates of PA, but individual assessments of moderate activity differed more than those of vigorous activity. BRFSS estimations of group compliance with national PA recommendations were similar to those of the HR+M.

Minnesota leisure time activity questionnaire and doubly labeled water in adolescents

PURPOSES

To validate the energy expenditure estimated from The Minnesota Leisure Time Physical Activity Questionnaire (MLTPAQ) with total energy expenditure (TEE) measured by doubly labeled water (DLW), and to present and examine the validity of an extended version of the MLTPAQ with additional questions about inactivity during leisure time (eMLTPAQ), in a sample of Swedish 15-yr-old adolescents.

METHODS

Thirty-five 15-yr-old adolescents were interviewed using the eMLTPAQ. In addition to anthropometry, indirect calorimetry was measured to assess basal metabolic rate, and TEE was assessed by the DLW method over a 14-d period.

RESULTS

Energy expenditure calculated from MLTPAQ correlated well with TEEDLW (r=0.49, P<0.01), and the correlation increased when including questions about inactivity (r=0.73, P<0.01). However, eMLTPAQ underestimated TEE in 34 of the 35 students, with a mean difference between the methods of 2.8 MJ.d(-1) (95% limits of agreement: -0.1 to 5.6 MJ.d(-1)), which mainly was explained by a relative high intensity in the time which remained unreported.

CONCLUSION

eMLTPAQ is valid in ranking adolescents energy expenditure and in describing patterns of leisure time physical activities.

Comparison of the LASA Physical Activity Questionnaire with a 7-day diary and pedometer

OBJECTIVE

First, to validate the LASA Physical Activity Questionnaire (LAPAQ) by a 7-day diary and a pedometer in older persons. Second, to assess the repeatability of the LAPAQ. Third, to compare the feasibility of these methods.

STUDY DESIGN AND SETTING

The study was performed in a subsample (n=439, aged 69-92 years) of the Longitudinal Aging Study Amsterdam (LASA). The LAPAQ was completed twice (1998/1999, 1999/2000). Respondents completed a 7-day activity diary and wore a pedometer for 7 days (1999/2000).

RESULTS

The LAPAQ was highly correlated with the 7-day diary (r=0.68, P<.001), and moderately with the pedometer (r=0.56, P<.001). The repeatability of the LAPAQ was reasonably good (weighted kappa: 0.65-0.75). The LAPAQ was completed in 5.7+/-2.7 min, and 0.5% of the respondents had missing values.

CONCLUSION

The LAPAQ appears to be a valid and reliable instrument for classifying physical activity in older people. The LAPAQ was easier to use than the 7-day diary and pedometer.

Estimating human energy expenditure: a review of techniques with particular reference to doubly labelled water

This review includes an historical overview of the techniques for measuring energy expenditure (EE). Following this overview, the "gold standard" method of measuring EE, the doubly labelled water (DLW) method, is emphasised. Other methods, such as direct calorimetry, indirect calorimetry systems, heart rate and EE relationships, questionnaires and activity recall, motion sensors, combined heart rate and motion sensors for the estimation of EE are then highlighted in relation to their validation against the DLW method. The major advantages and disadvantages for each method are then considered. The preferred method to determine EE is likely to depend principally on factors such as the number of study participants to be monitored, the time period of measurements and the finances available. Small study participant numbers over a short period may be measured accurately by means of indirect calorimetric methods (stationary and portable systems). For periods over 3-4 days, EE should ideally be measured using the DLW method. However, the use of motion sensors is very promising in the measurement of EE, and has a number of advantages over the DLW method. Furthermore, if used correctly, both heart rate and questionnaire methods may provide valuable estimates of EE. Additional studies are needed to examine the possibility of improving the accuracy of measurement by combining two or more techniques. Such information, if confirmed by scientific rigour, may lead to an improvement in the estimation of EE and population-based physical activity levels. The accurate measurement of physical activity and EE is critical from both a research and health prospective. A consideration of the relevant techniques used for the estimation of EE may also help improve the quality of these frequently reported measurements.

Participant characteristics associated with errors in self-reported energy intake from the Women's Health Initiative food-frequency questionnaire

BACKGROUND

Errors in self-reported dietary intake threaten inferences from studies relying on instruments such as food-frequency questionnaires (FFQs), food records, and food recalls.

OBJECTIVE

The objective was to quantify the magnitude, direction, and predictors of errors associated with energy intakes estimated from the Women's Health Initiative FFQ.

DESIGN

Postmenopausal women (n = 102) provided data on sociodemographic and psychosocial characteristics that relate to errors in self-reported energy intake. Energy intake was objectively estimated as total energy expenditure, physical activity expenditure, and the thermic effect of food (10% addition to other components of total energy expenditure).

RESULTS

Participants underreported energy intake on the FFQ by 20.8%; this error trended upward with younger age (P = 0.07) and social desirability (P = 0.09) but was not associated with body mass index (P = 0.95). The correlation coefficient between reported energy intake and total energy expenditure was 0.24; correlations were higher among women with less education, higher body mass index, and greater fat-free mass, social desirability, and dissatisfaction with perceived body size (all P < 0.10).

CONCLUSIONS

Energy intake is generally underreported, and both the magnitude of the error and the association of the self-reporting with objectively estimated intake appear to vary by participant characteristics. Studies relying on self-reported intake should include objective measures of energy expenditure in a subset of participants to identify person-specific bias within the study population for the dietary self-reporting tool; these data should be used to calibrate the self-reported data as an integral aspect of diet and disease association studies.

Physical activity: measurement in mid-life women

OBJECTIVES

To review methods of assessing physical activity, and to compare two different questionnaires that were administered in the Melbourne Women's Midlife Health Project (MWMHP).

METHODS

Cross-sectional and subsequent longitudinal population-based study of Australian-born women who were aged 45-55 at baseline. Self-administered modified form of the Minnesota Leisure-Time Physical Activity questionnaire and interviewer-administered short physical activity question.

RESULTS

Two hundred and ninety-two women completed the Minnesota Leisure-Time Physical Activity questionnaire at both cross-sectional and 3rd year of follow-up (L3) and there was no difference in the total mean time spent exercising at both phases [5.9 (SD, 5.7) and 5.8 (SD, 5.0) hours per week, respectively]. The responses to the two questionnaires were significantly associated (beta = -0.89, SE 0.17, p < 0.0005). Using the Minnesota Leisure-Time Physical Activity questionnaire between the cross-sectional and L3 phases, 10% of the women increased the time they spent exercising by 5 h per week and 10% decreased it by the same amount. Using the short exercise question, 12% of women decreased their participation by two or more sessions per week and 14% increased their participation by this amount between the cross-sectional and L3 phases.

CONCLUSION

In this cohort of mid-life women the short exercise question was comparable in terms of measuring participation and change in physical activity with the more complex Minnesota Leisure-Time Physical Activity questionnaire.

Menopause, energy expenditure, and body composition

OBJECTIVES

The effects of menopause transition on metabolic and cardiovascular disease risk in women are unclear. It is unknown whether estrogen deficiency, aging, or a combination of both factors are independent contributors to a worsening health profile in women. We considered the effects of menopause transition and hormone replacement therapy on body composition, regional body fat, energy expenditure, and insulin sensitivity.

METHODS

A brief review of current literature that has considered the role of menopause transition and hormone replacement therapy on body composition, energy expenditure, and insulin sensitivity with an emphasis on longitudinal investigations.

RESULTS

Preliminary evidence suggests that natural menopause is associated with reduced energy expenditure during rest and physical activity, an accelerated loss of fat-free mass, and increased central adiposity and fasting insulin levels. Hormone replacement therapy has been shown to attenuate these changes. Longitudinal and longer intervention studies are needed to confirm these initial findings.

CONCLUSIONS

Menopause transition may represent a risky period in a woman's life, 'triggering' adverse metabolic and cardiovascular processes that predispose women to a greater incidence of obesity-related comorbidities. Dietary, exercise, and hormonal interventions specifically targeted at premenopausal women may help mitigate the worsening cardiovascular and metabolic risk profile associated with menopause.

Estimating energy expenditure from the Minnesota Leisure Time Physical Activity and Tecumseh Occupational Activity questionnaires - a doubly labeled water validation

An accurate, simple method for assessing energy expenditure in individuals and in free-living populations continues to be elusive. To compare estimates of energy expenditure (EE) from a combination of two previously validated physical activity questionnaires: Tecumseh Occupational (EE(TEC)) and a 4-wk history version of the Minnesota Leisure Time Physical Activity that included household activities (EE(MNLTPA)) and EE from sleep (EE(SLEEP)), to EE obtained from doubly labeled water (EE(DLW)). We studied free-living males (n = 24) eating a controlled diet designed to maintain body weight and determined EE from doubly labeled water (DLW) during 14 days and EE from physical activity instruments used in epidemiological studies (EE(TEC) and EE(MNLTPA)). There was excellent agreement between EE(DLW) (mean +/- SEM, 13.55 +/- 0.38 MJ/d) and EE(TEC) + EE(MNLTPA) + EE(SLEEP) (EE(TOTAL1)) (13.79 +/- 0.89 MJ/d) with a difference of only 1.0% +/- 5.4%. When the EE from watching TV, reading, and childcare activities was added the total EE (EE(TOTAL2)) (14.87 +/- 0.90 MJ/D) overestimated EE(DLW) by 8.9% +/- 5.4%. Both of these estimates of EE had significant regressions against EE(DLW) (EE(TEC) + EE(MNLTPA) + EE(SLEEP), R(2) = 0.38, P < 0.001; EE(TOTAL2), R(2) = 0.39, P < 0.001). Men whose occupations involved significant intermittent moderate activity had the largest disagreement between EE(DLW) and estimates from the questionnaires. This investigation demonstrates that a combination of previously validated physical activity questionnaires can be used to accurately determine the mean energy expenditure of a population of employed males.

Comparison of energy expenditure estimates from doubly labeled water, a physical activity questionnaire, and physical activity records

BACKGROUND

Various methods are used by epidemiologists to estimate the energy cost of physical activity; these include physical activity records and recalls. However, there is limited validation of these methods against the doubly labeled water technique for determining energy expenditure (EE).

OBJECTIVE

We compared EE as estimated by indirect methods (physical activity records and recall questionnaires) used in epidemiologic studies with EE obtained from doubly labeled water (EE(DLW)) in free-living men.

DESIGN

We determined EE(DLW), energy intake at weight maintenance, and EE from 7-d physical activity records (EE(Record)) and a 7-d physical activity recall questionnaire (EE(Recall)) in 24 men aged 41 plus minus 2.0 y ( plus minus SEM) with a body mass index (in kg/m(2)) of 25.1 plus minus 0.5.

RESULTS

There was excellent agreement between EE(DLW) (13.27 plus minus 0.35 MJ/d) and energy intake (13.19 plus minus 0.36 MJ/d), with a difference of 0.5 plus minus 1.0% ( plus minus SE). The indirect measures of physical activity and EE were 14.17 plus minus 0.37 MJ/d for EE(Record) (difference from EE(DLW): 7.9 plus minus 3.2%) and 17.40 plus minus 1.45 MJ/d for EE(Recall) (difference from EE(DLW): 30.6 plus minus 9.9%).

CONCLUSIONS

Seven-day physical activity records provide an acceptable estimate of EE in free-living adults compared with EE(DLW), but 7-d physical activity recalls have limited application to estimate daily EE. For optimal validity, the 7-d physical activity records require good subject compliance and the provision of careful instructions for their use.

Validation of the Arizona Activity Frequency Questionnaire using doubly labeled water

PURPOSE

Physical activity questionnaires (PAQs) are considered the most cost-efficient method to estimate total energy expenditure (TEE) in epidemiological studies. However, relatively few PAQs have been validated using doubly labeled water (DLW) in women or in samples with diverse ethnic backgrounds. This study was conducted to validate the Arizona Activity Frequency Questionnaire (AAFQ) for estimation of TEE and physical activity energy expenditure (PAEE) over 1 month using DLW as a reference method.

METHODS

Thirty-five relatively sedentary women completed the AAFQ before participating in an 8-d DLW protocol to measure TEE. TEE and PAEE were estimated from the AAFQ by calculating resting metabolic rate (RMR) using the equation of Mifflin et al. (AAFQmif), by measuring RMR using indirect calorimetry (AAFQic), and using MET conversion (AAFQmet). A predictive equation for TEE was generated.

RESULTS

The mean +/- SD for TEE and PAEE from DLW were 9847 +/- 2555 kJ x d(-1) and 5578 +/- 2084 kJ x d(-1), respectively. Formulas using RMR to calculate the TEE and PAEE from the AAFQ tended to underestimate TEE and PAEE, whereas those that included only weight tended to overestimate TEE and PAEE. On the basis of the Mifflin et al. equation, the AAFQ tends to underestimate PAEE by 13%. This underestimation may be explained by the low lean body mass of the sample population and by effectiveness of the METs/RMR ratio in the obese. The following predictive equation was calculated: TEE (kJ x d(-1)) = (86.0 * average total daily METs) + (2.23 * RMRmif) - 6726. When the predictive equation is used, TEE calculated from the AAFQ is highly correlated with DLW TEE (adjusted r(2) = 0.70, P < 0.001).

CONCLUSION

The AAFQ is an effective tool for the prediction of TEE and PAEE in epidemiological studies.

Estimation of energy expenditure from physical activity measures: determinants of accuracy

OBJECTIVE

To describe the determinants, specifically age, body mass index, percentage of body fat, and physical activity (PA) level, associated with over- and underestimation of energy expenditure (EE) using PA records and the Stanford Seven-Day Physical Activity Recall (7DR) compared with doubly labeled water (DLW).

RESEARCH METHODS AND PROCEDURES

We collected PA measures on 24 males eating a controlled diet designed to maintain body weight, and we determined EE from DLW and estimated EE from PA records and 7DR.

RESULTS

Absolute differences in the estimation of EE between DLW and PA assessment methods were greater for the 7DR (30.6 +/- 9.9%) than PA records (7.9 +/- 3.2%). In PA records, overestimation of EE was greater with older age and higher body fatness; EE was overestimated by 16.7% among men 50 years and older compared with only 5.3% among men <40 years of age. For percentage of body fat, EE was overestimated by 19.7% among men with a percentage of body fat > or =30% compared with only 5.6% among men with a percentage of body fat <25%. A trend for less overestimation of EE with higher levels of PA (measured by DLW/basal metabolic rate [BMR]) also was observed in the PA records. In the 7DR, the estimates of EE varied widely and no trends were observed by age, percentage of body fat, and PA levels.

DISCUSSION

Estimation of EE from the 7DR is considerably more variable than from PA records. Factors related to age and percentage of body fat influenced the accuracy of estimated EE in the PA record. Additional studies are needed to understand factors related to accurate reporting of PA behaviors, which are used to estimate EE in free-living adults.

Accuracy and repeatability of the Yale physical activity survey in assessing physical activity of older adults

The purpose of this study was to extend the initial evaluation of the Yale Physical Activity Survey to assess physical activity in older adults. The survey yields three indicators of physical activity reflecting activities performed during a typical week of the previous month (Total Time, Total Energy Expenditure) and the past month (Total Activity Summary Index). Questionnaire validity was studied in 56 men and women, ages 56 to 86 years, by comparing the average of 3- or 7 day 24-hr. physical activity records (n=56), predicted maximal oxygen consumption (VO2 max) (n = 23) and the sum of three skinfold measurements. Two-week repeatability was estimated by calculating an intraclass coefficient using an analysis of variance with repeated measures. Spearman rhos were used to study questionnaire validity. Analysis showed the survey was easily administered and scored and exhibited moderate-to-good repeatability. For the first administration the Total Energy Expenditure Index was significantly associated with the physical activity diary (r = .27). On the second administration, correlations were significant for the physical activity diary with the Total Energy Expenditure Index (r = .30), the Total Activity Summary Index (r = .36), and the Total Time Index (r = .27), and for VO2 max and the Total Time Index (r = .49) and Total Activity Summary Index (r = .64). Relative to the criterion measures used in this study, some validity was evident for the second administration in this relatively active and healthy sample of older adults.

An evaluation of three self-report physical activity instruments for older adults

PURPOSE

To assess the known-groups and construct validity of measures from the CHAMPS Physical Activity Questionnaire, Physical Activity Survey for the Elderly (PASE), and the Yale Physical Activity Survey (YPAS).

METHODS

The three questionnaires were administered to a convenience sample of older adults (N = 87) recruited from community centers and retirement homes. Validation measures included the SF-36 measures of physical functioning, general health, mental health, and pain; body mass index; performance-based tests of lower body functioning and endurance; and Mini-Logger activity monitor data from ankle and waist sensors. Validity was estimated by testing hypotheses about associations between physical activity and validation measures.

RESULTS

As hypothesized, differences in activity levels on all measures were found between older adults in retirement homes (less active) and community centers (more active) (P-values < 0.0001). Correlations of physical activity measures with performance-based measures ranged from 0.44 to 0.68, conforming to hypotheses; hypotheses regarding associations with the SF-36 measures were also confirmed. Body mass index was not correlated with any of the physical activity measures, contrary to hypotheses. Correlations of physical activity measures with Mini-Logger counts ranged from 0.36 to 0.59 (ankle) and 0.42 to 0.61 (waist) as hypothesized. Correlations among the measures from the three instruments ranged from 0.58 to 0.68.

CONCLUSIONS

The PASE, YPAS, and CHAMPS each demonstrated acceptable validity, as all measures met nearly all hypotheses. Higher validity coefficients were found for subgroups (men, 65-74 yr, retirement home), suggesting that these instruments may perform better for certain segments of the older adult population.

Sleep estimation from wrist movement quantified by different actigraphic modalities

Progress in transducer design and empirical characterization of wrist movement has led to diverse wrist activity monitors, each with its unique features and modality of operation. This study compared sleep--wake estimates from nocturnal wrist activity quantified by different motion-quantifying algorithms. Healthy young adults wore an Actillume and a Mini Motionlogger on the same wrist while nocturnal polysomnography data were recorded simultaneously in the laboratory. Activity data were analyzed with ACTION3 using scoring algorithms independently calibrated for each measurement modality. Overall, each modality yielded accurate and reliable sleep estimates relative to polysomnographic estimates (agreement rates: 91.4--96.5%, correlations for sleep duration: 0.79--0.94). Estimates derived from Actillume modalities were comparable to those of Mini Motionloggers, suggesting that the transducers of these two devices performed comparably for monitoring sleep and wakefulness. Wrist movement quantified by the Mini Motionlogger proportional-integrating mode yielded the best accuracy for detection of sleep--wake states.

Challenges and opportunities for measuring physical activity in sedentary adults

Increasing the physical activity of typically sedentary adult populations is at the forefront of the public health agenda. This review addresses the challenges in defining and measuring physical activity in this target group, for a number of purposes, namely, scientific or academic inquiry, surveillance, clinical application and programme evaluation. First, we clarify the conceptual distinctions between the terms sedentarism, physical inactivity, physical activity and energy expenditure. Next, we review and compare the utility of different approaches for quantifying and expressing physical activity in these populations. Physical activity in typically sedentary populations is most likely a simple pattern of behaviour that has been largely obscured by existing measures and its expression as energy expenditure. Existing self-report methods are practical, but suffer from floor effects and recall bias. Walking, the most important activity to assess in this target group, is very difficult to measure through self-report methods. Motion sensors are more appropriate for quantifying physical activity behaviours in typically sedentary populations. Of the 2 types of motion sensors - the accelerometer and the pedometers--the latter is more appealing because it is both an affordable and a 'good enough' measure of physical activity, specifically ambulatory activity. Although a common measurement approach would greatly facilitate our understanding of physical activity behaviour patterns, the selection of an approach ultimately depends on the purpose of the study and to a great extent, its budget. Researchers, clinicians and practitioners interested in accurately capturing the lower end of the continuum of physical activity (that is characteristic of sedentary populations) must thoughtfully consider the relative advantages and disadvantages of the available approaches.

Simultaneous validation of ten physical activity questionnaires in older men: a doubly labeled water study

OBJECTIVE

The purpose of this study was to simultaneously validate 10 physical activity (PA) questionnaires in a homogenous population of healthy elderly men against the reference method: doubly labeled water (DLW).

DESIGN

Cross-sectional study.

SETTING

Community-based sample from Lyon, France.

PARTICIPANTS

Nineteen healthy old men (age 73.4 +/- 4.1 years), recruited from various associations for elderly people in Lyon, agreed to participate in the study.

MEASUREMENTS

The questionnaire-derived measures (scores) were compared with two validation measures: DLW and maximal oxygen uptake (VO2max). With the DLW method three parameters were calculated: (1) total energy expenditure (TEE), (2) physical activity level (PAL), i.e., the ratio of TEE to resting metabolic rate, (3) energy expenditure of PA.

RESULTS

Relative validity. Correlation between the questionnaires and TEE ranged from 0.11 for the Yale Physical Activity Survey (YPAS) total index to 0.63 for the Stanford usual activity questionnaire. This questionnaire also gave the best correlation coefficients with PAL (0.75), and with VO2max (0.62). Significant results with TEE measured by the DLW method were also obtained for college alumni sports score, Seven Day Recall moderate activity, and Questionnaire d'Activité Physique Saint-Etienne sports activity (r = 0.54, r = 0.52, and r = 0.54, respectively). Absolute validity. No difference was found between PA measured by the Seven Day Recall or by the YPAS and DLW, on a group basis. The limits of agreement were wide for all the questionnaires.

CONCLUSIONS

Only a few questionnaires demonstrated a reasonable degree of reliability and could be used to rank healthy older men according to PA. Correlation coefficients were best when the Stanford Usual Activity Questionnaire was compared with all the validation measures. The two questionnaires reporting recent PA, the Seven Day Recall, and YPAS accurately assessed energy expenditure for the group. The individual variability was high for all the questionnaires, suggesting that their use as a proxy measure of individual energy expenditure may be limited.

Daily physical activity and ageing

A typical aspect of aging is the increase in variability of a feature within a population, suggesting individual variation in the decline with age. The decline is probably inevitable (predisposed), but some show slower declines than others. Physical activity might be one of the avenues to influence the aging process. There is still a need for validated techniques of estimating habitual physical activity to study the relationship between physical activity and health. Doubly labeled water studies show a decrease in the average proportion of daily energy expenditure for physical activity of about 35% at the age of 20 to 25% at the age of 90. In absolute figures, the activity-induced energy expenditure falls to one third of the initial value over the corresponding age interval. Exercise training does not seem to prevent the age-associated decline in physical activity because of compensation by a decrease in non-training physical activity, in contrast to younger age groups. The effects of the habitual activity level and of exercise on the age-related decline in muscle mass are small if present at all. There is, however, a clear-cut effect of habitual activity and exercise training on muscle function. The positive effects are reflected in muscle fiber type, capillary density, and aerobic capacity. Physical inactivity is an important determinant of disability and mortality risk. Even a recent increase in activity level can have an important effect, although the benefits are also easily lost when the activity level is again reduced.

Respiratory fitness, free living physical activity, and cardiovascular disease risk in older individuals: a doubly labeled water study

The objective of this study was to examine the importance of cardiorespiratory fitness vs. physical activity energy expenditure on selected cardiovascular disease risk factors in older individuals. One hundred and seventeen older individuals, 53 men (68 +/- 9 yr) and 63 women (67 +/- 7 yr), participated in the study. This cohort was divided into 4 groups: 1) high cardiorespiratory fitness and high physical activity, 2) high cardiorespiratory fitness and low physical activity, 3) low cardiorespiratory fitness and high physical activity, and 4) low cardiorespiratory fitness and low physical activity. Cardiorespiratory fitness (VO2max) was determined from a graded exercise test, physical activity energy expenditure was measured by doubly labeled water and indirect calorimetry, body composition was determined by dual energy x-ray absorptiometry, and dietary practices were determined by a 3-day recall. Cardiorespiratory fitness exerted greater effects on the cardiovascular disease risk profile than physical activity. That is, older individuals with higher levels of cardiorespiratory fitness, regardless of their physical activity levels, showed lower levels of fasting insulin (P < 0.01), triglycerides (P < 0.05), total cholesterol (P < 0.05), total to high density lipoprotein cholesterol ratio (P < 0.05), low density lipoprotein (P < 0.05), and lower waist circumference (P < 0.01). Moreover, individuals with a high cardiorespiratory fitness but low physical activity energy expenditure displayed a more favorable cardiovascular disease risk profile than individuals with low cardiorespiratory fitness and high physical activity energy expenditure. The results suggest that higher levels of cardiorespiratory fitness have greater cardioprotective effects than higher levels of free living physical activity in older individuals. Although these findings do not discount the health benefits of being physically active, it is possible that greater emphasis should be placed on aerobic exercise to increase cardiorespiratory fitness in the elderly.