The influence of physical activity-induced energy expenditure on the variance in body weight change among individuals during a diet intervention. Total free living energy expenditure in patients with severe chronic obstructive pulmonary disease. Weight-Loss Induced Changes in Physical Activity and Activity Energy Expenditure in Overweight and Obese Subjects before and after Energy Restriction Effect of calorie restriction on the free-living physical activity levels of nonobese humans: results of three randomized trials. Measurement of physical activity to assess health effects in free-living populations. Energy costs of physical activities in children and adolescents. Energy expenditure in critically ill children Feasibility of heart-rate monitoring to estimate total level and pattern of energy expenditure in a population-based epidemiological study: the Ely Young Cohort Feasibility Study 1994-5. Assessment of energy expenditure in overweight women. Validity of physical activity monitors during daily life in patients with COPD Nonprescribed physical activity energy expenditure is maintained with structured exercise and implicates a compensatory increase in energy intake. Validity and repeatability of the EPIC-Norfolk Physical Activity Questionnaire. Predicted versus measured energy expenditure by continuous, online indirect calorimetry in ventilated, critically ill children during the early postinjury period* Work Ability, Physical Activity, and Cardiorespiratory Fitness: 2-year Results From Project Active Predictive Validity and Classification Accuracy of ActiGraph Energy Expenditure Equations and Cut-Points in Young Children Physiologic changes after diet combined with structured aerobic exercise or lifestyle activity. Physical activity is associated with incident disability in community-based older persons.
SUMMARY OBJECTIVE We investigated the relationship between the variability in body weight change among individuals and diet restriction or physical activity during a 14-week intervention . DESIGN A prospect i ve clinical trial with a 14-week weight reduction intervention design . In total , 90 middle aged , Japanese , obese women enrolled as subjects . MEASUREMENTS The outcome variable was the change in body weight during the intervention period . Other primary variables were total energy intake , carbohydrate intake , fat intake , protein intake , total energy expenditure ( TEE ) , and activity energy expenditure ( AEE ) . Diet intake  was assessed by 3 days , weighed dietary records and dietary recall interviews . Physical activity  was assessed by a uniaxial accelerometry sensor and a diary of exercise . RESULTS Significant reductions were observed in body weight ( -8.5 kg ) as a result of intervention . When the subjects were assigned to three categories depending on AEE during intervention , the loss of body weight was significantly greater for subjects within the upper ( -9.6 kg ) AEE category than for those in the middle ( -8.5 kg ) or lower AEE ( -7.5 kg ) categories . In addition , a significant correlation ( r = 0.57 , p < 0.0001 ) was observed between a subject 's AEE before and during the intervention . On the other h and , no significant correlation was observed between body weight reduction and energy intake , indicating that strict diet restriction does not always result in a large weight loss . CONCLUSION Activity energy expenditure , not only through voluntary exercise but also through spontaneous , daily , physical activities can have a positive effect on reducing body weight Resting  energy expenditure ( REE )  is often elevated in patients with chronic obstructive pulmonary disease ( COPD ) , but no data are available regarding total energy expenditure in free living conditions . We compared total daily energy expenditure ( TDE ) in eight COPD patients ( FEV1 36 + /- 13 % ) admitted to a pulmonary rehabilitation center and eight independently living healthy subjects , matched for sex , age , and body mass index ( BMI ) .  TDE was measured over a 2-wk interval using doubly labeled water in combination with measurement of REE and body composition .  The COPD patients had a significantly higher TDE than the healthy subjects ( 2,499 + /- 320 kcal/d and 2,107 + /- 88 kcal/d , respectively , p < 0.01 ) . The nonresting component of TDE ( TDE-REE : physical activity and diet-induced thermogenesis [ DIT ] ) was significantly higher in the COPD patients than in the healthy subjects , result ing in a ratio between TDE and REE of 1.7 + /- 0.2 and 1.4 + /- 0.1 , respectively ( p < 0.01 ) . The results indicate that COPD patients exhibit an increased TDE in comparison with healthy subjects . The difference could by attributed to an increase in the nonresting component of TDE , since REE was comparable between the groups Activity energy expenditure ( AEE ) is the component of daily energy expenditure that is mainly influenced by the amount of physical activity ( PA ) and by the weight of the body displaced . This study aim ed at analyzing the effect of weight loss on PA and AEE . The body weight and PA of 66 overweight and obese subjects were measured at baseline and after 12 weeks of 67 % energy restriction .  PA was measured using a tri-axial accelerometer for movement registration ( Tracmor ) and quantified in activity counts . Tracmor recordings were also processed using a classification algorithm to recognize 6 common activity types engaged in during the day . A doubly-labeled water vali date d equation based on Tracmor output was used to estimate AEE . After weight loss , body weight decreased by 13±4 % , daily activity counts augmented by 9 % ( 95 % CI : + 2 % , + 15 % ) , and this increase was weakly associated with the decrease in body weight ( R(2 ) = 7 % ; P<0.05 ) . After weight loss subjects were significantly ( P<0.05 ) less sedentary ( -26 min/d ) , and increased the time spent walking ( + 11 min/d ) and bicycling ( + 4 min/d ) . However , AEE decreased by 0.6±0.4 MJ/d after weight loss . On average , a 2-hour/day reduction of sedentary time by increasing ambulatory and generic activities was required to restore baseline levels of AEE . In conclusion , after weight loss PA increased but the related metabolic dem and did not offset the reduction in AEE due to the lower body weight . Promoting physical activity according to the extent of weight loss might increase successfulness of weight maintenance The objective of this study was to evaluate the influence of calorie restriction ( CR ) on free-living physical activity levels among humans . Data were from three CALERIE phase I site-specific protocol s. Participants were nonobese ( body mass index = 23.5 - 29.9 kg/m² adults r and omly assigned to 25 % CR , low-calorie diet ( LCD , 890 kcal/day supplement diet until 15 % weight loss , then weight maintenance ) , or control at Pennington Biomedical Research Center ( PBRC ) ; 30 % or 10 % CR  at Tufts University ; and 20 % CR or control  at Washington University School of Medicine ( WUSM )  . Activity was measured at months 0 , 3 , and 6 ( PBRC ) and at months 0 , 3 , 6 , 9 , and 12 ( WUSM and Tufts ) . Total daily energy expenditure ( TEE ) by doubly labeled water and resting metabolic rate ( RMR ) were used to compute activity energy expenditure : AEE = TEE - RMR - 0.1 * TEE . Accelerometry and 7-day recall categorized activities by intensity . At Tufts , the 10 % and 30 % CR groups experienced significant decreases in AEE at months 6 , 9 , and 12 . At month 6 , a larger decrease in AEE was observed in the CR than the control group at WUSM . At months 3 and 6 , larger decreases in AEE were observed in the CR and LCD groups than the control group at PBRC . Accelerometry and 7-day PAR did not consistently detect changes in activity categories . CR-associated changes in AEE were variable but , generally , reduced the energy deficit , which would reduce the expected rate of weight loss . Accelerometry and recall did not consistently explain reduced AEE , suggesting that increased muscle efficiency and /or decreased fidgeting accounted for decreased AEE . Inaccuracy of accelerometry and recall also likely negatively affected sensitivity For physical activity surveys that would identify relations to chronic diseases , quality of life , and longevity , the method of choice remains the question naire , especially if it can be st and ardized and administered in uniform fashion to large population s. A sample question naire derived largely from epidemiological experience with the Harvard Alumni Health Study is presented that requests anthropometric estimates ; physician-diagnosed diseases by year of onset ; contemporary physical activities including walking , stair-climbing , and recreational pursuits ; food-frequency data that estimate nutrient values and caloric intakes ; and social habits affecting health . The question naire presents opportunities for cross-sectional , retrospective , and prospect i ve studies . Personal characteristics , physical activities , and other elements of lifestyle may be used as predictor or outcome variables in testing specific hypotheses . Representative surveys are described that have vali date d and used question naires of various complexities , some complemented by measures of physiological fitness . The epidemiological survey question naire , when properly design ed and administered , can measure effectively energy intake , energy retention , energy expenditure , physiological fitness , quality of life , and health maintenance PURPOSE The primary aim was to determine the energy expenditure ( EE : kcal.kg(-1).h(-1 ) ) in terms of caloric cost and metabolic equivalents of activities commonly performed by children and adolescents . Secondary aims were to determine at what age and pubertal developmental stage values approach those of adults . METHODS In this descriptive study , 295 volunteer youth 8 - 18 yr of age completed 18 common physical activities ( including rest ) while EE was measured continuously with a portable metabolic system . Three sets of activities were assigned in r and om order for each subject . Activities ranged from television viewing and video game play to running and rope skipping . Pubertal development was estimated from a self-report question naire . RESULTS At rest , VO(2 ) and EE were highest in the youngest children and decreased with advancing age and higher pubertal stage in both genders . The age-adjusted and puberty-adjusted energy expenditure values were generally lower than the compendium MET values for sedentary and moderate activities but were more varied for high-intensity activities . However , the ratio of activity EE to REE was comparable in children and adults . CONCLUSIONS Energy expenditure per kilogram of body mass at rest or during exercise is greater in children than adults and varies with pubertal status , thus using the definition of a MET in the compendium of physical activities without adjustment is inadequate for energy estimation in children , until a child reaches Tanner Stage 5 . However , the ratio of activity EE to resting EE in children appears to be similar or slightly less than in the compendium , suggesting that the compendium MET increments used with our adjusted EE values more closely approximate the true EE of activities in children than present adult norms Objectives : To measure energy expenditure in critically ill children and compare it with the energy expenditure predicted by recommended formulas , and relate the measured energy expenditure to nutritional and clinical indices . Design : A prospect i ve , clinical study . Setting : Tertiary care pediatric intensive care unit in a university children 's hospital . Patients : A total of 37 patients with critical illness who were mechanically ventilated for ≥24 hrs were studied . Interventions : None . Measurements and Main Results : Chronic protein‐energy malnutrition ( CPEM ) and acute protein‐energy malnutrition were defined by the Waterlow 's stages and fat and protein stores were classified as defined by Frisancho , Ryan , and Martinez . Severity of illness was assessed by the Pediatric Risk of Mortality Score , the Therapeutic Intervention Scoring System , and indices of organ failure . Oxygen consumption , carbon dioxide production , and the respiratory quotient were measured by indirect calorimetry , and energy expenditure ( MEE ) was calculated using the modified Weir formula . Resting energy expenditure ( PBMR ) , predicted energy expenditure , and caloric intake were calculated using recommended formulas . A total of 77 measurements were made in 37 children .  MEE was significantly lower than PBMR as estimated by all equations except the Talbot equations . MEE was significantly lower than predicted energy expenditure and the recommended daily allowances . On the first day , the MEE/PBMR ratio was < 0.9 in 56.8 % , 0.9‐1.1 in 21.6 % , and > 1.1 in 21.6 % of patients . MEE did not differ significantly among disease groups or between medical and surgical patients . There was no difference in MEE with or without neuromuscular blockade . MEE was lower in the presence of multiple organ system failure ( MOSF ) ( 1019 + 166 kcal/m2 without MOSF vs. 862 + 241 with MOSF ; p = .025 ) . A total of 21 % had CPEM and 8.1 % had acute protein‐energy malnutrition . Multivariate stepwise regression analysis showed that the protein intake , midarm muscle area , midarm fat area , the use of vasoactive agents , and sedation correlated with MEE ( p < .05 ) . With CPEM , MEE was correlated to the severity of illness ( p < .05 ) . Patients at risk for protein stores depletion ( midarm muscle areas 1 and 2 ) had a higher incidence of MOSF compared with nutritionally normal children ( p < .05 ) , whereas patients with fat stores depletion ( midarm fat area 2 ) had a higher probability of death ( 50 % vs. 6 % , respectively ) . Conclusions : Recommended daily allowances and energy expenditure predicted by using a stress‐related correction to the resting energy expenditure grossly overestimate MEE . MEE is close to PBMR and in many patients , it is lower than PBMR . MEE that is lower than PBMR is associated with a higher morbidity . Nutritional repletion should thus be based on MEE to avoid the problems of over‐ or underfeeding Increasing the precision of measurements of total energy expenditure in population -based epidemiological studies is important for accurately quantifying the relationship between this exposure and disease . Current question naire-based methods can not accurately quantify total energy expenditure , although they may provide an estimate of the frequency of vigorous activities . Heart rate monitoring with individual calibration has been advocated as a method for assessing energy expenditure in field studies and has been compared with the ' gold st and ard ' techniques of doubly-labelled water and indirect calorimetry . However the method has previously only been used on small and selected population s. This study was , therefore , established to test the feasibility of using heart rate monitoring in a population -based study of adults . A total of 167 individuals aged 30 - 40 years were r and omly selected and underwent 4 d heart-rate monitoring . Only three individuals could not complete the protocol . The mean physical activity level ( PAL ) measured over 4 d was 1.89 ( SD 0.40 ) in men and 1.76 ( sd 0.31 ) in women . There was no difference between mean PAL on weekend days compared with weekdays ( mean paired difference 0.0008 , 95 % CI -0.06 + 0.06 ) . The estimate of mean PAL was not correlated with BMI , percentage body fat or the waist : hip ratio . It was , however , correlated with cardio-respiratory fitness as measured by VO2(max ) per kg ( Spearman rank correlation coefficient 0.50 in men and 0.42 in women ) . The pattern of energy expenditure was assessed by calculating the percentage of daytime hours in which PAL was greater than five times basal energy expenditure . This measure was strongly correlated with the mean PAL in both men ( Spearman correlation coefficient 0.77 ) and women ( 0.71 ) . We conclude that heart-rate monitoring is a feasible method for assessing the pattern and total level of energy expenditure in medium-sized epidemiological studies . It may also prove useful as the reference technique for calibrating question naires to estimate energy expenditure in larger scale studies PURPOSE To compare field measures of average daily energy expenditure ( ADEE ) against criterion data by the doubly labeled water method ( DLW ) in overweight women . METHODS The subject were 20 overweight ( BMI 29.9 + a- 3.0 kg.m-2 ) premenopausal women .  Energy expenditure was measured by DLW and by the factorial method ( activity diary , two techniques differing by method to obtain resting energy expenditure , REE ) , heart-rate monitoring ( HR , two techniques differing by the FLEX-point to discriminate sedentary and activity HR ) , accelerometer , and pedometer . RESULTS The ADEE(DLW ) was 10.26 + a- 1.1 MJ.d-1 . The mean bias ( ADEE by the alternative minus ADEE(DLW ) was smallest for the accelerometer ( + 0.08 + a- 1.63 MJ ) and HR-FLEX10 ( + 0.11 + a- 1.67 MJ ) . The HR-FLEX(0 ) technique ( lower FLEX-point ) overestimated ADEE by + 1.18 ( + a- 1.97 MJ ) . However , the r and om error ( SD of bias ) was smaller for both factorial techniques ( REE measured : -0.48 + 2- 0.81 MJ ; REE calculated from the WHO equation : -0.22 + 2- 0.88 MJ ) . CONCLUSION The results show that simple factorial methods may assess ADEE with small r and om errors in population with a rather narrow range of physical activity . The accelerometer and HR with the higher FLEX-point have comparable results with smaller bias but larger r and om error compared with the factorial techniques Symptoms during physical activity and physical inactivity are hallmarks of chronic obstructive pulmonary disease ( COPD ) . Our aim was to evaluate the validity and usability of six activity monitors in patients with COPD against the doubly labelled water ( DLW ) indirect calorimetry method . 80 COPD patients ( mean±sd age 68±6 years and forced expiratory volume in 1 s 57±19 % predicted ) recruited in four centres each wore simultaneously three or four out of six commercially available monitors vali date d in chronic conditions for 14 consecutive days . A priori validity criteria were defined . These included the ability to explain total energy expenditure ( TEE ) variance through multiple regression analysis , using TEE as the dependent variable with total body water ( TBW ) plus several physical activity monitor outputs as independent variables ; and correlation with activity energy expenditure ( AEE ) measured by DLW . The Actigraph GT3X ( Actigraph LLC , Pensacola , FL , USA ) , and DynaPort MoveMonitor ( McRoberts BV , The Hague , the Netherl and s ) best explained the majority of the TEE variance not explained by TBW ( 53 % and 70 % , respectively ) and showed the most significant correlations with AEE ( r=0.71 , p<0.001 and r=0.70 , p<0.0001 , respectively ) . The results of this study should guide users in choosing valid activity monitors for research or for clinical use in patients with chronic diseases such as COPD . This study vali date s six activity monitors in the field against indirect calorimetry ( DLW ) in patients with COPD BACKGROUND Exercise interventions elicit only modest weight loss , which might reflect a compensatory reduction in nonprescribed physical activity energy expenditure ( PAEE ) . OBJECTIVE The objective was to investigate whether there is a reduction in nonprescribed PAEE as a result of participation in a 6-mo structured exercise intervention in middle-aged men . DESIGN Sedentary male participants [ age : 54 ± 5 y ; body mass index ( in kg/m² ) : 28 ± 3 ] were r and omly assigned to a 6-mo progressive exercise ( EX ) or control ( CON ) group . Energy expenditure during structured exercise ( prescribed PAEE ) and nonprescribed PAEE were determined with the use of synchronized accelerometry and heart rate before the intervention , during the intervention ( 2 , 9 , and 18 wk ) , and within a 2-wk period of detraining after the intervention . RESULTS Structured prescribed exercise increased total PAEE and had no detrimental effect on nonprescribed PAEE . Indeed , there was a trend for greater nonprescribed PAEE in the EX group ( P = 0.09 ) . Weight loss in the EX group ( -1.8 ± 2.2 kg compared with + 0.2 ± 2.2 kg in the CON group , P < 0.02 ) reflected only ≈40 % of the 300 - 373 kcal/kg body mass potential energy deficit from prescribed exercise . Serum leptin concentration decreased by 24 % in the EX group ( compared with 3 % in the CON group , P < 0.03 ) , and we estimate that this was accompanied by a compensatory increase in energy intake of ≈100 kcal/d . CONCLUSIONS The adoption of regular structured exercise in previously sedentary , middle-aged , and overweight men does not result in a negative compensatory reduction in nonprescribed physical activity . The less-than-predicted weight loss is likely to reflect a compensatory increase in energy intake in response to a perceived state of relative energy insufficiency BACKGROUND Physical activity is an important lifestyle which is often poorly assessed in epidemiological studies . The European Prospect i ve Investigation into Cancer Study -Norfolk cohort ( EPIC-Norfolk ) , a large population -based cohort study , has developed a comprehensive question naire to assess activity in different domains of life aim ed at assessing total energy expenditure . We report the repeatability of this instrument and its validity against repeated objective measures of fitness and energy expenditure undertaken throughout the time frame of reference of the question naire . METHODS The validity of the instrument was measured in 173 individuals r and omly selected from a continuing population -based cohort study .  Energy expenditure was assessed by four separate episodes of 4-day heart-rate monitoring , a method previously vali date d against whole body calorimetry and doubly-labelled water . Cardio-respiratory fitness was assessed by four repeated measures of sub-maximum oxygen uptake . At the end of the 12-month period , participants completed the physical activity question naire that assesses past-year activity at home , work and in recreation . Repeatability was assessed in a separate group of 399 r and omly selected participants in EPIC who completed the physical activity question naire twice with a 3-month interval . RESULTS The age- and sex-adjusted correlation between the objective measure of daytime energy expenditure and the sum of recreational and occupational reported physical activity ( in MET h per week ) was 0.28 ( P < 0.001 ) . The reported time spent in vigorous activity was correlated with cardio-respiratory fitness ( 0.16 , P < 0.05 ) and with the proportion of time when energy expenditure was more than five times basal ( 0.17 , P < 0.05 ) . The repeatability of the sum of recreational and occupational reported activity was high , r = 0.73 . CONCLUSIONS The indices of physical activity derived from this question naire have levels of validity and repeatability comparable to other physical activity instruments that are used in large epidemiological studies and which have undergone such intense development and testing Objective Compare the energy expenditure , predicted by anthropometric equations , with that measured by continuous on-line indirect calorimetry in ventilated , critically ill children during the early postinjury period . Design Prospect i ve , clinical study . Setting Pediatric intensive care unit of a pediatric university hospital . Patients A total of 43 ventilated , critically ill children during the first 6 hrs after injury . Interventions An indirect calorimeter was used to continuously measure the energy expenditure for 24 hrs . Measurements and Main Results Clinical data collected were age , gender , actual and ideal weight , height , and body surface . Nutritional status was assessed by Waterlow and Shukla Index . Severity of illness was determined by Pediatric Risk of Mortality , Physiologic Stability Index , and Therapeutic Intervention Scoring System . Energy expenditure was measured ( MEE ) by continuous on-line indirect calorimetry for 24 hrs . Predicted Energy Expenditure ( PEE ) was calculated using the Harris-Benedict , Caldwell-Kennedy , Schofield , Food and Agriculture/World Health Organization/United Nation Union , Maffeis , Fleisch , Kleiber , Dreyer , and Hunter equations , using the actual and ideal weight . MEE and PEE were compared using paired Student ’s t-test , linear correlation ( r ) , intraclass correlation coefficient ( pI ) , and the Bl and -Altman method . Mean MEE result ed in 674 ± 384 kcal/day . Most of the predictive equations overestimated MEE in ventilated , critically ill children during the early postinjury period . MEE and PEE differed significantly ( p < .05 ) except when the Caldwell-Kennedy and the Fleisch equations were used . r2 ranged from 0.78 to 0.81 ( p < .05 ) , and pI was excellent ( > .75 ) for the Caldwell-Kennedy , Schofield , Food and Agriculture/World Health Organization/United Nation Union , Fleisch , and Kleiber equations . The Bl and -Altman method showed poor accuracy ; the Caldwell-Kennedy equation was the best predictor of energy expenditure ( bias , 38 kcal/day ; precision , ±179 kcal/day ) . The accuracy in the medical group was higher ( pI range , .71–.94 ) than in surgical patients ( pI range , .18–.75 ) . Conclusions Predictive equations do not accurately predict energy expenditure in ventilated , critically ill children during the early postinjury period ; if available , indirect calorimetry must be performed An adequate level of physical activity may maintain or promote work ability in aging workers . Project Active is a r and omized trial comparing a Lifestyle physical activity program with a Structured exercise program in sedentary but healthy adults aged 35 to 60 years . Subjects in both groups received 6 months of intensive intervention followed by 18 months of active follow-up .  The total number of subjects was 235 , from which 80 subjects participated in the work ability assessment . Primary outcome measures were energy expenditure ( kcal · kg−1 · day−1 ) , cardiorespiratory fitness ( peak oxygen uptake in ml · min−1 · kg−1 ) , and the Work Ability Index . At 6 months , daily energy expenditure had increased significantly over baseline ( mean ± SD , from 33.0 ± 0.9 to 34.4 ± 1.8 kcal · kg−1 · day−1 ) and was maintained over baseline at 24 months ( 34.0 ± 2.5 kcal · kg−1 · day−1 ) . The significant increase in energy expenditure was observed particularly in moderate levels of activity . The average percentage of body fat was significantly higher at baseline compared with 6 months and 24 months . Peak oxygen uptake increased from baseline significantly during the first 6 months ( from 29.6 ± 5.7 to 30.6 ± 6.3 ml · min−1 · kg−1 ) and decreased to the baseline level ( 29.1 ± 5.5 ml · min−1 · kg−1 ) at 24 months . At baseline , the average Work Ability Index was 44.2 ± 4.0 , and it remained unchanged at 6 months ( 44.4 ± 3.9 ) and at 24 months ( 44.2 ± 3.1 ) . In conclusion , a 2-year physical activity intervention increased daily energy expenditure , reduced body fat , and maintained peak oxygen uptake in healthy , middle-aged , sedentary subjects .  The average Work Ability Index score at baseline was excellent and did not change during the 2-year physical activity interventions Objectives Evaluate the predictive validity of ActiGraph energy expenditure equations and the classification accuracy of physical activity intensity cut-points in preschoolers . Methods Forty children aged 4–6 years ( 5.3±1.0 years ) completed a ∼150-min room calorimeter protocol involving age-appropriate sedentary , light and moderate-to vigorous-intensity physical activities . Children wore an ActiGraph GT3X on the right mid-axillary line of the hip . Energy expenditure measured by room calorimetry and physical activity intensity classified using direct observation were the criterion methods . Energy expenditure was predicted using Pate and Puyau equations . Physical activity intensity was classified using Evenson , Sirard , Van Cauwenberghe , Pate , Puyau , and Reilly , ActiGraph cut-points . Results The Pate equation significantly overestimated VO2 during sedentary behaviors , light physical activities and total VO2 ( P<0.001 ) . No difference was found between measured and predicted VO2 during moderate-to vigorous-intensity physical activities ( P = 0.072 ) . The Puyau equation significantly underestimated activity energy expenditure during moderate-to vigorous-intensity physical activities , light-intensity physical activities and total activity energy expenditure ( P<0.0125 ) . However , no overestimation of activity energy expenditure during sedentary behavior was found . The Evenson cut-point demonstrated significantly higher accuracy for classifying sedentary behaviors and light-intensity physical activities than others . Classification accuracy for moderate-to vigorous-intensity physical activities was significantly higher for Pate than others . Conclusion Available ActiGraph equations do not provide accurate estimates of energy expenditure across physical activity intensities in preschoolers . Cut-points of ≤25counts⋅15 s−1 and ≥420 counts⋅15 s−1 for classifying sedentary behaviors and moderate-to vigorous-intensity physical activities , respectively , are recommended Moderate intensity physical activity achieved through changes in lifestyle may promote weight management . However , little is known about changes in physiologic and metabolic variables when patients lose weight using moderate intensity lifestyle activity  instead of traditional structured vigorous aerobic exercise . To compare changes in resting metabolic energy expenditure ( REE ) , fat mass ( FM ) , and fat-free mass ( FFM ) associated with a 12-week weight loss program combined with either : ( 1 ) aerobic exercise ( AER ) ; or ( 2 ) lifestyle activity ( LIFE ) , we r and omized 39 overweight adults ( mean body mass index [ BMI ] = 30.9 + /- 2.8 kg/m(2 ) ) to either diet plus AER ( N = 18 ) or diet plus LIFE  ( N = 21 ) . Both groups consumed a self-selected diet of 1,200 to 1,800 kcal/d ( 5,021 to 7,531 kJ/d ) . The AER group performed vigorous aerobic exercise for up to 45 minutes 3 to 4 d/wk . The LIFE group accumulated 30 minutes of moderate intensity physical activity on most days of the week . Compliance with the respective protocol s was monitored on a weekly basis . REE was measured before and after treatment via open-circuit spirometry . The AER group decreased body weight by 8.4 % (P<.001)while the LIFE had a reduction of 6.7 % ( P < .001 ) after treatment . Over the course of the interventions , the AER and LIFE groups experienced 10.9 % ( P < .001 ) and 10.2 % ( P < .001 ) reductions in REE , respectively . Aerobic exercise did not prevent reductions in REE to a greater extent than did lifestyle activity in patients consuming a reduced calorie diet . Change in REE was not related to changes in FFM or FM for either group , and there were no differences between groups in reductions of REE , weight , FM , or FFM . A program of diet plus lifestyle physical activity may be a suitable alternative for dieting adults who have difficulty adhering to a program of vigorous activity OBJECTIVES To examine the association between physical activity and the risk of incident disability , including impairment in activities of daily living ( ADLs ) and instrumental activities of daily living ( IADLs ) , in community-based older persons free of dementia . DESIGN Prospect i ve , observational cohort study . SETTING Approximately 40 retirement communities across the Chicago metropolitan area . PARTICIPANTS More than 1,000 older persons from the Rush Memory and Aging Project , an ongoing longitudinal clinical -pathological study of common chronic conditions of old age . MEASUREMENTS All participants underwent detailed annual clinical evaluations that included assessment s of  physical activity , ADLs , IADLs , and gait performance . The associations between  physical activity , mortality , and incident disability were examined using a series of Cox proportional hazards models controlled for age , sex , education , and baseline gait . RESULTS At baseline , participants spent a mean+/-st and ard deviation of 3.0+/-3.5 hours per week engaging in physical activity ( range 0 - 35 ) . In a proportional hazards model , the risk of death decreased 11 % ( hazard ratio (HR)=0.89 , 95 % confidence interval (CI)=0.83 - 0.95 ) for each additional hour of physical activity per week . For those who were not disabled at baseline , the risk of developing disability in ADLs decreased 7 % ( HR=0.93 , 95 % CI=0.88 - 0.98 ) for each additional hour of physical activity per week . Similarly , the risk of disability in IADLs decreased 7 % ( HR=0.93 , 95 % CI=0.89 - 0.99 ) for each additional hour of physical activity . CONCLUSION For community-based older persons without dementia , physical activity is associated with maintenance of functional status , including a reduced risk of developing impairment in ADLs and IADLs
Conclusions : We conclude that there is large heterogeneity across studies in the explained variance of AEE when estimated based on accelerometry .
Background / Objectives : Activity-related energy expenditure ( AEE ) might be an important factor in the etiology of chronic diseases .
However , measurement of free-living AEE is usually not feasible in large-scale epidemiological studies but instead has traditionally been estimated based on self-reported physical activity .