Twenty-four-hour analysis of elevated energy expenditure after physical activity in a metabolic chamber: models of daily total energy expenditure

BACKGROUND: The Institute of Medicine proposed that 15% of energy expenditure (EE) as excess post-exercise oxygen consumption should be added to additional physical activity energy expenditure (DeltaPAEE) to estimate total EE. However, the magnitude of elevated post-physical activity energy expenditure (EPEE) under normal daily living conditions has not been examined. OBJECTIVE: We examined the effects of EPEE on 24-h EE by modeling standard living conditions in a metabolic chamber. DESIGN: Eleven Japanese men completed three 24-h metabolic chamber measurements: a control day (C-day), a day with high-frequency moderate-intensity physical activity (M-day), and a day with high-frequency vigorous-intensity physical activity (V-day). RESULTS: Mean (+/- SD) 24-h EE for the C-day, the M-day, and the V-day was 2228 +/- 143 kcal, 2816 +/- 197 kcal, and 2813 +/- 163 kcal, respectively. No significant difference was observed in 24-h EE between an M-day and a V-day. Mean EPEEs on the M-day and the V-day did not significantly contribute to increasing 24-h EE. Relative EPEEs to DeltaPAEEs were 6.2 +/- 13.9% (M-day) and 5.1 +/- 9.2% (V-day). However, EPEE/24-h EE was negatively correlated with maximal oxygen uptake on the V-day (r = -0.68, P = 0.02), although no significant correlation between these variables was observed on the M-day (r = -0.41, P = 0.21). CONCLUSIONS: These results suggest that EPEE has a small effect on 24-h EE in the course of normal daily activities, findings that do not support the proposition by the Institute of Medicine for estimating TEE. However, persons with low physical fitness levels could enhance EE as EPEE by increasing vigorous-intensity daily physical activity.     

Within-subjects variation over 10 months in 24-hour energy expenditure at a fixed physical activity programme

In order to estimate within-subjects variability in 24-hour energy expenditure at a fixed physical activity programme with a physical activity index of 1.30, this quantity was measured in four apparently healthy subjects once a month over 10 months. The coefficient of variation of the measurements was found to be between 2.7 and 4 per cent and in agreement with previously published data.     

24-hour energy expenditure and the menstrual cycle

To determine whether 24-h energy expenditure changes during the menstrual cycle, 10 normally menstruating women in their 20s and 40s were measured repeatedly for periods of 36 and 46 h by simultaneous direct and indirect calorimetry. A standardized sedentary daily schedule included three meals to provide food intake equal to expenditure. Eight of the 10 women showed increases of 8-16% during the 14-day luteal phase following ovulation, a significant increase (p less than 0.00002 by direct calorimetry, p less than 0.001 by indirect calorimetry). One subjects, whose increase was 14% following ovulation, showed no significant change during a month when she took an oral contraceptive. Progesterone from the corpus luteum is the likely cause of a 9% increase in 24-h energy expenditure in normally menstruating women.     

Effects of exercise training on resting energy expenditure during caloric restriction

Resting energy expenditure (REE), maximum oxygen uptake (VO2max), and body composition were measured in seven moderately obese women during 9 wk of dietary restriction (800 kcal/d). During weeks 4-6, subjects underwent exercise training (30 min cycling/d, 5 d/wk, at 70% VO2max). The first 3 wk of caloric restriction decreased REE by 13% (from 1437 +/- 76 to 1254 +/- 66 kcal/24 h, means +/- SEM, p less than 0.05). Exercise training increased VO2max (from 1717 +/- 108 to 1960 +/- 120 mL/min, means +/- SEM, p less than 0.05) but did not elevate the dietary-depressed REE (from 1254 +/- 66 to 1262 +/- 62 kcal/24 h). The greatest decrease in body fat (3.7 +/- 0.4 kg) occurred during exercise training, resulting in a small apparent increase in REE when expressed per kilogram total body weight. However, expressed per unit lean body mass, REE remained suppressed throughout the period of caloric restriction. We conclude that exercise training of sufficient intensity to substantially increase VO2max does not reverse the dietary-induced depression of REE.     

Daily energy expenditure of middle-aged Japanese housewives measured by 24-hour heart rate and diary

Measurements of daily energy expenditure were made in 20 middle-aged Japanese housewives by 24-hour heart rate monitoring. The values were compared with the estimates derived from the diaries being simultaneously recorded by the subjects on the nature and duration of activities during the 24-hours. The mean of the energy expenditure derived from the 24-hour heart rate was 1476 kcal, while the mean of the estimates from the diaries was 2007 kcal. The assessed error in the heart rate method was about 10% over-estimation. As the energy expenditure derived from the diary method was 36% greater than that of the heart rate method, the error involved in the diary method was much greater than that in the heart rate method. The difference in the estimation between the two methods resulted from two causes. The first is in the resting metabolic rate which accounts for a 15% greater estimate; 0.84 kcal/min (31.0 kcal/kg fat-free mass/24 hour) determined by oxygen consumption, and 0.96 kcal/min (35.6 kcal/kg fat-free mass/24 hour) calculated from the Japanese standard basal metabolic rate. The second is a suggested limitation of the diary method that the recorded activities may not appropriately reflect dominant activities, which accounts for the rest of 21% greater estimate. If the daily energy expenditure is estimated on the basis of the diary method without knowing the extent of error involved, an erroneous conclusion would be drawn.     

Marginal malnutrition in school-aged Colombian boys: metabolic rate and estimated daily energy expenditure

Total daily energy expenditure (TDEE) and energy expenditure in activity (EAc) were estimated in 114 free-ranging, nutritionally normal, and undernourished boys 6-16 yr of age by measuring basal and resting metabolic rates, average daily heart rate while awake, and oxygen consumption and heart rate during exercise on a treadmill. Mean daily heart rates were in the range of exercising heart rates and gave reasonable estimates of TDEE and EAc. TDEE increased with age (p less than 0.001) and was reduced in undernourished boys (p = 0.011). Results indicate that nutritional group differences in TDEE were due to differences in body size. EAc increased with age but did not show significant differences between nutritional groups, indicating that in the marginal malnutrition of school-aged children, reduced growth and associated economy of energy expenditure in locomotion is sufficient physiological adaptation. Peer pressure in school and play activities may interfere with the protective mechanism of reduced activity.     

Impacts of vigorous and non-vigorous activity on daily energy expenditure

Activity intensity is a potential determinant of activity-induced energy expenditure. Tri-axial accelerometery is the most objective measurement technique for the assessment of activity intensity, in combination with doubly-labelled water for the measurement of energy expenditure under free-living conditions. Data on the effects of subject characteristics, including body size and age, and exercise training on the relationship between activity intensity and daily energy expenditure are reviewed. Average daily metabolic rate and non-basal energy expenditure are positively related to body size. The duration and intensity of physical activities do not need to be equivalent to the energy spent on activity. Obese subjects spend more energy on physical activity but can perform fewer activities, especially high-intensity (weight-bearing) activities, because of their higher body weight. Physical activity generally declines gradually from about 60 years of age onwards. Most subjects > 80 years have an activity level well below the level defined for sedentary middle-aged adults. Spending relatively more time on low-intensity activities has a negative effect on the mean physical activity level. To obtain a higher physical activity level does not necessarily imply high-intensity activities. In an average subject 25% of the activity-induced energy expenditure may be attributed to high-intensity activities. Exercise training, as a form of high-intensity activity, affects the physical activity level more in younger subjects than in elderly subjects.     

A simple method of measuring total daily energy expenditure and physical activity level from the heart rate in adult men

OBJECTIVE: To evaluate a simple method that uses only a heart rate monitor to predict total energy expenditure (TEE) and physical activity level (PAL) from 24 h heart rate (HR) measurements. DESIGN: The simple method involved the determination of the physical activity ratio (PAR) from corresponding heart rate ratios (HRR) (ratio of observed to resting HR), from an individualized calibration curve relating activities with known PAR to the HRR. Several curve fits were evaluated for this curve. The PAL was calculated from minute to minute PAR. The TEE was computed as the product of the PAL and the predicted basal metabolic rate (BMR). The accuracy of the simple method was assessed by within-subject comparisons of the simple method versus the oxygen consumption - HR method and a time and motion study. SETTING: Bangalore City, India. Subjects: In all, 17 healthy male subjects between 18 and 44 years were recruited for the study. Interventions: None. RESULTS: The simple method correlated well with both the reference methods when using a calibration curve that involved the fitting of two straight lines at low and high PAR activities, respectively, to the PAR and HRR data. The mean error in TEE, as a product of BMR and PAL, was about 1%, but with limits of agreement between the methods that were about 20% of the TEE. However, the low mean error could have been due to a canceling of errors in the determination of BMR and PAL. CONCLUSIONS: The simple method is a relatively cheap, useful technique for evaluating TEE and PAL in resource-poor situations. It may particularly be of use in epidemiological investigations where population estimates of TEE and PAL are required.     

Evaluation of methods for measuring daily physical activity in terms of energy expenditure]

Various methods exist for measuring daily physical activity and daily energy expenditure and daily pedometer readings are most commonly used for the amount of physical activity. In this study, three methods for measuring energy expenditure-24-hr heart rate method (HR), time study method, and caloric expenditure accumulator (CC)-, and the feasibility of a pedometer for the assessment of energy expenditure were examined under laboratory conditions and during normal daily life. Daily physical activity was measured by four methods (HR, Time study, CC, Pedometer) in a field study of 14 young, healthy and sedentary women, and compared. Laboratory validation of the three methods with measurement of oxygen uptake was performed with 5 young men and 1 woman walking and running at different speeds and grades on a treadmill. In addition validation tests of whether pedometer readings reflect differences in energy expenditure due to speed and grade and whether pedometer counts steps exactly were also conducted. The 24-hr energy expenditure derived from CC was significantly lower than that derived from HR and Time study, due to lower estimation of energy expenditure from activities compared to other methods. In the laboratory study, the energy expenditure measured at 5% grade was low by CC and differences in energy expenditure for changes in grade could not be differentiated. Time study revealed a significant relationship between CC and HR in field study. These results suggest that CC tends to underestimate the 24-hr energy expenditure from activity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of exercise and food restriction on body composition and metabolic rate in obese women

Obese women (140-180% of ideal body weight) were studied on a metabolic ward during 1 wk of maintenance feeding, followed by 5 wk of 800 kcal/d (liquid formula diet). Five subjects participated in a supervised program of daily aerobic exercise and three subjects remained sedentary. Total weight loss was not different between exercising and nonexercising subjects but significantly more of the weight loss came from fat and less from fat-free mass in the exercising subjects. Resting metabolic rate (RMR) declined similarly in both groups (approximately 20%), even though exercising subjects were in greater negative energy balance due to the added energy cost of exercise. In summary, results from this controlled inpatient study indicate that exercise is beneficial when coupled with food restriction because it favors loss of body fat and preserves fat-free mass.     

Basal metabolic rate and energy expenditure of pregnant Nigerian women

The purpose of the present study was to compare basal metabolic rates (BMR) of pregnant Nigerian women from rural and urban areas with values from similar studies in other Third World countries. We also investigated possible changes in BMR during the course of pregnancy. An open-circuit indirect calorimeter was used to measure BMR and energy expenditure (EE) during sedentary activity in forty-one pregnant Nigerian women. The results showed marked variability in BMR among individuals. A correlation analysis between BMR and other biological and physical characteristics revealed bodyweight and gestation as the only variables related to BMR and oxygen consumption. The study revealed no significant difference between BMR and EE of sedentary activity in the subjects. The wide variability may have been due to the nutritional status of the subjects studied, who were drawn largely from the lower socioeconomic groups of Nigerian society. The present study shows that socioeconomic status and nutritional interventions should be taken into account when framing recommendations for maternal nutrition during pregnancy.     

Alcohol intake, smoking, sleeping hours, physical activity and the metabolic syndrome

OBJECTIVE: To evaluate the association between physical activity, sleeping hours, alcohol intake and smoking and metabolic syndrome. METHODS: Social, demographic, personal and family medical histories and behavioral characteristics were collected as self-reported for 2164 participants (1332 women; 832 men), aged 18-92 years old, randomly selected during 1999-2003, among residents in Porto, Portugal, evaluated in the Department of Epidemiology of Porto Medical School. Metabolic syndrome was defined according to the NCEP-ATPIII. Associations between metabolic syndrome and lifestyles factors were computed as odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: After adjustment, higher total physical activity (OR=0.63 95% CI%: 0.43, 0.94--females; OR=0.55 95% CI: 0.33, 0.91--males) and work activity levels in females (OR=0.55; 95% CI: 0.33, 0.91) were significantly associated with lower prevalence of the metabolic syndrome. More sleeping hours were positively associated with metabolic syndrome (OR=1.25; 95% CI: 1.13, 1.38--females; OR=1.19; 95% CI: 1.04, 1.36--males). Regarding smoking, the only statistically significant association was found in women that smoked less than 10 cigarettes per day (OR=0.32 95% CI: 0.11, 0.92). No statistically significant association was found between ethanol intake and metabolic syndrome. CONCLUSIONS: An association between decreased physical activity, increased sleeping hours and metabolic syndrome was found. No association was found between cigarette smoking, alcohol intake and the metabolic syndrome.     

Total daily energy expenditure and pattern of physical activity measured by minute-by-minute heart rate monitoring in 14-15 year old Swedish adolescents

OBJECTIVE: To assess total daily energy expenditure (TDEE) and patterns of physical activity among Swedish male and female adolescents and to relate the amount and intensity of physical activity to existing recommendations (energy expenditure equal to or above 12.4 kJ/kg/day or accumulation of 30 min/day in moderate physical activity equal to 4.5 times sedentary energy expenditure or more). DESIGN: TDEE, physical activity level (PAL=TDEE/BMR), energy expenditure (EE) and time spent in different intensities of physical activity were assessed by using minute-by-minute heart rate monitoring in combination with laboratory measured sedentary energy expenditure (SEE) and peak oxygen uptake. SETTING: Department of Physical Education and Health, Orebro University, and Department of Clinical Physiology, Orebro Medical Centre Hospital, Sweden. SUBJECTS: Eighty-two 14-15 y old adolescents (42 boys, 40 girls) from the city of Orebro, randomly selected through a two-stage sampling procedure. RESULTS: TDEE was 12.8 MJ/day and 10.0 MJ/day for boys and girls respectively (P<0.001) and PAL was 1.74 and 1.67 (NS). Forty-four percent and 47%, respectively, of TDEE referred to EE in physical activity, of which 70% for both genders referred to light physical activity (corresponding to <4.5 times SEE). Eleven boys and 14 girls had an EE lower than 12.4 kJ/kg/day and/or did not accumulate 30 min/day in physical activity >/=4.5 SEE. Those (n=20) with the highest PAL values (>2.01 and 1.81, respectively) spent 149 min/day at a >/=4.5 SEE intensity level compared to 40 min/day for those (n=30) with the lowest PAL values (<1.55 and 1.45, respectively). CONCLUSIONS: Swedish adolescent boys and girls are similarly physically active. The major amount of time devoted to physical activity refers to light physical activity. At least thirty percent of adolescents seem not to achieve appropriate levels of physical activity considered to be beneficial for health. SPONSORSHIP: Orebro County Council, The Public Health Committee of Stockholm County Council, Sweducation Foundation.     

Effect of 12 weeks' light-moderate underfeeding on 24-hour energy expenditure in normal male and female subjects

The effect of 12 weeks' light-moderate underfeeding on the 24-h energy expenditure of a fixed physical activity programme was studied in six male and six female subjects. During a control period of 2 weeks, measurements were made of 24-h energy expenditure by direct calorimetry, the lean and fat body masses and the subjects' habitual energy intakes. The average body weight was 107 per cent of ideal, and did not change significantly during the control period. The subjects were asked to continue to record their daily food intake while reducing it by 25 per cent and to continue their daily activity habits during a period of 12 weeks. The mean change in body weight was -2.9 kg with an average change in body energy content of -66 MJ. The 24-h energy expenditure was measured three times during the period, ie, after 4, 8 and 12 weeks from the start of the decreased energy intake, and found to be practically the same as the control value, ie, with average differences (s.d.) of -0.2(3.9), -0.8(5.7) and +0.6(4.2) per cent from the control value. In the six subjects who had the largest loss of body weight, this was found to be 5.0 kg, and the mean differences (s.d.) in energy expenditure were found to be -1.0(3.4), 0.0(5.6) and -0.6(3.9) per cent, respectively, from the control value. A significant part of the between-subjects variation in the differences from the control value is due to random measurement error and it is concluded that a loss of body energy content of the magnitude reported here, and due mainly to a reduced food intake, does not result in a significant increase in the efficiency of energy conversion, ie, in metabolic adaptation.