Standing economy: does the heterogeneity in the energy cost of posture maintenance reside in differential patterns of spontaneous weight-shifting?

Standing or Very Low-Intensity Cycling as Sedentary Breaks: Does Physical Activity Level Matter?

BACKGROUND

Active breaks and very low- to low-intensity exercises such as walking or cycling at an active desk have been shown to significantly counteract the negative effect of prolonged sedentary behaviors. The objective was to investigate the effect of physical activity level (PAL) on changes in energy expenditure (EE), heart rate, and substrate oxidation from sit-to-stand and sit-to-light cycling.

METHODS

Fifty healthy young males and females (age: 23.9 [3.9] y, body mass index: 22.9 [2.3] kg/m2) were submitted to a fixed 1 hour session of different posture allocations: 15-minute sitting, 15-minute standing, 15-minute sitting, and 15-minute very low-intensity cycling. EE, substrate oxidation rates, and heart rate were continuously assessed throughout the experimental visit. Data were then compared between participants according to their PAL in tertiles (low, medium, or high). The high-PAL group showed lower sedentary time (P < .0001) and higher time spent in low (P < .0001), moderate (P < .0001), and vigorous physical activity (P = .0034).

RESULTS

ANOVA's analysis showed that EE significantly increased when standing (+11%) and cycling (+94%) relative to the seated position (P < .05) without any differences between groups. There was also a significant increase in heart rate during standing and cycling compared with sitting (P < .05) without any differences between groups. Relative EE (in kilocalories per minute per kilogram) was significantly higher when seated (P < .05) independent of PAL but marginally higher in the high-PAL group when standing relative to the medium-PAL group (P = .06).

CONCLUSION

The findings of this study suggest that people's PAL does not impact energetic and metabolic adaptations during sit-to-stand and sit-to-very-light-intensity cycling exercise.

The Energetic Saver Profile From Sit-to-Stand Does Not Persist During Very Low-Intensity Physical Activity in Healthy Men and Women

BACKGROUND

It is essential to better characterize the energetic profile of individuals during very low-intensity physical activity. The objectives of the present study were to determine whether the saver profile from sit-to-stand persists during light physical activity and characterize patterns in substrate utilization from sit-to-stand and during very low-intensity physical activity in healthy men and women.

METHODS

Sixty-two healthy adults (38 women) performed an experimental sequence that corresponded to 15-minute sitting (SIT1), followed by 15-minute standing (STAND), 15-minute sitting again (SIT2), and finally 15 minutes of light cycling. Continuous indirect calorimetry was allowed to calculate energy expenditure (EE) and respiratory quotient through the entire sequence. Savers and nonsavers (<5% and ≥ 5% increase in EE from sitting to standing, respectively) were determined.

RESULTS

There was an interaction effect in EE between savers and nonsavers through the whole sequence (P = .008). Only nonsavers (71%) exhibited a significant increase in EE from SIT1 to STAND (P < .001). Nonsavers and savers significantly increased EE during 15 minutes of light cycling relative to sitting or standing (P < .001), without any difference between groups. The percentage of change in respiratory quotient from SIT1 to STAND was significantly different between the 2 groups, with increased values in savers and decreased values in nonsavers (P = .03). Significantly lower values in respiratory quotient and EE were found during 15 minutes of light cycling in women compared with men (P < .001).

CONCLUSIONS

It is essential to determine individuals' energetic phenotype to determine those who may benefit more from strategies such as standing or light physical activity. The sexual dimorphism in terms of substrate use during such exercise should be considered.

Weight loss does not affect the sit-to-stand metabolic cost in adolescents with obesity

PURPOSE

There is considerable interest in simple and effective methods to reduce sitting time and increase energy expenditure, and standing breaks have emerged as a realisable approach in individuals with obesity. The aim of the present study was to determine the extent to which energy expenditure in standing differs from sitting, and whether this energetic and metabolic-related responses are modified following a weight loss program in adolescents with obesity.

METHODS

After body composition assessment (DXA), cardiorespiratory and metabolic variables were continuously recorded (indirect calorimetry) during 10 min while sitting and then during 5 min standing posture before (n = 21; T1) and at the end of a multidisciplinary intervention (n = 17; T2) in adolescents with obesity.

RESULTS

Before and after the intervention, energy expenditure and fat oxidation rates were significantly increased in standing compared with sitting. Weight loss did not change the relationship between sitting and standing energy expenditure. Sitting energy expenditure represented 1.0 and 1.1 Metabolic Equivalent of Task at T1 and T2, and increased to 1.1 and 1.2 during standing at T1 and T2, respectively. The percentage of change of android fat mass between T1 and T2 was positively associated with the percentage of change in energy expenditure from sitting to standing at T2.

CONCLUSION

The vast majority of the adolescents with obesity significantly increased their energy expenditure between sitting and standing, both before and after a weight loss intervention. However, the standing posture did not allow breaking the sedentary threshold. Abdominal fat mass is associated with energic profile.

Effects of reducing sedentary behaviour duration by increasing physical activity, on cognitive function, brain function and structure across the lifespan: a systematic review protocol

INTRODUCTION

Greater engagement in sedentary behaviours has been related to poorer cognitive functions in epidemiological research. However, the effects of reducing sedentary behaviour duration on cognitive function, brain function, and structure remain poorly understood. This systematic review aims to synthesise the evidence on the effects of reducing sedentary behaviour duration by increasing time spent in physical activity on cognitive function, brain structure and function in apparently healthy children, adolescents and adults.

METHODS AND ANALYSIS

The protocol follows Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The literature search will be conducted (search dates: August-September 2022) across six databases: PubMed, Scopus, Cumulative Index to Nursing and Allied Health Literature (via EBSCO Host), PsycINFO (via ProQuest), SPORTDiscus and Web of Science (Science and Social Science Citation Index). The inclusion criteria are as follows: randomised and non-randomised experimental studies as defined by the Cochrane Handbook, published in English, in peer-reviewed journals, and as theses or dissertations. References of included papers will be screened for additional studies. Acute and chronic interventions targeting children (≥ 4 years), adolescents, younger adults (≥ 18-40 years), middle-aged (40-64 years) and older adults (65+ years) will be eligible. Methodological quality will be assessed with the Effective Public Health Practice Project quality assessment tool for quantitative studies. Qualitative synthesis will be stratified by intervention type (acute vs chronic), intervention content (reducing sedentary time or interrupting prolonged sitting) and outcome (cognitive, brain structure and function).

ETHICS AND DISSEMINATION

No primary data collection will be conducted as part of this systematic review. Study findings will be disseminated through peer-reviewed publications, conference presentations and social media.

PROSPERO REGISTRATION NUMBER

CRD42020200998.

Posture economy: the importance of metabolic state on metabolic phenotype assessment and the energy cost of sitting and standing. A whole body calorimetry trial

BACKGROUND

Metabolic state (fed vs fasted) can result in marked differences in exercise metabolism, fat, and carbohydrate oxidation. In addition, a large inter-individual range in metabolic response to sitting and standing when fasted has been observed. Here, we examined the effect of metabolic state on the energy cost of posture allocation.

METHODS

Thirty male participants were recruited and followed a 1 h sit-stand protocol in a fasted and fed state inside a whole body calorimeter to measure energy expenditure (EE) and respiratory quotient (RQ). Body composition and resting metabolic rate were measured before the start. Fasted EE response was used to phenotype participants as energy savers (≤5% ΔEE from sitting to standing) or energy spenders (>5% ΔEE).

RESULTS

In a fasted state, ΔEE from sitting to standing in energy spenders was 10.2 ± 2.7% compared to 2.6 ± 1.9% in energy savers (p < 0.001). Postprandial, there was no difference in ΔEE between energy spenders and energy savers (10.8 ± 5.1% vs 9.4 ± 5.7%). In a fasted state, significant correlations were observed between body fat (%) and ΔEE (%) (R² = 0.55, p < 0.001), body fat (%) and ΔRQ (R² = 0.28, p < 0.001) and ΔEE (%) and ΔRQ (R² = 0.43, p < 0.001); these correlations were not present after the meal.

CONCLUSIONS

The current study showed for the first time, that the observed difference between energy spenders and energy savers in a fasted state, disappeared after the consumption of a meal. Therefore, metabolic state may be important to consider when assessing metabolic phenotypes. Differences in body composition were observed between the energy spender and energy saver phenotype. The current findings may have implications on health and weight management recommendations on posture to increase non-exercise activity thermogenesis. This trial was retrospectively registered on 19 December 2017 as NCT03378115 on Clinicaltrials.gov .

Metabolic profile in women differs between high versus low energy spenders during a low intensity exercise on a cycle-desk

Active-desks are emerging strategies aiming at reducing sedentary time while working. A large inter-individual variability in energy expenditure (EE) profile has been identified and has to be explored to better optimize and individualize those strategies. Thus the present study aimed at comparing the metabolic and physical profile of individuals characterized as high spenders (H-Spenders) versus low spenders (L-Spenders) based on EE during a cycle-desk low intensity exercise. 28 healthy women working in administrative positions were enrolled. Anthropometric, body composition and fasting metabolic profile parameters were assessed. EE was determined by indirect calorimetry, at rest and during a 30-min cycle-desk use. Participants were categorized as H-Spenders and L-Spenders using the median of the difference between EE at rest and during the 30-min exercise. H-Spenders had higher mean EE (p < 0.001) and carbohydrate oxidation (p = 0.009) during exercise. H-Spenders displayed higher values for fasting plasma insulin (p = 0.002) and HOMA-IR (p = 0.002) and lower values for HDL-cholesterol (p = 0.014) than L-Spenders. The percentage of body fat mass was significantly higher in H-Spenders (p = 0.034). Individuals expending more energy during a low intensity cycling exercise presented a less healthy metabolic profile compared with L-Spenders. Future studies will have to explore whether the chronic use of cycle-desks during work time can improve energy profile regarding metabolic parameters.

Cardiometabolic and neuromuscular analyses of the sit-to-stand transition to question its role in reducing sedentary patterns

To counteract the detrimental health effect of sitting all day long, it has been suggested to regularly break sitting time by standing. However, while the difference in energy expenditure, neuromuscular and/or cardiovascular demand of various postures from lying, sitting, and standing is well documented, little is known regarding the dynamic changes occurring during the sit-to-stand transition itself. The aim of the present study was then to describe the cardiometabolic and neuromuscular responses from sitting to standing and specifically during the time-course of this transition. Twelve healthy young participants were asked to perform standardized raises from sitting posture, while cardiometabolic (cardiorespiratory and hemodynamic variables) and neuromuscular (calf muscles' myoelectrical activity, spinal and supraspinal excitabilities) parameters were monitored. As a result, while there was a rapid adaptation for all the systems after rising, the neuromuscular system displayed the faster adaptation (~ 10 s), then hemodynamic (~ 10 to 20 s) and finally the metabolic variables (~ 30 to 40 s). Oxygen uptake, energy expenditure, ventilation, and heart rate were significantly higher and stroke volume significantly lower during standing period compared to sitting one. In calf muscles, spinal excitability (H-reflexes), was lowered by the sit-to-stand condition, while supraspinal drive (V-wave) was similar, indicating different cortico-spinal balance from sitting to standing. Although very heterogenous among participants in terms of magnitude, the present results showed a rapid adaptation for all the systems after rising and the health benefit, notably in terms of energy expenditure, appears rather modest, even if non negligeable.

Effects of Interrupting Prolonged Sitting with Physical Activity Breaks on Blood Glucose, Insulin and Triacylglycerol Measures: A Systematic Review and Meta-analysis

BACKGROUND

Physical activity (PA) breaks in sitting time might attenuate metabolic markers relevant to the prevention of type 2 diabetes.

OBJECTIVES

The primary aim of this paper was to systematically review and meta-analyse trials that compared the effects of breaking up prolonged sitting with bouts of PA throughout the day (INT) versus continuous sitting (SIT) on glucose, insulin and triacylglycerol (TAG) measures. A second aim was to compare the effects of INT versus continuous exercise (EX) on glucose, insulin and TAG measures.

METHODS

The review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) recommendations. Eligibility criteria consisted of trials comparing INT vs. SIT or INT vs. one bout of EX before or after sitting, in participants aged 18 or above, who were classified as either metabolically healthy or impaired, but not with other major health conditions such as chronic obstructive pulmonary disease or peripheral arterial disease.

RESULTS

A total of 42 studies were included in the overall review, whereas a total of 37 studies were included in the meta-analysis. There was a standardised mean difference (SMD) of - 0.54 (95% CI - 0.70, - 0.37, p = 0.00001) in favour of INT compared to SIT for glucose. With respect to insulin, there was an SMD of - 0.56 (95% CI - 0.74, - 0.38, p = 0.00001) in favour of INT. For TAG, there was an SMD of - 0.26 (95% CI - 0.44, - 0.09, p = 0.002) in favour of INT. Body mass index (BMI) was associated with glucose responses (β = - 0.05, 95% CI - 0.09, - 0.01, p = 0.01), and insulin (β = - 0.05, 95% CI - 0.10, - 0.006, p = 0.03), but not TAG (β = 0.02, 95% CI - 0.02, 0.06, p = 0.37). When energy expenditure was matched, there was an SMD of - 0.26 (95% CI - 0.50, - 0.02, p = 0.03) in favour of INT for glucose, but no statistically significant SMDs for insulin, i.e. 0.35 (95% CI - 0.37, 1.07, p = 0.35), or TAG i.e. 0.08 (95% CI - 0.22, 0.37, p = 0.62). It is worth noting that there was possible publication bias for TAG outcomes when PA breaks were compared with sitting.

CONCLUSION

The use of PA breaks during sitting moderately attenuated post-prandial glucose, insulin, and TAG, with greater glycaemic attenuation in people with higher BMI. There was a statistically significant small advantage for PA breaks over continuous exercise for attenuating glucose measures when exercise protocols were energy matched, but no statistically significant differences for insulin and TAG. PROSPERO Registration: CRD42017080982.

PROSPERO REGISTRATION

CRD42017080982.

The Energy Cost of Sitting versus Standing Naturally in Man

PURPOSE

Prolonged sitting is a major health concern, targeted via government policy and the proliferation of height-adjustable workstations and wearable technologies to encourage standing. Such interventions have the potential to influence energy balance and thus facilitate effective management of body/fat mass. It is therefore remarkable that the energy cost of sitting versus standing naturally remains unknown.

METHODS

Metabolic requirements were quantified via indirect calorimetry from expired gases in 46 healthy men and women (age, 27 ± 12 yr; mass, 79.3 ± 14.7 kg; body mass index, 24.7 ± 3.1 kg·m, waist/hip, 0.81 ± 0.06) under basal conditions (i.e., resting metabolic rate) and then, in a randomized and counterbalanced sequence, during lying, sitting and standing. Critically, no restrictions were placed on natural/spontaneous bodily movements (i.e., fidgeting) to reveal the fundamental contrast between sitting and standing in situ while maintaining a comfortable posture.

RESULTS

The mean (95% confidence interval [CI]) increment in energy expenditure was 0.18 (95% CI, 0.06-0.31 kJ·min) from resting metabolic rate to lying was 0.15 (95% CI, 0.03-0.27 kJ·min) from lying to sitting and 0.65 (95% CI, 0.53-0.77 kJ·min) from sitting to standing. An ancillary observation was that the energy cost of each posture above basal metabolic requirements exhibited marked interindividual variance, which was inversely correlated with resting heart rate for all postures (r = -0.5; -0.7 to -0.1) and positively correlated with self-reported physical activity levels for lying (r = 0.4; 0.1 to 0.7) and standing (r = 0.6; 0.3-0.8).

CONCLUSIONS

Interventions designed to reduce sitting typically encourage 30 to 120 min·d more standing in situ (rather than perambulation), so the 12% difference from sitting to standing reported here does not represent an effective strategy for the treatment of obesity (i.e., weight loss) but could potentially attenuate any continued escalation of the ongoing obesity epidemic at a population level.

Accuracy of 12 Wearable Devices for Estimating Physical Activity Energy Expenditure Using a Metabolic Chamber and the Doubly Labeled Water Method: Validation Study

Background

Self-monitoring using certain types of pedometers and accelerometers has been reported to be effective for promoting and maintaining physical activity (PA). However, the validity of estimating the level of PA or PA energy expenditure (PAEE) for general consumers using wearable devices has not been sufficiently established.

Objective

We examined the validity of 12 wearable devices for determining PAEE during 1 standardized day in a metabolic chamber and 15 free-living days using the doubly labeled water (DLW) method.

Methods

A total of 19 healthy adults aged 21 to 50 years (9 men and 10 women) participated in this study. They followed a standardized PA protocol in a metabolic chamber for an entire day while simultaneously wearing 12 wearable devices: 5 devices on the waist, 5 on the wrist, and 2 placed in the pocket. In addition, they spent their daily lives wearing 12 wearable devices under free-living conditions while being subjected to the DLW method for 15 days. The PAEE criterion was calculated by subtracting the basal metabolic rate measured by the metabolic chamber and 0.1×total energy expenditure (TEE) from TEE. The TEE was obtained by the metabolic chamber and DLW methods. The PAEE values of wearable devices were also extracted or calculated from each mobile phone app or website. The Dunnett test and Pearson and Spearman correlation coefficients were used to examine the variables estimated by wearable devices.

Results

On the standardized day, the PAEE estimated using the metabolic chamber (PAEEcha) was 528.8±149.4 kcal/day. The PAEEs of all devices except the TANITA AM-160 (513.8±135.0 kcal/day; P>.05), SUZUKEN Lifecorder EX (519.3±89.3 kcal/day; P>.05), and Panasonic Actimarker (545.9±141.7 kcal/day; P>.05) were significantly different from the PAEEcha. None of the devices was correlated with PAEEcha according to both Pearson (r=−.13 to .37) and Spearman (ρ=−.25 to .46) correlation tests. During the 15 free-living days, the PAEE estimated by DLW (PAEEdlw) was 728.0±162.7 kcal/day. PAEE values of all devices except the Omron Active style Pro (716.2±159.0 kcal/day; P>.05) and Omron CaloriScan (707.5±172.7 kcal/day; P>.05) were significantly underestimated. Only 2 devices, the Omron Active style Pro (r=.46; P=.045) and Panasonic Actimarker (r=.48; P=.04), had significant positive correlations with PAEEdlw according to Pearson tests. In addition, 3 devices, the TANITA AM-160 (ρ=.50; P=.03), Omron CaloriScan (ρ=.48; P=.04), and Omron Active style Pro (ρ=.48; P=.04), could be ranked in PAEEdlw.

Conclusions

Most wearable devices do not provide comparable PAEE estimates when using gold standard methods during 1 standardized day or 15 free-living days. Continuous development and evaluations of these wearable devices are needed for better estimations of PAEE.

Ruiz J. Energy expenditure differences across lying, sitting, and standing positions in young healthy adults

The time spent in sedentary behaviour represents an important public health burden. To reduce sedentary time in the general population, the simplest, most effective, and most accessible method is to decrease lying and sitting time. We aimed to compare differences on energy expenditure (EE) across lying, sitting, and standing positions; and to analyse the associations between the change on EE of changing from one position to another and anthropometric and body composition parameters in young healthy adults. A total of 55 (69% women) young healthy adults aged 21.7 ± 2.2 participated in the study. We measured EE by indirect calorimetry across lying, sitting, and standing positions following the standard procedures. The EE was significantly higher in standing than in both lying and sitting positions (mean difference: 0.121±0.292 and 0.125±0.241 kcal/min, respectively; all P<0.001), and no differences were observed between lying and sitting positions (P = 1.000). There was a negative association between the EE differences in sitting vs. standing position and lean body mass (P = 0.048), yet no associations between EE differences with the rest of the anthropometric and body composition parameters were observed in each position pair studied (all P>0.321). Our findings support the fact that increasing the time spent standing could be a simple strategy to slightly increase EE. Therefore, our results have important clinical implications including a better monitoring, characterizing, and promoting countermeasures to sedentariness through low-level physical activities.

Gender-specific considerations in physical activity, thermogenesis and fat oxidation: implications for obesity management

With current 'one-size-fits-all' obesity prevention and management strategies proving largely ineffective, the focus has shifted towards a more tailored, individualized approach. However, investigation of the mechanisms underlying inter-individual variability in metabolic profile and response to intervention often yield conflicting results. Indeed, it is perhaps surprising that despite at least a century of recognition that sex hormones influence metabolism, firm conclusions regarding the effects of the menstrual cycle, hormonal contraception and menopause on many aspects of energy expenditure and substrate utilization remain to be drawn. In this review, we examine current evidence relating to gender-specific considerations in the promotion of physical activity, thermogenesis and fat oxidation for body-weight regulation, including the relationship between sex hormone status and non-exercise activity thermogenesis - an energy expenditure compartment that is often overlooked in favour of traditional exercise/sport physical activities yet presents a viable target in the search for effective weight management.

Disentangling the relationship between sedentariness and obesity: Activity intensity, but not sitting posture, is associated with adiposity in women

BACKGROUND

The relationship between free-living sedentary behaviour (SB) and obesity is unclear. Studies may arrive at disparate conclusions because of inconsistencies and limitations when defining and measuring free-living SB. The aim of this cross-sectional study was to examine whether the relationship between SB and adiposity differed depending on the way SB was operationally defined and objectively measured.

METHODS

Sixty-three female participants aged 37.1 years (SD = 13.6) with a body mass index (BMI) of 29.6 kg/m² (SD = 4.7) had their body composition measured (BodPod, Concord, CA) then were continuously monitored for 5-7 days with the SenseWear Armband (SWA; sleep and activity intensity) and the activPAL (AP; posture). Data from both activity monitors were analysed separately and integrated resulting in a third measure of SB (activity intensity and posture; SED^INT). SB outputs were compared according to week or weekend day averages then correlated against body composition parameters after adjusting for moderate-to-vigorous physical activity (MVPA).

RESULTS

SED^SWA resulted in the most sedentary time 11.74 h/day (SD = 1.60), followed by SED^AP 10.16 h/day (SD = 1.75) and SED^INT 9.10 h/day (SD = 1.67). There was a significant positive association between SED^SWA and body mass [r(61) = 0.29, p = .02], BMI [r (61) = 0.33, p = .009] and fat mass [r(61) = 0.32, p = .01]. SED^AP and SED^INT were not associated with any of the indices of adiposity. Correlations between SB and adiposity were non-significant when controlling for MVPA.

CONCLUSIONS

The relationship between SB and adiposity differed depending on how SB was operationally defined and measured, and was dependent on MVPA. The definition of SB based on a sitting posture (SED^AP) was not strongly related to body fat, whereas the accumulation of any behaviour (sitting or standing) with an intensity of <1.5 METs (SED^SWA) (offset by the presence of MVPA) was positively associated with indices of adiposity. These data suggest that the postural element of SB (sitting) is not sufficient for the accumulation of adiposity, rather activities requiring low EE (<1.5 METs) and the absence of MVPA, regardless of posture, are associated with higher fat mass.

Validity of a triaxial accelerometer and simplified physical activity record in older adults aged 64-96 years: a doubly labeled water study

BACKGROUND

The aim was to examine the validity of a triaxial accelerometer (ACCTRI) and a simplified physical activity record (sPAR) in estimating total energy expenditure (TEE) and physical activity level (PAL) in older adults with the doubly labeled water (DLW) method.

METHODS

A total of 44 Japanese elderly individuals (64-96 years), of which 28 were community-dwelling healthy adults with or without sporting habits (S or NS group) and 16 were care home residents with frailty (F group), were included in the study. Basal metabolic rate (BMR) was measured by indirect calorimetry, TEE was obtained by the DLW method, and PAL was calculated as TEE/BMR. Daily step count was monitored by a pedometer (Lifecorder). The 24-h average metabolic equivalent was assessed by ACCTRI and sPAR.

RESULTS

The TEE_DLW in men was 2704 ± 353, 2308 ± 442, and 1795 ± 338 kcal d^-1, and that in women was 2260 ± 208, 1922 ± 285, and 1421 ± 274 kcal d^-1 for the S, NS, and F groups, respectively. ACCTRI and sPAR systematically underestimated actual TEE (- 14.2 ± 11.6 and - 15.3 ± 12.3% for ACCTRI and sPAR, respectively). After diet-induced thermogenesis was taken into account for ACCTRI and sPAR, TEE_DLW was significantly correlated with TEE_ACCTRI (R² = 0.714) and TEE_sPAR (R² = 0.668). PAL_DLW was also significantly correlated with PAL_ACCTRI (R² = 0.438) and PAL_sPAR (R² = 0.402).

CONCLUSIONS

Age, living conditions, frailty, and sporting habits contribute to TEE and PAL in the elderly population. ACCTRI and sPAR underestimated TEE and PAL, and adequate corrections are required. The corrected ACCTRI and sPAR are both useful tools to estimate TEE and PAL.

Posture Allocation Revisited: Breaking the Sedentary Threshold of Energy Expenditure for Obesity Management

There is increasing recognition that low-intensity physical activities of daily life play an important role in achieving energy balance and that their societal erosion through substitution with sedentary (mostly sitting) behaviors, whether occupational or for leisure, impact importantly on the obesity epidemic. This has generated considerable interest for better monitoring, characterizing, and promoting countermeasures to sedentariness through a plethora of low-level physical activities (e.g., active workstations, standing desks, sitting breaks), amid the contention that altering posture allocation (lying, sitting, standing) can modify energy expenditure to impact upon body weight regulation and health. In addressing this contention, this paper first revisits the past and more recent literature on postural energetics, with particular emphasis on potential determinants of the large inter-individual variability in the energy cost of standing and the impact of posture on fat oxidation. It subsequently analyses the available data pertaining to various strategies by which posture allocations, coupled with light physical activity, may increase energy expenditure beyond the sedentary threshold, and their relevance as potential targets for obesity management.