Sit-stand workstations offer a potential strategy to reduce prolonged occupational sitting. This controlled intervention study examined the effects of an environmental intervention on occupational sedentary time, musculoskeletal comfort and work ability, and the usability of sit-stand workstations in office work via a self-reported questionnaire. The intervention group (n = 24) used sit-stand workstations during the 6-month intervention period, and the control group (n = 21) used traditional sitting workstations. The results showed that working at sit-stand workstations can reduce sitting time significantly compared to control workstations (-6.7% vs. 5.0%, p = .019), which is reallocated mostly to standing (r = -0.719, p < .001). Sit-stand workstations improved perceived musculoskeletal comfort in the neck and shoulders (p = .028), as well as work ability (p = .022). The majority of intervention subjects rated sit-stand workstation adjustability as good (83.3%), and 75.0% were satisfied with the workstation. About 41.7% of the intervention participants, who were exclusively female, used the sit-stand function on a daily basis. While the environmental change alone was effective, it is likely that promoting the daily use of sit-stand workstations with counselling would lead to even more substantial positive effects.

Purpose: While merely standing up interrupts sedentary behavior, it is important to study acute metabolic responses during single bouts of sitting and standing to understand the physiological processes affecting the health of office workers. Methods: 18 healthy middle aged women aged 49.4 ± 7.9 years (range: 40 to 64) with a BMI of 23.4 ± 2.8 kg·m -2 volunteered for this laboratory-based randomized crossover trial where they performed two hours desk work either in sitting or standing postures after overnight fasting. Muscle activity (normalized to walking at 5 km/h), respiratory gas exchange and blood samples were assessed following glucose loading (75 g). Results: Compared with seated work, continuous standing resulted in greater activity in the thigh muscles (mean of biceps femoris and vastus lateralis: 17 ± 8% vs. 7 ± 2%, p < 0.001), and leg muscles (mean of tibialis anterior, gastrocnemius medialis and soleus: 16 ± 6% vs. 7 ± 3%, p<0.001), but no increases in back muscle activity (thoracic erector spinae, lumbar erector spinae and multifidus). Concomitant with ~9% higher energy expenditure (EE) (p = 0.002), standing resulted in higher fat oxidation (48 ± 9%EE vs. 39 ± 7%EE, p = 0.008) and lower carbohydrate oxidation (52 ± 9%EE vs. 61 ± 7%EE, p = 0.008) than sitting. Glucose total and net incremental area under the curve were ~10% (p = 0.026) and ~42% (p = 0.017) higher during standing than sitting, respectively. Insulin concentration did not differ between conditions. Conclusion:Compared to sitting, two hours of standing increased muscle activity, fat oxidation and circulating glucose level. These results suggest fuel switching in favor of fat oxidation during standing despite extra carbohydrate availability.

We investigated the ability of energy expenditure, movement sensing, and muscle activity to discriminate sedentary and non-sedentary activities in children. Thirty-five 7–11-year-old children participated in the study. Simultaneous assessment of oxygen uptake (V̇O 2 ), triaxial accelerometry, and thigh muscle electromyography (EMG) were performed during eight different sedentary and non-sedentary activities including lying down, sitting-, standing-, and walking-related activities, which were performed in a random order. Mean values of V̇O 2 , accelerometry, and EMG from the concurrent 2 min epochs during each activity were computed. Resting energy expenditure (REE) was measured during 30 min supine rest. Directly measured metabolic equivalent of tasks (METs, V̇O 2 in activities/V̇O 2 in REE) were calculated for each activity. Mean amplitude deviation (MAD) was computed for accelerometry. EMG was normalized for mean muscle activity during self-paced walking. The classification accuracy of METs, MAD, and EMG to discriminate sedentary activities from physical activities was investigated by receiver operating characteristic curves and optimal cut-offs based on maximal sensitivity and specificity. Mean (SD) REE was 5.0 ± 0.8 ml/kg/min. MET, MAD, and EMG values ranged from 1.0 to 4.9, 0.0020 to 0.4146 g, and 4.3 to 133.9% during lying down and walking at 6 km/h, respectively. Optimal cut-offs to discriminate sedentary activities from non-sedentary activities were 1.3 for METs (sensitivity = 82%, specificity = 88%), 0.0033 g for MAD (sensitivity = 80%, specificity = 91%), and 11.9% for EMG (sensitivity = 79%, specificity = 92%). In conclusion, this study provides applicable thresholds to differentiate sitting and standing and sedentary and non-sedentary activities based on METs, MAD, and EMG in young children.

To investigate the association between overall life satisfaction and healthy lifestyle, knowledge of breast cancer, physical examination, and detection rate of breast cancer and benign breast disease in Chinese women. In a multicentered breast disease screening program in China, we enrolled 33,057 women aged 45–65 years without prior diagnosis of breast cancer. After completing an epidemiological questionnaire, all participants were examined by clinical breast examination, breast ultrasound, and mammography independently. All breast cancer cases and a selected sample of benign breast diseases were confirmed pathologically. Univariate and multivariate odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association between life satisfaction and lifestyle, knowledge of breast cancer, physical examination, and detection rate of breast diseases. Overall life satisfaction was positively associated with women's healthy lifestyle. Compared with less satisfied women, satisfied women were less likely to be smokers (OR = 0.54; 95% CI: 0.47–0.62), have more exercise (OR = 1.49; 95% CI: 1.26–1.75), eat less fried (OR = 0.60; 95% CI: 0.50–0.71), smoked (OR = 0.54, 95% CI: 0.47–0.63), pickled (OR = 0.66, 95% CI: 0.55–0.79), and grilled (OR = 0.63, 95% CI: 0.54–0.74) foods. Satisfied women were more likely to have knowledge of breast cancer (OR = 1.48, 95% CI: 1.29–1.70), and have regular physical examinations (OR = 1.11, 95% CI: 1.01–1.12). Compared to less satisfied women, we found significantly lower detection rate of benign breast diseases (OR = 0.90, 95% CI: 0.82–0.99), and lower but nonsignificant detection rate of breast cancer (OR = 0.66, 95% CI: 0.35–1.25) in satisfied women. Women with a higher overall life satisfaction are more likely to have healthy lifestyle, knowledge of breast cancer, and regular physical examination, thus resulting in a lower detection rate of breast diseases in screening.

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