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Objectives: We aimed to investigate accelerometer output corresponding to physical activity intensity cut-points based on percentage of peak oxygen consumption (%VO 2 peak) and Metabolic Equivalent of Task (MET) value in women treated for breast cancer., Design: Laboratory study., Methods: Fifty female patients shortly after completion of treatment for breast cancer were included. VO 2 peak was determined during a cardiopulmonary exercise test. Subsequently, patients performed ten activities with different intensities while wearing an accelerometer on the right hip and a mobile oxycon to assess oxygen consumption. We studied the relationship between energy expenditure (expressed as %VO 2 peak and MET-value) and accelerometer output (in counts per minute (cpm)) with linear regression analyses. We determined accelerometer output corresponding to physical activity intensity cut-points (40% and 60%VO 2 peak; 3 and 6 MET) using regression equations., Results: VO 2 peak was 22.4mL/kg/min (SD 5.2) and resting metabolic rate was 3.1mL/kg/min (SD 0.6). Accelerometer output corresponding to the cut-points for moderate (40% VO 2 peak) and vigorous intensity (60% VO 2 peak) were 1123 and 1911, respectively. The analyses based on MET-values resulted in accelerometer output of 1189cpm for the moderate (3 MET) and 2768 cpm for the vigorous intensity cut-point (6 MET)., Conclusions: Accelerometer outputs for moderate and vigorous intensity physical activity were lower than commonly used cut-points (i.e. 1952 and 5724 cpm), irrespective of the method used to express energy expenditure (%VO 2 peak versus MET-value). Thus, categorizing physical activity intensities based on general-population cut-points, may underestimate physical activity intensities for women treated for breast cancer., (Copyright © 2019 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Objectives: Standing desks and stability balls are increasingly popular to increase muscle activity and thereby prevent potential adverse cardiometabolic effects of prolonged sitting. The present study examined the effects of (1) sitting on a stability ball ('active sitting') and (2) hourly 10-min standing interruptions during prolonged sitting on postprandial cardiometabolic biomarkers., Design: Experimental crossover study., Methods: Twenty healthy-weight males (19.2±0.6years) participated randomly in three 5-h conditions: (1) sitting on an office chair (SIT), (2) sitting on a stability ball (SIT-ACTIVE) and (3) sitting with hourly 10-min standing interruptions (SIT-STAND). In each condition, participants consumed a standardized mixed meal at baseline. Hourly blood samples and pre/post saliva samples were collected and analyzed for levels of insulin, glucose and cortisol. Pre/post hemodynamic monitoring (middle finger; Nexfin-monitoring) was conducted; heart rate was measured continuously (Polar) and muscle activity (leg and lower-back, Portilab) was measured during periods of sitting (on an office chair and on a stability ball) and standing., Results: Muscle activity and heart rate during standing periods were significantly higher than during sitting (both SIT and SIT-ACTIVE). Generalized estimating equations revealed no significant difference in any of the biomarkers between the three experimental conditions. Systolic blood pressure was lower during SIT-STAND, while stroke volume was lower during SIT-ACTIVE than during SIT. Although significant, these differences were small, approximating the day-to-day variability in blood pressure and stroke volume., Conclusions: We conclude that hourly standing interruptions during 5h prolonged sitting or continuously sitting on a stability ball do not significantly affect postprandial cardiometabolic biomarkers in healthy young men., Trial Registration: This trial is registered in the NTR trial register (NTRcode 5723)., (Copyright © 2019 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Objectives: Evidence suggests that physical activity is positively related to several aspects of cognitive functioning in children, among which is selective attention. To date, no information is available on the optimal frequency of physical activity on cognitive functioning in children. The current study examined the acute effects of one and two bouts of moderate-intensity physical activity on children's selective attention., Design: Randomized controlled trial (ISRCTN97975679)., Methods: Thirty boys and twenty-six girls, aged 10-13 years, were randomly assigned to three conditions: (A) sitting all morning working on simulated school tasks; (B) one 20-min physical activity bout after 90min; and (C) two 20-min physical activity bouts, i.e. at the start and after 90min. Selective attention was assessed at five time points during the morning (i.e. at baseline and after 20, 110, 130 and 220min), using the 'Sky Search' subtest of the 'Test of Selective Attention in Children'. We used GEE analysis to examine differences in Sky Search scores between the three experimental conditions, adjusting for school, baseline scores, self-reported screen time and time spent in sports., Results: Children who performed two 20-min bouts of moderate-intensity physical activity had significantly better Sky Search scores compared to children who performed one physical activity bout or remained seated the whole morning (B=-0.26; 95% CI=[-0.52; -0.00])., Conclusions: Our findings support the importance of repeated physical activity during the school day for beneficial effects on selective attention in children., (Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)