clinicaltrials.gov: NCT01435005.

Purpose: To prescribe different physical activity (PA) intensities using activity trackers to increase PA, reduce sedentary time, and improve health outcomes among breast cancer survivors. The maintenance effect of the interventions on study outcomes was also assessed. Methods: The Breast Cancer and Physical Activity Level pilot trial randomized 45 breast cancer survivors to a home-based, 12-wk lower (300 min•wk−1 at 40%-59% of HR reserve) or higherintensity PA (150 min•wk−1 at 60%-80% of HR reserve), or no PA intervention/control. Both intervention groups received Polar A360® activity trackers. Study outcomes assessed at baseline, 12 and 24 wk included PA and sedentary time (ActiGraph GT3X+), health-related fitness (e.g., body composition, cardiopulmonary fitness/VO2max), and patient-reported outcomes (e.g., quality of life). Intention-to-treat analyses were conducted using linear mixed models and adjusted for baseline outcomes. Results: Increases in moderate-vigorous intensity PA (least squares adjusted group difference [LSAGD], 0.6; 95% confidence interval [CI], 0.1-1.0) and decreases in sedentary time (LSAGD, −1.2; 95% CI, −2.2 to −0.2) were significantly greater in the lowerintensity PA group versus control at 12 wk. Increases in VO2max at 12 wk in both interventions groups were significantly greater than changes in the control group (lower-intensity PA group LSAGD, 4.2; 95% CI, 0.5-8.0 mL•kg−1•min−1; higher-intensity PA group LSAGD, 5.4; 95% CI, 1.7-9.1mL•kg−1•min−1). Changes in PA and VO2max remained at 24wk, but differences between the intervention and control groups were no longer statistically significant. Conclusions: Increases in PA time and cardiopulmonary fitness/VO2max can be achieved with both lower-and higher-intensity PA interventions in breast cancer survivors. Reductions in sedentary time were also noted in the lower-intensity PA group.

ObjectiveReducing sedentary behaviour (SB) might improve the health of older adults. However, we know little about how objectively measured SB impacts on self-rated health in older adults. We aimed to explore the associations between objectively measured SB and self-rated health in English older adults.ResultsA random sub-sample of older adults (≥ 65 years old) from the 2008 Health Survey for England wore an ActiGraph GT1M accelerometer for 7 days. Self-rated health was measured using an item from the General Health Questionnaire. Linear regression and analysis of covariance were used to test the associations between percentage time spent in SB and mean daily minutes in SB and self-rated health (very good/good; fair; bad/very bad), adjusting for covariates. Valid accelerometry datasets were returned by 578 individuals. Significant negative associations between percentage time and mean daily minutes in SB and self-rated health were found. In particular, individuals spending reduced percentages of time being sedentary had higher self-rated health. In conclusion, SB appears to be associated with self-rated health in older people independently from MVPA. If longitudinal research could determine how changes in SB influence self-rated health as individuals’ age, this might be an important lifestyle variable to target for health improvement.

This randomized dose comparison trial examined if higher exercise volume decreased inflammatory biomarkers, associated with postmenopausal breast cancer risk, more than moderate exercise volume. The Breast Cancer and Exercise Trial in Alberta was a two-center, two-armed randomized trial in 400 inactive, healthy, postmenopausal women, aged 50 to 74 years, with a body mass index of 22 to 40 kg/m 2 . Participants were randomized to high (300 minutes/week) or moderate (150 minutes/ week) volumes of aerobic exercise while maintaining usual diet. Fasting blood concentrations of C-reactive protein (CRP), IL6, and TNFa were measured at baseline, 6 and 12 months. Intention-to-treat (ITT) analysis was performed using linear mixed models adjusted for baseline biomarker concentrations. ITT analyses of 386 (97%) participants showed no statistically significant group differences for changes in biomarker levels at 6 and 12 months. In addition, we did not observe any modification of this effect by baseline characteristics of participants. In post hoc analyses based on self-selected exercise level (measured in minutes/week), CRP decreased by 22.45% for participants who exercised >246 minutes/week (highest quintile) and increased by 0.07% for those who exercised <110 minutes/week (lowest quintile, P trend ¼ 0.04), adjusted for baseline covariates. When this analysis was restricted to include exercise time in the target heart rate zone only, statistically significant trends were observed for both CRP (P < 0.01) and IL6 (P ¼ 0.04). Prescribing 300 minutes/week of moderate-to-vigorous aerobic exercise did not improve inflammatory markers compared with 150 minutes/week in postmenopausal women. Decreases in CRP were observed with higher self-selected exercise volume.Cancer Prev Res; 9(2); 196-203. Ó2015 AACR.

The mechanisms whereby regular exercise reduces chronic inflammation remain unclear. We investigated whether regular aerobic exercise alters basal levels of interleukin (IL)‐10 and IL‐4 in two randomized trials of physical activity. The Alberta Physical Activity and Breast Cancer Prevention Trial (ALPHA, n = 320) and the Breast Cancer and Exercise Trial in Alberta (BETA, n = 400) were two‐center, two‐armed randomized trials in inactive, healthy, postmenopausal women. Both trials included an exercise intervention prescribed five times/week and no dietary changes. In ALPHA, the exercise group was prescribed 225 min/week versus no activity in the controls. BETA examined dose‐response effects comparing 300 (HIGH) versus 150 (MODERATE) min/week. Plasma concentrations of IL‐10 and IL‐4 were measured at baseline, 6, and 12 months. Intention‐to‐treat (ITT) analysis was performed using linear mixed models adjusted for baseline biomarker concentrations. Circulating anti‐inflammatory cytokine levels decreased among all groups, with percent change ranging from −3.4% (controls) to −8.2% (HIGH) for IL‐4 and −1.6% (controls) to −7.5% (HIGH) for IL‐10. No significant group differences were found for IL‐4 (ALPHA P = 0.54; BETA P = 0.32) or IL‐10 (ALPHA P = 0.84; BETA P = 0.68). Some evidence for moderation of the effect of exercise by baseline characteristics was found for IL‐10 but not for IL‐4. Results from these two large randomized aerobic exercise intervention trials suggest that aerobic exercise does not alter IL‐10 or IL‐4 in a manner consistent with chronic disease and cancer prevention.