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Purpose: Sex-steroid hormones are associated with postmenopausal breast cancer but potential confounding from other biological pathways is rarely considered. We estimated risk ratios for sex-steroid hormone biomarkers in relation to postmenopausal estrogen receptor (ER)-positive breast cancer, while accounting for biomarkers from insulin/insulin-like growth factor-signaling and inflammatory pathways., Methods: This analysis included 1208 women from a case-cohort study of postmenopausal breast cancer within the Melbourne Collaborative Cohort Study. Weighted Poisson regression with a robust variance estimator was used to estimate risk ratios (RRs) and 95% confidence intervals (CIs) of postmenopausal ER-positive breast cancer, per doubling plasma concentration of progesterone, estrogens, androgens, and sex-hormone binding globulin (SHBG). Analyses included sociodemographic and lifestyle confounders, and other biomarkers identified as potential confounders., Results: Increased risks of postmenopausal ER-positive breast cancer were observed per doubling plasma concentration of progesterone (RR: 1.22, 95% CI 1.03 to 1.44), androstenedione (RR 1.20, 95% CI 0.99 to 1.45), dehydroepiandrosterone (RR: 1.15, 95% CI 1.00 to 1.34), total testosterone (RR: 1.11, 95% CI 0.96 to 1.29), free testosterone (RR: 1.12, 95% CI 0.98 to 1.28), estrone (RR 1.21, 95% CI 0.99 to 1.48), total estradiol (RR 1.19, 95% CI 1.02 to 1.39) and free estradiol (RR 1.22, 95% CI 1.05 to 1.41). A possible decreased risk was observed for SHBG (RR 0.83, 95% CI 0.66 to 1.05)., Conclusion: Progesterone, estrogens and androgens likely increase postmenopausal ER-positive breast cancer risk, whereas SHBG may decrease risk. These findings strengthen the causal evidence surrounding the sex-hormone-driven nature of postmenopausal breast cancer., (© 2024. The Author(s).)

Purpose: There is strong evidence that leisure-time physical activity is protective against postmenopausal breast cancer risk but the association with premenopausal breast cancer is less clear. The purpose of this study was to examine the association of physical activity with the risk of developing premenopausal breast cancer., Methods: We pooled individual-level data on self-reported leisure-time physical activity across 19 cohort studies comprising 547,601 premenopausal women, with 10,231 incident cases of breast cancer. Multivariable Cox regression was used to estimate hazard ratios (HRs) and 95% CIs for associations of leisure-time physical activity with breast cancer incidence. HRs for high versus low levels of activity were based on a comparison of risk at the 90th versus 10th percentiles of activity. We assessed the linearity of the relationship and examined subtype-specific associations and effect modification across strata of breast cancer risk factors, including adiposity., Results: Over a median 11.5 years of follow-up (IQR, 8.0-16.1 years), high versus low levels of leisure-time physical activity were associated with a 6% (HR, 0.94 [95% CI, 0.89 to 0.99]) and a 10% (HR, 0.90 [95% CI, 0.85 to 0.95]) reduction in breast cancer risk, before and after adjustment for BMI, respectively. Tests of nonlinearity suggested an approximately linear relationship ( P nonlinearity = .94). The inverse association was particularly strong for human epidermal growth factor receptor 2-enriched breast cancer (HR, 0.57 [95% CI, 0.39 to 0.84]; P het = .07). Associations did not vary significantly across strata of breast cancer risk factors, including subgroups of adiposity., Conclusion: This large, pooled analysis of cohort studies adds to evidence that engagement in higher levels of leisure-time physical activity may lead to reduced premenopausal breast cancer risk.

Background: Sedentary behaviours have been associated with increased risks of some common cancers in epidemiological studies; however, it is unclear if these associations are causal., Methods: We used univariable and multivariable two-sample Mendelian randomisation (MR) to examine potential causal relationships between sedentary behaviours and risks of breast, colorectal and prostate cancer. Genetic variants associated with self-reported leisure television watching and computer use were identified from a recent genome-wide association study (GWAS). Data related to cancer risk were obtained from cancer GWAS consortia. A series of sensitivity analyses were applied to examine the robustness of the results to the presence of confounding., Results: A 1-standard deviation (SD: 1.5 h/day) increment in hours of television watching increased risk of breast cancer (OR per 1-SD: 1.15, 95% confidence interval [CI]: 1.05-1.26) and colorectal cancer (OR per 1-SD: 1.32, 95% CI: 1.16-1.49) while there was little evidence of an association for prostate cancer risk (OR per 1-SD: 0.94, 95% CI: 0.84-1.06). After adjusting for years of education, the effect estimates for television watching were attenuated (breast cancer, OR per 1-SD: 1.08, 95% CI: 0.92-1.27; colorectal cancer, OR per 1-SD: 1.08, 95% CI: 0.90-1.31). Post hoc analyses showed that years of education might have a possible confounding and mediating role in the association between television watching with breast and colorectal cancer. Consistent results were observed for each cancer site according to sex (colorectal cancer), anatomical subsites and cancer subtypes. There was little evidence of associations between genetically predicted computer use and cancer risk., Conclusions: Our univariable analysis identified some positive associations between hours of television watching and risks of breast and colorectal cancer. However, further adjustment for additional lifestyle factors especially years of education attenuated these results. Future studies using objective measures of exposure can provide new insights into the possible role of sedentary behaviour in cancer development., (© 2023 World Health Organization; licensed by John Wiley & Sons Ltd. Cancer Medicine published by John Wiley & Sons Ltd.)

Purpose: Physical activity can improve health in people living with and beyond breast cancer; however, how to best support physical activity participation in this population is unclear. This qualitative study sought to identify important physical activity program components for breast cancer., Methods: Women with previous breast cancer (n = 11) and allied health professionals (n = 7) participated in one-on-one semi-structured interviews (n = 15) or focus groups (n = 1). Qualitative data were analyzed using reflexive thematic analysis methods., Results: Four main themes were generated including (1) the need for physical activity programs; (2) person-centered programs; (3) flexible physical activity programs; and (4) systems factors. These reflected the health and non-health benefits of physical activity, the need to facilitate agency, the diversity in individual characteristics, preferences, abilities, and commitments of people with lived experience of cancer, as well as the need for physical activity programs to be integrated within the broader health system., Conclusion: Strategies to support physical activity engagement for breast cancer should embrace the diversity of those who are diagnosed with cancer as well as the diversity in which physical activity can be achieved., (© 2023. The Author(s).)

Purpose: Circadian rhythms control a wide range of physiological processes and may be associated with fatigue, depression, and sleep problems. We aimed to identify subgroups of breast cancer survivors based on symptoms of fatigue, insomnia, and depression; and assess whether circadian parameters (i.e., chronotype, amplitude, and stability) were associated with these subgroups over time., Methods: Among breast cancer survivors, usual circadian parameters were assessed at 3-4 months after diagnosis (T0), and symptoms of fatigue, depression, and insomnia were assessed after 2-3 years (T1, N = 265) and 6-8 years (T2, N = 169). We applied latent class analysis to classify survivors in unobserved groups ("classes") based on symptoms at T1. The impact of each of the circadian parameters on class allocation was assessed using multinomial logistic regression analysis, and changes in class allocation from T1 to T2 using latent transition models., Results: We identified 3 latent classes of symptom burden: low (38%), moderate (41%), and high (21%). Survivors with a late chronotype ("evening types") or low circadian amplitude ("languid types") were more likely to have moderate or high symptom burden compared to "morning types" and "vigorous types," respectively. The majority of survivors with moderate (59%) or high (64%) symptom burden at T1 had persistent symptom burden at T2., Implications for Cancer Survivors: A late chronotype and lower circadian amplitude after breast cancer diagnosis were associated with greater symptoms of fatigue, depression, and insomnia at follow-up. These circadian parameters may potentially be novel targets in interventions aimed at alleviating symptom burden among breast cancer survivors., (© 2022. The Author(s).)

The protective effect of physical activity on breast cancer incidence may partially be mediated by inflammation. Systematic searches of Medline, EMBASE, and SPORTDiscus were performed to identify intervention studies, Mendelian randomization studies, and prospective cohort studies that examined the effects of physical activity on circulating inflammatory biomarkers in adult women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the Grading of Recommendations Assessment, Development, and Evaluation system was used to determine the overall quality of the evidence. Thirty-five intervention studies and one observational study met the criteria for inclusion. Meta-analyses of randomized controlled trials (RCT) indicated that, compared with control groups, exercise interventions reduced levels of C-reactive protein (CRP) [standardized mean difference (SMD) = -0.27, 95% confidence interval (CI) = -0.62 to 0.08), tumor necrosis factor alpha (TNFα, SMD = -0.63, 95% CI = -1.04 to -0.22), interleukin-6 (IL6, SMD = -0.55, 95% CI = -0.97 to -0.13) and leptin (SMD = -0.50, 95% CI = -1.10 to 0.09). Owing to heterogeneity in effect estimates and imprecision, evidence strength was graded as low (CRP, leptin) or moderate (TNFα and IL6). High-quality evidence indicated that exercise did not change adiponectin levels (SMD = 0.01, 95% CI = -0.14 to 0.17). These findings provide support for the biological plausibility of the first part of the physical activity-inflammation-breast cancer pathway., (©2023 The Authors; Published by the American Association for Cancer Research.)

The purpose of this study is to examine the effects of a 16-week exercise intervention (mat Pilates or belly dance) on body image, self-esteem and sexual function in breast cancer survivors receiving hormone therapy. Seventy-four breast cancer survivors were randomly allocated into mat Pilates, belly dance, or control group. The physical activity groups received a 16-week intervention, delivered 3 days a week, and 60 min a session. The control group received three education sessions. Data collection occurred at baseline, post-intervention, 6 and 12 months of follow-up with a questionnaire including body image (Body Image After Breast Cancer Questionnaire), self-esteem (Rosenberg Self-Esteem Scale), and sexual function (Female Sexual Function Index) measures. The belly dance group significantly improved body image on limitations scale in the short term and long term, the mat Pilates significantly improved body image on limitations only in the long term, and the control group significantly decreased body image on limitations in the long term. The belly dance group experienced reduced discomfort and pain during sexual relations in the short and long term. All groups showed a significant improvement in self-esteem, but orgasm sub-scale scores declined over time. No adverse events were found for any of the exercise intervention groups. Belly dance seem to be more effective than mat Pilates and control group in improving limitations of body image and sexual discomfort in the short term for breast cancer survivors. ClinicalTrials.gov (NCT03194997) - "Pilates and Dance to Breast Cancer Patients Undergoing Treatment"., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: Breast cancer treatment leads to several side effects. Exercise can help to reduce these side effects. However, it is unknown whether a mat Pilates or a belly dance intervention can improve the patient-reported outcomes of these women., Objective: Examine the effects of a 16-week exercise intervention (mat Pilates or belly dance) on patient reported outcomes (PROs) among breast cancer survivors, at 16 weeks, six months, and 12 months; and investigate sociodemographic and clinical predictors of intervention adherence., Methods: Seventy-four breast cancer survivors who were receiving hormone therapy were randomly allocated into mat Pilates (n = 25), belly dance (n = 25) or control group (educational sessions) (n = 24). Mat Pilates and belly dance groups received a 16-week intervention, delivered three days a week and 60 min a session. The control group received three education sessions and continue usual care. The patient reported outcomes assessed were depressive symptoms (Beck Depression Inventory), stress (Perceived Stress Scale), optimism (Life Orientation Test), fatigue (FACT-F), sleep quality (Pittsburgh Sleep Quality Index) and pain (VAS), clinical and sociodemographic characteristics, and habitual physical activity (IPAQ short)., Results: All three groups showed a significant improvement in fatigue, and this effect was maintained during follow-up. No significant effects were found for depressive symptoms, optimism, stress, or pain. A history of exercise prior to breast cancer and be inactive after diagnosis were significant predictors of adherence to interventions., Conclusion: Mat Pilates, belly dance and a few educational sessions can be effective in improving fatigue after 16 weeks of intervention., Registration: ClinicalTrials.gov (NCT03194997)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Perturbation of the insulin/insulin-like growth factor (IGF) signaling system is often cited as a mechanism driving breast cancer risk. A systematic review identified prospective cohort studies and Mendelian randomization studies that examined the effects of insulin/IGF signaling (IGF, their binding proteins (IGFBP), and markers of insulin resistance] on breast cancer risk. Meta-analyses generated effect estimates; risk of bias was assessed and the Grading of Recommendations Assessment, Development and Evaluation system applied to evaluate the overall quality of the evidence. Four Mendelian randomization and 19 prospective cohort studies met our inclusion criteria. Meta-analysis of cohort studies confirmed that higher IGF-1 increased risk of breast cancer; this finding was supported by the Mendelian randomization studies. IGFBP-3 did not affect breast cancer. Meta analyses for connecting-peptide and fasting insulin showed small risk increases, but confidence intervals were wide and crossed the null. The quality of evidence obtained ranged from 'very low' to 'moderate'. There were insufficient studies to examine other markers of insulin/IGF signaling. These findings do not strongly support the biological plausibility of the second part of the physical activity-insulin/IGF signaling system-breast cancer pathway. Robust conclusions cannot be drawn due to the dearth of high quality studies. See related article by Swain et al., p. 2106., (©2022 American Association for Cancer Research.)

Physical activity may reduce the risk of developing breast cancer via its effect on the insulin/insulin-like growth factor (IGF) signaling system. A systematic review searched for randomized controlled trials (RCT), Mendelian randomization and prospective cohort studies that examined the effects of physical activity on insulin/IGF signaling [IGFs, their binding proteins (IGFBP), and markers of insulin resistance] in adult women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the Grading of Recommendations Assessment, Development, and Evaluation system used to determine the overall quality of the evidence. Fifty-eight RCTs met our inclusion criteria, no observational or Mendelian randomization studies met the criteria for inclusion. Meta-analyses indicated that physical activity interventions (vs. control) reduced fasting insulin, the Homeostatic Model Assessment for Insulin Resistance and fasting glucose. Physical activity increased IGF-1, but there was no clear effect on IGFBP-3 or the ratio of IGF-1:IGFBP-3. Strong evidence was only established for fasting insulin and insulin resistance. Further research is needed to examine the effect of physical activity on C-peptide and HBA1c in women. Reductions in fasting insulin and insulin resistance following exercise suggest some biological plausibility of the first part of the physical activity-insulin/IGF signaling-breast cancer pathway. See related article by Drummond et al., p. 2116., (©2022 American Association for Cancer Research.)

Objectives: Physical inactivity and sedentary behaviour are associated with higher breast cancer risk in observational studies, but ascribing causality is difficult. Mendelian randomisation (MR) assesses causality by simulating randomised trial groups using genotype. We assessed whether lifelong physical activity or sedentary time, assessed using genotype, may be causally associated with breast cancer risk overall, pre/post-menopause, and by case-groups defined by tumour characteristics., Methods: We performed two-sample inverse-variance-weighted MR using individual-level Breast Cancer Association Consortium case-control data from 130 957 European-ancestry women (69 838 invasive cases), and published UK Biobank data (n=91 105-377 234). Genetic instruments were single nucleotide polymorphisms (SNPs) associated in UK Biobank with wrist-worn accelerometer-measured overall physical activity (n snps =5) or sedentary time (n snps =6), or accelerometer-measured (n snps =1) or self-reported (n snps =5) vigorous physical activity., Results: Greater genetically-predicted overall activity was associated with lower breast cancer overall risk (OR=0.59; 95% confidence interval (CI) 0.42 to 0.83 per-standard deviation (SD;~8 milligravities acceleration)) and for most case-groups. Genetically-predicted vigorous activity was associated with lower risk of pre/perimenopausal breast cancer (OR=0.62; 95% CI 0.45 to 0.87,≥3 vs. 0 self-reported days/week), with consistent estimates for most case-groups. Greater genetically-predicted sedentary time was associated with higher hormone-receptor-negative tumour risk (OR=1.77; 95% CI 1.07 to 2.92 per-SD (~7% time spent sedentary)), with elevated estimates for most case-groups. Results were robust to sensitivity analyses examining pleiotropy (including weighted-median-MR, MR-Egger)., Conclusion: Our study provides strong evidence that greater overall physical activity, greater vigorous activity, and lower sedentary time are likely to reduce breast cancer risk. More widespread adoption of active lifestyles may reduce the burden from the most common cancer in women., Competing Interests: Competing interests: MWB conducts research funded by Amgen, Novartis and Pfizer. PAF conducts research funded by Amgen, Novartis and Pfizer. He received honoraria from Roche, Novartis and Pfizer. AWK declares research funding to her institution from Myriad Genetics for an unrelated project (funding dates 2017-2019). SL declares grants and honoraria paid to her institution from Amgen, Novartis, Pfizer, Roche, and, outside the submitted work, grants and/or honoraria paid to her institution from AbbVie, Celgene, Seattle Genetics, PrIME/Medscape, Daiichi-Sankyo, Lilly, Samsung, BMS, Puma, Immunomedics, AstraZeneca, Pierre Fabre, Merck, GlaxoSmithKlein, EirGenix, and Bayer, and personal fees from Chugai; SL also has a patent EP14153692.0 pending. UM declares stock ownership in Abcodia Ltd. RAM has been a consultant for Pharmavite. No other authors have conflicts to declare., (© Author(s) (or their employer(s)) 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

We examined associations between sex-specific alcohol intake trajectories and alcohol-related cancer risk using data from 22 756 women and 15 701 men aged 40 to 69 years at baseline in the Melbourne Collaborative Cohort Study. Alcohol intake for 10-year periods from age 20 until the decade encompassing recruitment, calculated using recalled beverage-specific frequency and quantity, was used to estimate group-based sex-specific intake trajectories. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated for primary invasive alcohol-related cancer (upper aerodigestive tract, breast, liver and colorectum). Three distinct alcohol intake trajectories for women (lifetime abstention, stable light, increasing moderate) and six for men (lifetime abstention, stable light, stable moderate, increasing heavy, early decreasing heavy, late decreasing heavy) were identified. 2303 incident alcohol-related cancers were diagnosed during 485 525 person-years in women and 789 during 303 218 person-years in men. For men, compared with lifetime abstention, heavy intake (mean ≥ 60 g/day) at age 20 to 39 followed by either an early (from age 40 to 49) (early decreasing heavy; HR = 1.75, 95% CI: 1.25-2.44) or late decrease (from age 60 to 69) (late decreasing heavy; HR = 1.94, 95% CI: 1.28-2.93), and moderate intake (mean <60 g/day) at age 20 to 39 increasing to heavy intake in middle-age (increasing heavy; HR = 1.45, 95% CI: 1.06-1.97) were associated with increased risk of alcohol-related cancer. For women, compared with lifetime abstention, increasing intake from age 20 (increasing moderate) was associated with increased alcohol-related cancer risk (HR = 1.25, 95% CI: 1.06-1.48). Similar associations were observed for colorectal (men) and breast cancer. Heavy drinking during early adulthood might increase cancer risk later in life., (© 2022 UICC.)

We undertook a systematic review and appraised the evidence for an effect of circulating sex steroid hormones and sex hormone-binding globulin (SHBG) on breast cancer risk in pre- and postmenopausal women. Systematic searches identified prospective studies relevant to this review. Meta-analyses estimated breast cancer risk for women with the highest compared with the lowest level of sex hormones, and the DRMETA Stata package was used to graphically represent the shape of these associations. The ROBINS-E tool assessed risk of bias, and the GRADE system appraised the strength of evidence. In premenopausal women, there was little evidence that estrogens, progesterone, or SHBG were associated with breast cancer risk, whereas androgens showed a positive association. In postmenopausal women, higher estrogens and androgens were associated with an increase in breast cancer risk, whereas higher SHBG was inversely associated with risk. The strength of the evidence quality ranged from low to high for each hormone. Dose-response relationships between sex steroid hormone concentrations and breast cancer risk were most notable for postmenopausal women. These data support the plausibility of a role for sex steroid hormones in mediating the causal relationship between physical activity and the risk of breast cancer. See related reviews by Lynch et al., p. 11 and Swain et al., p. 16 ., (©2021 The Authors; Published by the American Association for Cancer Research.)

Epidemiologic research suggests that physical activity is associated with a reduced risk of breast cancer, but the causal nature of this link is not clear. Investigating mechanistic pathways can provide evidence of biological plausibility and improve causal inference. This project will examine three putative pathways (sex steroid hormones, insulin signaling, and inflammation) in a series of two-stage systematic reviews. Stage 1 used Text Mining for Mechanism Prioritisation (TeMMPo) to identify and prioritize relevant biological intermediates. Stage 2 will systematically review the findings from studies of (i) physical activity and intermediates and (ii) intermediates and breast cancer. Ovid MEDLINE, EMBASE, and SPORTDiscus will be searched using a combination of subject headings and free-text terms. Human intervention and prospective, observational studies will be eligible for inclusion. Meta-analysis will be performed where possible. Risk of bias will be assessed using the Cochrane Collaboration tool, or the ROBINS-I or ROBINS-E tool, depending on study type. Strength of evidence will be assessed using the GRADE system. In addition to synthesizing the mechanistic evidence that links physical activity with breast cancer risk, this project may also identify priority areas for future research and help inform the design and implementation of physical activity interventions. See related reviews by Swain et al., p. 16 and Drummond et al., p. 28 ., (©2021 The Authors; Published by the American Association for Cancer Research.)

The effect of physical activity on breast cancer risk may be partly mediated by sex steroid hormones. This review synthesized and appraised the evidence for an effect of physical activity on sex steroid hormones. Systematic searches were performed using MEDLINE (Ovid), EMBASE (Ovid), and SPORTDiscus to identify experimental studies and prospective cohort studies that examined physical activity and estrogens, progestins, and/or androgens, as well as sex hormone binding globulin (SHBG) and glucocorticoids in pre- and postmenopausal women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the GRADE system was used to appraise quality of the evidence. Twenty-eight randomized controlled trials (RCT), 81 nonrandomized interventions, and six observational studies were included. Estrogens, progesterone, and androgens mostly decreased, and SHBG increased, in response to physical activity. Effect sizes were small, and evidence quality was graded moderate or high for each outcome. Reductions in select sex steroid hormones following exercise supports the biological plausibility of the first part of the physical activity-sex hormone-breast cancer pathway. The confirmed effect of physical activity on decreasing circulating sex steroid hormones supports its causal role in preventing breast cancer. See related reviews by Lynch et al., p. 11 and Drummond et al., p. 28 ., (©2021 The Authors; Published by the American Association for Cancer Research.)

Introduction: Physical activity interventions can improve sleep quality in breast cancer survivors. This paper examines the effects of the ACTIVATE Trial, a wearable-based physical activity intervention (Garmin Vivofit2® coupled with behavioral feedback, goal setting, and health coaching) on sleep outcomes., Methods: Post-primary treatment, inactive, postmenopausal breast cancer survivors were recruited and randomized to primary intervention or waitlist. Wrist-worn actigraphy (sleep onset latency, SOL; total sleep time, TST; sleep efficiency, SE; wake after sleep onset, WASO; and number of awakenings, NWAKE) and questionnaire-derived sleep measures (Pittsburgh Sleep Quality Index) were assessed at baseline (T1), 12 weeks (end of primary intervention and start of waitlist intervention, T2), and at 24 weeks (T3)., Results: Eighty-three women (mean age = 62 years) were randomized; trial retention was 94% at T2 and 87% at T3. At T2, primary intervention participants had greater improvements in WASO (- 5.7 min, 95% CI - 11.7 to - 0.2) and NWAKE compared with the waitlist arm (- 2.0, 95% CI - 3.6 to - 0.4). At T3, within-group improvements were observed for SE (both groups), WASO (both groups), NWAKE (primary intervention group only), total PSQI score (primary intervention group), and sleep efficacy (primary intervention group)., Conclusions: The intervention reduced actigraphy-measured sleep disturbances. Within-group analyses suggest that improvements in sleep quality are sustained over a longer duration, and there may be similar benefits from an abridged intervention (wearable device only). Actigraphy-measured effects appeared stronger in participants who were poor sleepers at study entry., Implications for Cancer Survivors: Wearable technology can increase physical activity and improve sleep for breast cancer survivors.

Adiposity increases estrogen receptor (ER)-positive postmenopausal breast cancer risk. While mechanisms underlying this relationship are uncertain, dysregulated sex-steroid hormone production and insulin signaling are likely pathways. Our aim was to quantify mediating effects of fasting insulin and free estradiol in the adiposity and ER-positive postmenopausal breast cancer association. We used data from a case-cohort study of sex hormones and insulin signaling nested within the Melbourne Collaborative Cohort Study. Eligible women, at baseline, were not diagnosed with cancer, were postmenopausal, did not use hormone therapy and had no history of diabetes or diabetes medication use. Women with ER-negative disease or breast cancer diagnosis within the first follow-up year were excluded. We analyzed the study as a cumulative sampling case-control study with 149 cases and 1,029 controls. Missing values for insulin and free estradiol were multiply imputed with chained equations. Interventional direct (IDE) and indirect (IIE) effects were estimated using regression-based multiple-mediator approach. For women with body mass index (BMI) >30 kg/m 2 compared to women with BMI 18.5-25 kg/m 2 , the risk ratio (RR) of breast cancer was 1.75 (95% confidence interval [CI] 1.05-2.91). The estimated IDE (RR) not through the mediators was 1.03 (95% CI 0.43-2.48). Percentage mediated effect through free estradiol was 72% (IIE-RR 1.56; 95% CI 1.11-2.19). There was no evidence for an indirect effect through insulin (IIE-RR 1.12; 95% CI 0.68-1.84; 28% mediated). Our results suggest that circulating free estradiol plays an important mediating role in the adiposity-breast cancer relationship but does not explain all of the association., (© 2019 UICC.)

Background: The ACTIVATE Trial examined the efficacy of a wearable-based intervention to increase physical activity and reduce sedentary behavior in breast cancer survivors. This paper examines the effects of the intervention on health-related quality of life (HRQoL) and fatigue at 12 weeks (T2; end of intervention) and 24 weeks (T3; follow-up)., Methods: Inactive and postmenopausal women who had completed primary treatment for stage I-III breast cancer were randomized to intervention or waitlist control. Physical activity and sedentary behavior were measured by Actigraph and activPAL accelerometers at baseline (T1), end of the intervention (T2), and 12 weeks follow-up (T3). HRQoL and fatigue were measured using the Functional Assessment of Cancer Therapy-Breast (FACT-B) and the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-Fatigue). Primary intervention effects were evaluated comparing intervention and waitlist group at T2 using repeated measures mixed effects models., Results: Overall, 83 women were randomized and trial retention was high (94%). A 4.6-point difference in fatigue score was observed between groups at T2 (95% CI: 1.3, 7.8) indicating improvement in fatigue profiles in the intervention group. In within groups analyses, the intervention group reported a 5.1-point increase in fatigue from baseline to T2 (95% CI: 2.0, 8.2) and a 3.3-point increase from baseline to T3 (95% CI: 0.1, 6.41)., Conclusions: Despite small improvements in fatigue profiles, no effects on HRQoL were observed. While the ACTIVATE Trial was associated with improvements in physical activity and sedentary behavior, more intensive or longer duration interventions may be needed to facilitate changes in HRQoL., (© 2019 John Wiley & Sons, Ltd.)

Background: The benefits of an active lifestyle after a breast cancer diagnosis are well recognized, but the majority of survivors are insufficiently active. The ACTIVATE Trial examined the efficacy of an intervention (use of the Garmin Vivofit 2 activity monitor coupled with a behavioral feedback and goal-setting session and 5 telephone-delivered health coaching sessions) to increase moderate to vigorous physical activity (MVPA) and reduce sedentary behavior in breast cancer survivors., Methods: This randomized controlled trial recruited 83 inactive, postmenopausal women diagnosed with stage I-III breast cancer who had completed primary treatment. Participants were randomly assigned to the intervention group or to the control group, and the intervention was delivered over a 12-week period. MVPA and sedentary behavior were measured with Actigraph and activPAL accelerometers at baseline (T1) and at the end of the intervention (T2)., Results: Retention in the trial was high, with 80 (96%) of participants completing T2 data collection. At T2, there was a significant between-group difference in MVPA (69 min/wk; 95% CI = 22-116) favoring the intervention group. The trial resulted in a statistically significant decrease in both total sitting time and prolonged bouts (≥20 min) of sitting, with between-group reductions of 37 min/d (95% CI = -72 to -2) and 42 min/d (95% CI = -83 to -2), respectively, favoring the intervention group., Conclusion: Results from the ACTIVATE Trial suggest that the use of wearable technology presents an inexpensive and scalable opportunity to facilitate more active lifestyles for cancer survivors. Whether or not such wearable technology-based interventions can create sustainable behavioral change should be the subject of future research., (© 2019 American Cancer Society.)

Background: In the cancer survivorship context, physical activity and sedentary behavior have been measured using different methods., Purpose: To conduct a narrative review of published research in cancer survivor populations to summarize the quality and identify gaps in reporting on accelerometer data collection, data processing, and outcome measures in cancer survivors., Methods: An initial PubMed® search of articles published in English was conducted in January 2017, and a final search was conducted in May 2017. Variables extracted included study characteristics, methods for accelerometry data collection (e.g., device used), data processing (e.g., cut points used), and data reporting (e.g., time spent in different activity intensities)., Results: A total of 46 articles were eligible for inclusion in the review. The majority of studies (34 of 46) targeted a single cancer group and 18 of these 34 studies were in survivors of breast cancer. Half (54%) of the studies used an ActiGraph® accelerometer. Methods of accelerometer data processing varied across studies. Definitions of non-wear time, vectors used during processing, and filters applied during processing were reported by 51%, 60%, and 8% of studies, respectively. Most studies reported moderate and vigorous physical activity (78%), 50% reported sedentary time, and 43% reported light-intensity activity. Cut points to categorize these activities varied between studies., Conclusions: This narrative review highlights inconsistency in the methods used to collect, process, and report accelerometry data across cancer survivor studies. Accelerometry has potential to add detailed knowledge of the levels and patterns of physical activities and sedentary behaviors across the cancer spectrum. Recommendations are made to improve data processing and reporting methods to maximize the scientific validity of future accelerometer research in this field.

Background: Physical activity is positively associated with survival and quality of life among breast cancer survivors. Despite these benefits, the majority of breast cancer survivors are insufficiently active. The potential health benefits of reducing sedentary behaviour (sitting time) in this population have not been extensively investigated. The ACTIVATE Trial will evaluate the efficacy of an intervention that combines wearable technology (the Garmin Vivofit2®) with traditional behavioural change approaches to increase physical activity and reduce sedentary behaviour performed by breast cancer survivors., Methods/design: This randomised controlled trial includes inactive, postmenopausal women diagnosed with stage I-III breast cancer who have completed their primary treatment. Participants are randomly assigned to the primary intervention group (Garmin Vivofit2®; behavioural feedback and goal setting session; and, five telephone-delivered health coaching sessions) or to the wait-list control group. The primary intervention is delivered over a 12-week period. The second 12-week period comprises a maintenance phase for the primary intervention group, and an abridged intervention (Garmin Vivofit2® only) for the wait-list control group. Moderate- to vigorous-intensity physical activity (MVPA) and sedentary behaviour are assessed by accelerometry at baseline (T1), end of intervention (T2), and end of maintenance phase (T3)., Discussion: The ACTIVATE Trial is one of the first studies to incorporate wearable technology into an intervention for cancer survivors. If the use of wearable technology (in combination with behaviour change strategies, or alone) proves efficacious, it may become an inexpensive and sustainable addition to the health promotion strategies available to health care providers in the cancer survivorship context., Trial Registration: ACTRN12616000175471., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Physical inactivity and sedentary behaviour are common amongst breast cancer survivors. These behaviours are associated with an increased risk of comorbidities such as heart disease, diabetes and other cancers. Commercially available, wearable activity trackers (WATs) have potential utility as behavioural interventions to increase physical activity and reduce sedentary behaviour within this population., Purpose: The purpose of the study is to explore the acceptability and usability of consumer WAT amongst postmenopausal breast cancer survivors., Methods: Fourteen participants tested two to three randomly assigned trackers from six available models (Fitbit One, Jawbone Up 24, Garmin Vivofit 2, Garmin Vivosmart, Garmin Vivoactive and Polar A300). Participants wore each device for 2 weeks, followed by a 1-week washout period before wearing the next device. Four focus groups employing a semi-structured interview guide explored user perceptions and experiences. We used a thematic analysis approach to analyse focus group transcripts., Results: Five themes emerged from our data: (1) trackers' increased self-awareness and motivation, (2) breast cancer survivors' confidence and comfort with wearable technology, (3) preferred and disliked features of WAT, (4) concerns related to the disease and (5) peer support and doctor monitoring were possible strategies for WAT application., Conclusions: WATs are perceived as useful and acceptable interventions by postmenopausal breast cancer survivors. Effective WAT interventions may benefit from taking advantage of the simple features of the trackers paired with other behavioural change techniques, such as specialist counselling, doctor monitoring and peer support, along with simple manual instructions.

Objective: Blood pressure (BP) and breast cancer may share a common pathophysiologic pathway involving chronic inflammation, hormone synthesis and metabolism. Previous studies investigating the association between BP and breast cancer measured BP at a single time point and did not examine associations by breast cancer molecular subtypes., Methods: We used data from 22 833 female participants in the Melbourne Collaborative Cohort Study. BP was objectively measured at baseline (1990-1994) and a follow-up visit (2003-2007). Cox regression was used to estimate hazard ratios for baseline BP and temporal changes in BP in relation to risk of breast cancer, overall and by molecular subtypes., Results: We did not observe any associations between BP measured at baseline and breast cancer risk overall (per 5 mmHg SBP, hazard ratio = 1.00, 95% confidence interval: 0.99-1.02), nor by subtype (per 5 mmHg SBP: estrogen-receptor-negative: hazard ratio = 0.99, 0.96-1.03, progesterone-receptor-negative: hazard ratio = 1.01, 0.99-1.04, human epidermal growth factor receptor 2 negative: hazard ratio = 1.00, 0.98-1.01). Temporal changes in BP were not associated with risk of breast cancer (per 5 mmHg change in SBP, hazard ratio = 1.00, 0.97-1.03). Increased DBP over time was associated with higher risk of triple-negative breast cancer (P = 0.04), based on a small number of cases (N = 41)., Conclusion: Our study supports previous findings of no association between BP and breast cancer. Similar conclusions were reached when assessing BP over time and when examining specific tumor subtypes.

Objective: To assess differences in accelerometer-assessed moderate- to vigorous-intensity physical activity (MVPA), light-intensity physical activity, and sedentary time between cancer survivors and adults without cancer., Patients and Methods: Accelerometer data collected from 241 breast cancer survivors (ACCEL-Breast study, 2013) and 171 colon cancer survivors (ACCEL-Colon study, 2012-2013) were pooled with data collected from adults without cancer (Australian Diabetes, Obesity and Lifestyle accelerometer substudy, 2011-2012). Linear regression was used to estimate differences in physical activity and sedentary behavior levels between cancer survivors and adults without cancer, adjusted for potential confounding factors., Results: The mean MVPA was significantly higher among breast cancer survivors than among females who had not had cancer (29 vs 22 min/d; P<.001). Colon cancer survivors had significantly lower levels of light activity than did adults without cancer (311 vs 338 min/d; P<.001), more sedentary time (532 vs 507 min/d; P=.003), and more prolonged sedentary time (210 vs 184 min/d; P=.002)., Conclusion: Contrary to findings from previous research (based on self-reported physical activity), cancer survivors engaged in more (breast) or equivalent (colon) MVPA compared with adults without cancer. Differences between colon cancer survivors and adults without cancer for light activity and sedentary behavior highlight the importance of considering the full activity spectrum in the context of cancer control., (Copyright © 2017 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

Background: Moderate-to-vigorous intensity physical activity (MVPA) is inversely associated with waist circumference and body mass index (BMI) among breast cancer survivors. Limited research has focused on behaviors that account for larger portions of the day [sleep, sedentary time, and light-intensity physical activity (LPA)]. We investigated the interdependent associations of self-reported sleep, objectively assessed prolonged and short bouts of sedentary time, total LPA, and total MVPA with waist circumference and BMI., Methods: A cross-sectional sample of breast cancer survivors (N = 256, mean age = 60 years; mean time since diagnosis = 3 years) wore an Actigraph GT3X+ accelerometer during waking hours for 7 days. Participants completed the Pittsburgh Sleep Quality Index and self-reported their waist circumference, height, and weight. An isotemporal substitution approach was used in linear regression models to explore the associations of reallocating time to sleep, sedentary and active behaviors on waist circumference, and BMI, after adjusting for potential confounders., Results: Reallocating 30 minutes to MVPA was significantly associated with lower waist circumference when allocated from sleep (-2.50 cm), prolonged sedentary time (-2.51 cm), or LPA (-2.71 cm). Reallocating 30 minutes of prolonged sedentary time to nonprolonged sedentary time was significantly associated with lower waist circumference (-0.94 cm). Similar results were observed for BMI., Conclusions: Reallocating 30 minutes to MVPA was associated with significantly lower waist circumference and BMI, as was reallocating 30 minutes of prolonged sedentary time to 30 minutes of nonprolonged sedentary time., Impact: Increasing MVPA levels and decreasing time spent in prolonged, unbroken sedentary bouts may be avenues for improving body composition in this population. Cancer Epidemiol Biomarkers Prev; 26(2); 254-60. ©2016 AACR., Competing Interests: None to declare, (©2016 American Association for Cancer Research.)

Purpose: Physical activity (PA) and sedentary behavior may influence the physical and mental health of breast cancer survivors; however, few studies have objectively measured these behaviors in this population. We used accelerometers to measure the PA and sedentary time levels of breast cancer survivors and examined the demographic, behavioral, and medical correlates of these behaviors using two complementary approaches., Methods: A total of 259 breast cancer survivors wore an accelerometer for 7 days during waking hours and completed a questionnaire. We used linear regression and classification trees to investigate correlates of PA and sedentary time., Results: The breast cancer survivors in this study (mean age = 61 years, mean time since diagnosis = 3 years) were sedentary for a daily average of 8.2 h, in light-intensity PA for 5.8 h and in moderate-to-vigorous intensity PA (MVPA) for 32 min, with 16 % meeting PA guidelines. Participants with high comorbidity were the least likely to be meeting guidelines (0 %), while a subgroup of participants with no/low comorbidity, a university degree, and higher levels of pre-diagnosis MVPA were the most likely to be meeting guidelines (47 %). Older participants (70+ years) were the most likely to have sedentary time levels at least twice as high as activity levels, while participants who were younger than 70 years and not in the lowest category of pre-diagnosis MVPA were the least likely., Conclusions: Interventions to facilitate physical activity and reduce sedentary time among breast cancer survivors should consider comorbidity status and previous PA experience.

Background: Exercise has favorable effects on biomarkers associated with a lower risk of breast cancer, however it is unclear if higher doses of exercise provide additional effects. No clinical trial has systematically examined how different exercise volumes influence the mechanisms underlying breast cancer etiology. The Breast Cancer and Exercise Trial in Alberta (BETA) - a follow-up study to the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) Trial - is examining how a one-year, high versus moderate volume aerobic exercise intervention influences several biomechanisms hypothesized to influence breast cancer risk in a group of postmenopausal women. Secondary aims are to compare intervention effects on psychosocial and quality of life outcomes as well as understand exercise adherence at 12 and 24 months, and maintenance of all study outcomes at 24 months., Methods/design: The BETA Trial is a two-center, two-armed randomized controlled exercise intervention trial conducted in 400 previously inactive, postmenopausal women aged 50-74 years, in Alberta, Canada. Participants were randomly assigned to a one-year aerobic exercise intervention of either high volume (300 minutes/week) or moderate volume (150 minutes/week). Blood draws and accelerometry were performed at baseline, six and 12 months. Baseline and 12-month measurements were taken of adiposity (including dual energy X-ray absorptiometry and computed tomography scans), physical fitness, dietary intake, self-reported physical activity and sedentary behavior, quality of life, perceived stress, happiness, sleep, and determinants of exercise adherence. Exercise maintenance was assessed and all study measurements were repeated at 24 months. Blood will be analyzed for endogenous estrogens, insulin resistance indicators, and inflammatory markers., Discussion: The BETA Trial will compare the impact of a high versus moderate volume of aerobic exercise on a variety of biological, physiological, and psychological outcomes of relevance to postmenopausal women. A tightly controlled exercise intervention and objective outcome measurements are methodological strengths. The BETA Trial will inform future prevention initiatives by assessing adherence to a high volume of exercise over 12 months by postmenopausal women, and the ability of these women to maintain activity over the longer-term. The ultimate objective is to inform public health guidelines for reducing breast cancer risk through physical activity., Clinical Trials Registration Number: NCT01435005.

Purpose: Sedentary behavior has been previously shown, in a cross-sectional study, to have deleterious associations with biomarkers of postmenopausal breast cancer risk. We examined the associations of change in sedentary behavior [daily television (TV) viewing time, h/day] over a 5-year period with putative markers of postmenopausal breast cancer risk., Methods: The analytic cohort consisted of 1,001 postmenopausal women from the Australian Diabetes, Obesity and Lifestyle (AusDiab) study (1999-2005). Multivariate linear regression models were used to examine associations of change in TV viewing time with biomarkers of the following risk mechanisms: adiposity (body mass index [BMI], waist circumference); metabolic dysfunction (fasting plasma glucose, 2-h plasma glucose, fasting insulin, insulin resistance [homeostasis model assessment of insulin resistance (HOMA-IR)]); and inflammation (high-sensitivity C-reactive protein (hs-CRP)). All analyses were adjusted for age, baseline TV viewing, and potential confounders., Results: Hourly increments of change in TV viewing time were positively associated with BMI (β = 0.50, 95% CI 0.20, 0.81; p = 0.001), waist circumference (β = 1.18, 95% CI 0.49, 1.87; p = 0.001), fasting insulin (β = 38.13%, 95% CI 37.08, 39.20; p = 0.01) and HOMA-IR (β = 37.93%, 95% CI 36.92, 38.98; p = 0.03) in fully adjusted models. Significant associations with BMI, waist circumference, fasting insulin and HOMA-IR were also present in analyses using categories of change in TV viewing time (reduced, same, increased)., Conclusions: The findings suggest that increasing habitual sedentary behavior over time could increase breast cancer risk among postmenopausal women. Further investigation into the role of sedentary behavior in breast cancer etiology is warranted.

Purpose: Sedentary behavior may be a unique risk factor for some cancers, including breast cancer. The objective of this study was to determine the association between lifetime occupational sitting and likelihood of breast cancer., Methods: A case-control study of 2,452 women was conducted in Alberta, Canada, between 1995 and 1997. A comprehensive measure of lifetime physical activity assessed frequency and duration of sedentary jobs. Logistic regression estimated the odds of being diagnosed with breast cancer across quartiles of lifetime occupational sitting, by menopausal status and family history of breast cancer, and within body mass index categories and physical activity quartiles., Results: There was no association between occupational sitting and breast cancer among pre-menopausal women and women with a family history of breast cancer. Unexpectedly, higher amounts of occupational sitting were associated with lower odds of breast cancer in post-menopausal women (top versus bottom categories of occupational sitting OR = 0.71, 95 % CI 0.52, 0.97), women without a family history of breast cancer (OR = 0.77, 95 % CI 0.60, 1.00), and women in the third highest quartile of total lifetime physical activity (OR = 0.57, 95 % CI 0.33, 0.97)., Conclusion: Occupational sitting levels were lower than would be expected in a contemporary study. Exposures may have been insufficient to make a determinable contribution to breast cancer risk.

Physical activity reduces the risk of postmenopausal breast cancer through multiple inter-related biologic mechanisms; sedentary time may contribute additionally to this risk. We examined cross-sectional associations of objectively assessed physical activity and sedentary time with established biomarkers of breast cancer risk in a population-based sample of postmenopausal women. Accelerometer, anthropometric and laboratory data were available for 1,024 (n = 443 fasting) postmenopausal women in the U.S. National Health and Nutrition Examination Survey 2003-2006. Associations of quartiles of the accelerometer variables (moderate- to vigorous-intensity activity, light-intensity activity and sedentary time per day; average length of active and sedentary bouts) with the continuous biomarkers were assessed using linear regression models. Following adjustment for potential confounders, including sedentary time, moderate- to vigorous-intensity activity had significant (P < 0.05), inverse associations with all biomarker outcomes (body mass index, waist circumference, C-reactive protein, fasting plasma glucose, fasting insulin and homeostasis model assessment of insulin resistance). Light-intensity activity and sedentary time were significantly associated in fully adjusted models with all biomarkers except fasting glucose. Active bout length was associated with a smaller waist circumference and lower C-reactive protein levels, while sedentary bout length was associated with a higher BMI. The associations of objectively assessed moderate- to vigorous-intensity activity with breast cancer biomarkers are consistent with the established beneficial effects of self-reported exercise on breast cancer risk. Our findings further suggest that light-intensity activity may have a protective effect, and that sedentary time may independently contribute to breast cancer risk.

Breast cancer is the most commonly diagnosed invasive malignancy and the second leading cause of cancer death in women. This chapter considers epidemiologic evidence regarding the association between physical activity and breast cancer risk from 73 studies conducted around the world. Across these studies there was a 25% average risk reduction amongst physically active women as compared to the least active women. The associations were strongest for recreational activity, for activity sustained over the lifetime or done after menopause, and for activity that is of moderate to vigorous intensity and performed regularly. There is also some evidence for a stronger effect of physical activity amongst postmenopausal women, women who are normal weight, have no family history of breast cancer, and are parous. It is likely that physical activity is associated with decreased breast cancer risk via multiple interrelated biologic pathways that may involve adiposity, sex hormones, insulin resistance, adipokines, and chronic inflammation. Future research should include prospective observational epidemiologic studies relating proposed biomarkers to breast cancer risk and also randomized controlled trials to examine how physical activity influences the proposed biomarkers. Exercise trials will provide more clarity regarding the appropriate type, dose, and timing of activity that relate to breast cancer risk reduction.

Objective: Obesity and physical inactivity are poor prognostic indicators for breast cancer. Studies to date have relied on self-report measures of physical activity, which tend mainly to assess moderate-to-vigorous intensity leisure-time physical activity. We report the cross-sectional associations of objectively assessed physical activity and sedentary time with adiposity in a sample of breast cancer survivors from the United States., Methods: One hundred and eleven women from the National Health and Nutrition Examination Survey (NHANES) 2003-2004 and 2005-2006 reported a history of breast cancer. Participants wore an accelerometer for 7 days, and activity levels were summarized as moderate-to-vigorous intensity (accelerometer counts/min > or =1,952), light intensity (counts/min 100-1,951), and sedentary time (counts/min <100). Anthropometric measures were taken by study staff at examination centers., Results: Participants spent the majority of their day in sedentary time (66%) or in light intensity activities (33%). Log moderate-to-vigorous intensity physical activity was negatively associated with adiposity (waist circumference beta = -9.805 [95% CI: -15.836, -3.775]; BMI beta = -3.576 [95% CI: -6.687, -0.464]). Light intensity physical activity was negatively associated with adiposity; however, the fully adjusted models did not retain statistical significance. Similarly, sedentary time was positively associated with adiposity, but the fully adjusted models were not statistically significant., Conclusions: This is the first study to describe the objectively assessed physical activity and sedentary time of breast cancer survivors. Increasing moderate-to-vigorous and light intensity physical activity, and decreasing sedentary time, may assist with weight management and improve other metabolic health outcomes for breast cancer survivors.

Background: This brief report examines the maintenance of moderate to vigorous physical activity (MVPA) and sedentary behavior changes approximately 12 weeks after the delivery of the ACTIVATE Trial primary intervention (use of the Garmin Vivofit 2 activity tracker coupled with a behavioral feedback and goal-setting session and 5 telephone-delivered health coaching sessions). We also examine the efficacy of an abridged intervention (use of the Garmin Vivofit 2 only) in the waitlist control group.Methods: A pre-post design was employed to examine the secondary aims of the ACTIVATE Trial (n = 80; mean age = 62 years). MVPA and sedentary behavior were measured using Actigraph and activPAL accelerometers after delivery of the primary intervention (T2), and again 12 weeks later (T3). Linear mixed models with random effects were used to examine within-group changes in MVPA and sitting time variables.Results: After the 12-week follow-up period, women in the primary intervention group had maintained their higher levels of MVPA (change from T2 to T3 = 14 min/wk; 95% CI = -18 to 46; P = .37). However, their sitting time increased slightly, by 7 min/d (95% CI = -20 to 34; P = .58), but it did not return to its preintervention level. After receiving the Garmin Vivofit 2, the waitlist control group increased their MVPA by 33 min/wk (95% CI = 3-64; P = .03) and reduced their sitting time by 38 min/d (95% CI = -69 to -7; P = .02) over the same 12-week period.Conclusion: The secondary outcomes from the ACTIVATE Trial suggest that wearable technology may generate sustainable changes in MVPA and sitting time. Wearable technology alone may be sufficient to change behavior, at least in the short term. [ABSTRACT FROM AUTHOR]