Physical Activity and Public Health for Adults: Is the Glass Mostly Empty or Half Full?

ABSTRACT: Early observations that only a small proportion of United States (US) adults were engaging in enough aerobic physical activity to provide substantial health benefit helped shape our public health messaging for physical activity. This messaging has consistently indicated that most adults should increase their activity levels. However, it has been difficult to accurately estimate the proportion of adults who engage in sufficient levels of aerobic activity in the population, with survey-based estimates ranging from 22% in 1994 to 54% in 2018 and widely differing estimates from device-based measures. Recent accelerometer-based studies of physical activity and mortality risk provide new evidence that at least 50% of US adults engage in enough aerobic physical activity to be at low risk for premature mortality. We argue that this observation should lend greater confidence to our current survey-based surveillance estimates which indicate that a large proportion of adults is physically active. This new insight may also provide clues that could further strengthen our public health messaging for physical activity by placing more emphasis on the maintenance of healthy activity levels throughout life and possibly by using descriptive social norms as an additional intervention element-while continuing current efforts to encourage the adoption of healthy activity levels for less active adults in the population.

Sleep and Risk of Pancreatic Cancer in the UK Biobank.

BACKGROUND: Light at night, which may cause circadian disruption, is a potential pancreatic cancer risk factor. However, evidence from related exposures such as poor sleep health and shift work remains inconclusive and sparsely investigated. METHODS: We evaluated associations between self-reported typical sleep duration, chronotype, shift work, insomnia symptoms, snoring, and daytime sleeping and pancreatic ductal adenocarcinomas (PDAC) incidence among 475,286 UK Biobank participants. We used Cox proportional hazards models to estimate HRs and 95% confidence intervals (CI) adjusting for age, sex, body mass index, smoking status, duration, and frequency, alcohol intake, diabetes status, race, and employment/shift work. RESULTS: Over 14 years of follow-up, 1,079 adults were diagnosed with PDAC. There were no associations observed between sleep characteristics, including sleep duration [<7 vs. 7-<9 hours; HR, 1.03; 95% CI, 0.90-1.19; ≥9 hours; HR, 1.00 (0.81-1.24), evening chronotype ("definitely" an evening person vs. "definitely" a morning person; HR, 0.99 (0.77-1.29)], shift work, insomnia symptoms, snoring, or daytime sleep and PDAC risk. CONCLUSIONS: Self-reported typical sleep characteristics and shift work were not associated with PDAC risk. IMPACT: Considering the role of light at night and shift work in circadian disruption and cancer risk, it is plausible that poor sleep health among a general population may be related to cancer risk through similar sleep and circadian disrupting processes. This work may suggest that typical sleep characteristics and shift work are not associated with PDAC, although additional work is needed to confirm these findings.

Associations between actigraphy-measured sleep duration, continuity, and timing with mortality in the UK Biobank.

STUDY OBJECTIVES: To examine the associations between sleep duration, continuity, timing, and mortality using actigraphy among adults. METHODS: Data were from a cohort of 88 282 adults (40-69 years) in UK Biobank that wore a wrist-worn triaxial accelerometer for 7 days. Actigraphy data were processed to generate estimates of sleep duration and other sleep characteristics including wake after sleep onset (WASO), number of 5-minute awakenings, and midpoint for sleep onset/wake-up and the least active 5 hours (L5). Data were linked to mortality outcomes with follow-up to October 31, 2021. We implemented Cox models (hazard ratio, confidence intervals [HR, 95% CI]) to quantify sleep associations with mortality. Models were adjusted for demographics, lifestyle factors, and medical conditions. RESULTS: Over an average of 6.8 years 2973 deaths occurred (1700 cancer, 586 CVD deaths). Overall sleep duration was significantly associated with risk for all-cause (p < 0.01), cancer (p < 0.01), and CVD (p = 0.03) mortality. For example, when compared to sleep durations of 7.0 hrs/d, durations of 5 hrs/d were associated with a 29% higher risk for all-cause mortality (HR: 1.29 [1.09, 1.52]). WASO and number of awakenings were not associated with mortality. Individuals with L5 early or late midpoints (<2:30 or ≥ 3:30) had a ~20% higher risk for all-cause mortality, compared to those with intermediate L5 midpoints (3:00-3:29; p ≤ 0.01; e.g. HR ≥ 3:30: 1.19 [1.07, 1.32]). CONCLUSIONS: Shorter sleep duration and both early and late sleep timing were associated with a higher mortality risk. These findings reinforce the importance of public health efforts to promote healthy sleep patterns in adults.

Observational and genetic associations between cardiorespiratory fitness and cancer: a UK Biobank and international consortia study.

BACKGROUND: The association of fitness with cancer risk is not clear. METHODS: We used Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for risk of lung, colorectal, endometrial, breast, and prostate cancer in a subset of UK Biobank participants who completed a submaximal fitness test in 2009-12 (N = 72,572). We also investigated relationships using two-sample Mendelian randomisation (MR), odds ratios (ORs) were estimated using the inverse-variance weighted method. RESULTS: After a median of 11 years of follow-up, 4290 cancers of interest were diagnosed. A 3.5 ml O2⋅min-1⋅kg-1 total-body mass increase in fitness (equivalent to 1 metabolic equivalent of task (MET), approximately 0.5 standard deviation (SD)) was associated with lower risks of endometrial (HR = 0.81, 95% CI: 0.73-0.89), colorectal (0.94, 0.90-0.99), and breast cancer (0.96, 0.92-0.99). In MR analyses, a 0.5 SD increase in genetically predicted O2⋅min-1⋅kg-1 fat-free mass was associated with a lower risk of breast cancer (OR = 0.92, 95% CI: 0.86-0.98). After adjusting for adiposity, both the observational and genetic associations were attenuated. DISCUSSION: Higher fitness levels may reduce risks of endometrial, colorectal, and breast cancer, though relationships with adiposity are complex and may mediate these relationships. Increasing fitness, including via changes in body composition, may be an effective strategy for cancer prevention.

Does Wrist-Worn Accelerometer Wear Compliance Wane over a Free-Living Assessment Period? An NHANES Analysis.

PURPOSE: Accelerometers are used to objectively measure physical behaviors in free-living environments, typically for seven consecutive days or more. We examined whether participants experience "wear fatigue," a decline in wear time day over day, during typical assessment period acquired in a nationally representative sample of 6- to 80-yr-olds in the United States. METHODS: Participants were instructed to wear an ActiGraph GT3X+ on their nondominant wrist continuously for seven consecutive days. Participants with seven complete days of recorded data, regardless of wear status, were included in the analyses ( N = 13,649). Wear was scored with the sleep, wake, and nonwear algorithm. RESULTS: Participants averaged 1248 ± 3.6 min·d -1 (mean ± SE) of wear over the assessment, but wear time linearly decreased from day 1 (1295 ± 3.2 min) to day 7 (1170 ± 5.3 min), resulting in a wear fatigue of -18.1 ± 0.7 min·d -1 ( ß ± SE). Wear fatigue did not differ by sex but varied by age-group-highest in adolescents (-26.8 ± 2.4 min·d -1 ) and lowest in older adults (-9.3 ± 0.9 min·d -1 ). Wear was lower in evening (1800-2359 h) and early morning (0000-0559 h) compared with the middle of the day and on weekend days compared with weekdays. We verified similar wear fatigue (-23.5 ± 0.7 min·d -1 ) in a separate sample ( N = 14,631) with hip-worn devices and different wear scoring. Applying minimum wear criteria of ≥10 h·d -1 for ≥4 d reduced wear fatigue to -5.3 and -18.7 min·d -1 for the wrist and hip, respectively. CONCLUSIONS: Patterns of wear suggest noncompliance may disproportionately affect estimates of sleep and sedentary behavior, particularly for adolescents. Further study is needed to determine the effect of wear fatigue on longer assessments.

Actigraphy-derived measures of sleep and risk of prostate cancer in the UK Biobank.

BACKGROUND: Studies of sleep and prostate cancer are almost entirely based on self-report, with limited research using actigraphy. Our goal was to evaluate actigraphy-measured sleep and prostate cancer and to expand on findings from prior studies of self-reported sleep. METHODS: We prospectively examined 34 260 men without a history of prostate cancer in the UK Biobank. Sleep characteristics were measured over 7 days using actigraphy. We calculated sleep duration, onset, midpoint, wake-up time, social jetlag (difference in weekend-weekday sleep midpoints), sleep efficiency (percentage of time spent asleep between onset and wake-up time), and wakefulness after sleep onset. Cox proportional hazards models were used to estimate covariate-adjusted hazards ratios (HRs) and 95% confidence intervals (CIs). RESULTS: Over 7.6 years, 1152 men were diagnosed with prostate cancer. Sleep duration was not associated with prostate cancer risk. Sleep midpoint earlier than 4:00 am was not associated with prostate cancer risk, though sleep midpoint of 5:00 am or later was suggestively associated with lower prostate cancer risk but had limited precision (earlier than 4:00 am vs 4:00-4:59 am HR = 1.00, 95% CI = 0.87 to 1.16; 5:00 am or later vs 4:00-4:59 am HR = 0.79, 95% CI = 0.57 to 1.10). Social jetlag was not associated with greater prostate cancer risk (1 to <2 hours vs <1 hour HR = 1.06, 95% CI = 0.89 to 1.25; ≥2 hours vs <1 hour HR = 0.90, 95% CI = 0.65 to 1.26). Compared with men who averaged less than 30 minutes of wakefulness after sleep onset per day, men with 60 minutes or more had a higher risk of prostate cancer (HR = 1.20, 95% CI = 1.00 to 1.43). CONCLUSIONS: Of the sleep characteristics studied, higher wakefulness after sleep onset-a measure of poor sleep quality-was associated with greater prostate cancer risk. Replication of our findings between wakefulness after sleep onset and prostate cancer are warranted.

Estimating cancers attributable to physical inactivity in Australia.

OBJECTIVES: It was previously estimated that 1814 (1.6 % of incident cancers) were attributable to physical inactivity in Australia in 2010, when only three sites were considered. We estimated the burden of cancer due to physical inactivity in Australia for 13 sites. DESIGN: The population attributable fraction estimated site-specific cancer cases attributable to physical inactivity for 13 cancers. The potential impact fraction was used to estimate cancers that could have been prevented in 2015 if Australian adults had increased their physical activity by a modest amount in 2004-05. METHODS: We used 2004-05 national physical activity prevalence data, 2015 national cancer incidence data, and contemporary relative-risk estimates for physical inactivity and cancer. We assumed a 10-year latency period. RESULTS: An estimated 6361 of the cancers observed in 2015 were attributable to physical inactivity, representing 4.8 % of all cancers diagnosed. If Australian adults had increased their physical activity by one category in 2004-05, 2564 cases (1.9 % of all cancers) could have been prevented in 2015. CONCLUSIONS: More than three times as many cancers are attributable to physical inactivity than previously reported. Physical activity promotion should be a central component of cancer prevention programmes in Australia.

Dose-response of accelerometer-measured physical activity, step count, and cancer risk in the UK Biobank: a prospective cohort analysis.

BACKGROUND: Cancer is an age-related condition, but changes to modifiable lifestyle-related behaviours, including physical activity, could impact risk. While step count is an accessible metric of activity for older adults, its association with cancer risk remains poorly understood. We investigated the association between accelerometer-measured total activity, step count, and cancer risk. METHODS: We analysed data from a prospective UK Biobank cohort of consenting participants who wore wrist-based Axivity AX3 accelerometer devices for 7 days between June 1, 2013 and Dec 23, 2015, had valid accelerometer data, and no previous cancer diagnosis at baseline. Machine learning models estimated total physical activity (vector magnitude) and step count. The primary outcome, a composite of 13 cancers previously associated with physical activity, was obtained from national registries. Hazard ratios (HR) and were calculated using Cox proportional hazard models, with attained age as the underlying timescale and adjustment for sex, ethnicity, smoking status, alcohol consumption, education, and Townsend Deprivation Index. The impact of reallocating time between behaviours was evaluated using compositional data analyses. Dose-response associations were assessed with restricted cubic splines. FINDINGS: We analysed data from 86 556 participants, who were followed up during an average of 6·1 years (age range 43-78; 48 478 [56%] female and 38 078 [44%] male; 83 830 [97%] white). 5577 incident malignant cancers occurred among these 86 556 participants. Greater total physical activity was associated with a lower risk of physical-activity-related cancer (HR per 1 SD [+8·33 milligravity per day] 0·85, 95% CI 0·81-0·89). Reallocating 30 min/day from other activities to moderate-to-vigorous physical activity behaviour was associated with lower cancer risk (HR 0·96, 0·94-0·98), as was reallocating 1 h/day to light intensity activity (HR 0·94, 0·92-0·96), compared with the mean behaviour composition among included participants. Compared with taking 5000 steps per day, taking 10 000 daily steps was associated with a significantly lower risk of physical-activity-related cancer (HR 0·81, 0·73-0·90). INTERPRETATION: In this sample from the UK Biobank, higher total physical activity and daily step count were associated with lower risk of physical-activity-related cancers. Findings suggest additional physical activity time, irrespective of intensity, may be beneficial. Increasing low intensity activity time and increasing daily step counts could be practical public health interventions to lower cancer risk, especially for aging adults. FUNDING: National Institute of Health Oxford Cambridge Scholars Program, Wellcome Trust, Swiss Re, Health Data Research UK, and Cancer Research UK.

Fitness Trackers to Guide Advice on Activity Prescription.

This Viewpoint discusses whether older self-report questionnaire studies and newer studies of fitness-tracking devices reach different conclusions about the dose of physical activity needed for health.

Upper Limb Morbidity in Newly Diagnosed Individuals After Unilateral Surgery for Breast Cancer: Baseline Results from the AMBER Cohort Study.

PURPOSE: We aimed to examine potential associations between post-surgical upper limb morbidity and demographic, medical, surgical, and health-related fitness variables in newly diagnosed individuals with breast cancer. METHODS: Participants were recruited between 2012 and 2019. Objective measures of health-related fitness, body composition, shoulder range of motion, axillary web syndrome, and lymphedema were performed within 3 months of breast cancer surgery, and prior to or at the start of adjuvant cancer treatment. RESULTS: Upper limb morbidity was identified in 54% of participants and was associated with poorer upper limb function and higher pain. Multivariable logistic regression analysis identified mastectomy versus breast-conserving surgery (odds ratio [OR] 3.51, 95% confidence interval [CI] 2.65-4.65), axillary lymph node dissection versus sentinel lymph node dissection (OR 2.67, 95% CI 1.73-4.10), earlier versus later time from surgery (OR 1.58, 95% CI 1.15-2.18), and younger versus older age (OR 1.01, 95% CI 1.00-1.03) as significantly associated with a higher odds of upper limb morbidity, while mastectomy (OR 1.57, 95% CI 1.10-2.25), axillary lymph node dissection (OR 2.20, 95% CI 1.34-3.60), lower muscular endurance (OR 1.10, 95% CI 1.01-1.16) and higher percentage body fat (OR 1.04, 95% CI 1.00-1.07) were significantly associated with higher odds of moderate or greater morbidity severity. CONCLUSIONS: Upper limb morbidity is common in individuals after breast cancer surgery prior to adjuvant cancer treatment. Health-related fitness variables were associated with severity of upper limb morbidity. Findings may facilitate prospective surveillance of individuals at higher risk of developing upper limb morbidity.

Social-cognitive, demographic, clinical, and health-related correlates of physical activity and sedentary behaviour in newly diagnosed women with breast cancer.

PURPOSE: Identifying correlates of physical activity and sedentary behaviour allows for the identification of factors that may be targeted in future behaviour change interventions. This study sought to determine the social-cognitive, demographic, clinical, and health-related correlates of physical activity and sedentary behaviour in individuals recently diagnosed with breast cancer. METHODS: Data were collected from 1381 participants within 90 days of diagnosis in the Alberta Moving Beyond Breast Cancer (AMBER) Cohort Study. Physical activity and sedentary behaviour were measured with ActiGraph GT3X+® and activPALTM devices, respectively, for seven consecutive days. Correlates were collected via a self-reported questionnaire, medical record extraction, or measured by staff. RESULTS: Multivariable models were fitted for sedentary behaviour, light physical activity, and moderate-to-vigorous physical activity. Greater sedentary behaviour was associated with higher body fat percentage (BF%) (ß=0.044; p<0.001) and being single (ß=0.542; p<0.002). Lower light physical activity was associated with higher BF% (ß=-0.044; p<0.001), higher body mass index (ß=-0.039; p<0.001), greater disease barrier influence (ß=-0.006; p<0.001), a HER2-positive diagnosis (ß=-0.278; p=0.001), and being single (ß=-0.385; p= 0.001). Lower moderate-to-vigorous physical activity was associated with higher BF% (ß =-0.011; p=0.001), greater disease barrier influence (ß=-0.002; p<0.001), and being of Asian (ß=-0.189; p=0.002) or Indian/South American (ß=-0.189; p=0.002) descent. Greater moderate-to-vigorous physical activity was associated with having greater intentions (ß=0.049; p=0.033) and planning (ß=0.026; p=0.015) towards physical activity. CONCLUSION: Tailoring interventions to increase physical activity for individuals recently diagnosed with breast cancer may improve long-term outcomes across the breast cancer continuum.

Depression, happiness, and satisfaction with life in women newly diagnosed with breast cancer: Associations with device-measured physical activity and sedentary time.

BACKGROUND: Few studies have examined depression after a cancer diagnosis and before initiating adjuvant or neoadjuvant systemic treatments. In this study, we present baseline data on device-measured physical activity, sedentary behaviour, depression, happiness, and satisfaction with life in newly diagnosed breast cancer survivors. PURPOSE: To examine associations of accelerometer-assessed physical activity and sedentary time with depression symptoms and prevalence, happiness, and satisfaction with life. METHODS: Shortly after diagnosis, 1425 participants completed depression, happiness, and satisfaction with life measures and wore an ActiGraph® device on their hip to measure physical activity and the activPALTM inclinometer on their thigh for 7 days to measure sedentary time (sitting/lying) and steps (1384 completed both device measures). ActiGraph® data were analysed using a hybrid machine learning method (R Sojourn package, Soj3x), and activPALTM data using activPALTM algorithms (PAL Software version 8). We used linear and logistic regression to examine associations of physical activity and sedentary time with depression symptom severity (0-27) and depression prevalence, happiness (0-100), and satisfaction with life (0-35). For the logistic regression analysis, we compared participants with none-minimal depression (n = 895) to participants with some depression (that is, mild, moderate, moderately-severe, or severe depression [n = 530]). RESULTS: Participants reported a mean depression symptom severity score of 4.3 (SD = 4.1), a satisfaction with life score of 25.7 (SD = 7.2), and a happiness score of 70 (SD = 21.8). Higher moderate-to-vigorous physical activity (MVPA) was associated with reduced depression symptom severity scores (ß = -0.51, 95% CI: -0.87 to -0.14, p = 0.007). A 1 hour increase in MVPA was associated with a reduced odds of at least mild or worse depression by 24% (Odds Ratio [OR] = 0.76, 95% CI: 0.62-0.94, p = 0.012). Higher daily step counts were associated with lower depression symptom severity scores (ß = -0.16, 95% CI: -0.24 to -0.10, p < 0.001). Perceptions of happiness was associated with higher MVPA (ß = 2.17, 95% CI: 0.17-4.17, p = 0.033). Sedentary time was not associated with depression severity, but higher sedentary time was associated with lower perceptions of happiness (ß = -0.80, 95% CI: -1.48 to -0.11, p = 0.023). CONCLUSIONS: Higher physical activity was associated with fewer depression symptom severity scores and reduced odds of mild or worse depression in women newly diagnosed with breast cancer. Higher physical activity and daily step counts were also associated with stronger perceptions of happiness and satisfaction with life, respectively. Sedentary time was not associated with depression symptom severity or odds of having depression, but was associated with stronger perceptions of happiness.

Development and Validation of a Machine Learning Wrist-worn Step Detection Algorithm with Deployment in the UK Biobank.

Background: Step count is an intuitive measure of physical activity frequently quantified in a range of health-related studies; however, accurate quantification of step count can be difficult in the free-living environment, with step counting error routinely above 20% in both consumer and research-grade wrist-worn devices. This study aims to describe the development and validation of step count derived from a wrist-worn accelerometer and to assess its association with cardiovascular and all-cause mortality in a large prospective cohort study. Methods: We developed and externally validated a hybrid step detection model that involves self-supervised machine learning, trained on a new ground truth annotated, free-living step count dataset (OxWalk, n=39, aged 19-81) and tested against other open-source step counting algorithms. This model was applied to ascertain daily step counts from raw wrist-worn accelerometer data of 75,493 UK Biobank participants without a prior history of cardiovascular disease (CVD) or cancer. Cox regression was used to obtain hazard ratios and 95% confidence intervals for the association of daily step count with fatal CVD and all-cause mortality after adjustment for potential confounders. Findings: The novel step algorithm demonstrated a mean absolute percent error of 12.5% in free-living validation, detecting 98.7% of true steps and substantially outperforming other recent wrist-worn, open-source algorithms. Our data are indicative of an inverse dose-response association, where, for example, taking 6,596 to 8,474 steps per day was associated with a 39% [24-52%] and 27% [16-36%] lower risk of fatal CVD and all-cause mortality, respectively, compared to those taking fewer steps each day. Interpretation: An accurate measure of step count was ascertained using a machine learning pipeline that demonstrates state-of-the-art accuracy in internal and external validation. The expected associations with CVD and all-cause mortality indicate excellent face validity. This algorithm can be used widely for other studies that have utilised wrist-worn accelerometers and an open-source pipeline is provided to facilitate implementation.

Associations between health-related fitness and quality of life in newly diagnosed breast cancer patients.

PURPOSE: Newly diagnosed breast cancer patients face substantial stress and uncertainty that may undermine their quality of life (QoL). The purpose of the present study was to examine the associations between health-related fitness (HRF) and QoL in newly diagnosed breast cancer patients from the Alberta Moving Beyond Breast Cancer Study. METHODS: Newly diagnosed breast cancer patients with early-stage disease (n = 1458) were recruited between 2012 and 2019 in Edmonton and Calgary, Canada to complete baseline HRF and QoL assessments within 90 days of diagnosis. HRF assessments included cardiorespiratory fitness (VO2peak treadmill test), muscular fitness (upper and lower body strength and endurance tests), and body composition (dual x-ray absorptiometry). QoL was assessed by the Medical Outcomes Study Short Form 36 (SF-36) version 2. We used logistic regression analyses to examine the associations between quartiles of HRF and poor/fair QoL (bottom 20%) after adjusting for key covariates. RESULTS: In multivariable analysis, the least fit groups compared to the most fit groups for relative upper body strength (OR = 3.19; 95% CI = 1.98-5.14), lean mass percentage (OR = 2.31; 95% CI = 1.37-3.89), and relative VO2peak (OR = 2.08; 95% CI = 1.21-3.57) were independently at a significantly higher risk of poor/fair physical QoL. No meaningful associations were found for mental QoL. CONCLUSIONS: The three main components of HRF (muscular fitness, cardiorespiratory fitness, and body composition) were independently associated with physical QoL in newly diagnosed breast cancer patients. Exercise interventions designed to improve these components of HRF may optimize physical QoL and help newly diagnosed breast cancer patients better prepare for treatments and recovery.

Relationship between neighborhood walkability and the prevalence, type, timing, and temporal characteristics of walking.

We examined associations of neighborhood walkability with the prevalence, type, timing, and temporal characteristics of walking in a representative sample of United States adults. Adults (N = 2649) completed the ACT24 previous-day recall. Home address was linked to block-group National Walkability Index. Survey-adjusted Poisson and logistic regression examined the association of walkability with outcomes. Those who lived in more walkable neighborhoods were more likely to walk overall, for transport, or in the evening. In those who walked, higher walkability was associated with less morning but more evening walking. There were no associations of walkability with the frequency or duration of walking episodes.

Prospective associations between accelerometry-derived physical activity and sedentary behaviors and mortality among cancer survivors.

BACKGROUND: Survival benefits of self-reported recreational physical activity (PA) during cancer survivorship are well-documented in common cancer types, yet there are limited data on the associations between accelerometer-derived PA of all domains, sedentary behavior, and mortality in large, diverse cohorts of cancer survivors. METHODS: Participants included adults who reported a cancer diagnosis in the National Health and Nutrition Examination Survey and wore an accelerometer for up to 7 days in 2003-2006. Participants were followed for subsequent mortality through 2015. We examined the association of light PA, moderate to vigorous PA, total PA, and sedentary behavior, with all-cause mortality. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographics and health indicators. RESULTS: A total of 480 participants (mean age of 68.8 years [SD = 12.4] at the time of National Health and Nutrition Examination Survey assessment) reported a history of cancer. A total of 215 deaths occurred over the follow-up period. For every 1-h/d increase in light PA and moderate to vigorous PA (MVPA), cancer survivors had 49% (HR = 0.51, 95% CI = 0.34 to 0.76) and 37% (HR = 0.63 , 95% CI = 0.40 to 0.99) lower hazards of all-cause mortality, respectively. Total PA demonstrated similar associations with statistically significantly lower hazards of death for each additional hour per day (HR = 0.68, 95% CI = 0.54 to 0.85), as did every metabolic equivalents of task-hour per day increase in total PA estimations of energy expenditure (HR = 0.88, 95% CI = 0.82 to 0.95). Conversely, more sedentary time (1 h/d) was not associated with statistically significantly higher hazards (HR = 1.08, 95% CI = 0.94 to 1.23). CONCLUSIONS: These findings reinforce the current recommendations for cancer survivors to be physically active and underscore the continued need for widespread PA promotion for long-term survival in older cancer survivors.

Association of Accelerometer-Measured Physical Activity Level With Risks of Hospitalization for 25 Common Health Conditions in UK Adults.

Importance: Higher physical activity levels are associated with lower risks of cancer, cardiovascular disease, and diabetes, but associations with many common and less severe health conditions are not known. These conditions impose large health care burdens and reduce quality of life. Objectives: To investigate the association between accelerometer-measured physical activity and the subsequent risk of hospitalization for 25 common reasons for hospitalization and to estimate the proportion of these hospitalizations that might have been prevented if participants had higher levels of physical activity. Design, Setting, and Participants: This prospective cohort study used data from a subset of 81 717 UK Biobank participants aged 42 to 78 years. Participants wore an accelerometer for 1 week (between June 1, 2013, and December 23, 2015) and were followed up over a median (IQR) of 6.8 (6.2-7.3) years; follow-up for the current study ended in 2021 (exact date varied by location). Exposures: Mean total and intensity-specific accelerometer-measured physical activity. Main Outcomes and Measures: Hospitalization for the most common health conditions. Cox proportional hazards regression analysis was used to estimate hazard ratios (HRs) and 95% CIs for mean accelerometer-measured physical activity (per 1-SD increment) and risks of hospitalization for 25 conditions. Population-attributable risks were used to estimate the proportion of hospitalizations for each condition that might be prevented if participants increased their moderate to vigorous physical activity (MVPA) by 20 minutes per day. Results: Among 81 717 participants, the mean (SD) age at accelerometer assessment was 61.5 (7.9) years; 56.4% were female, and 97.0% self-identified as White. Higher levels of accelerometer-measured physical activity were associated with lower risks of hospitalization for 9 conditions: gallbladder disease (HR per 1 SD, 0.74; 95% CI, 0.69-0.79), urinary tract infections (HR per 1 SD, 0.76; 95% CI, 0.69-0.84), diabetes (HR per 1 SD, 0.79; 95% CI, 0.74-0.84), venous thromboembolism (HR per 1 SD, 0.82; 95% CI, 0.75-0.90), pneumonia (HR per 1 SD, 0.83; 95% CI, 0.77-0.89), ischemic stroke (HR per 1 SD, 0.85; 95% CI, 0.76-0.95), iron deficiency anemia (HR per 1 SD, 0.91; 95% CI, 0.84-0.98), diverticular disease (HR per 1 SD, 0.94; 95% CI, 0.90-0.99), and colon polyps (HR per 1 SD, 0.96; 95% CI, 0.94-0.99). Positive associations were observed between overall physical activity and carpal tunnel syndrome (HR per 1 SD, 1.28; 95% CI, 1.18-1.40), osteoarthritis (HR per 1 SD, 1.15; 95% CI, 1.10-1.19), and inguinal hernia (HR per 1 SD, 1.13; 95% CI, 1.07-1.19), which were primarily induced by light physical activity. Increasing MVPA by 20 minutes per day was associated with reductions in hospitalization ranging from 3.8% (95% CI, 1.8%-5.7%) for colon polyps to 23.0% (95% CI, 17.1%-28.9%) for diabetes. Conclusions and Relevance: In this cohort study of UK Biobank participants, those with higher physical activity levels had lower risks of hospitalization across a broad range of health conditions. These findings suggest that aiming to increase MVPA by 20 minutes per day may be a useful nonpharmaceutical intervention to reduce health care burdens and improve quality of life.

Non-exercise estimated cardiorespiratory fitness and cancer incidence: The NIH-AARP diet and health study.

BACKGROUND: Non-exercise estimated cardiorespiratory fitness (NEE-CRF) has been shown to be associated with mortality, although its association with cancer incidence is unknown. The study aimed to assess the prospective association between NEE-CRF and cancer incidence in a large cohort of men and women. METHODS: The National Institutes of Health-American Association of Retired Persons diet and health study is a prospective cohort that included 402,548 participants aged 50-71 years who were free from cancer at baseline (1995-1996) (men (n = 238,835) and women (n = 163,713)) and were followed until December 31, 2015. The exposure variable was NEE-CRF expressed in metabolic equivalents. NEE-CRF was estimated using a validated equation of self-reported predictors on demographics and lifestyle behaviors derived from baseline questionnaires. Primary outcomes were total cancer incidence and incidence of prostate, breast, lung, and colorectal cancers. Cox proportional hazards models were analyzed for the association between NEE-CRF and cancer incidence outcomes adjusted for established cancer risk factors. RESULTS: During 13.7 ± 3.2 years of follow-up (mean ± SD), 64,344 men and 31,315 women developed a new cancer. For every 1-metabolic equivalent higher NEE-CRF, the hazard ratios and 95% confidence intervals (95%CIs) were 0.96 (95%CI: 0.94-0.97) and 0.88 (95%CI: 0.84-0.92) of total and colorectal cancer incidence among men, and 0.95 (95%CI: 0.93-0.97) and 0.94 (95%CI: 0.91-0.97) of total and breast cancer incidence among women, respectively (all p < 0.001). NEE-CRF was not associated with incidence of prostate and lung cancers in men or colorectal and lung cancers in women. CONCLUSION: These results suggest that higher CRF levels, as assessed by the applied non-exercise estimated method, may provide preventive benefits against the development of cancer, while low CRF could potentially serve as a modifiable cancer risk factor. Integrating NEE-CRF into screening paradigms and referring low-fit individuals to improve CRF could complement the public health prevention strategy against cancer.

Physical Activity Levels (PAL) in US Adults-2019.

PURPOSE: Physical activity levels (PAL) are associated with mortality risk and were instrumental in estimating national energy requirements, but we are unaware of population-based estimates of PAL in US adults. Thus, we conducted a nationwide survey using a validated previous-day recall method to estimate PAL and the behavioral determinants of low and higher PAL. METHODS: Participants from the AmeriSpeak panel 20-75 yr of age ( N = 2640) completed Activities Completed over Time in 24-hours previous-day recalls. PAL values were estimated as the average metabolic equivalent value over 24 h. Recalls were conducted on randomly selected days in October and November 2019. Survey sample design weights were applied to reflect the US population. RESULTS: Mean age was 45.3 yr, 51% were female, 67% were non-Hispanic White, and 37% had a body mass index of ≥30 kg·m -2 . US adults reported a mean PAL of 1.63 (95% confidence interval, 1.60-1.65), and 39% (37%-42%) of adults reported PAL ≥1.6 on a given day. Men reported higher PAL than women (1.67 vs 1.59), and older adults reported lower PAL. Adults with PAL <1.4 spent 81% (12.1 h·d -1 ) of their waking day sedentary and 19% (2.7 h·d -1 ) in total physical activity. Adults with PAL considered to be "active"(1.6-1.89) spent only 49% (8.0 h·d -1 ) of their waking day sedentary, and 51% (8.3 h·d -1 ) physically active. CONCLUSIONS: Our study provides novel estimates of PAL in a nationwide sample of US adults and a description of the type and intensity of sedentary and physically active behaviors contributing to low and higher PAL. These findings may inform public health messages aimed at increasing physical activity in adults and potentially contribute to obesity prevention efforts.