Purpose: Differential effects on fitness are hypothesized to contribute to the opposing health effects of leisure-time physical activity (LTPA) and occupational physical activity (OPA). As such, this study examined cross-sectional and longitudinal associations of fitness with LTPA and OPA. Methods: This study examined fitness associations with LTPA and OPA across 13 yr in the Coronary Artery Risk Development in Young Adults study (years 7 (baseline), 10, 15, and 20 (follow-up) examinations). Fitness was measured at baseline and follow-up via symptom-limited maximal graded exercise test (GXT) duration (in seconds), whereas LTPA and OPA were self-reported during each examination. Baseline and follow-up cross-sectional associations of LTPA (low, medium, high) and OPA (0, 1-6, and ≥6 months with OPA) with fitness were examined using linear regression. Longitudinal linear regression examined associations between 13-yr LTPA (low, medium, or high) and OPA (no, decreasing, or increasing) trajectories with fitness at follow-up, adjusted for baseline values.All models adjusted for center, sex, race, age, education, smoking history, alcohol intake, resting blood pressure, diabetes status, and body mass index. Stratified analyses examined associations by sex (female/male), race (Black/White), and LTPA groups. Results: Compared with low, medium, and high LTPA were positively associated with fitness in all analyses (P < 0.001). Reporting 1-6 or ≥6 months with OPA was negatively associated with fitness in cross-sectional follow-up models (β = −15.6 and −15.4, respectively; P ≤ 0.01). Longitudinally, those with increasing OPA had lower follow-up fitness compared with no OPA (β = −16.41, P < 0.01). Negative associations of OPA with fitness were not meaningfully different across sex and race groups. Significant LTPA-OPA interactions were observed (P < 001). Conclusions: Physical activity research and public health promotion should consider domain-specific associations on cardiovascular health.

Introduction: Leisure-time physical activity (LTPA) is known to promote cardiovascular health, while occupational physical activity (OPA) may have paradoxically negative impacts. One proposed, though untested, explanation for the paradoxical associations may be unfavorable vascular remodeling from OPA-induced chronic cardiovascular strain. Hypothesis: High amounts of OPA over 25 years from young adulthood to midlife is associated with adverse left ventricular (LV) structure and function. Methods: Data are from 1,893 participants (48.9% female, 57.3% White, aged 30.4±3.4 years at baseline [the Year 5 exam]) from the Coronary Artery Risk Development in Young Adults (CARDIA) Study who reported working full time at baseline and two years later. LV structure and function was measured as LV mass, end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), stroke volume (SV), and e/a-wave ratio (EA) via M-mode and 2-dimensional echocardiograms at baseline and 25-years later. OPA was reported at seven exams during the study period as months/year where the participant performed “vigorous job activities such as lifting, carrying, or digging” for ≥5 hours/week. The 25-year OPA patterns were categorized into three trajectories: zero OPA (0 months/year; n=995), medium OPA (~2-3 months/year; n=526), and high OPA (~6-8 months/year; n=372). Linear regression estimated longitudinal associations between the OPA trajectories and the echocardiogram variables at final follow-up after adjusting for baseline values. Case-wise deletion was used for each model where only those with valid outcome data were included (n=623-1,475). Results: EF and EA were significantly lower in high versus zero OPA. No other statistically significant associations were observed. (Figure 1) Conclusions: In this sample, OPA’s paradoxical impact on cardiovascular health was partially supported by null or adverse associations between high OPA and LV structure and function. Confirmation is needed using more precise OPA measures.

Objective The aim of the study is to evaluate the metabolic demands and internal breathing environments when covering an N95 with a surgical mask, cloth mask, and/or FS. Methods Three N95 models approved by the National Institute for Occupational Safety and Health were evaluated under six covering conditions using the National Institute for Occupational Safety and Health Automated Breathing and Metabolic Simulator. All conditions used one trial with each N95 for six incremental 5-minute work rates. Inhaled oxygen and carbon dioxide concentrations, peak inhaled and exhaled pressures, and inhaled wet-bulb and dry-bulb temperatures were measured continuously and averaged across all work rates and covering conditions. Conclusions Results suggest that metabolic demands and internal breathing environments are significantly impacted by all combinations of coverings tested when compared to N95 only.

Introduction: Sedentary behavior (SB) has emerged as a cardiovascular disease (CVD) risk factor, independent of physical inactivity. Yet, preliminary research suggests that these relationships may differ if SB is accumulated during occupational or non-occupational time. Thus, we examined associations of SB with CVD risk factors, by domain, in desk workers. Hypothesis: We hypothesized that non-occupational SB would have more unfavorable associations with CVD risk factors compared to occupational SB. Methods: This cross-sectional, secondary analysis of baseline data from the RESET BP clinical trial included 269 desk workers (age=45.2±11.6 years; 83.5% white; 59.3% female). Total SB was measured by activPAL3 and was partitioned into occupational and non-occupational domains. CVD risk factors included resting and nocturnal systolic/diastolic blood pressure (SBP/DBP) and heart rate (HR), resting carotid-femoral (cf) and carotid-radial (cr) pulse wave velocity (PWV), and heart rate variability (HRV) [i.e., natural log transformed standard deviation of R-R intervals (lnSDNN), root mean square of successive differences (lnRMSSD), and high frequency (lnHF)]. Adjusted linear regression estimated associations of SB with CVD risk factors. A Wald test compared the beta-coefficients associating occupational vs. non-occupation SB with these CVD risk factors. Results: Participants spent 69%, 77%, and 64% of their time in total, occupational, and non-occupational SB, respectively. Agnostic of the domains, a 1-hour increase in total SB was only associated with higher cfPWV (0.18 m/s; p<0.05). A 1-hour increase in occupational SB was associated with lower (favorable) resting DBP and nocturnal SBP and DBP (-1.02, -1.52, and -1.12 mmHg, respectively; p<0.05). Paradoxically, a 1-hour increase in non-occupational SB was associated with higher (unfavorable) resting DBP (1.04 mmHg), HR (1.07 beat/minute), cfPWV (0.23 m/s), nocturnal SBP (1.41 mmHg), and lower resting lnSDNN (-0.07), lnRMSSD (-0.10), and lnHF (-0.18). Wald tests revealed significant differences in beta coefficients (p<0.05 for all) for all these outcomes where occupational SB was favorably associated with these CVD risk factors while non-occupational SB was unfavorably associated with these CVD risk factors. Conclusions: While desk workers accumulate high amounts of occupational and non-occupational SB, paradoxical associations with CVD risk were observed with non-occupational SB being unfavorable and occupational SB being favorable for CVD risk factors. Confirmation is needed in longitudinal and experimental studies.