The COVID-19 Pandemic Decreases Cardiorespiratory Fitness: A 3-Year Follow-Up Study in Industry

Background: We aimed to determine if maximal oxygen uptake (V(center dot)O(2)max), resting heart rate (RHR), and self-reported leisure- time moderate to vigorous physical activity (MVPA) changed over a 3-year follow-up (FU) among industrial workers. Methods: We assessed cardiorespiratory fitness (CRF) August 2018 and August 2021. The last 17-18 months coincided with the COVID-19 pandemic. Data from 86 participants were collected; demographics by questionnaire and cardiovascular outcomes from medical examination: (VO2max)-O-center dot, RHR, and fat mass (%). Workers reported on their leisure-time MVPA twice. To assess changes in health outcomes we applied a linear mixed model, adjusting for baseline (BL) age, sex, pack-years, shift work, and a 5-month plant shutdown. Further, we adjusted for actual age instead of BL age. Results: (VO2max)-O-center dot decreased from 39.6 mL/kg/min at BL to 34.0 at FU, a reduction of 5.6 mL/kg/min (95%CI, -7.6, -3.7). Adjusted for actual age, the corresponding figure for (VO2max)-O-center dot was 5.4 mL/kg/min, (95%CI, -7.4, -3.4), an annual loss of 4.6%. RHR increased from 61.3 to 64.4 beats per minute (95%CI, 0.8, 5.4). Self-reported MVPA decreased by 43.9 min/week, (95%CI, -73.5, -14.4). Conclusions: We observed a decrease in (VO2max)-O-center dot, an increase in RHR and a decrease in self-reported MVPA, suggesting physical inactivity during the COVID-19 pandemic.