Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 May 4;12(5):e0177042.
doi: 10.1371/journal.pone.0177042. eCollection 2017.

On the health paradox of occupational and leisure-time physical activity using objective measurements: Effects on autonomic imbalance

David M Hallman  1 , Marie Birk Jørgensen  2 , Andreas Holtermann  2
Affiliations

On the health paradox of occupational and leisure-time physical activity using objective measurements: Effects on autonomic imbalance

David M Hallman et al. PLoS One. .

Abstract

Objective: Leisure-time physical activity (LTPA) has considerable benefits for cardiovascular health and longevity, while occupational physical activity (OPA) is associated with an elevated cardiovascular risk. This "health paradox" may be explained by different effects on the autonomic nervous system from OPA and LTPA. Thus, we aimed to investigate whether objectively measured OPA and LTPA are differentially associated with autonomic regulation among workers.

Methods: The study comprised 514 blue-collar workers from the Danish cohort DPHACTO. Physical activity (i.e. walking, climbing stairs, running and cycling) was assessed objectively using accelerometers worn on the thigh, hip and trunk over multiple working days. During this period, a heart rate monitor was used to sample heart period intervals from the ECG signal. Heart rate and heart rate variability (HRV) indices were analyzed during nocturnal sleep as markers of autonomic regulation. Multiple regression analysis was used to determine the main effects of OPA and LTPA and their interaction on heart rate and HRV, adjusting for multiple confounders.

Results: Statistically significant interaction was found between OPA and LTPA on heart rate (adjusted p<0.0001) and HRV indices in time (rMSSD, adjusted p = 0.004) and frequency-domains (HF, adjusted p = 0.022; LF, adjusted p = 0.033). The beneficial effect of LTPA on nocturnal heart rate and HRV clearly diminished with higher levels of OPA, and high levels of both OPA and LTPA had a detrimental effect.

Conclusion: We found contrasting associations for objectively measured OPA and LTPA with heart rate and HRV during sleep. Differential effects of OPA and LTPA on autonomic regulation may contribute to the physical activity health paradox.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Predicted nocturnal heart rate and heart rate variability indices from the multiple regression analyses adjusted for age, gender, body-mass index and smoking.
The x-axes represent percent time in leisure-time physical activity (LTPA), and the lines represent tertiles (low, middle and high) of occupational physical activity (OPA).
Fig 2
Fig 2. Mean predicted heart rate and RMSSD (parasympathetic index) across tertiles (low, middle and high) of occupational (OPA) and leisure-time physical activity (LTPA).
Lines represent tertiles of OPA, and the y-axis represents tertiles of LTPA. Error bars represent 95% confidence intervals.
See this image and copyright information in PMC

References

    1. Reiner M, Niermann C, Jekauc D, Woll A. Long-term health benefits of physical activity–a systematic review of longitudinal studies. BMC Public Health. 2013;13(1):1–9. - PMC - PubMed
    1. Blair SN, Morris JN. Healthy Hearts‒and the Universal Benefits of Being Physically Active: Physical Activity and Health. Ann Epidemiol. 2009;19(4):253–6. doi: 10.1016/j.annepidem.2009.01.019 - DOI - PubMed
    1. Warburton D, Charlesworth S, Ivey A, Nettlefold L, Bredin S. A systematic review of the evidence for Canada's Physical Activity Guidelines for Adults. International Journal of Behavioral Nutrition and Physical Activity. 2010;7(39):1–220. - PMC - PubMed
    1. Li J, Loerbroks A, Angerer P. Physical activity and risk of cardiovascular disease: what does the new epidemiological evidence show? Curr Opin Cardiol. 2013;28(5):575–83. doi: 10.1097/HCO.0b013e328364289c - DOI - PubMed
    1. Lahti J, Holstila A, Lahelma E, Rahkonen O. Leisure-Time Physical Activity and All-Cause Mortality. PLoS One. 2014;9(7):e101548 doi: 10.1371/journal.pone.0101548 - DOI - PMC - PubMed