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Relative and Absolute Intensity Accelerometer Metrics Decipher the Effects of Age, Sex, and Occupation on Physical Activity

Abstract

Background: To investigate whether quantifying both the absolute and relative intensity of physical activity (PA) improves understanding of age, sex, and occupation-related differences in PA in healthy adults aged 20-89.

Methods: In the cross-sectional COmPLETE study, participants (N = 460, 48% women, age 55 [IQR 37, 71]) wore accelerometers for up to 14 days and underwent cardiopulmonary exercise testing. Average acceleration (AvAcc) and distribution of intensity (IG) of PA across the day were expressed in absolute terms (_) and relative (_) to the acceleration at the individual´s maximum intensity, predicted from cardiorespiratory fitness.

Results: After initial increases, AvAcc_ and IG_ continuously declined beyond age 40-45, whereas AvAcc_ and IG_ increased until stabilising at age ~ 70 and declining at age ~ 60, respectively. Cardiorespiratory fitness constantly declined. Women had trivially higher AvAcc_ and moderately higher AvAcc_, but not IG_ and IG, than men. Occupations involving at least moderate PA showed higher AvAcc_ and AvAcc_, but not IG_ and IG indicating longer periods of low-intensity PA, compared to sitting/standing occupations.

Conclusions: Distinct age trajectories of absolute and relative metrics as well as cardiorespiratory fitness suggest that the age-related decline in the latter preceded that of PA. Women's higher AvAcc_ and AvAcc_ relate to more low-intensity PA combined with lower cardiorespiratory fitness rather than more health-enhancing higher-intensity PA. Finally, the intensity profile of occupational PA may provide insight into why occupational PA appears to lack a prophylactic association with health. Quantifying both the absolute and relative intensity of accelerometer-assessed PA provides greater insight than either alone.

Trial Registration: On clinicaltrials.gov (NCT03986892). Retrospectively registered 14 June 2019.

References
1.
Wagner J, Knaier R, Infanger D, Konigstein K, Klenk C, Carrard J . Novel CPET Reference Values in Healthy Adults: Associations with Physical Activity. Med Sci Sports Exerc. 2020; 53(1):26-37. DOI: 10.1249/MSS.0000000000002454. View

1.
Fairclough S, Rowlands A, Del Pozo Cruz B, Crotti M, Foweather L, Graves L . Reference values for wrist-worn accelerometer physical activity metrics in England children and adolescents. Int J Behav Nutr Phys Act. 2023; 20(1):35. PMC: 10039565. DOI: 10.1186/s12966-023-01435-z. View

2.
Dempsey P, Rowlands A, Strain T, Zaccardi F, Dawkins N, Razieh C . Physical activity volume, intensity, and incident cardiovascular disease. Eur Heart J. 2022; 43(46):4789-4800. DOI: 10.1093/eurheartj/ehac613. View

3.
Dawkins N, Yates T, Edwardson C, Maylor B, Henson J, Hall A . Importance of Overall Activity and Intensity of Activity for Cardiometabolic Risk in Those with and Without a Chronic Disease. Med Sci Sports Exerc. 2022; 54(9):1582-1590. DOI: 10.1249/MSS.0000000000002939. View

4.
Rowlands A, Fairclough S, Yates T, Edwardson C, Davies M, Munir F . Activity Intensity, Volume, and Norms: Utility and Interpretation of Accelerometer Metrics. Med Sci Sports Exerc. 2019; 51(11):2410-2422. DOI: 10.1249/MSS.0000000000002047. View