Dosage of Physical Activity to Avoid Impairment of Activities Due to Pain: Analysis of Population-based Conditional Processes

Abstract

Background: Physical activity's established health benefits include pain control, yet there is no consensus on the required dosage according to the literature. Aim: To test the influence of exercise on perceived health in patients whose daily activities are limited due to pain. Besides, analyze the possible moderating effect of age and find a formula for exercise dosage based on the perceived level of health. Methods: Cross-sectional study based on the 2017 Spanish National Health Survey with 4,123 participants reporting activity limitations in their daily activities due to pain. The International Physical Activity Questionnaire (short version) was used to calculate energy expenditure. Data included age, sex, leisure-time physical activity, sitting time, pain-related impairments, pain medication, and perceived health. Mediation regression analysis was conducted using the SPSS PROCESS 4.0 macro. Results: Results indicate a decline in perceived health with age. The relationship between exercise (energy expenditure) and perceived health was highly significant (d=-0.224, p<0.001). Age moderated the association between pain and energy expenditure up to 75.61 years (0.1568, p=0.05) and between energy expenditure and perceived health up to 75.74 years (-0.289, p=0.05), but this effect diminished afterwards. A formula was developed to estimate energy expenditure based on the desired level of health. Conclusions: The perception of health in people who are limited in their daily activities due to pain (moderate to very much) is mediated by the amount of physical activity they perform. Besides, this perception is moderated by age, up to 76 years.