Authors: Ian Duncan, FIA CSPA MAAA (1), Wade Herndon, PhD (1) and Xiyue Liao, PhD (2)
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Abstract
Introduction: As interest has grown in the effect of healthy behaviors on health outcomes, programs have been developed to incent healthy behavior. The growth of devices able to transmit information about program participant activities has allowed researchers to analyze physical activity (PA). We analyzed the relationship between positive changes in device-reported physical activity levels and changes in health-related variables in a longitudinal cohort of US based employees.
Methods: Exercise levels were measured and recorded by a device (such as a pedometer or heart-rate monitor) or gym visit and recorded by the health promotion program provider, The Vitality Group. The devices recorded the number and intensity of workouts, which were then classified as either light or standard. We obtained detailed data on 8,519 individuals who participated continuously between January 1, 2013 and August 31, 2015 in the health promotion program. Clinical measures, which were recorded either by a participant’s primary care physician or at employer-sponsored health fair (worksite events organized by employers that include voluntary blood and other health testing), included Body Mass Index (BMI), cholesterol level and triglycerides, blood glucose level and blood pressure. We performed multi-variate regression modeling on the data to evaluate the impact of different variables on the measured health outcomes.
Results: We provide statistical models to predict improvements in clinical measures depending on demographic factors, initial health status and number/intensity of workouts. We find that working out at both light and standard levels can lead to improvements in some clinical measures, specifically body mass index and high-density lipoprotein (for which we found that sustained, regular and intense exercise was beneficial for reducing BMI in obese and overweight participants). Similar results were observed for the high-density lipoprotein model. Unlike prior studies we did not observe any effect of PA on blood pressure. Our models also indicate deterioration in clinical measures over time for participants in the normal range who did not exercise regularly, indicating that regular, sustained exercise is necessary to maintain normal clinical measures over time.
Conclusions: While some improvement in clinical measures is associated with physical activity, our models indicate that improvement in clinical measures generally requires both sustained and intense physical activity.
Affiliation:
1. University of California Santa Barbara
2. California State University Long Beach