The Independent And Combined Effects Of Aerobic Physical Activity And Muscular Strengthening Activity On All-Cause Mortality: An Analysis Of Effect Modification By Race-Ethnicity

Abstract

The relationship between aerobic physical activity (PA) and all-cause mortality risk is well documented. However, the combined effects of sufficient aerobic PA and muscular strengthening activity (MSA) on all-cause mortality risk need further exploration. Moreover, the 2018 PA guidelines committee report suggests that effects of race-ethnicity on this relationship need to be examined. PURPOSE: To examine the independent and joint relationship between meeting the current aerobic PA and MSA recommendations and all-cause mortality while considering potential effect modification by race-ethnicity. METHODS: This study sample (n=14,384), included adults (20-79 years of age), who participated in the 1999-2006 NHANES. Participants self-reported participation in aerobic PA (leisure-time, transportation, household) and MSA. PA was categorized into 6 categories based around the 2018 PA guidelines: category 1 (no aerobic PA and no MSA), category 2 (insufficiently active and no MSA), category 3 (active and no MSA), category 4 (no PA and meeting the MSA recommendations), category 5 (insufficiently active and meeting the MSA recommendations), and category 6 (meeting both the aerobic and MSA recommendations). All-cause mortality was the dependent variable. Race-ethnic groups examined included non-Hispanic White (NHW), non-Hispanic Black (NHB) and Mexican American (MA). Cox-proportional hazard models were used for the total sample and for individual race-ethnicity estimates. RESULTS: A significant interaction was found between aerobic PA and race-ethnicity (p=0.0001) and MSA and race-ethnicity (p=0.0005). Significant risk reductions were found for categories 2,3 and 6 among NHW (cat 2: HR 0.76, 95% CI 0.64-0.91; cat 3: HR 0.63, 95% CI 0.52-0.74; cat 6: HR 0.58, 95% CI 0.44-0.76) and NHB (cat 2: HR 0.63, 95% CI 0.52-0.74; cat 3: HR 0.51, 95% CI 0.41-0.65; cat 6: HR 0.54, 95% CI 0.38-0.77). Among MA, only those meeting both guidelines had significant reductions in all-cause mortality risk (HR 0.54, 95% CI 0.32-0.92). CONCLUSIONS: In support of the most recent PA guidelines, participation in sufficient volumes of both aerobic PA and MSA lead to significant reductions in risk for all-cause mortality across race-ethnic groups. The positive effects of aerobic PA alone seem to be isolated to NHW and NHB.