Mode-specific physical activity and leukocyte telomere length among US adults: Implications of running on cellular aging

Background. Previous research demonstrates that physical activity participation is associated with longer leukocyte telomere length, with shorter leukocyte telomere length being a hallmark characteristic of cellular aging. What remains under-investigated, however, is whether there is a mode-specific association of physical activity on leukocyte telomere length, which was this study's purpose. Methods. Data from the 1999-2002 National Health and Nutrition Examination Survey were used (N 6474 adults analyzed). Leukocyte telomere length was assessed using quantitative polymerase chain reaction. Physical activity was assessed via self-report, with participants classified as meeting physical activity guidelines (L-2000 metabolic equivalent of task-min-month) for 9 separate physical activities, including aerobics (unweighted percent meeting guidelines: 2.98%; n = 193), basketball (2.0%; n = 129), bicycling (3.71%; n = 240), dance (2.30%; n = 149), running (3.09% n = 200), stair climbing (1.33%, n = 86), swimming (1.85%, n = 120), walking (13 53% N 876), and weight lifting (2.61%; n 169). Results. In a single multivariable linear regression model including the independent variables of age, gender, race-ethnicity, weight status, total cholesterol, C-reactive protein, total metabolic equivalent of task-min-month of physical activity and the 9 binary meeting physical activity guideline variables, the only mode of physical activity that was significantly associated with leukocyte telomere length was meeting physical activity guidelines from running (beta - 0.06; 95% Cl: 0.01-0.11; P = 0.03). Conclusion. Running-specific physical activity was the only evaluated physical activity associated with leukocyte telomere length, which may provide one potential mechanism (i.e., leukocyte telomere length) through which running-based physical activity may help to prevent cardiovascular disease and premature mortality. (C) 2016 Elsevier Inc. All rights reserved.