PROJECT SUMMARY/ABSTRACT
Approximately 8.5 million high school and collegiate athletes engage annually in competitive sport. While
competitive sport offers many benefits, it also poses underappreciated risks to long-term health. Competitive
sport profoundly increases risk for injury (e.g., knee injury) and may position athletes for early onset of chronic
diseases (e.g., osteoarthritis), chronic pain, poor health-related quality of life, and disability. Preliminary
evidence indicates former athletes in mid-life (mean age 53) perform worse on functional tests than non-athlete
peers, but did not account for prior injury status. Quantifying function in former athletes with and without a prior
injury and non-athlete controls is therefore critical to informing targeted interventions and ultimately increasing
healthspans and quality of life. One modifiable factor that may explain the association between sports
participation and poor long-term health is physical activity (PA) patterns including prolonged sedentary
behavior (SB). Even among adults who meet recommended PA guidelines, SB is strongly associated with a
host of poor outcomes including chronic disease and all-cause mortality. Current male professional athletes
are substantially more sedentary outside their practice times than non-athletes, but whether this harmful
pattern of SB also exists in amateur (e.g., high school, collegiate) or female athletes or persists in former
athletes is unknown. The long-term research goal is to improve musculoskeletal, cardiometabolic, and general
health and function across the lifespan of male and female former athletes, emphasizing early behavioral
interventions that prevent this underrepresented and at-risk population from developing chronic diseases by
mid-life. The overarching hypothesis is that former athletes, especially those with a prior injury, will have poorer
function and health in mid-life and that current and former athletes will engage in greater overall and longer
bouts of SB compared to matched non-athletes. Using a cross-sectional design, Aim 1 will compare function,
strength, and cardiometabolic indicators among former athletes with and without prior knee injury and non-
athlete matched controls in mid-life (age 45-64). Hypothesis 1 is that former athletes with a prior injury will have
the poorest (1a) function (30-second chair stand, 6-minute walk, stair climb), (1b) quadriceps and hamstring
strength, and (1c) cardiometabolic indicators (body composition, cardiovascular disease risk). Aim 2 will
compare SB and PA patterns in current (age 18-25) and mid-life former athletes to matched non-athlete
controls. Hypothesis 2.1 is that current athletes will have greater SB, longer SB bouts, and higher levels of
moderate-to-vigorous PA. Hypothesis 2.2 is that former athletes in mid-life will have greater SB, longer SB
bouts, and lower PA levels. Identifying and ultimately intervening on risk factors for early chronic disease will
not only benefit many millions of male and female former athletes—a group in which minorities are increasingly
more represented than in the overall United States population—but also provide an efficient means to prevent
or delay chronic disease development in the population at large, a recent NIH emphasis (e.g., PA-18-849).