Competitive sport increases risk for musculoskeletal injury (e.g., traumatic knee injury) and may position former athletes for early onset of chronic diseases, chronic pain, poor health-related quality of life, and disability. Quantifying function in former athletes with and without a prior injury and non-athlete controls is critical to understanding long-term health trajectories in athletes and informing potential interventional studies. One modifiable factor that may be associated with long-term health in athletes is physical activity patterns. The purpose of this study is to evaluate strength, function, physical activity, dietary patterns, and cardiometabolic health among current and former competitive athletes and in nonathlete controls to evaluate the impact of prior knee injury and sedentary behavior as two potential determinants of later poor health and reduced function.
The overarching hypothesis is that former athletes, especially those with a prior injury, will have poorer function and health in midlife and that current and former athletes will engage in greater overall and longer bouts of sedentary behavior compared to non-athletes. Aim 1 will compare function, strength, and cardiometabolic indicators among former athletes with and without prior knee injury and non-athlete controls in midlife (age 40-64). Hypothesis 1 is that former athletes with a prior injury will have the poorest function, muscle strength, and cardiometabolic indicators. Aim 2 will compare sedentary behavior and physical activity patterns in current (age 18-25) and midlife former athletes to non-athlete controls. Hypothesis 2.1 is that current athletes will have greater sedentary behavior, longer sedentary behavior bouts, and higher levels of moderate-to-vigorous physical activity compared to non-athlete controls. Hypothesis 2.2 is that former athletes in midlife will have greater sedentary behavior, longer sedentary behavior bouts, and lower physical activity levels compared to non-athlete controls. An exploratory aim will evaluate longitudinally the trajectory of physical activity patterns, cardiometabolic indicators, function, and strength annually in each cohort, comparing how these variables change over time in each subgroup.
Study Type
OBSERVATIONAL
Enrollment
450
Marquette University
Milwaukee, Wisconsin, United States
RECRUITING30-Second Chair Stand Test (primary outcome for Aim 1)
Physical function (functional performance) will be evaluated using the 30-Second Chair Stand Test, 6-Minute Walk Test, and Stair Climb Test. The 30-Second Chair Stand Test uses a standard height chair and requires the participant to stand up and sit down as many times as possible in 30 seconds. More completions indicate better physical function.
Time frame: Baseline
Sedentary Behavior (primary outcome for Aim 2)
Physical activity will be monitored continuously using an accelerometer worn for 2 weeks. Physical activity will be classified throughout the day as sedentary, light, moderate, or vigorous using established algorithms. The primary outcome for aim 2 is the mean percentage of waking hours in sedentary behavior.
Time frame: Baseline
Strength
Isometric quadriceps and hamstring strength will be assessed using a standardized strength testing machine (i.e., electromechanical dynamometer).
Time frame: Baseline
Body Composition
Body composition (i.e., percent body fat) will be assessed via dual-energy x-ray absorptiometry (DXA).
Time frame: Baseline
Step Counts
Average daily step counts will also be recorded using an objective physical activity monitor.
Time frame: Baseline
Cardiovascular Disease Risk
The American College of Cardiology/American Heart Association Atherosclerotic Cardiovascular Disease Risk Estimator will be used in the midlife participants to estimate 10-year cardiovascular disease risk.
Time frame: Baseline
6-Minute Walk Test
The 6-Minute Walk Test evaluates the distance participants can walk in 6 minutes and is a widely used indicator of function and aerobic capacity. The 6-minute walk test will be evaluated in the midlife participants only.
Time frame: Baseline
Stair Climb Test
The Stair Climb Test assesses the time it takes the participant to ascend and descend a flight of stairs. Faster times on the Stair Climb Test are associated with better strength and function. The Stair Climb Test will be evaluated in the midlife participants only.
Time frame: Baseline
Sedentary Behavior (follow-up)
Physical activity will be monitored continuously using an accelerometer worn for 2 weeks. Physical activity will be classified throughout the day as sedentary, light, moderate, or vigorous using established algorithms. Mean percentage of waking hours in sedentary behavior and each physical activity classification will be assessed.
Time frame: Follow-up (an average of 1 year post-baseline)
30-Second Chair Stand Test (follow-up)
The 30-Second Chair Stand Test uses a standard height chair and requires the participant to stand up and sit down as many times as possible in 30 seconds. More completions indicate better physical function.
Time frame: Follow-up (an average of 1 year post-baseline)
Strength (follow-up)
Isometric quadriceps and hamstring strength will be assessed using a standardized strength testing machine (i.e., electromechanical dynamometer).
Time frame: Follow-up (an average of 1 year post-baseline)
Body Composition (follow-up)
Body composition (i.e., percent body fat) will be assessed via dual-energy x-ray absorptiometry (DXA).
Time frame: Follow-up (an average of 1 year post-baseline)
Step Counts (Follow-up)
Average daily step counts will also be recorded using an objective physical activity monitor.
Time frame: Follow-up (an average of 1 year post-baseline)
6-Minute Walk Test (follow-up)
The 6-Minute Walk Test evaluates the distance participants can walk in 6 minutes and is a widely used indicator of function and aerobic capacity. The 6-minute walk test will be evaluated in the midlife participants only.
Time frame: Follow-up (an average of 1 year post-baseline)
Stair Climb Test (follow-up)
The Stair Climb Test assesses the time it takes the participant to ascend and descend a flight of stairs. Faster times on the Stair Climb Test are associated with better strength and function. The Stair Climb Test will be evaluated in the midlife participants only.
Time frame: Follow-up (an average of 1 year post-baseline)
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