The aging runner or athlete struggles to maintain or improve on their younger performance measures but the effects of aging on athletic performance are without exception. Recent studies from the sports medicine department of the University of Burgundy in France have found that over the past 19 years that runners 50 years and older are increasingly the highest age group of finishers in the NYC Marathon. There has been a surge in the number of medium and older age athletes that compete.
The consensus is that athletic performance peaks to age 35 years and then diminishes at a steady rate until age 50-60 years and then accelerates after that.
Some of the more common factors recognized as contributing factors are mentioned below.
VO2 max is defined as the maximum amount of oxygen that the body is capable of absorbing in one minute of intense exercise. It will determine how long a conditioned athlete can sustain vigorous exercise. VO2 max is genetic but can be increased through training and exercise intensity. VO2 max does decrease with age.
The aging runner’s cardiac function also contributes to diminished performance. As we age the maximum heart rate is reduced and the elasticity of cardiac muscle decreases, leading to decreases in cardiac output. This decreased output diminishes blood and oxygen to working muscles causing more rapid fatigue. Decreases in cardiac output lead to changes in lactate threshold which is the body’s ability to metabolize lactate. When lactate production exceeds lactate clearance this is the point of anaerobic metabolism. In this state, exercise is limited in duration. Lactate clearance is decreased with aging which limits high intensity workouts leading to poorer physical conditioning and performance.
The solution is to maximize short high intensity workouts such as hill repeats, interval training and short tempo runs.
The musculoskeletal changes of aging that affect runners are decreased soft tissue flexibility and elasticity along with decreased joint mobility that causes decreased stride length and muscle power. A study from Duke University on muscle elasticity found that a significant amount of a runner’s propulsion comes from energy left over from elasticity of lengthened muscle and tendon from the previous stride. It then becomes obvious that if older tissue is less elastic and flexible then it will result in a decrease in intrinsic energy which effects performance.
The solution to slow this process is to stretch routinely. Easily stated but seldom followed. It is best to perform dynamicstretches prior to exercise that will concentrate on the muscle groups that the particular activity will utilize the most. Staticstretches are best performed after the activity. Yoga done routinely is very helpful in maintaining flexibility and core strength. Soft tissue mobilization using a foam roller will limit the effects of fibrosis and soft tissue contracture. This is especially beneficial on the quads, hamstrings and ITB. In extreme cases, a massage therapist or a rolfer can also help to mobilize soft tissue adhesions.
Muscle strength and mass are also diminished with aging as a result of decreased activity, exercise intensity and possibly decreased testosterone.
In runners, decreased lower extremity strength is first recognized asthe loss of fast and intermediate muscle twitch fibers that causes a slowing cadence and turnover which results in slower time. The solution is to slow down the loss of fast twitch muscle fiber and recruit what remains. This is accomplished by fast high intensity workouts several times a week. It can be with speed work or strength training with weights or resistance bands. Runners should not neglect their upper body and core strength as it can be influential in strong and efficient running. All muscle groups should be trained at least twice a week.
It is important to stress the need for adequate rest to allow soft tissue time to recover from workouts and especially true in older runners. This will help to prevent injury and down time. Cross training should be explored with activities that require limited weight bearing and low impact such as biking and swimming.
Aging is part of life! You can embrace it or use it as an excuse. There are many movers out there with the same physical struggles as you who derive physical, emotional and social benefits from exercise. Keep moving!