The effects of chronological age on our bodies are undisputed. There are changes that occur in all of our bodies systems that affect our ability to participate in sports and other vigorous physical activities. The changes seen in typical healthy adults are quite dramatic and include loss of muscle mass and tone, loss of muscular power, loss of aerobic endurance, increase on body fat, and overall decrease in functional capacity to do physical work. The effects observed in highly trained older athletes are significantly less than that see in the general population. The following paragraphs provide facts about some of the changes we experience as older athletes as well as how training and nutrition can modulate the effects.
Scientific studies have shown that on average, after our late twenties or early thirties we lose about 10% of our aerobic capacity each decade up to age 60-70 at which time it decreases at a much faster rate . Studies of Masters endurance athletes show that peak performance can be maintained until 35 years of age, with a modest reduction in performance thereafter up to age 60-70 . The main reason for this decline is a decrease in maximal aerobic capacity (Vo2 max). It is interesting to note that the reason for the decrease in maximum aerobic capacity with age is not fully understood. Besides the decrease in maximum heart rate, studies have not been able to identify many factors that cannot be counteracted by training. It appears that the main reason for this decrease in capability is due to socio-behavioral reasons . With age we tend to not train as frequently, consistently or intensely, and this results in reduced capability over time. Typical reasons are job and family responsibilities as well as illness or injuries. A funny side note is that studies show that laboratory rats (and other mammals too) are significantly less likely to spontaneously use the running wheel in their cage when they get older. Yes, rats get lazy too. We are in good company indeed.
While not as much data is available for power and speed sports, similar reductions in capability are seen for older athletes in power as in aerobic capacity. In the general population, with age there is significant loss of muscle mass as well as a loss of the kind of muscle fibers that enable powerful movement (fast twitch fibers). Studies of Masters athletes show that these two factors can be nearly eliminated with training. It is also interesting to note that loss of muscle mass contributes significantly to the slow down of metabolism, and commensurate increase in body fat that we see as we get older. Similar to what is seen in aerobic capacity, the loss of our ability to perform powerful movements is most likely due to the decrease in training with age.
Athlete or not, we all feel the affects of slower recovery either from injury or from over doing it. One of the major effects of aging is that our bodies become less effective at repairing itself. When we are young the cells in our various organs are highly differentiated, such that they are very effective at performing their functions. For reasons that are not fully understood, as we age the cells in our organs become less differentiated, and are not as efficient and effective as they once were. I like to draw an analogy between our life cycle and one of a building. During our first couple decades our building is being constructed. The frame, the exterior, the wiring are all being installed and refined. A huge amount of energy is spent and many workers are involved in this phase. Once the building is complete, the effects of wear and tear begin to show their effects. The maintenance crew takes over and begins to make repairs to stem the many things that begin to break down. As the building ages, this job becomes harder. Not only does the building age, but the repairmen also age. They don’t do quite as good of a job as they did when they were younger. Unfortunately it’s not as simple as firing the repairmen and replacing them with more able repairmen. So what can we do? We all know the answer – physical training and controlling what we eat.
Physical training does help the repairmen stay sharp. Training however, has two opposing affects. On one hand training improves our bodies ability to repair itself by improving circulation as well as improving many of our bodies functions. It is well known that a person who is fit will most likely recover from a surgery faster than someone who is unfit. On the other hand, training puts wear and tear on our bodies and exposes us to injury. Training hard while staying injury free is a significant challenge for older athletes.
The changes described above pose challenges to aging athletes. There are however, a growing number of athletes that continue to improve well beyond their 30s, where many of the effects above begin to show up. It is my goal to find some gold nuggets of wisdom on how best to deal with these things from the interviews I will conduct for the book, and pass them on so we can all benefit.
 Taylor, A.W., Johnson, M.J., “Physiology of Exercise and Healthy Aging,” Human Kinetics, 2008
 Tanaka, H., Seals, D.R., “Invited Review: Dynamic exercise performance in Masters athletes: insight into effects of primary human aging on physiological functional capacity,” J Appl Physiol 95: 2152-2162, 2003; doi:10.1152/japplphysiol.00320.2003