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For the past few decades there has been a continual increase in the number of master athletes (> 40 years old) participating in endurance and ultra-endurance sports. Some of these have been participating in such sports for decades and are simply continuing. Others, like me, started training later in life. Why is this?

In most sports athletes reach peak performance between their late 20’s and early 30’s. However, the average age of elite athletes in endurance sports like the marathon and the ultramarathon has increased over the past few decades alongside performance. There are many examples of athletes outperforming competitors more than a decade younger: Meb Keflezighi won the 2014 New York City Marathon two weeks before his 39th birthday and Canadian Krista DuChene finished third in the 2018 Boston Marathon at the age of 41.

This is not a coincidence.

Runners forty years and older represent the majority of participants in many marathons. For example, in the 2018 NYC Marathon 46% of the runners were 18-39 and 54% were over forty. In the 2019 Boston Marathon the percentage of runners who were forty and older was even higher: they represented 60% of the total finishers. This is not unique to marathons and ultra-marathons. Similar trends have been observed in other endurance disciplines like triathlons and cycling.

Of course, individuals age differently and not everyone is interested in achieving or continuing to achieve high performance. Some just want to maintain a training routine that allows them to stay healthy, strong, active and motivated, or allows them to maintain a vibrant social life. But what is it about endurance sports specifically that attracts the older populations? One answer may be that endurance, unlike other physical qualities, can be retained as we age.


I'm not suggesting that we can escape the inevitable effects of aging and perform the same at eighty years of age as we could at forty. Far from it. In fact, all middle-age athletes experience four changes...

1) A decline in aerobic capacity and maximum heart rate.

Aerobic capacity is a measure of how much oxygen we use when exercising at a sustained, maximal workload. As we age our capacity to deliver oxygen to working muscles declines. Changes in oxygen uptake also become one of the limiting factors in endurance performance. This, in combination with other physiological changes, affects the aerobic capacity of elite athletes as well as recreational athletes.

2) A decline in muscle mass.

Muscle mass starts to decrease around the fourth decade and the loss accelerates as we get older. Multiple factors contribute to this loss, including a decrease in hormone production. For some, this decline is not obvious, especially if body weight is stable or higher than in previous years, but it does happen.

Here's why: as we age the neurons supplying our muscles begin to die. The atrophy is more pronounced and occurs first in fast-twitch muscle fibers, the type of muscle fibers that produce speed and power. Later on it impacts the slow-twitch fibers that endurance athletes count on. That's why many runners experience a decline in speed while they are still able to maintain endurance.

This loss of skeletal muscle mass is accompanied by the loss of muscle strength, rate of force development and muscle power.

3) An increase in fat gain.

It is not a conspiracy against the middle-aged: as we add years we also add pounds. This applies to both the sedentary and the active. The impact: muscles that allow you to move during training have to work harder in order to maintain the same pace you were able to maintain before. The effect of weight on performance varies depending on the sport, however. For example, it has a larger impact on running and less on swimming or biking.

But weight alone does not tell us the full story: the amount of muscle mass versus the amount of fat and how this ratio changes over time has an impact on performance. And we know that as we age body composition tends to change. Even if we maintain the same weight, unfortunately, it is common to gain body fat and lose muscle mass resulting in an increase in the percentage of body fat relative to lean tissue.

4) Lower hormone levels.

The body is a complex, interconnected system. All three of the above both cause and are caused by a drop in hormone levels. Our hormones affect how we respond and recover, how we feel, how much energy we have and so much more. However, as we age we become less efficient at producing them and we become less responsive to what we do produce. Some notable declines are estrogen (in women), testosterone (in men), growth hormone and melatonin.

As you can see, aging is a biological process. But multiple studies in the field of aging have concluded that lifestyle factors like nutrition, daily activity levels, and sleep have an impact on the natural progress of aging too. For many endurance master athletes aging is also related to reductions in exercise training volume and intensity.

So, do we lose “physical performance” because we age or because we have adopted a more sedentary lifestyle? Does getting older, especially passing fifty, mean we have to slow down and avoid vigorous exercise? No. Those who have the ability to maintain a high level of exercise training are able to limit the rate of decline in endurance performance. In other words, keep training and you will preserve your endurance levels.


(Caution! Veteran athletes are advised to consult with a doctor periodically to assess the risk of cardiovascular disease. It is also recommended for veteran athletes to consult a doctor before making significant changes to a training regime if a) they have concerns about their health, b) they are taking medications or c) they have been injured recently.)

"Keep training" is the simplest advice when it comes to slowing the onset of aging, but that advice has multiple components. The main one is to train smarter. For masters athletes that means directly countering the biological effects of aging mentioned above.

The decline of aerobic capacity can be combated with an emphasis on variable intensity: Some researchers suggest that to get faster or remain fast we need to maintain or improve aerobic capacity and the most effective way to do that is by using high-intensity workouts. Interval training is a great way to perform high-intensity workouts, but there are some risks associated with such training. It is always recommended to take into account your current level of fitness. Especially if high-intensity training is something you haven’t done for a long time. If this is the case, take a conservative approach and increase the intensity progressively over several weeks.

Short HIIT workouts with several bouts of “all-out” for a minute, for example, followed by a brief recovery, have been shown to result in improvements in heart function and VO2 Max. Conversely, habitual physical activity, not only purposeful exercise, but occupation-related physical tasks and daily movement are likely to improve aerobic capacity.

The decline in muscle mass can be combated with a strength training program: We need strong muscles in order to maintain or improve our level of fitness and performance. Some might feel discouraged by the fact that they have never done consistent strength training or might think it is too late to increase muscle strength. The reality is that it is possible for all populations to improve muscle strength at an older age.

Keep in mind, strength training is not only high-weight training. Lifting lighter weights for more reps is an alternative to heavy lifting. For endurance athletes, it is often recommended to include strength training during the “building block” or “base period” of training.

The increase in fat gain can be combated with an active lifestyle and proper nutrition: An active lifestyle is beneficial for maintaining muscle and helps us by limiting gains in body fat. And while those who have been training for some time might have already figured out how to maintain a balanced diet, there are some who haven't. If you are seeing a decline in performance it may be time to look at your diet.

There is no one-diet-fits-all and you will find a lot of conflicting information from fellow runners, coaches and nutrition experts. But it seems that for those that like to keep things simple the fundamental rules of nutrition apply. Make sure that you eat enough calories to fuel your training and maintain a stable body weight. Eat before and after every training session, especially during workouts longer than an hour. Since maintaining muscle mass is critical, a diet that provides enough protein is critical.

The lowering of hormone levels can be combated by all of the above: Training with a variety of intensities, implementing a strength training program, building an active lifestyle and eating sensibly will have an impact on your hormone production and reception.

There are a few other things that masters athletes must keep in mind:

Know your As and Bs: Your level of improvement is relative to your starting point. Those that had to take a break or have been on the sidelines can always make gains once they start training again. It is never too late. There are many examples of endurance athletes that make a comeback and are able to regain the same level of performance they had before, or even surpass it. Some just decide to get more serious with their training and find out that there was still room for improvement.

Expect slower adaption: Your level of improvement is not just relative to your starting point. It is also linked to your age. The young adapt faster than the old, especially in the realm of the physical. A young runner may improve a time by 5% in just a few weeks; an older runner may achieve the same, but it could take a few months. Which brings me to the next point...

Embrace the suck: In order to improve fitness and performance you need to put your body and mind under stress consistently. This will later translate into growth. Hard workouts are challenging. They often hurt and result in sore muscles and joints. As we age we might also start avoiding the discomfort that hard training sessions bring and place more focus on lower intensity, lower volume, slower pace training. Of course, this will have an impact on our performance. But we are capable of achieving far more than we imagine and we often sell ourselves short. Using age as an excuse, no matter what the number is, will prevent us from achieving our goals. Young or old, there are no quick fixes. Results require consistency.

Remember to recover: Stress is only one half of the growth equation, however. The other half is recovery. One of the reasons master athletes get injured is that they underestimate the need for recovery periods. As we get older recovery times get longer and many fail to adjust. As we age we cannot afford to neglect recovery. So we must vary the intensity of our training, get a good quality and quantity of sleep, take rest days, extend warm-ups and cool-downs, consider working with physical therapists and other health professionals on a more regular basis, and generally take more care of our minds and bodies.


When it comes to lifestyle choices, especially those concerning nutrition and physical activity, humans are remarkably bad at judging the long-term harm and benefits. Providing scientific information and studies is often not enough to motivate us to do something that does not provide an immediate reward. But we also know that we get older every single day.

It doesn't matter whether we decide to be sedentary in our spare time, join a local running club or continue with an activity we've been doing for decades. Aging cannot be stopped. But it can be somewhat controlled. So keep training. Continue to stress your mind and your body and continue to aide them in their recovery. Don't use age as an excuse to slow down, because if you're an endurance athlete it turns out you can still go quite fast.

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