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How Does Age Affect Triathlon Performance?

Most of us are very aware that age affects triathlon performance, we can’t get away from that fact that no matter how hard an 80 year old trains, they won’t be able to keep up with an 18 year old. However, there is a lot we can do to slow down the ageing process and prolong our athleticism, even when we’re past our biological prime. However, in some cases, we might even be able to excel and feel better than ever in our sixth or event seventh decade. Let’s take a look at some of the basics.

When do we reach our physiological peak?

Most of us will be in our biological prime around the age of 25. Most of those reading this will be past that point, and probably feeling it too. As I write this I am only age 35, but my ability to rock up at a 5K with minimal speed training and still go under 20 minutes fairly easily isn’t what it used to be.

The good news for those of us in our 30s and 40s is that the decline is quite gradual to start with. We can’t gain muscle as easily as we used to, and we have to work to maintain things we may have previously taken for granted such as flexibility and explosive power, but with a well written programme we can achieve much more than we could at 25.

With apologies to those who are in their mid 20s, at that age you’re probably not fully mature. There’s still a huge amount of distractions, hormones and stress in your system you just don’t have in the same way as when you get older and find yourself in a more stable position. You’re a world apart from where you were 10 years ago, but very few 25 year olds have the ability to dedicate themselves fully to a programme while also thinking critically and engaging fully with a coach. They have all the enthusiasm and drive in the world, but this can come at the expense of more reasoned, long term thinking.

As a result, unless you were very mature in your mid 20s and had been training at a very high level since you were a pre-teen, your best years may still be ahead of you. A 40 year old with ten years of solid aerobic fitness behind them is going to come out on top against a 25 year old who has only just started in the sport every single time. If you did very little exercise until the age of 50, you may hit your athletic peak in your 60s, maybe even your 70s. It’s never too late to start.

What causes the decline in performance?

There are dozens of physiological changes which explain how age affects triathlon performance, but I’m going to stick to the biggest and most notable changes. I want this piece to look at actionable changes people can make, rather than get bogged down in science and lose most of the readership.

The biggest culprit is a condition known as sarcopenia. This is the reduction in muscle size and strength as we age. This accelerates between the age of 65 and 80, but begins in your 30s. For the first couple of decades, the effects can be minimised with a well rounded strength and conditioning programme. 

As well as the muscles decreasing in size, they also lose elasticity and the ability to generate force in an explosive manner. Someone’s ability to generate power in an explosive fashion is likely to be the first thing to notably decrease as someone ages. In the swim and on the bike this is less noticeable, but as running is essentially a series of hops, it will be the first discipline to deteriorate out of the three.

This doesn’t mean we need to send a white flag up the mast and stop all power training after our 30th birthday, in fact it means we probably need to do more, to slow the decline and loss of performance. This can be achieved by performing exercises such as med ball slams, pogo hops, box jumps or any other dynamic exercise which involves rapid acceleration. If all of those sound a bit intimidating, you can start by standing with your arms making a T shape, and slap them down to your thighs in an explosive manner. You don’t need a gym or expensive equipment to get started.

Maintaining overall muscle size and strength is the real key to maintaining high performance in triathlon though. In a strength session I’m very unlikely to set someone more than two power exercises in a session, most of the time is spent strengthening our larger muscle groups to ensure we can keep pushing those pedals round with high levels of force for many years to come.

By maintaining the strength of our muscles, we are also looking after our connective tissues, which are incredibly important for preventing injury. Often it’s tendons and ligaments which are the cause injury rather than the muscle itself, so we get a double benefit to our strength work.

On the theme of injury reduction, our mobility and flexibility also decrease with age. Look at how well children move, they all have a beautiful rang of motion, instinctively squat down to pick up something heavy and can bend themselves in shapes that most of us could only dream of. As we get older, we tend to spend most of our time sat down which further limits our mobility. You don’t want to turn into your dad who makes those embarrassing noises every time he gets out of his armchair. 

Decreasing hormone levels

While the changes in a woman’s body as she ages quite rightly gets more attention than the changes a man experiences, we need to address both if we want to help athletes.

As women enter perimenopause, this can bring with it high levels of fatigue, difficulty managing body composition, low mood, sore joints and more. All of these can be a barrier to turning up for physical activity, let alone performing at a high level. The benefits of physical activity during this time are well documented, but the tools we have to slow the decline in performance are somewhat limited, as hormones are so central to someone’s wellbeing and sense of balance in life. The menopause is a natural part of life, and while we can’t avoid it, we can take proactive steps to maintain our health and wellbeing.

I’m not really the person to start dishing out advice about dealing with the menopause to women I’ve never even met, but if you are serious about maintaining your physical performance as you age, I recommend you book an appointment with your GP to discuss hormone replacement therapy if you haven’t explored it already, and go into it with an open mind to decide if it’s right for you. You can find some more information here.

For men it’s a lot simpler, we suffer from a drop in testosterone levels which manifests itself in many ways, however for the athlete it will be most notable in an accelerated drop in muscle mass and reduced levels of strength.

There are lots of “inspirational” images of men in their 70s still crushing in in the gym with bulging biceps and six packs, but we would be naive to believe that photoshop, testosterone pills and even steroids weren’t involved. Similar to above, if you are a man struggling with what you believe to be low levels of testosterone (reduced libido, fatigue, low mood and loss of body hair), you may want to organise an appointment with your GP to discuss if supplementation may help.

I STRONGLY recommend against just buying testosterone from the internet without seeing a physician, as like HRT it can come with a number of side effects. This is a decision which needs to be taken incredibly seriously, and not simply as a result of reading an article on the internet.

Having testosterone levels over a certain amount is also in violation of anti-doping laws, and could land you with a ban from the sport. While testing is rare in amateur sport, it definitely happens at the pointy end of age group racing, so ensure you take every precaution possible to ensure any treatment you begin won’t fall foul of anti-doping laws.

Other areas to consider

While I have covered the two most important points above, there are still a few areas where we can focus our energy to maintain our performance and maintain a quality of life.

Bone health is often overlooked, as our bone density can really suffer as we age. By ensuring we have a good intake of calcium and engage in strength training, we can go a long way to reducing the risks associated with osteoporosis.

Your VO2 max will drop as you get older, but not as much as previously thought. It is believe that VO2 max will only drop by around 10% between the age of 35 and 55 ( which isn’t as much as we have been led to believe previously.

We also find it more difficult to regulate our temperature as we get older, overheating more easily in hot conditions, while also struggling to get warm in colder weather. Don’t be afraid to take the time on race day to put on some extra layers or choose events in warmer climates.

Our nutrition also needs to be taken more seriously. Many senior citizens are lacking in protein intake, which contributes to a loss of muscle mass, strength and general wellbeing. As we slow down later into life our calorific needs will reduce, but it’s important to ensure we maintain a well balanced diet, instead of grazing our way through the day on a packet of biscuits then having a jacket potato for dinner.

Finally, there’s no shame in competing in aquabike. What was once seen as a triathlete’s graveyard is now a well attended, competitive format. If your running is letting you down, or injuries are preventing you from running at all, I’d much rather you keep the healthy habit of daily exercise in your life than roll over and stop training altogether.


As we age our upper limit for performance decreases, but unless you were competing at a very high level in your youth, there’s nothing to stop you getting faster and enjoying the sport more as you get older.

Including strength work in your training becomes of critical importance,  to not only maintain your performance but also good bone health and functionality. One of the reasons that falls can be so devastating for older people is they lack the strength to pick themselves off of the floor, so it’s important on many levels to maintain our strength levels. 

Your hormone levels will drop, and as an athlete it may be worth discussing this with your doctor. The effects on your life and performance are very complex, so as an athlete we can’t afford to bury our heads in the sand. 

Whatever you do, don’t fall into the trap of saying “back in my day…” as soon as you hit 30. Triathlon is possibly the best way of maintaining a quality of life and we age, so try to find more of a purpose in the sport than simply focusing on lifetime PBs.