Despite all the positive effects, there are a number of negative effects of endurance exercise. Our unconscious bias can obscure these, but they're real all the same.
I don’t spend all my time in the endurance community. It’s one of things that I believe makes me a better endurance coach. It’s not uncommon for me to converse with strength athletes, powerlifters, rugby players and bodybuilders to name but a few. I follow the ideas of coaches in these and many other sports, some through their writings and some I know personally.
In the strength community it’s not uncommon to hear that cardio or long endurance exercise is bad for you. It does nothing to enhance your physique, causes muscle breakdown etc.
As a coach who is always looking for ways to improve the performance of my athletes, I’ve long looked for both the negative effects of long distance endurance exercise, especially for performance, and ways to counteract these negative effects.
Most people reading this probably love doing endurance sport, have reaped enormous physical, social and emotional benefits from their efforts and can’t imagine that there could be much negative about their pursuit. Bad news though, lots of long distance training isn’t really that good for you.
So what are the negative effects? Here are some of them:
The bodybuilders aren’t completely wrong when they say that cardio causes muscle loss. There’s no getting away from it, it does.
This could be viewed as positive if you’re simply looking at performance. How would Chris Froome get on the French mountains if he was carrying another stone or two? Can you imagine a 200 pound Kenenisa Bekele trying to run a 2:05 marathon?
However it’s not that positive for the average person who wants to live a healthy life into old age. Because of most people’s fuelling strategies and reliance on the dodgy science pushed by sports nutrition companies, a significant amount of that precious muscle gets broken down in order to fuel your brain during extended exercise, especially once the glycogen stores of a sugar-dependent athlete get low - and no matter how many gels you eat, they will. Put another slightly more alarming way, in order to satisfy your desire to finish your workout or race, your body will eat itself in order to let you keep going.
Of course this is only a short term term risk assuming you're not exercising to exhaustion all the time. However, if you're doing this often, your decreased muscle mass puts you at risk of conditions such as osteoporosis (loss of bone mass, with the associated weakness).
Increased Injury Risk
Most people have had an injury they just couldn’t explain. However it's not that hard to explain. Bad patterning….
I’ve often described it this way: Your central nervous system stores the patterns from what you were doing in order to save time. It’s called learning. The problem arises when you run, swim, bike or whatever until you’re tired. The pattern ingrained is the tired one, where your system is once again doing whatever it can to allow you to continue. Usually you’re moving badly. Next time (and every subsequent time) you do the same activity, your central nervous system repeats that tired pattern and eventually you get injured.
Worse than that, because of the ingrained pattern, most long distance athletes will see the same injury over & over again because they don't address the root cause of the injury, the patterning that their chronic endurance habit has ingrained in their nervous system.
Weakened Immune System
We’ve all heard that old chestnut: You can’t be very fit and healthy at the same time. First of all, that’s complete nonsense if your training programme is a balanced one. However for many people it is true, the negative effects of their endurance exercise is damaging their immune system.
Have you ever met an athlete who always has a cough, a cold or some similar upper respiratory infection? Are you one of those athletes?
This is ironic, seeing as most people start exercising in order to improve their health!
Chronic Oxidative Stress
Someone whose work I read described this as being in a perpetual post workout state. Put another way, they never recover from their previous workout and the one before that, and the one before that… It all adds up. Eventually it gets to be too much and they break.
In combination with a weakened immune system, the scary end point of this scenario is some kind of chronic fatigue syndrome. I have a couple of friends who dug themselves so far down this particular hole that it took years to recover - and there is a question as to whether they will ever recover fully.
Excess Stress Hormone Release
The release of too much cortisol could be argued to be at the root of many of the previous items.
What we often miss is that our training is not the only stressor we experience. Our lives outside of our sport contribute significantly to our overall stress levels and the related hormone imbalances.
This is one thing that often we and our coaches don’t realise is a big difference between age-group athletes and the professionals. There is just so much more to balance for an age-grouper trying to perform in a time-intensive sport and thus we cannot simply do the same programme as a pro or for that matter any other athlete.
But It's Not All Negative
Wow, that all seems really negative. Why would you do endurance exercise at all? Here are a few reasons:
- It improves your mood.
- A reasonable volume of endurance exercise is great for your cardiovascular system.
- It means you’re just able to do stuff - I wouldn’t think twice about hopping on my bike and riding 10 miles towing my son in a trailer just because it’s a lovely day & I fancy buying him an ice cream on the other side of the estuary.
- Humans need competition, it’s how we’re made.
- Some of us are just not made to deadlift 1000lbs.
Thankfully, there is no need to suffer these potential negative effects of endurance exercise. With just a few tweaks and a little knowledge it is possible to outperform most of your competitors and gain massive benefits from our endurance habit.
In a future blog post I’ll discuss some ways that we can mitigate many of these effects, both increasing performance & decreasing the negative effects of the sports we love.