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Do performance enhancing drugs work in Enduro?

The MTB world was recently rocked by the news that a few top riders have been caught using performance enhancing drugs (PEDs). A lot of people have reached out on social media asking my thoughts.

***Before you read further, it is worth noting that I give every athlete the benefit of the doubt, and I encourage you to do the same. I will mention this a few times throughout the article***

When I give talks about supplements in sports, I preface by saying that it is slippery slope.

And we need to look at both sides.

One one side, we need to consider that water is performance enhancing.

Seriously! Losing just 1% of your body’s mass in sweat can decrease performance! But nobody would argue about drinking water during a race. Or ever, really.

You could take it a step further and say that an isotonic sports drink is performance enhancing, or that having a diet high in dietary nitrate is performance enhancing–but nobody would shout at you for drinking a bottle of beetroot juice on the start line.

Heck, even training at all is performance enhancing….

Of course, these are only ‘ethical’ arguments, and rules are rules. One the flip side, there is a clear list of banned substances in MTB, and I contract my riders to never take any PEDs while working with me.

Or ever for that matter.

If they do, we are done.


This is caffeine. Caffeine is fine up until a certain point. While it is indeed a drug, we seem to have accepted this in society at low levels.

Do PEDs work in Enduro?


While it is absolutely clear that winning in enduro comes down to raw speed, riders can still go faster down hills by improving their fitness.

This is because muscles that use oxygen more efficiently allow us to recover more quickly between the very short, very hard efforts in race runs. Recovering just a little bit quicker will allow us to pump and flow and focus better during a race run.

Not to mention improved ability to repeat another hard effort.

I always tell people to think of the last all-out max effort they did up a hill. Then I ask if they thought they could pull over and work out a maths problem, or hop on to a pump track and flow through like butter.

The answer is that they probably couldn’t do either very well!

The drugs currently at question – oxilofrine and higenamine – have effects that may mimic improved fitness and increased ability to concentrate.

Oxilofrine and higenamine have such effects as improved fat utilisation and increased delivery of oxygen to the working muscles.

They are both banned, according to WADA.

So I say ‘mimic improved fitness’ because some of the main goals of training for enduro are to improve the body’s ability to use oxygen– and specifically, to use fat as fuel.

But then again, the dietary nitrates found in beetroot and the caffeine in coffee might have similar benefits.


Why are some substances banned?

I’d be really interested in seeing what constitutes a substance worth banning or not. I must say that I do not know the criteria.

Presumably, safety should be the main concern when determining if something is allowed or not.

Both higenamine and oxilofrine are potentially dangerous.

As an example of danger, blood doping (storing your own [or someone else’s] blood and putting it back into your system) improves the body’s ability to transport oxygenated blood to the muscles.

This will absolutely boost your performance!

However, blood doping can be dangerous. Besides the point that there are needles and direct safety concerns, becoming dehydrated while blood doping can lead to blood vessel blockages!

But then again, caffeine has been shown to decrease our reaction time and increase our rate of fat oxidation (just as Oxilofrine), but you don’t see us putting away our espresso machines.

coffee bike

Please don’t take my coffee or my bikes.

Are these riders guilty?

I don’t know.


Who is to say?

It is without a doubt in any riders’ best interest to maximize their ability to use oxygen in any type of mountain biking. They train very very hard to do this.

That’s why we get fit for enduro (check out why you need to be fit HERE), and why we do testing (link HERE) and why we try different pacing or coasting strategies.

At the same time, it is easy to always want more.

And this is where it gets a bit muddy.

When 0.5 seconds matter – and you’ve trained as hard as you can – it’s easy to reach for everything to help you get that 0.5 seconds.

Some riders reach for water. Some riders reach for an isotonic sports drink. Some riders reach for something off the shelf. And a very small percentage of riders reach for something dodgy.

I really do like to give people the benefit of the doubt, and I’d encourage you to do the same.

Could it be an accident?


Supplement companies absolutely want you to perform. If you perform better on their stuff, you will buy more!

And $money$ is one of the world’s greatest evils; people and things change.


Often times there is little to no regulation with supplements.

Higenamine is legal to use in food supplements in most of the western world, despite being illegal to use according to WADA.

But then again, I encourage you to give everyone the benefit of the doubt.

Bottom line

PEDs could improve enduro performance based purely on the potential for improved oxygen transport.

You shouldn’t take them.



Setting yourself on a path of proper training and rest is probably more fun, more safe, and definitely legal.

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