Episode 268 - Can Triathletes Get Rhabdomyolysis? The Causes, Warning Signs and How to Avoid It

Can triathletes get rhabdomyolysis, and should you be worried about it?

A 24-year-old woman recently died after collapsing near the end of her first New York City Marathon, and her family have said the cause was rhabdomyolysis. If that story has you wondering whether rhabdo could happen to you, this one is for you. Rhabdo is rare, but it is not random. I break down what it actually is, where the risk really sits for a triathlete and the warning signs that mean you stop and get help.

WHAT YOU’LL LEARN

• What rhabdomyolysis actually is, and why your sore quads after a hard long run are not it
• The type of training that carries the most rhabdo risk for a triathlete, and the type that generally doesn’t
• Why the jump into Hyrox or CrossFit-style training worries me more than your long ride
• The other triggers on the list, from heat and illness to a painkiller sitting in most athletes’ cupboards
• Where fuelling fits, and what a mountain marathon study found about carbohydrate and muscle damage
• The red flags that mean you go straight to the emergency department

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Episode Transcription

Episode 268: Can Triathletes Get Rhabdomyolysis? The Causes, Warning Signs and How to Avoid It

Welcome to the Triathlon Nutrition Academy podcast. The show designed to serve you up evidence-based sports nutrition advice from the experts. Hi, I'm your host Taryn, Accredited Practicing Dietitian, Advanced Sports Dietitian and founder of Dietitian Approved. Listen as I break down the latest evidence to give you practical, easy-to-digest strategies to train hard, recover faster and perform at your best. You have so much potential, and I want to help you unlock that with the power of nutrition. Let's get into it.

A 24-year-old woman collapsed near the end of her first marathon in New York recently, and she died hours later. Her family have said that the cause was rhabdomyolysis, or rhabdo for short, and my heart goes out to them. If you’ve seen that story and wondered whether it could happen to you, then keep listening.

I’m not here to scaremonger you. Rhabdo is rare, but it’s not random. And in a sport like triathlon, where it’s really easy to do too much, you need to know what it is, what drives it and the signs that mean you stop and get help. So let’s get into it. If you’re new here, hi, I’m Taryn. I’m an Advanced Sports Dietitian and triathlon nutrition specialist.

A quick disclaimer before we start. I’m a sports dietitian. I’m not a doctor, and diagnosing rhabdomyolysis is a medical job. So if you think you’ve got it, ask your doctor, go to the emergency department. What I’m here to do is help you to understand what it is, what to look out for and where your training load and fuelling fit in.

So what actually is rhabdomyolysis? It’s a serious and life-threatening medical condition that occurs when, in plain English, your muscle fibres break down and they release the contents into your bloodstream. The big one is myoglobin, which is a protein from inside your muscle cells, as well as electrolytes and enzymes like creatine kinase.

And when that happens, it creates serious systemic complications, because your kidneys have to filter all of that out and too much of that overwhelms them. So you can damage your kidneys, disrupt your body chemistry and, in severe cases like this one, cause cardiac arrhythmias, which in basic terms means you have heart rhythm problems.

It is treated in hospital with a drip and close monitoring of your kidneys and your electrolyte balance. In really bad cases, it may lead to dialysis, which is a machine filtering out your blood for you to take the load off your kidneys.

Now, just to reassure you, and I need you to hear this bit, having sore legs on the day or the days after training is not rhabdo, okay? That is training. It’s probably DOMS from training. Your muscle enzyme creatine kinase naturally goes up after every training session and race. And the longer it is and the harder it is, the more it’s going to rise. Now that is normal and expected. A high creatine kinase on its own is not necessarily rhabdomyolysis.

Clinical rhabdo is muscle damage plus those severe symptoms, and it means the kidneys are getting dragged into that. So please, I don’t want you lying awake on Sunday after doing a really hard run and your quads are sore. So keep listening and I’ll help you with what to look for.

So if it’s rare, who actually gets it? And should you be worried as a triathlete? The short answer is it is more rare in triathlon, but it’s not random. The triggers are really well known, and I’m going to draw on the literature and put these links in the show notes if you want to dive further. The military see it more than anyone, and their guidelines sum it up as too much exercise, too fast and too soon.

The biggest driver is unaccustomed exercise, something that your muscles aren’t used to, at a volume or intensity that they aren’t used to. And the type of muscle work also matters. Lengthening work, where the muscle is braking under load, carries the most risk. So think hard running, or in particular downhill running. Exercise like steady zone two riding is generally not where this happens.

In one study of ultra endurance athletes, the runners developed rhabdo more often than the mountain bikers. So for you as a triathlete, the main risks are going to be running and gym work. It’s generally not your long, steady zone two rides.

The risk sits with high-intensity functional training. So think things like CrossFit and Hyrox. And I know a lot of triathletes are getting into Hyrox at the moment. In a 2024 systematic review, they put together 63 cases of this kind of training. The sessions most likely to cause it were unfamiliar ones with really high volume and/or really high intensity.

Now, Hyrox isn’t the problem. That’s not what I’m saying. But the jump into Hyrox or CrossFit-type training can be problematic. And your risk is going to be the highest if you are writing your own programming, or you’re adding in these HIIT-style gym sessions on top of structured triathlon training and potentially not telling a coach about it. Your coach might be writing your swim, bike and run, and hopefully some strength training, and then you go and add some extra HIIT-style gym sessions because you want to train with a friend, or you’re trying to lose some weight, and your coach has no idea about it. Your load has just spiked, and that’s the one that worries me the most.

Some other triggers on the list for rhabdo include heat, especially if you’re not acclimatised. At the really hot 2022 New York Marathon, nearby hospitals treated 24 runners for rhabdo, compared with only about 15 across five other years combined. It takes your body about 10 to 14 days to acclimatise to the heat.

So the risk is going to lie with maybe early summer events where you’re not acclimatised to the hot weather yet, or you’re training in a cold environment and travel to race in a hot environment and don’t have any heat acclimatisation protocols in the lead-up, or don’t have enough time to acclimatise on the ground when you arrive. So be so careful and make sure you have a plan.

Another risk is training or racing when you’re sick. Anti-inflammatory drugs like ibuprofen or naproxen. Some of the stimulant pre-workouts. And if you’re a masters athlete and you take a statin, statins can make the muscle damage post-exercise bigger, even in well-trained athletes. So talk to your GP if you’re taking a statin and you’re worried. Never stop taking a medication, though, without their guidance. Sickle cell trait raises the risk. And if you’ve had rhabdo before, you are also at greater risk.

So where does nutrition fit into all this? This is where I put my sports dietitian hat on. No study has shown that underfuelled athletes get rhabdo more often. But commonly what I see with triathletes is athletes training really hard, doing lots of hard, high-intensity sessions and underfuelling. Not having enough carbohydrate in their daily nutrition, and then not having enough carbohydrate in training sessions. And then adding all these extra training sessions into their program because they’re trying to lose weight. So they’re basically burning the candle at both ends. Be careful if this is you.

Carbohydrate, or muscle glycogen, is our main source of fuel for high-intensity work. If you are asking your muscles to do really hard, unfamiliar training without enough carbohydrate on board, you’re basically asking more of them with less to work with. And the evidence points in that direction.

There’s a key paper in ultra mountain runners that I have talked about on the podcast before, and it compared runners doing 120 grams of carbs an hour to runners doing 60 or 90 grams, or somewhere in between. And they found that the athletes that had more carbohydrate had smaller rises in their muscle damage markers compared to athletes that had 60 to 90 grams of carbs. Now, it measured markers, things like creatine kinase. It didn’t measure rhabdo, and it was a small study. If you’d like to dive into that, go back and listen to episode 249, where I pull that paper apart. The military guidelines list nutritional deficits as a risk factor too.

So you might be thinking, look, I’m fit, I’m healthy. But the right nutrition to support your training matters so much more than you probably realise. And nutrition to support training is exactly what I help my athletes with in the Triathlon Nutrition Academy. This is my online education program where I teach triathletes how to fuel for three sports. I know a lot of triathletes out there that are trying to lose body fat. They’re adding extra strength training, extra Hyrox sessions into an already stacked program and are not eating the food to match that.

So from a practical application, never do a brand new high-intensity session fasted or on a low-carb day. You need to fuel for the work required before, during and after the hard stuff. This is not my area of expertise, but add training load gradually. And then my area of expertise is to add the food alongside that. If you’re not sure if you are overtraining or underfuelling, then go back and take a listen to episode 254, where I talk about the similarities and differences of both.

So how do you tell the difference between “okay, I’m sore” and “I need some help”? Here are your rhabdo warning signs and what to do.

You’ve probably experienced normal training soreness or even DOMS, delayed onset muscle soreness. You might be feeling sore and stiff, and it peaks a day or two after a really hard session, but then it gets better. And it gets a little bit better every day until it’s gone.

The red flags for rhabdomyolysis, though, are pain or swelling way out of proportion to what you did. A real weakness, like struggling to walk up the stairs or not being able to lift your arms after a gym session. Dark urine that’s the colour of tea or cola. Passing very little urine or none at all. Nausea, vomiting, fever or confusion. Soreness that gets worse rather than better after a few days. It can show up on the day or in the days after, and it’s not always just your legs. Three female amateur triathletes turned up to an emergency department with tummy pain after training, and it was rhabdo.

So what do you do if you think this is you? Go to the emergency department. Don’t wait it out. Don’t be a hero. Just go. Tell them what you’ve done: the training that you’ve done, the race that you’ve done, the new class that you’ve added in. Do not take ibuprofen or naproxen, and don’t try to sort it out yourself at home. This is not a harden up moment. It’s not a pain is just weakness leaving your body moment. Go and get help.

So in summary, rhabdo is rare, but it is serious. It is driven by too much, too fast, too soon. So new high-intensity work, hard running, heat, being sick while you’re training hard, taking anti-inflammatories and some other medication. Generally speaking, your zone two rides are unlikely to be the problem. The extra Hyrox class your coach doesn’t know about might be.

At the end of the day, you need to fuel for the work required, especially before, during and after any new training sessions or anything really high intensity. Know the red flags, and if you see them, go to ED. Don’t be a hero.

If this episode has you wondering if your nutrition is actually keeping up with your training, start by doing a self-audit with my free Triathlon Nutrition Checklist. It’s a 50-step checklist that’s going to show you very quickly where your gaps are, so you know what to focus on first to fix it. You can grab it for free at dietitianapproved.com/checklist.

And if you’ve got a training buddy that is signed up for their first Hyrox or their first marathon, please send them this episode. Not to scare them, but just to equip them with the knowledge and understanding so that this doesn’t happen to them. Thank you for putting me in your earholes today. Train hard, recover well and I’ll see you next week.

Thanks for joining me for this episode of the Triathlon Nutrition Academy podcast. I would love to hear from you. If you have any questions or want to share with me what you've learned, email me at [email protected]. You can also spread the word by leaving me a review and taking a screenshot of you listening to the show. Don't forget to tag me on social media, @dietitian.approved, so I can give you a shout out, too. If you want to learn more about what we do, head to dietitianapproved.com. And if you want to learn more about the Triathlon Nutrition Academy program, head to dietitianapproved.com/academy. Thanks for joining me and I look forward to helping you smashed in the fourth leg - nutrition!