Nerve Damage During Races: What causes it? Can it be prevented? And, what to do if it strikes.

A physical phenomenon many ultra cyclists are familiar with is mild to severe nerve damage at the contact points, but it need not be this way.

The long kilometres spent in the saddle can result in nerve disturbance in varying places, including the hands, feet and groin. A loss of sensation in the palms and fingers is so common it’s been coined cyclist’s palsy. We put it to Gail Brown to share her sage advice built on a combination of extensive racing experience over the years and a career as a physiotherapist. We asked Gail to share her knowledge on why nerve damage happens, how to prevent it and what to do if it strikes mid-race.

Gail's many kilometres on races such as the Transcontinental Race, GBDURO20, Highland Trail 550, the Atlas Mountain Race and Tour Divide have provided her with an intimate knowledge of her own body and the effects of racing long distances. She has woven these findings together with her learnings from studying the human body and working with patients who present a wide range of physical ailments. As a physiotherapist experienced at working with people with neurological conditions, she knows a thing or two about pain management and recovering from a sudden change to our bodies.

It is our intention that this piece serves as an educational broad overview with some sensible and implementable advice on preventing and treating pain. Knowledge is power, after all.

This is not personalised advice, please seek professional medical advice for your symptoms if they are severe and persist.

You are a physiotherapist, has this changed your approach to prehab and managing nerve injuries from cycling?

Absolutely, having an understanding of how nerves work has really helped when it comes to injury prevention, racing mentality, making sense of pain and managing recovery post race.

However, I’d also say my prehab and bike set up in terms of nerve symptoms has improved largely due to experience and trial and error with what works for me. When I raced The Transcontinental Race in 2019 I had a very numb second toe on my left foot which took several months to resolve. Whereas, following this year’s Tour Divide 2023 I had no nerve related injuries, in fact, no injuries at all.

What are the most common nerve damage complaints from long-distance racers and why does this happen?

Most commonly experienced in the hands and feet, nerve symptoms in cyclists can range from sensation changes like tingling or numbness to loss of movement quality. These symptoms often resolve shortly after an event but for some individuals, they can persist for weeks to months, even occasionally, years.

To understand why this happens and what makes the difference between mild and long lasting symptoms, we need to look closer at nerves:

This is the structure of a peripheral nerve, you can see that it is made up of long, insulated pathways (axons) along which impulses travel. They are held together in bundles with their blood supply. These bundles are held together by a more protective outer coating. When under compression or there is swelling around the nerve then there is an interruption in the blood supply which can affect the conduction of impulses in the pathway. Most cases will be just a change in conduction but occasionally repeated and prolonged compression can make changes at the cells which insulate the axons, this can heal without medical intervention but it does take much longer, but we always recommend seeing a professional.

Once out of the spinal cord, nerves are referred to as ‘peripheral nerves’. They’re made up of bundles of cells, a bit like electricity cables, insulated and held together with their blood supply by an outer coating. They make the pathway connecting our tissues to our central nervous system. Incoming impulses inform what we feel and outgoing impulses initiate movement. However if there is a disturbance in the pathway or to the insulation, conduction of these impulses can get disrupted, hence the changes in sensation and movement we might experience.

For cyclists, compression at contact points with the bike or swelling can provide that disturbance. The deciding factor for what symptoms are experienced and how fast they resolve is to do with the changes at a cellular level.

Short term disturbance such as numbness or loss of movement quality are the most common, normally due to a reduction in blood supply and therefore changes in conduction but not accompanied by a structural change. But in some cases the nerve structure has been altered through compression or long term lack of blood supply and therefore symptoms are much longer lasting.

Here are some classic post race ulnar nerve symptoms in video by Paul Addy after GBDURO 2020. You can see the difference in movement quality between his fingers. The ulnar nerve informs the sensation at your little finger and the outside half of your ring finger and innervates the muscles that flex those fingers too. It is a very commonly affected nerve in cyclist due to pressure through the handlebars and sometimes at the elbow. Paul's symptoms resolved in 8 weeks.

Nerves regenerate very slowly, even where there is no structural change, symptoms can take from several days to several months to fully resolve. If there is structural change then the timescale is longer.

Do certain terrains or distances increase the risk of nerve symptoms?

No distance or terrain should guarantee nerve disturbance.

It is possible to experience these symptoms even on a short ride, the cause would likely be a set up that puts excess pressure through a contact point with your bike. It’s also possible to ride thousands of kilometres and have barely any issues.

However, the things most likely to cause symptoms are time spent with compressed tissue and repetitive impact, prolonged time in any one position, swelling, lack of sleep and under-fueling. Therefore the risk of experiencing long lasting nerve symptoms is much higher in ultra events, especially if under-biked and off-road.

What measures can be taken to minimise nerve damage ahead of an event?

We can split it down into several categories:

• Preparation of body: having endurance through your central body can prevent leaning heavily through contact points. This can be improved by making strength and stability part of your training, it’s less about specifically what exercises, more about consistency.

• Reducing pressure at the bike-body interface can help: wearing padded gloves, making sure your shoes are well fitting and that there’s minimal localised pressure from the cleat and a saddle that spreads pressure comfortably.

• Preparation of bike: it can be tempting to choose ‘speed’ over comfort for a race bike but in reality this is rarely faster overall when it comes to ultra-distance and certainly raises your chances of nerve injury. For off-road events seriously consider the use of suspension or larger tyres to reduce the impact of rough surfaces.

Aerobars are partly for getting more aero but mostly useful for moving around and relieving those pressure points. This photo is from my cockpit from the Tour Divide.

• Dialling in your bike fit: aim have your weight spread between all contact points, if you need help with this it’s worth investing in a professional bike fitter. Think about how you can give yourself multiple positions for your hands with shaped grips and aerobars.

• Practise prevention: even before the event you can get into good habits of regular position changes. Think about how you’ll manage if you do develop symptoms and have a plan for if they worsen.

If a rider does start to experience nerve pain or numbness in their hands or feet during an event, what measures can they take to reduce the pain and mitigate damage?

Movement is key: move through your neck and back regularly. Nerves pass out of your spine and through other tissues to reach their destination and so it’s not just about the pressure point itself. If you can, do arm circles, dance with your arms - it glides the nerves through their outer coating and reduces tension in your other tissues. As with so many aspects of the body: motion is lotion.

Try to change your position to reduce contact with the pressure point:

• Switch up between aerobars if you have them and hold your handlebars in different ways.
• Regularly stand up to relieve pressure through your saddle.
• Wiggle your toes, take your feet off the pedals and move your ankles around.

Gail riding on the Tour Divide. Photo credit: Danielle Vilaplana

Think about other modifiable factors for overall tissue health. Optimise what you’re eating, include macronutrients (protein, fat, fibre and micronutrients) vitamins and minerals. Optimise your sleep. Even if it’s not ‘more’ sleep - you can optimise the depth and quality by your choice of sleep location.

If you’re tracking symptoms and they’re worsening to the point that you’re losing function, for example, if your hands aren’t able to brake or change gear, seriously weigh up the importance of finishing vs safety and impact of your symptoms on your life post-event. Sometimes having weighed this up beforehand can make the decision easier when you face it during an event.

While some riders experience nerve damage during an event, it can also present itself and worsen a few days after an event has finished and recovery has started. What advice would you give to a rider who’s facing this phenomenon for the first time?

Symptoms can often feel quite alarming and numbness can change to discomfort, burning, itching, tingling and hyper-sensitivity. These are all normal symptoms of nerve disturbance. If you want to track your symptoms you can keep a diary for each day to track the trend to know whether you are improving, it can also be useful if you later see a health professional.

Mindset can influence our pain, the more worried and threatened we are the more intense our symptoms. Whilst it’s important not to normalise nerve symptoms, know that they are a response to compression and although they may take a long time to resolve that doesn’t mean that your nerves aren’t healing. For even a mild nerve injury, with no structural damage, for symptoms to fully disappear can sometimes take weeks to months.

Movement is really important to recovery, moving regularly through your neck and back, the affected limb and area of symptoms.

Avoiding further repetitive or continual pressure over your affected area to promote recovery, remove/move the pressure point. Consider the other recovery factors; food, hydration, stress, sleep. Optimising these can really help with recovery.

Don’t be afraid to invest in seeking professional help, they might suggest specific nerve glides and movements to aid your nerve recovery and work to prevent compensatory movement. Further investigation and intervention is possible for more serious peripheral nerve injuries where function has been lost.

Finally, remember that we learn by experience, use your symptoms to find where your pressure points or weaknesses are, change things up for your next race and hopefully you won’t have many issues next time.