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Cycling Science: Is stress ruining your performance?

Anna Cipullo
7 Nov 2018

Don’t train harder, train calmer, say experts

Most of us understand how the human body responds to physical training. Every time you complete an intense training session, you become fatigued and you need a few days to rest and recover before you come back stronger than before.

‘This is a normal function of training and is termed “functional overreaching”,’ says Nick Grantham, performance specialist at ZERO226 Performance. But if you are physically or mentally stressed, your recovery can be inadequate and your sporting performance will eventually plateau. This, Grantham says, is known as ‘non-functional overreaching’, and it can take weeks, or even months, to return to normal.

Dr Tommy Wood is a specialist in performance biochemistry at Nourish Balance Thrive, and he sees the effects of stress on performance every day.

‘When it comes to thinking about how stress affects performance, it’s important to mention that a bit of stress is beneficial – if you weren’t a little stressed at the start of a race, you wouldn’t be able to sprint off when the gun starts,’ he says. ‘So stress isn’t necessarily good or bad, it depends entirely on the context.’

Riders like Tom Dumoulin have to deal with the mental and physical stress of a Grand Tour

After all, exercise in itself is a stress on the body, albeit one that usually leads to a beneficial adaptation, but even then it is possible to over-train, or under-recover, which has adverse effects on performance.

You’ve probably heard of the ‘fight or flight’ mechanism – the way your body reacts to stressful situations. Thousands of years ago, this could be dealing with a bear attack, which would result in the body releasing adrenaline and cortisol to either fight your way out of danger or to flee from it. In today’s world, our stress is a little different, but our body reacts in the same way.

While adrenaline disappears from the body relatively quickly, cortisol is much slower to disperse, which means it can build up over time and cause adverse effects.

‘The way we think about stress in our athletes is as a total load on the body, also known as “allostatic load”.’ Says Dr Wood. ‘We know that our brains and physiology respond to all kinds of stress in a very similar manner. Therefore, all the stressors in your life (especially training, diet, work/home life and social life) need to be kept in balance, and the most common ways we see stress affect performance comes from an imbalance in these four areas.’

This means that it is entirely possible for you to display symptoms of stress fatigue without over-training.

What are the symptoms of stress fatigue?

If your body starts to build up high levels of cortisol, you will start to feel inexplicably fatigued, achy and unable to perform during high intensity sessions on the bike or in the gym. Cortisol can also pool in the joints, making you feel sore in places like your back, neck and elbows, and can even lead to problems such as tendonitis, hence why athletes suffering from stress are more likely to develop injuries.

As cortisol is a hormone, your body can physically block other useful hormones from being released, such as gonadotropin (the ‘sex hormone’) and dopamine (the ‘happy hormone’), as it prepares your body for bigger threats. 

High cortisol levels can even lower your metabolism and slow down your fat burning rate, which then leads to weight gain. It can also have an adverse effect on your V02 max levels, which will hamper your energy output during rides and races.

VO2 max threshold

The more stressed you are, the more it can impact on your performance on the bike

In short, if your training has plateaued, your sex drive or joie-de-vivre has faded, and if you’re struggling to make decisions or you feel unwell, but you’re not ill, or you’re mysteriously putting on weight, then these could all be signs of stress fatigue.

What can you do about stress fatigue?

Many of us use exercise as an outlet for stress, and some of us might even increase our training load when things get more stressful at work or at home, but this can lead to a downward spiral in performance if you don’t give your body a chance to recover. 

If you are displaying symptoms of stress fatigue, it’s time to look at what is causing it: training, life, or both? 

Is it a short-term problem you can ride through, or is it something you need to learn to cope better with? Or is it simply that you’re training too hard alongside a career and a busy life, and something needs to give? 

Knowing the symptoms and acting quickly will help you shorten the recovery. If it is left too long and chronic fatigue or chronic stress sets in, even if you eliminate the cause of the problem you’ll still need to give your body enough time to recover. 

Recovery doesn’t necessarily mean stopping your training altogether, but high intensity training or long rides will only continue to stress the body. Try exercising gently, or dial back the intensity of your training plan. Try shortening your rides, lightening weights and keeping your heart rate low.

Sometimes it's better just to enjoy the ride

‘Tracking various metrics of your heart rate over time can give you a good idea of how “stressed” your body is,’ says Dr Wood, ‘but it takes some time to understand the patterns, and it doesn’t tell you anything about what’s causing the stress. For that, you need to be mindful of all the things you have going on, and be able to subjectively figure out which stressors you can modify or reduce.’

Diet can be both a cause and a solution to stress fatigue. For example, starving the body will rush it into ‘survival mode’, which affects your mood and metabolism. 

‘Training less and eating more is incredibly hard for the committed endurance athlete,’ says Dr Wood, ‘but nothing boosts performance like allowing your body to recover and giving it the nutrition it needs. 

‘Sometimes, getting a coach to look over your training and diet plan can be a great way to get an unbiased second opinion,’ Wood continues. Also, try reducing grains and sugars from your diet, as these can cause natural highs and lows that leave your body feeling unsettled.

Nutrition is key for performance

And finally, there’s meditation. This doesn’t necessarily mean buying yourself a Moroccan prayer cushion and chanting a mantra over sitar music. Meditation is just a period of time set aside to quiet your mind. If you choose to do this while chopping carrots for dinner, or just sitting on the sofa with your eyes closed, then so be it. 

The aim of meditation is to let stressful thoughts wash away. Acknowledge them and let go of them, or take time to think of a productive way to get around them. 

If you’re hell-bent on using every bit of your spare time on training, then try a bit of yoga. While your mind has a chance to shed your worries, your body can get a good stretch and core workout.

This article first appeared on in February 2018

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