How Stress Impacts Performance
Dating life got you down? Had an argument with a colleague at work? Just having a bad day for no particular reason?
You’ve probably been told that a good way to deal with stress is to sweat it out, and a lot of us take that advice - 62% of adults surveyed by the American Psychological Association who said they exercised or walked to manage stress found the technique very or extremely effective. Hitting the treadmill or smashing the weights section at the gym can be a productive way to blow off some steam, clear your head, and release some endorphins.
But if you’re routinely feeling low and unmotivated before you workout, you might notice you’re not quite seeing the same results that you used to. This can be your body’s way of signalling to you that high intensity exercise isn’t what would best serve you in that moment. Working out itself causes a stress response, and overloading your body while your brain is in bad shape isn’t always the best move.
The hormone linked to stress is called cortisol. Cortisol is actually a good thing in regulated amounts: the “stress hormone” helps to manage the nervous system, the immune system, and even our daily systems (it’s cortisol that wakes us up in the morning, for example.) However, stress-induced spikes to our cortisol levels can be counterproductive to us, not only mentally, but to our fitness goals, too.
Sometimes, your mental and physical health would benefit more from some time out to recover and reset. Instead of pushing through, opt for some gentler forms of exercise, or lower the intensity of your workouts. Alternatively, just take a few days out altogether and give your body some time to recover.
Not convinced? Here are just a few ways in which stress can negatively impact your performance, both inside and outside the gym.
Stress decreases motivation
First of all, you’re far less likely to even make it to the gym if you’re feeling mentally stressed. Studies have found that people with high levels of stress, anxiety and distress miss more exercise sessions, are less likely to stick to an exercise programme, and spend more time sedentary.
One way to combat this is to skip the high intensity workout and opt for something a bit more calming on the nervous system instead. Exercise that incorporates forms of mindfulness, like a gentle yoga flow or even an uphill walk are less taxing both physically and mentally. Missing your scheduled workout altogether might cause you to feel even more stressed, so taking it easy on yourself with some gentle stretches is a great way to refresh both your body and your mind.
If you think you build muscle while you’re in the gym, you’d be wrong! When you work out, your tear muscle fibres - sleep gives your body time to recover and repair the muscles worked during exercise. Not getting enough sleep is a big mistake to make, as this recovery time is crucial for maximising the benefits of working out. Getting the recommended 8 hours (or more) of sleep per night helps you feel more energised, work out harder and see results quicker.
Mental stress can cause sleepless nights, but sleep deprivation is also a stress on your body in itself. After sleep deprivation, subjects in several studies had higher levels of cortisol in the evening, when their levels of the stress hormone should’ve been at their lowest to prepare their body to rest. High cortisol levels trigger the body to store more fat, and use other soft tissue like muscle such as energy, meaning that sleep deprived athletes lose more muscle and gain more fat.
Not only that, but the quality of sleep is also essential. The most significant growth hormone spike occurs around 70 to 120 minutes after you fall asleep but an erratic sleep schedule can reduce your growth hormone level significantly.
The classic advice of turning your screens off an hour before bedtime, sticking to a sleep schedule and tucking yourself in earlier for a good amount of sleep apply here. If you routinely have trouble sleeping, dedicating some time to winding down with a book or meditation before sleep will help your body and mind relax, for an optimised sleep cycle.
Stress puts you at an increased risk of injury
Sometimes, even working out isn’t a good enough distraction for when you’re emotionally stressed, and your mind might be partially occupied by some other worries or troubles. Attention deficit means you’re way more likely to injure yourself by not paying enough attention to your technique, or missing the cues your body gives when it’s exhausted. Studies have even found that stress impairs motor coordination and visual perception, which can negatively affect the way you see things and process visual cues, endangering your workout.
There’s also a bodily response to stress that increases the risk of injury. The nervous system can put more pressure on blood vessels when you’re stressed, causing reduced blood flow to the muscles. This tension and pain can be enhanced more by high levels of cortisol, so relieving the stress through relaxation techniques might be a better option than trying to push through it.
Stress doesn’t just impact your performance at the gym, but it can also have consequences when it comes to longer term recovery. According to a study in the Journal of Strength and Conditioning Research, people who said they were stressed felt more tired, sore and low on energy 24 hours after a tough workout than those who reported fewer life pressures. Equally, a study from Yale University found that participants with lower stress levels experienced greater recovery in a shorter amount of time.
That’s because when you exercise you create microscopic tears in your muscle fibres, which your body repairs during recovery. High levels of cortisol can lead to reduced protein synthesis, suppressed production of growth hormones, reduced blood flow and a build-up of lactic acid, all of which inhibit muscle repair and growth.
So make sure you recover from one high impact workout fully (both mentally and physically) before tackling the next!
Stress encourages weight gain
Bad news: elevated cortisol levels can cause cravings for sweet, fatty and salty foods, meaning you’re more likely to ditch the healthy eating and indulge in a takeaway. That’s why “stress eating” is a thing!
Worse news: even if you have been diligently sticking to a healthy diet and a rigorous exercise programme, you still might find it hard to shed those last few pounds! That’s because cortisol is responsible for regulating your metabolism. When you’re stressed, your body goes into fight-or-flight mode, temporarily pausing bodily functions and slowing your metabolism.
… But it’s not all bad news
Anecdotally, there’s a lot to suggest that exercise can be effective in reducing stress - and there’s also some biological evidence to support that! When you’re in a state of stress, your body is anticipating having to either run away or fight the cause of the stress, hence the state of fight-or-flight. Your body has already anticipated physical activity, having instructed the liver to release sugar for energy, so one way to tackle the stress is to give it that pumped up, physical workout it’s expecting.
If you reckon you are able to put your stress to one side and fully concentrate on your workout, you could also find yourself emerging from the gym feeling rejuvenated and refreshed, with a clear head and a more positive mindset.
The take away from all this?
Next time you’re thinking of just sucking it up and pushing through another workout, take some time to check in with yourself. Would an intense session of physical exercise really make you feel better? Or are you better off admitting that, maybe, today isn’t your day. Maybe today requires a different type of training: mind training. As important as physical activity is, relaxation is also a practice that needs to be honed and refined - and sometimes, doing nothing is harder than doing something! Listen to your body, treat it with the compassion it deserves, and your health certainly won’t suffer for it.
Take care of yourselves!
‘Exercise: A healthy stress reliever’
‘The Effects of Stress on Physical Activity and Exercise’ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3894304/
‘The Power of Exercise: Buffering the Effect of Chronic Stress on Telomere Length’ https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0010837
‘The Journal of Strength and Conditioning Research’ https://journals.lww.com/nsca-jscr/pages/default.aspx
‘Emotional stress can affect motor coordination and other cerebellum-dependent cognitive functions: Study’ https://www.news-medical.net/news/20110113/Emotional-stress-can-affect-motor-coordination-and-other-cerebellum-dependent-cognitive-functions-Study.aspx
‘Psychological stress impairs short-term muscular recovery from resistance exercise’ https://pubmed.ncbi.nlm.nih.gov/22688829/
‘How sleep can help you build muscle’ https://www.poulin.healthcare/blog/how-sleeping-can-help-you-build-muscle
https://www.orlandohealth.com/content-hub/how-too-much-stress-can-cause-weight-gain-and-what-to-do-about-it#:~:text=in%20excess%20amounts.-,Cortisol%20Can%20Lead%20to%20Weight%20Gain,sweet%2C%20fatty%20and%20salty%20foods.‘Stress and metabolism’ https://pubmed.ncbi.nlm.nih.gov/18370704/#