Should you exercise when you're tired?

Have you ever wondered whether you should give the gym a miss if you’re just not feeling it? Dr Dan looks at whether exercising when you’re tired is ever a good idea.

What is being tired?

Let’s start by broadly splitting tiredness into two sections: 

• Acute tiredness 
• Chronic fatigue

Acute tiredness may be because of a night out, jet lag, or working late. You’ll probably feel like a good night’s sleep, or two can do the trick.

Chronic fatigue is more insidious. You may be chronically fatigued by shift work (especially nights), illness, or babies. If so, you probably won’t feel yourself – you’ll struggle through okay, but someone might point out the bags under your eyes along the way.

What happens when you’re tired?

When you’re tired, reaction speeds will be slower, heart rates higher, balance not so tuned, and much more. This could lead to injury and a long period of recovery. If you’re able to take a rest day, then do it. Your performance will be better tomorrow. 

We see this in jet-lagged athletes who need a day or two of pure rest and recovery before training again. It’s a spectrum, though – so there’s everything in between. Everyone is different, but here are some tips on what to do when you're tired. 

What if I’m only a bit tired?

Essentially you have to work out the difference for your own body because if you’re just a bit tired then exercise can be a good thing! 

Exercise can help wake you up and put you in a better state for optimal sleep later. You may want to think about dialling down on your maximum effort, though. Sometimes, even just getting out for a light jog, a short cycle, or a walk is enough.

For optimal wellness, we like to say you should be trying to get active for at least 30 minutes a day if you can. Just getting out and getting some fresh air each day can help and subsequently keep you more alert.

Does tiredness affect performance?

Absolutely. Studies have shown that athletes who are sleep-deprived miss more basketball hoops, are less accurate with darts, can’t bench, press and deadlift as much as they usually can, and have a higher heart rate and breathing rate, and a lower mood than they normally do.

This is why top athletes and their teams put a lot of effort into a more holistic approach to peak performance. It isn’t just training and match play, it’s sleep, food, recovery, mindfulness, and downtime.

What can you do about it?

1. If you’re tired, sleep! 
2. Listen to your body.
3. Think about your sport more holistically. Easy wins for the amateur athlete tend to be diet, sleep hygiene, and mindfulness. 

How to exercise when you're tired

1. Listen to your body

If you stick to a routine, you may find this particularly tricky. But, if you feel tired, then it’s your body’s way of telling you that you need to sleep and you need to rest. And, you should listen to your body because you could end up injuring yourself.

2. Optimise your sleep hygiene 

No caffeine after midday, no screens (especially blue screens) a few hours before bedtime, eat well and not too late, meditate if you like, think about having dimming lights, don’t drink alcohol, and try to get 7-9 hours of sleep. 

Find out more about how to optimise yourself for sleep.

3. Track yourself

If you feel you have chronic fatigue, then take a look at your blood. 

The two best tests would be an Endurance Fitness Blood Test or an Ultimate Performance Blood Test. Both of these are designed to help you optimise yourself because it’s not just a lack of sleep that can contribute to fatigue but also a lack of vitamins and minerals, increased stress markers, and much more. 

A snapshot result can provide a good baseline. But if you make some lifestyle changes, you can monitor the trends over time to see if things are improving. And if you voice your concerns to our doctors, they’ll be able to give you tailored advice when they go through your report.

4. Find your motivation

It’s easy to dish out the advice, but we know it’s not always easy to follow it. So, here are a few motivation tips that might be useful:

• Get into your activewear. Studies show that just putting on active clothes makes it far more likely you’ll leave the house!
• Don’t do it alone. Pretty easy if you do a team sport, but if you’re training then do it with someone else. You’ll motivate each other!
• Do classes. Similar to above if you book yourself in you’ll feel more obligated to turn up (especially if you’ve paid for it!).
• Get the right music. The right up-tempo beat can get you going.
• Pump your fists as if you’ve just won Wimbledon. Imagine the crowd, imagine the cheering and get pumping! Just don’t do it when someone’s filming you.
• Put some rewards in place. Fancy a tasty treat or that new Netflix episode? Well, you can’t have it until you get back from the gym.

So, should you exercise when tired?

Sleep is essential for peak performance though unless you’re extremely tired there’s probably no harm in exercising at a sub-maximal level it may help you sleep better the next night. 

If you’re looking for peak performance or have a competition coming up, then a blood test can help you to ensure you’ve optimised yourself both internally, in your day-to-day life, and bed to ensure you hit your goals.

References

1. Sleep Hygiene. The Sleep Foundation. Dr Nilong Vyas. https://www.sleepfoundation.org/sleep-hygiene (accessed Dec 2021)
2. Mah, Cheri D et al. “The effects of sleep extension on the athletic performance of collegiate basketball players.” Sleep vol. 34,7 943-50. 1 Jul. 2011, doi:10.5665/SLEEP.1132
3. Mougin F, Simon-Rigaud ML, Davenne D, Renaud A, Garnier A, Kantelip JP, Magnin P. Effects of sleep disturbances on subsequent physical performance. Eur J ApplPhysiolOccup Physiol. 1991;63(2):77-82. DOI: 10.1007/BF00235173. PMID: 1748108.
4. Reilly T, Piercy M. The effect of partial sleep deprivation on weight-lifting performance. Ergonomics. 1994 Jan;37(1):107-15. DOI: 10.1080/00140139408963628. PMID: 8112265.
5. Edwards BJ, Waterhouse J. Effects of one night of partial sleep deprivation upon diurnal rhythms of accuracy and consistency in throwing darts. Chronobiol Int. 2009 May;26(4):756-68. DOI: 10.1080/07420520902929037. PMID: 19444754.
6. Belenky G, Wesensten NJ, Thorne DR, Thomas ML, Sing HC, Redmond DP, Russo MB, Balkin TJ. Patterns of performance degradation and restoration during sleep restriction and subsequent recovery: a sleep dose-response study. J Sleep Res. 2003 Mar;12(1):1-12. DOI: 10.1046/j.1365-2869.2003.00337.x. PMID: 12603781.
7. Hill DW, Hill CM, Fields KL, Smith JC. Effects of jet lag on factors related to sports performance. Can J Appl Physiol. 1993 Mar;18(1):91-103. DOI: 10.1139/h93-009. PMID: 8471997.
8. Hill DW, Borden DO, Darnaby KM, Hendricks DN, Hill CM. Effect of time of day on aerobic and anaerobic responses to high-intensity exercise. Can J Sports Sci. 1992 Dec;17(4):316-9. PMID: 1330271.
9. Samuels C. Sleep, recovery, and performance: the new frontier in high-performance athletics. Neurol Clin. 2008 Feb;26(1):169-80; ix-x. doi: 10.1016/j.ncl.2007.11.012. PMID: 18295089.