To ensure you’re able to function at your best, you want to keep your cortisol levels balanced. They might spike in response to a threat or fall when you’re asleep, but you want them to return to a comfortable ‘middle ground’ in the aftermath.

Signs that your cortisol levels are too high might include having trouble switching off at night, feeling irritable or struggling with intestinal issues. Some techniques to rectify this could involve having a structured wake-up and bedtime routine, spending time with friends and family or avoiding habits that you know tend to contribute to your stress levels, like scrolling through social media in the evenings or starting the day by watching the news.

On the flipside, your cortisol levels may be slightly too low if you consistently find it hard to wake up in the morning or feel lethargic all day. The tricky thing is that you can feel like that if you’re living with chronic stress too – so if you’re snowed under at work, exercising hard or going through a difficult patch, then rest and stress management is probably your best option.

If you have no obvious cause for tiredness, however, try giving HIIT a go and getting some early sunlight exposure to regulate your circadian rhythm. And if you don’t notice an improvement, it’s always a good idea to talk to your GP about ongoing energy issues or stress management.

It’s not all bad: why some cortisol is good for you (and how to keep yours in check)