3 reasons you’re not sleeping after a tough workout

·1-min read
Photo credit: B2M Productions
Photo credit: B2M Productions


Running releases all manner of wonderful chemicals into the bloodstream, including serotonin, the “happiness hormone”. But it also releases cortisol, a stress hormone that can interfere with sleep. During exercise – especially hard sessions – cortisol is released by the adrenal cortex. This has the benefit of preserving carbohydrate stores, but it also activate the hypothalamic-pituitary-adrenal axis, increasing arousal – handy for tough sessions, problematic for sleep.

What to do about it: tuck in! Don’t skimp on fuelling, especially during tough training blocks, and be sure to replenish glycogen stores before hitting the hay.

Body temperature

Sleep onset is linked with a decrease in core body temperature of about two degrees that begins about two hours prior to bedtime. Interference with this normal circadian process – for example, through doing a tough interval session – means that deep sleep suffers. Because exercise can raise body temperature by several degrees, the normal night-time drop is counteracted, leading to more difficulty falling and staying asleep.

What to do about it: use fans, air conditioners and cool compresses to decrease you core temperature.


Caffeine’s performance-enhancing properties are well known. But before you drink an espresso before an evening or afternoon workout, consider the sleep-affecting consequences. Research has shown that caffeine consumption even as much as six hours prior to bedtime can cause disruptions.

Cure: have a caffeine cut-off time, ideally at least six hours before you intend on falling asleep. So if you’re hoping to be asleep by 10pm, drink your final tea or coffee by 4pm.

You Might Also Like

Our goal is to create a safe and engaging place for users to connect over interests and passions. In order to improve our community experience, we are temporarily suspending article commenting