Swap the espresso for exercise: Just 20 minutes boosts energy levels after a bad night sleep

We’re all familiar with that groggy feeling you experience after a bad night’s sleep.

But just 20 minutes of exercise could help boost your brain if you’ve not been getting enough shut-eye, a study suggests.

A team led by researchers at the University of Portsmouth ran two experiments involving 12 people in each.

In the first, participants were only allowed five hours of sleep a night over three days.

Each morning they were given seven tasks to perform while resting, and then asked to repeat the tasks after 20 minutes of moderate-intensity cycling.

The study showed each person’s performance on the tasks improved after they had been exercising on the bikes

Analysis revealed that having little sleep affected each person differently – possibly because some people may be more resilient to being tired.

However, each person’s performance on the tasks improved after they had been exercising on the bikes.

In the second experiment, participants went an entire night without sleep and then were put in a hypoxic – low levels of oxygen – environment.

They underwent the same tests and, even though oxygen levels had been lowered, still improved their performance after exercise.

Writing in the journal Physiology and Behaviour, the researchers wrote: ‘We have demonstrated that moderate intensity cycling for 20 minutes improves executive functions after three nights of partial sleep deprivation and one night of total sleep deprivation, regardless of hypoxic status.’

The team suggested that exercise could affect the release of brain-regulating hormones and the rate at which blood is delivered to the brain.

It could also boost arousal and motivation, they added.

Co-lead author Dr Thomas Williams said: ‘One potential hypothesis for why exercise improves cognitive performance is related to the increase in cerebral blood flow and oxygenation.

‘However, our findings suggest that even when exercise is performed in an environment with low levels of oxygen, participants were still able to perform cognitive tasks better than when at rest in the same conditions.’

Sleep is fundamental to maintaining a healthy lifestyle, with adults recommended between seven and nine hours per night.

However, studies suggest that 40 per cent of the world’s population don’t get enough.

In the short term, a lack of sleep can reduce cognitive performance which can affect attention span, judgement and emotional state.

But over time, it can lead to the likes of cardiovascular disease, obesity and depression.

Dr Joe Costello, who also worked on the study, said if the exercise was any longer or harder it may have amplified the negative effects of sleep deprivation.

‘The findings significantly add to what we know about the relationship between exercise and these stressors [lack of sleep], and helps to reinforce the message that movement is medicine for the body and the brain,’ he added.

The researchers called for further research into the mechanisms behind how exercise boosts cognitive function, as it could help anyone who experiences broken sleep or low oxygen – including shift workers, parents of young children and even climbers and skiers.