Sleep Deprivation, Performance & Health

The importance of sleep

Research shows that in the last 4 decades, we have been working more and sleeping less. In 2013, the Sleep Council found that 70% of Brits sleep for 7 hours (or less) and 41% sleep 6 hours (or less) per night. All in, Brits now sleep about 20% less than we did a lifetime ago.

From politicians to athletes and entrepreneurs, various high-profile people talk about thriving on minimal sleep. Yet 10,000 different research papers largely agree that the percentage of adults who can survive on 6 hours (or less) sleep and show no impairment is technically 0%. 

Virtually no-one can maintain, let alone excel, when they’re deficient in lengthy, healthy sleep.

Sleep and body

When we get too little sleep, our bodies don’t fully recover from the day’s aches and pains. The immune system doesn’t have the time it needs to charge up. With the tank half full, we’ll probably feel sluggish as we wander into the day. And in this weakened state, we’re more likely to catch bugs and short term illnesses.

A poor sleep pattern also increases insulin resistance, which stimulates our appetites, particularly cravings for high fat and high sugar foods. Interestingly, both undersleeping and oversleeping (> 9 hours) increase our likelihood of weight gain and obesity.

Longer term, chronic sleep deprivation is associated with an increased risk of heart disease, diabetes and cancers. 

Sleep and mind

Sleep deprivation impairs the brain’s ability to clean itself, so the consequences of sleeping fewer than 7 hours a night will hit us directly and immediately:

On a short run of 2 poor nights’ sleep there’s clear evidence we see rapid deterioration in key thinking patterns:

  • Mood stability
  • Rational decision making
  • Willpower
  • Self control

When we’re tired we’re more likely to make mistakes and poor decisions. These effects come into play after just 48hrs of sleep deprivation. In other words, one night of poor sleep is manageable – any more and we’re in a damaging deficit. 

If we get 6 hours (or fewer) a night for 7 nights, we’ll be impaired in the same way as if we entirely missed one night’s sleep.

And because the effects play out almost immediately, catch-up or recovery sleeps at the weekend won’t counter the effects of short sleeps in the week. We will never catch up on all the sleep we lose.

Sleep and exercise

There’s a mountain of scientific evidence connecting exercise with strong, restful sleep and a considerable volume of evidence suggesting exercise is one of the best ways to combat insomnia. 

Fairly obviously, exercise tires us and our muscles and primes us for healthy and restorative sleep, speeding up the time it takes for us to drift off.

It’s also worth noting that the combination of exercise in the day, and with the resulting high-quality sleep at night, we attack stress on two fronts.