A burst of stress is just what you need in the morning. How you wake up predicts how well you’re going to function over the rest of the day, according to Professor of Psychophysiology Angela Clow, at the University of Westminster.
Professor Clow said. ‘People who wake up late have much higher incidences of psychological morbidity, and are much more prone to a range of psychological conditions.” (Perhaps Winston Churchill’s ‘black dog’ – his depression, was due in part to his life-long habit of late to bed, late to rise?)
When we wake, she says, our brains get a burst of cortisol, a stress hormone that scientists used to think had a negative effect on the body. They now know that this burst, known as the cortisol awakening response (CAR), is in fact a positive, natural process that “primes the rest of the brain for maximum functioning”, releases stored energy and prepares the muscles for action.
If you still have small children who wake you up by whooping and jumping on you while it’s still dark, you’ll be alright then. But only if it’s between 6.00 am and 830 am, when the body is most responsive to sunlight, which fits our natural rhythms.
The reason waking up late is bad for you is because it throws your circadian rhythm – the 24-hour cycle that our bodies are synchronised to – off track. ‘For maximal flourishing we need to function around this 24-hour cycle and sleeping, at night, is an important part of this.’
But at other times of the day stress is something to avoid, particularly long term or chronic stress. Multiple studies show how it affects you: it slows down your mental processing speed by impairing your ‘working memory’. It also sabotages concentration, and impairs motor coordination. It can even affect your eyesight – it’s been linked with everything from simple eye twitches to temporary blindness. Stress causes your pupils to dilate and the muscles around your face tighten, constricting blood vessels feeding the eyes which leads to eye strain and headaches.
Long term stress in middle aged people is linked statistically with a 40% increased risk of developing dementia in old age.
And – stress can stop you losing weight.
There’s a whole host of negative effects of stress, but perhaps among the most troublesome is that it impedes weight loss. In a Kaiser Permanente study in the USA, 472 overweight adults were put on a diet and an exercise programme designed to help them lose weight. They were first assessed for their level of stress. Researchers found that the highest stressed participants lost less weight, and worst – when they became more stressed during the study they actually gained weight.