To prepare for a motoring marathon, be it the Le Mans 24 Hours or a late trip home from the office, it’s good to know what’s taking place in your mind and body so you can develop a diet and sleep strategy to deal with it.
Our bodies follow a daily routine, known as circadian rhythm. Crudely put, it judges light and dark then pumps hormones around our system to switch our brains and guts off at night and wake them in the morning. That’s why jet lag makes you feel sick and dehydrated. We also follow longer energy cycles during the week. They vary from individual to individual, but don’t we all hate Monday mornings?
In addition to the evening sleep there’s a secondary dip in alertness after midday, exacerbated by how much and what you eat, because blood flow diverted to your stomach leaves less for your brain. For adults, who have slower metabolisms, this stage of the day is a danger zone for falling asleep at the wheel. The morning period brings on drowsiness among teenagers because they produce more melatonin, the sleep hormone, later in their sleep cycle.
Sleeping at the wheel is the most common cause of vehicles leaving the road. Most sleep-related crashes occur between midnight and 8am, especially between 4- and 6am, and between 1- and 3pm.
Sleep-related accidents are often fatal because the driver rarely decelerates before hitting something solid. Even if you do wake at the last moment, your reaction time and thought processes will be poor. Eighty-five per cent of those responsible will be male and young, because we do more miles and in our manliness believe we can push through the sleep barrier. I know several racing drivers who have met this fate.