20/12/2011 18:15 GMT | Updated 19/02/2012 05:12 GMT

Sleeping in Extremes - Competing in the Vendée Globe

Survival instinct is our human, natural reaction to risk, threat and danger. But it is weakened by fatigue and other factors playing on the mind and body like stress and cold. And there aren't many places colder or more stressful than the middle of the Southern Ocean when you're on your own on a 60 foot yacht that's bucking in huge waves.

The Vendée Globe is a non-stop, round-the-world ocean yachting race. It takes around three months to complete the race if you have no major hitches, and that is three months of an almost non-stop physical workout; hauling around sails which weigh up to 70kg each, grinding winches and battling against freezing conditions.

The rules of the race dictate that we are not allowed to receive any help from our shore teams while the race is in progress. That means that I'm constantly responsible for the direction the boat is heading in, the choice of sail, the on-board computer, monitoring the weather and deciding on my routing. All of this is so important and the situation can change dramatically within just a few seconds, so I can't afford to lose focus. But focus means being alert, and that means that body and mind need to be working as well as they can be in the challenging conditions.

Nothing supplies the body with a better recharge than a sleep. No amount of Red Bull or Mars Bars prepares you as well as a nap. But with the preoccupations that I have when I'm alone on the boat, all of which are constantly important to not only my competitiveness in the race, but also my survival, I can't afford to sleep for more than a short time.

It's hard enough when I'm racing double-handed with a co-skipper, as I did in the Transat Jacques Vabre last month. With someone else to keep an eye on things on-deck, I can be downstairs catching an hour of sleep here and there, or just relaxing for a short while. But you can't get too comfortable - tasks like climbing the mast or changing a sail are more efficient with two people. Aside from that, our boat isn't set up for a good night's sleep; it's made of carbon fibre which is a far cry from a feather duvet and mattress, it's really noisy below as the waves pound the boat, and it's either as hot as a furnace or freezing cold depending on where we're sailing.

Despite the uncomfortable conditions, I don't have much trouble falling asleep when I'm on my own on the boat. Weeks before a major race such as the Vendée Globe I prepare myself for an alternative sleeping pattern - it's not at all natural and it's pretty tough to master, but it allows me to sleep for 20 minutes every four hours. This is the best compromise between the need to sleep and a need to be awake all the time. With a one-year-old son, sleep deprivation comes pretty naturally to me, but I still recognise that I'm much more alert when I've had a chance to recharge. Polyphasic sleep is the only option when you have a competitive goal - every time you sleep the boat slows down, so you have to keep it to a minimum if you expect to win.