What 99 Days At Sea Does To Your Body

Have you ever considered what happens to the human body after sailing solo, non-stop around the world?  That’s exactly what Ollie and 15 fellow Vendée Globe skippers set out to discover during their Vendée Globe race.

Led by Swiss bioengineer Bérénice Charez in association with IMOCA and the University of Caen, her groundbreaking study tracked physical changes prior to the race start, then again within an hour of stepping ashore post-race finish.

Here’s what Charez found and what it says about the physical demands on the body of sailing for 99 days non-stop.

Weight Loss

By the end of the 99 days at sea Ollie had lost 3.5kg. In previous, shorter races he had lost much more, so this was an extremely positive result showing that Ollie and the team have improved his onboard nutrition to suit the extreme conditions.

Ocean racing pushes the human body to its limits. The boat is always in motion, requiring constant physical effort, manoeuvring sails weighing up to 100kg and more when wet, grinding winches, and adapting in a short period of time to extreme temperature shifts.

Pre-race, the team estimated Ollie would require on average, 5,500 calories per day to maintain energy levels, with slightly fewer calories in warmer climates and more in colder conditions. Throughout the preparation races the team experimented with different flavours and high-energy food types to help Ollie achieve optimum nutrition and identify meals and snacks he enjoyed.

For the Vendée Globe, Ollie’s food was prepacked into daily portions, to help him monitor how much he should be eating. Each pack contained 3 main meals plus snacks and daily vitamins provided by our title partner “Burgerstein Vitamine” as well as a weekly ‘treat pack’ containing cured meats and pickles.

All in all, this race proved that this approach was successful, as smart fuelling and preparation kept Ollie’s weight loss to a minimum and his energy levels high.

Muscle Changes

Interestingly, most of the weight loss came from a reduction of leg muscle, which was a pattern consistent across all the skippers. In fact, on returning to shore, Ollie struggled to walk very far and need to go on daily walks to recover his leg strength.

However, Ollie’s grip strength increased considerably.

These changes reflect the nature of activity on the boat; his grip strength increasing from constantly hauling heavy sails and grinding activity, while his leg-muscle was noticeably reduced as a direct result of less lower-body activity.

The study also shows that ocean racing is a physical challenge that relies as much on technique and efficiency as on brute strength – one of the reasons sailing remains a rare sport where men and women truly compete on equal terms even at this elite level.

Surprisingly, Ollie also gained in flexibility during the race! This could be due to crawling in the small spaces around the boat?

Balance

A number of other tests assessed the skippers' balance with eyes open and closed. All skippers showed a significant decrease in their ability to walk in a straight line with their eyes closed after the race.

This is a fascinating reminder of how well the brain adapts to its environment, balance is adjusted taking into account the constant rolling and rocking motion of the sea. Once back on flat land this adaptation is no longer helpful, leading to the phenomena of ‘land wobbles’ or ‘disembarkation sickness’.

During this period of re-adjustment, the brain is reliant on eyesight to provide a clear sense of balance, hence the reason everyone struggled when their eyes are closed.

Interestingly, Ollie was the only skipper whose spatial orientation actually improved during the race — suggesting that long weeks alone at sea just might suit him!

Ollie summed it up:

“You start to feel at home with the boat, more tuned into its rhythms and movements. It’s fascinating to see scientific data that confirms how much your body adapts. I’m especially pleased with the minimal weight loss – it shows we’re getting the preparation and nutrition right.”

Post Race Normality

Sailing for 99 days solo, requires the mind and body to be alert almost non-stop. There is the regular checking of weather forecasts, making decisions on the best route and optimum sail choices, plus the constant movement of the boat, combined with the continual noise of the water crashing against the hull, the sound of the wind above decks and alarms wailing to indicate various parameters have been met or breached.

Far from a sensory overload, Ollie quickly tuned in to the rhythm of information and sounds of his boat, listening out for signs of equipment failure, looking for unforseen changes in the weather or sea state, or anything else which might require a reaction. Things can change very quickly at sea, and any skipper has to be ready for anything, at any time.

As a solo sailor, there is no-one else to share the responsibility with. No-one to take over whilst you take a break.

This constant vigilance puts the body into a ‘fight-or-flight’ mode, a state of elevated stress and tension. After 99 days this becomes the new normal, and the mind and body perceive relaxation as the biggest danger.

Switching off from this high-alert state is much harder than switching it on. It took several weeks for Ollie and his body to switch off the hyper-vigilance and accept that it was ok to rest and relax.

Although Ollie's sleep patterns weren't part of Charez’s study, Ollie also noted how he found adapting to the short burst of sleep on board relatively easy. He knew he needed to manage his sleep and did his best to follow his plan of regular short naps throughout the day, or whenever conditions were stable and predictable and he was away from hazards.

However, Ollie found it far more challenging to adapt to a full night’s sleep again once back ashore. He regularly woke up in the night, wide-awake and ready to go.  It took about 8 weeks before he was able to sleep ‘normally’.

Building on Ollie's own Vendée Globe experiences, combined with these scientific insights, Ollie is in better informed and more determined than ever to approach his next challenge stronger, smarter, and fitter.