A new study of human performance in the Vendée Globe could be a game changer
by Ed Gorman / IMOCA Globe Series 14 May 08:53 PDT
Sailors put themselves through one of the biggest tests in extreme sport © Monnoyeur-Duo for a job
What effect does racing alone around the world on a high performance IMOCA yacht have on the human body and mind? It's a question you might well ask, as our sailors put themselves through one of the biggest tests in extreme sport to be found anywhere in the world.
But the remarkable element here is how little is known about this, even after 10 editions of the Vendée Globe. And that itself is surprising because the more sailors know about what is going to happen to them, the better they are able to prepare and even to protect themselves against some of the more impactful consequences of the challenge of racing alone for up to 100 days.
But new ground breaking research - the IMOCA Human Performance Project - is shining a light on this unexplored area. And it is revealing some remarkable early findings about what happens to sailors after months at sea.
For example, IMOCA sailors come back to the dock at the end of the Vendée Globe slightly shorter in height than when they left; they experience muscle atrophy in both their legs and their arms; they lose an element of overall physical flexibility, and their balance is affected, just as it is for astronauts returning from a stint in the International Space Station.
The research is being carried out by the Swiss bio-engineering specialist Bérénice Charrez who is working with IMOCA and with the University of Caen Normandy on the first full-scale study of Vendée Globe sailors. "Although the discoveries, or most of them, were expected, I think the whole sailing community, or at least the skippers that were part of it, were surprised by the numbers they saw," says Charrez. "At least it will raise awareness on how important it is to think more about their physiology."
An accomplished sailor herself and triathlon competitor, Charrez, 32, was racing in the 2023 Ocean Race VO65 Sprint Cup with Team Viva México when it struck her that unlike triathlon, for example, there was no monitoring of any kind to see how sailors' bodies were performing under the stress of competition. "There was pretty much nothing that was being monitored and optimised for performance with existing tools," she recalled.
Having previously worked with cycling teams and fire fighters, Charrez proposed the first ever study of Vendée Globe sailors of this kind and, with IMOCA's backing, set about gathering information from 15 of the 40 competitors who started the last Vendée Globe. In the days leading up to the race start, she carried out a comprehensive series of measurements and assessments of the sailors who each volunteered to take part in the study.
These ranged from basic medical measurements like weight, height and body composition to measurements of muscle girth in thighs, calves and arms. The skippers did VO2 Max tests to understand how many calories they burned during exercise, their sweat patterns and their overall physical conditioning. Charrez also tested hand-grip strength and jump heights.
During the race the skippers wore a Garmin watch that continuously measured biometric data - heart rate, blood oxygen, blood pressure, skin temperature and so on. An environmental sensor in the cockpit, developed at the University of Caen, measured elements like temperature, humidity and noise so Charrez could compare the sailors' psychological state at any point with the environment they were living in at the time. She also studied sleep patterns and, with three of the skippers, carried out a daily psychological questionnaire that asked them about perceived stress, perceived fatigue, their state of mood and how much they were eating and drinking.
"I had a lot of hypotheses because I am a sailor myself and there were things I was expecting and things I wanted to confirm scientifically," said Charrez, who is still working her way through the data. "I guess the biggest hypothesis I had was that offshore sailors, and especially sailors that race for so long, are more comparable to astronauts than typical athletes."
Among the first results was a surprising finding that sailors lose height - between one and one-and-a-half centimetres - during a Vendée Globe. Charrez is not sure why, but thinks it may be related to the compression element of being cramped in a cockpit for weeks on end and the consequent loss of flexibility. "It was interesting that it was consistent with all the sailors," she said, adding that the lost height would be quickly regained once back on land.
Another surprise was that on average there was no significant weight loss among Vendée Globe sailors, despite the rigours of the race and a diet of mainly freeze dried food. There were some outliers - a sailor who lost a massive eight kilos, or 10% of body mass, for example - but it seems that most competitors and their shore teams had come up with the right nutritional mix for the race as a whole.
On the issue of balance, a simple walking test carried out immediately after the sailors hit the dock - placing one foot in front of the other, but with the heel of the advancing foot touching the toe of the placed one, and with eyes closed - produced results directly comparable to astronauts. They couldn't do it...
Muscle atrophy, meanwhile, saw big changes with loss of girth in muscles in the thigh and calves of up to 10%. There was also loss of girth in biceps - a surprising finding given the amount of work sailors do on the pedestal winch, grinding in sails. "It seems like they are less active than what we thought," commented Charrez. "Even when you spend time working the winch, there is only so much time that you are doing it in a day and the rest of the time you are sitting down."
There is still a long way to go. Charrez has yet to analyse the data from the biometric and environmental sensors and from saliva and urine samples taken before and after the race. These could shed light on hormonal changes and the all-important effects of sleep deficiency and dehydration.
Charrez is planning to work on other races and says it's easy to see how the results of this study can help improve sailors' performance: "In recovery after the race, for example, they can leverage this information to recover better, but also use it to prepare better. That comes with optimising nutrition and food plans and hydration as well. But also it will be interesting in the future to assess what kind of muscle fibre the different sailors have to see if a certain type of fibre is more prone to atrophy."
Overall, using this information could be a game changer as sailors prepare for the ordeal of the Vendée Globe and other solo and short-handed races. Charrez says the younger generation are more attuned to using this sort of data than older groups and it is easy to see how, in the prevailing philosophy in endurance sport of marginal gains, using this information could be part of a winning package.
In summary, Charrez says we know - and the skippers themselves know - that solo offshore sailing can have detrimental effects on the body but now we can quantify these. "The question is how can they mitigate, or at least lessen these effects," she said.