Is the human factor the key to performance?

A human machine ignored for too long

Despite its ten editions, the Vendée Globe has until now remained an enigma from a medical point of view. The technological machinery of the 60-foot boats was studied in minute detail, but the human machine remained largely neglected. "There's a real lack of data in ocean racing about the conditions in which the sailors evolve," observes Laure Jacolot. We had to wait until the 2024-2025 edition for the first large-scale study to be carried out on the physiological and mental consequences of racing, led by Bérénice Charrez and supported by IMOCA. The initial results are both eagerly awaited... and startling. Marked muscular atrophy, loss of flexibility, balance problems, osteoarticular tensions, chronic stress, hormonal imbalances: the Vendée Globe transforms our bodies. These observations are reminiscent of the effects of a prolonged stay in weightlessness. "Some skippers lose up to a centimetre and a half in height, probably as a result of vertebral compression due to the confined posture and loss of mobility," explains the Swiss woman, who holds a doctorate in medical engineering from the University of California at Berkeley. "It's reversible, but revealing." Even the best-prepared skippers return to the dock with sometimes invisible, but very real after-effects. 

The body, under stress, overexposed to noise, shocks, vibrations and lack of sleep, enters a state of extreme hypervigilance, with consequences that are as yet poorly measured over the long term.

Tools for objectivity, understanding... and prevention

The study collected an unprecedented amount of biometric and environmental data. Before the start, each volunteer skipper was subjected to a full battery of tests: weight, height, muscle perimeters, VO2 Max tests, grip strength, jump height, etc. During the race, connected watches and on-board sensors continuously monitored heart rate, energy expenditure, sleep quality, humidity, temperature and noise levels in the cockpit. The result: some sailors burned up to 5,000 calories a day. An unexpected finding, given the relative immobility on board. "In reality, they tend to be sedentary, but their brains are always working. And that consumes an enormous amount of energy", explains Bérénice Charrez. The poor quality of sleep further accentuates this physiological stress: 

These findings open up concrete possibilities: reviewing cockpit ergonomics, incorporating secure recovery areas, adapting watch and rest schedules, personalizing nutrition according to actual energy expenditure, and incorporating simple but regular physical routines. "Sailors need to incorporate isometric contraction exercises, such as the chair against a wall, to maintain their muscle mass even without space or equipment," suggests the researcher.

A new era of human-centred performance

One of the project's major contributions is its revelation that a new frontier in performance is no longer to be found in materials or pure speed, but in human optimisation. "Until now, we have underestimated the physiological impact of racing. Boats are evolving, going faster, hitting harder, vibrating more. These new constraints must be taken into account in preparation," emphasises Laure Jacolot. The work has just begun. The analysis of saliva and urine samples, the effects of hormonal variations, the neurological impact of vibrations and digestive disorders remain to be explored. The integration of real-time monitoring systems on board is one promising avenue: a human data hub alongside navigation systems so that skippers can adjust their recovery, nutrition and vigilance strategies. Another avenue for exploration is the transposition of astronaut training methods. "They exercise for two hours a day on the ISS. They also follow vestibular balance protocols. We can learn from them, particularly when it comes to limiting muscle atrophy and improving proprioception," says Bérénice Charrez. Because the challenge is also a long-term one. It is not just a matter of bringing sailors back to land safely, but of enabling them to continue sailing, year after year, without paying a heavy price. Preparing the body and mind for such a challenge is no longer a luxury, but a necessity. "The real question today is no longer whether this race leaves its mark. It's: how can we anticipate, measure and reduce that impact?" sums up the scientist and sailor. This approach is part of the very DNA of the Vendée Globe: understanding in order to push the boundaries further.