Every year, racing drivers migrate back to the Grand Prix circuits. Formula 1 has become an engineering battle-ground, a technological and human challenge. Just like the engines, the drivers are fitted out with sensors: heartbeat, oxygen consumption, stress levels... François Duforez, a doctor, and Pierre Portéro, a bio technician, run the “Biomedical Sports and Life Institute” (IBSV), one of the only centres in the world to research into the physiology and reactions of Formula 1 drivers... Stress, adrenalin surges, energy reserves: an unprecedented report on men who push themselves to the extreme limit.