The Marathon des Sables is a 6-day, 250 km run across the Sahara Desert in temperatures reaching 50 °C. Describe how an athlete acclimatizes when preparing for the race.

Explain the physiological adaptations that occur during heat acclimatization.

perform training sessions in similar conditions / desert >5 days prior to race;

use an environmental chamber;

initially reduce intensity of training;

increased plasma volume as a response to increased stroke volume;

lower rest and exercise core body temperature;

increased sweat response, as sweat becomes more diluted;

reduced rate of muscle glycogen, as cardiac output increases;

Candidates identified the requisite time and aspects of training required for acclimatization. A surprising number did not mention training must occur at the desired environmental conditions.

Candidates struggled to do more than identify the physiological changes with a little explanation required to access more marks in this question.