Every year, the MDS comprises around 250 km to be covered in 7 days, and that means ultra! To prepare yourself, is it enough to just increase the amount of training you do? Well, not exactly: increase the amount and reduce the intensity, yes, but an excessive amount of training is not necessary. The secret of running an ultra is to build up your muscles. A marathon runner who wants to move to 100 km needs to increase his or her endurance, a 100 km runner who wants to start running 24 hours has to become more sturdy, and that's all the more true for ultra-trails, and especially for a run in stages through the desert.
Your muscle building should be specific to running, but to ensure harmony and coordination and avoid imbalances, it needs to involve the whole body.
It could take a number of forms, for example: