The race is spread across six days, covering 500 km, 3250 mt above sea level.
Pinto, a national champion who is world number 9 and seeded sixth in Europe, and his compatriots Eduardo Pereira and Luis Canto Moniz were teh first to complete the first stage of the race, covering 40km.
Indian Army riders are also in fray in the competition, which is considered the world's third toughest MTB race.
The event feature races in the open men solo, open women solo, team of two open masters categories.