PS Taken from the Dogue de Bordeauxs site
Exercise
Although one wouldn’t necessarily think it (given the Dogue’s massive size), the Dogue de Bordeaux doesn’t require a great deal of exercise in order to stay healthy. Quite the reverse is true, in fact–too much exercise during the dog’s first year of life can result in underdeveloped or overstressed bones and muscles, which can result in severe health problems (or even in early mortality.) So it’s wise to restrict the Dogue de Bordeaux’s exercise during its early years, only playing with the dog for perhaps an hour a day.
The energy level of the Dogue de Bordeaux is low when compared with its potential power and strength, and this should be respected when exercising even adult Dogues. One or two walks (or more) per day should be considered a given, but can for older dogs also often be considered sufficient. Giving the Dogue free reign to run and play is also a good idea if you have the space for it.