Bulldogs are not very active indoors and do not require much exercise (although they do need daily walks to avoid obesity). They are house dogs and prefer a relaxed lifestyle. After about 15 minutes of play, they are ready for their nap.
During the cooler part of the day you can take the bulldog for a 1.5 to 3km walk, or a short walk up and down the street will suffice.
When they're warm, they breathe heavily and don't dissipate heat well. They are particularly prone to heat stroke. Even half an hour at 30 degrees Celsius can kill the dog. Make sure he's in an air-conditioned environment and has plenty of fresh water.
Their massive heads pull them straight down. If you have a pool, spa, or pond, protect your Bulldog from falling into it.