High intensity cardiovascular exercise are the best kind for fat loss. This will burn more calories more effectively during exercise and, by speeding up your metabolism, will help to keep burning the calories after exercise has finished.
The most important piece of information is the number of calories burned per unit of time. The more calories you expend the greater the amount of fat that will be broken down. For example, walking for 60 minutes will burn approximately 270kcal of which 160kcal (60% calories) comes from fat. Running for 60 minutes will burn 680kcal of which 270kcal (40% calories) comes from fat. Therefore, the running will lead to greater fat loss over the same amount of time.