Others have posted good information.
Diet is much more important than exercise when losing weight.
You can burn body fat equally with short intense exercise or long less intense exercise, provided you use the same amount of energy.
Short intense exercise will result in larger muscle mass. You can see this if you compare weight lifters with marathon runners. Also if you compare cyclists in sprint events, with cyclists in endurance events.
Cyclists in sprint events are known as weight-lifters who sometimes ride bikes. Sprint specialists in road racing aren't all that different looking, IOW no matter how you ride, it won't make you huge. I do some strength training to try to maintain muscle mass for general living and other sports.