I am 5 ft 1 (155cm) and weigh 165 pounds (75kg) and most of the weight is around my stomach area. The only sport i enjoy AND can do on a daily basis is bike riding, i was just wondering is this a good source of exercise? Will it burn the fat on my stomach (because my abs dont move much when i'm biking? and how far will i have to bike daily for it to actually work eg. 20kms or whatever??