I would guess that this is very different for people. I personally don't see much of a difference myself. I'm 23lbs lighter from the first of the year (332lbs now). Not long after I started riding I saw more definition in my legs and could feel them toning under the fat layer with my hands. I don't feel any smaller, my waist is still the same size. Others around me say they see a big difference, mainly in my gut. I feel a lot better. I feel a lot stronger. Due to rain I only have about 375-400 miles in this year. Also you have t0o take into account some miles are harder then others. I ride a lot of flat lands for now but if I was on the hills my miles would be less but my workout would still be killer.