You know things work differently for everyone.
In what we are all doing, some people do this diet, or that diet, or eliminate carbs, or in my case eat carbs, and the way that people's bodies respond to diet and excercise is all different.
High reps/low reps more weight / less weight /etc etc
We all know that it is all mathmatics in the end, burn more calories than you eat by 500 cal per day, and lose a pound per week.
That being said, I recently read ( doesnt make it true) that if you do a half hour or so cardio on an empty stomach, and you will burn fat, because your body wont really have fuels in it because your last meal was the previous evening.
I climb the stairs in my building( 7 floors)on Mon, Weds, and Fri 15 times, takes about 35 minutes.
Today, I didnt eat breakfast before playing my favorite sport, I waited about and hour and a half, then I started to eat some sandwiches that I had brought with me.
I do this because the article that I read suggested it, and even if it isnt true, I am still better conditioned from climbing my stairs 3 times per week, especially when previously, I wasn't doing any cardio, which reálly means that I am about 200 percent a head of the fat losing game no matter how you look at it.
I would say ride on the empty stomach especially since it is for that magic number of more than 25 minutes.