In college I used exercise bikes frequently and it really helped my stamina when I ran long distances. Im just wondering if the exercise bike helps shed some stomach fat.
I would choose swimming if an indoor pool is available in your area. I personally ride an exercise bike at home for convenience and time conservation. I think any helpful advice to you should be based on the climate where you live. And since you had exercise bike success in your past, I would be biased to returning to the bike. All factors being equal.