Background:I have suffered a severe shoulder injury, and have therefore been completely bedridden the last four months. This has resulted in some extra kilos around my belly, enough to make me look like a stuffed sausage in some of my clothes. Under normal circumstances I would consider myself an athlete (I did an Ironman, a marathon and a few long bike races last year). I've never had problems getting in good shape fast, but this time everything goes much slower.
Current status: Due to the shoulder injury, there are a few exercises I can't do (for instance running, swimming and pushups).
Until now, (after the injury), I've been riding my bicycle trainer for 30-60 minutes (approx. 30 km/h, 180 rpm, 80% of max HR), followed by a three sets of 30 crunches, 60 sec plank, and 10 reps with the superman. In the end I do my mandatory shoulder exercises (resistance band for the rotator cuff, something like this).
The time I have available is 60 minutes three times and 90 minutes once a week.
Question: Is there something I can change, in order to loose some belly weight faster, not including dieting (I have found a lot of information about this already). I'm pretty much restricted to the exercises I mentioned above, so it's mainly a question of intensity, order, number of repetitions etc.
Would it be better to do intervals on the bike? Lower intensity? Or maybe mix it up: 10 minutes with high intensity on the trainer, then one set of core exercises, 10 minutes on the trainer etc.?
Note 1: I know it's not possible to reduce the fat percentage on one body part alone. However, my belly is the only place I have (visible) fat. My arms are skinny and my legs are well-trained.
Note 2: I have no problems with motivation.
Note 3: I do not have a gym membership.
Note 4: My BMI is exactly 25, so I'm not "overweight". The problem is that all the kilos are on my belly.