Extended Cardio?

[Kachok]

Recently had a wrist injury and I gained 31lbs while on the Prednisone. As soon as I could take my wrist out of the splint I joined a gym desperate to loose this weight ASAP! I cannot fit into my clothes and it feels like it is suffocating me when I lay down. Given the fact that my wrist is still recovering I cannot do alot of work with free weights so I really need to rely on cardio more to work this off, but many experts I have been reading online say not to do cardio for more then an hour because your body starts to break down muscle which is counterproductive. Is there any way I can extend my cardio to 2-3 hours without negative side effects? One hour a day cardio even at 75-85% MHR is not making much of a dent in this stubborn fat. Anybody have any suggestions?
Other information.
36 years old, 5'6" 217lbs, cannot calorie restrict diet or do "fasting cardio" due to hypoglycemia.

 

[allcdnboy1]

That is partially correct. If you do a lot of cardio, you will exhaust your carb stores and start relying on protein. This happens at a slower rate, even if you only exercise for 10m. However, to maximize fat burning and decrease muscle loss, do high intensity interval training (HIIT), is your best bet. And, you only have to exercise for a fraction of what you are doing before to get the same benefit.

As far as your wrist goes, all that does is limit what you can do with one hand. No reason you can't train the other. And, if you are able to run with your wrist flopping around, you can probably still do really light weights (have you seen a rehab specialist?), which will speed up your recovery. It has also been proven that people who are in casts that work out their good arm, see less atrophy in the broken arm, and in some cases have an increase in muscle density during recovery. There are a ton of exercises that can be done with only 1 wrist. You can still do everything with your legs, so there is no reason to completely stop the weight training.