Lots of good suggestions. Not so sure about the hernia---have had one and it hurt more than just exercising...mine hurt when going to bathroom and sneezing and laughing.
As a fitness instructor and trainer for 9 years, here's my suggestion:
Hydrate before working out---water, not juice or coffee....drink water during exercise---always!
no food before
Mix up your work-out. Sounds like you are doing the same thing for an hour according to what you wrote. Why not walk/jog for 20 min., then do some (15 - 20 min) abs or some weights, then 20 min. on elliptical and always stretch at end.
Don't run every day....but do stretch every day.
Use a heart rate monitor or google the formula for "target heart rate"
You must work in the target zone for 20 minutes for fat burning. If you go over the top end of your zone, not only are NOT burning fat, but you are also increasing the likelihood of over stressing your heart and injury to your body.
If you are a new exerciser....gradually work into longer work-outs. If you go to aerobics class, be sure to modify your intensity once you feel very winded.
If you want to do half the class, tell the instructor beforehand that you are "OK" but you need to leave a bit early. Then next time you go back, add 5 more minutes.
If you cannot catch your breath, you are working too hard. If you are breathing incorrectly, your stomach will hurt, too.
Don't do what the veterans or the instructor is doing all the time.
I have taught spin classes. Many times, people brand new to spinning are encouraged to be in class for 20 minutes to start. Then they go on to something else...and drink water. The next time, come for 25...see the progression?
Good luck to you and congrats on wanting a healthy life for YOU!