If your walking is tiring keep doing it and you'll ba amazed how good it makes you feel..but also add something else to help more... I found that I could walk with a small weight in each hand and either squeeze them or even swing your arms slightly...this will help your arm stregth and it's not tough..just find light weight... maybe 3 pounds...

You are on the right track! At the beginning of summer I found out what cruddy shape I was in by trying to take a walk and about passing out! I was pushing my 2 kids in a jogger stroller and thought I'd never make it out again. BUT My husband and I started taking the kids out walking every evening after dinner. then 3 weeks ago I started atkins and was more determined than ever to get in shape... I bought 2 step aerobic videos and a couple AB workout tapes too. Up until last night I was only able to do a good 15-20 minutes of the step before having to stop and I would relax then do my ABs. Last night (after 3 weeks of consistently trying 5-6 nights a week) I made the whole 50 minutes with energy to spare plus abs! I am very proud of myself! I have only lost 17 pounds so far but 5-6 inches from my waist and thats a pretty big deal! Now I dont look pregnant anymore!

good luck...you can do it!