Walking is good but you need to start changing the walking routine up a bit as you lose weight and get fitter otherwise your body just adapts to the same speed of walking. Some suggestions for you
- Maybe buy a pedometer and start each week to improve the number of steps you do within your set time period i.e. means you are walking faster/further in the same amount of time
- Look for different routes with mixed terrains like some hills or stairs to vary the routine
- Google Couch to 5km program - its a 9 week program that will get you running 5km in 30 mins and is designed to be used 3 times per week. It starts off in week 1 like this a brisk five-minute warmup walk. Then alternate 60 seconds of jogging and 90 seconds of walking for a total of 20 minutes. Then a 5 minute brisk walk again to cool down. You start extending your jogging vs walking each week. Its is a great program. You can even download free podcasts to load onto an mp3 player that tells you when to jog and when to walk.
- Definitely get the elliptical out, again this will help vary your routine so you dont get bored and provides an excellent workout that is low impact on your joints. I still find the eliptical for me is one of my best calorie burning exercises.
- Buying some light - medium weighted dumbbells would be great as well for some strength training on the days you dont walk/jog or use the elliptical. You can google heaps of exercises that show you how to perform the exercise eg squatting, dead lifts, lunges, tricep curls just by using these weights.
Hope this helps. These are all things you can do within 30-40 mins per day so definitely workable into your lifestyle. Best of luck!