Susan:
since you like walking, let's begin with this activity and make it more challenging for you, to produce better results. What kind of distances do you cover each day, or each time you walk? How many times per week are you walking?
You want to add some intervals to each walk: at least 1 minute intervals where you really crank up the pace, or say "from here to that lampost," or for the duration of a song with a faster beat, powerwalk that section so you are huffing and puffing. If you walk really fast, it is harder than breaking into a run and is harder on the body, so it will help burn more calories and improve cardiovascular fitness. People underestimate what walking can do for the body all the time. The regular 12 mile powerwalks I do each week keep in good enough shape to hit the treadmill when I want and do 5-7 mile runs without prior running training.
So, make sure you have 3 or 4 walking days per week, with faster blasts inserted in each one. Then, how about some weight training to build some more muscle, add an additional calorie burn and crank up your metabolism? You could purchase individual total body weight training DVDs from Cathe and this would be an excellent start. How about High Reps or Muscle Endurance?
I think it would also be a good idea for you to invest in the Low Impact Series Cathe put out last year. The collection of workouts will offer you all you need to get in great shape, and there's only 1 step aerobics workout in it, which is also low impact, so you may or may not choose to use it, depending upon what it is about step that you do not like. You will need to invest in some gliding discs, and maybe some resistance bands and weights from 3 to 15 pounds to begin with. As you get stronger, you can buy additional weights and maybe a barbell?
The LIS will offer a range of workouts that will help with calorie burn, building strength and muscle, raising your metabolic rate and making you feel better, healthier and happier. These workouts are low impact throughout, using pace, height, depth, gliding discs, weights and high reps to get the job done. Some of the workouts will be tough at first, others are more immediately approachable. But, you are the boss, so you get to decide each day how much you can do and you can mix and match sections at will.
This is a good place to start. Keep up the walking, which you already know, and add some new workouts into the mix in a manageable but still challenging manner.
Hope this helps, and come back for further help, advice and inspiration and to let us all know you are getting on, yes?
Clare