– Toni, Nevada
Given your history of serious back problems, you are wise to ask this question before starting an exercise program. It is extremely important for you to find an exercise plan that will help you achieve your goal weight without putting you at risk for further injury.
I believe you should discuss this with your physician. He or she can refer you to a physical therapist or exercise physiologist who can help you create a personalized plan. That being said, I would like to make a few general suggestions to you.
First, it's important to stretch before you attempt any kind of exercise. Stretching exercises will help increase the mobility and flexibility of the soft tissues that surround your spine. Focus especially on the hamstrings, in the backs of your thighs, and the gluteal muscles of your buttocks. It's also important to increase the strength of your core muscles, which stabilize your back and abdomen. There are a number of different approaches for this that a therapist can teach you.
Finally, remember that you should seek low-impact activities, such as walking, biking, and swimming. Try to avoid exercises that put undue strain on your back, like sit-ups, or those that require you to twist or use weights. These approaches will help you reach your desired goal of losing weight without the risk of reinjuring your back.