Your exercise regime should be based on regular moderate exercises like walking, biking, skating or swimming. During these exercises you can set a brisk pace, but you should be able to carry out a normal conversation without panting or feeling faint. This way you ensure that you stay in the optimal fat burning zone. Just walking 30 minutes every day is easy to keep up, clears your head and recharges your energy levels.
On top of that, it’s healthy to lift some weights (remember your own body is a weight too) a few times a week and do one high intensity exercise (like a 10-20 second sprint) every day. This will help you build muscle mass and keep your cardiovascular responses healthy.
When you exercise, don’t worry about reps or speeds or distances. Make regular exercise a habit. It doesn’t matter if you can do 3 push-ups or 300, as long as you put in time and real effort. Exercise within your ability. If you push yourself just a little bit every time, you will find yourself improving.