This is a question people ask often. There is not easy answer, but generally speaking, as with all things, moderation is the key. No exercise is definitely not good, but neither is too much exercise.
If you have not exercised in a long time, a good place to start is by walking a couple times a week. Your walks can be 15-20 minutes long and you will still benefit quite a bit.
Another easy exercise you can do rather quickly is stretching in the morning. Make sure you read about how to do stretches on health websites so you are doing them correctly.
The ideal amount of exercise in my opinion is 30 – 90 minutes a day. The following will all count as exercise:
- Riding a bike
- Playing a sport