Exercise - The Bottom Line:
Exercise is an important component of a healthy lifestyle. Even a little exercise is better than no exercise at all. Both aerobics and strengthening should be part of a comprehensive exercise plan.
But too much exercise all at once can be bad. Exercise should be done carefully, regularly, and for most of us, in moderation.
If you are just starting an exercise program, or if you have questions about your program, you should consult a healthcare professional.