Twelve to seventeen minutes is plenty on the treadmill--if it's done fast. That's all you need for cardiovascular benefit. You don't need to spend that extra time unless you are over weight and you need to burn off extra calories. Do it vigorously, like somebody is chasing you. You've got to do it hard. Otherwise, if you just take it easy and do it longer, you are spending all that time when you don't need it. Use that extra time with your weights instead.
Jack LaLanneThe secret to a long and healthy marriage is to work at it and don't try and change each other.
Jack LaLanneWhatever you can handle, it's up to you. Pick something where you are going to do it to failure--in other words, where you can hardly do it. That's the key. So many people will just take five pound weights and do something 10 times. What are they getting out of it? Nothing! Say you are going to build up your bank account. If you put in a penny a day, it's going take a long while. It's the same with exercise--the more you put into it the more you take out.
Jack LaLanneMy goal has always been to help people help themselves. Your body is your most priceless possession; you've go to take care of it!
Jack LaLanne