"The most important thing to do as you age is to stay physically active. Lots of people just throw in the towel if they can't do what they used to do, and that's terrible," digitalspy.co.uk quoted Fonda as saying.
The 75-year-old insists every person should remain active as they get older, modifying their activities to suit their abilities.
"If you can't run then walk, if you can't downhill ski then cross-country ski, if you can't lift ten pounds, then lift five one. Keep moving. Of all the things that can allow you to age successfully, staying physically active is number one.
"I stay motivated because it makes me feel good. I know how I'm going to feel afterwards, and that's what gets me to do it even if I don't feel like it," she added.