(CNN) -- In the 1980s, Jane Fonda was the face of fitness for millions of Americans.
"The Jane Fonda Workout" became the highest-selling home video ever, with more than a million copies purchased. Since then, Fonda has produced and starred in over 20 home exercise tapes and DVDs.
After a 15-year hiatus, the Oscar award-winning actress returned to the fitness field with the goal of helping baby boomers feel better and stay active. Her latest DVD, "Prime Time: AM/PM Yoga for Beginners," releases Tuesday.
Fonda turns 75 later this month. We spoke with her Monday about aging, eating and living life abundantly.
Q: When you released your first workout tape in 1982, did you have a sense of how big a phenomenon you were on to?
I did not have a clue. I had no idea. It was pure luck. I didn't realize the role timing would play in the whole thing. There was no video industry. I didn't know anyone who owned a video, because no one could afford the hardware to play a video. And there was no video that beckoned people to do it over and over and over again until that tape came out. That's what caused the video industry to explode ... it was all very synergistic ... it had no strategic thought on my part.
Q: How do you stay motivated?
What motivates me is how good I feel afterwards. (Laughs) I don't wake up saying "Oh goody, I am going to work out." But I do it because of how it makes me feel when it's over. I feel so good. If I've felt depressed or down at all, it picks me up and makes me feel great.
Q: Do you feel you have to do as much as you did 10 years ago?
Absolutely not, no. I can't do what I used to do. My body just wouldn't tolerate what I used to do. (Fonda has had hip and knee replacement surgeries.) The mistake that so many people make is that if they can't do what they once did, then they don't do anything. Big mistake. It's important just to do something. If you can't run, walk. ... If you can't lift heavy weights, so lift light weights. But just keep yourself physically active. It makes all the difference not just for your body, but for your brain as well.
Q: What do you eat?
I eat fish, chicken and eggs. I eat red meat maybe twice a week. But when you are older, it is very important what you eat because your cells regenerate more slowly and also you put on weight more easily because you have less muscle than you used to, so every single calorie you put in your body has to count for something. I eat by color. I try to eat something dark green, dark purple, red, orange, yellow, white, because they all have different vitamins and minerals in them.
Q: What foods do you avoid at all costs?
Well, I am not a purist. I am not perfect. Now that the Christmas holiday is coming, I will take a bite of a pecan pie, but I won't eat a whole pecan pie. I will take a few bites of the dressing, but I will eat a lot of the turkey. Turkey meat is so good. I will eat it with cranberry sauce and gravy. But I try to eat less of the very fattening food and more of the really healthy food.
Q: What do you think is the secret to a well-lived life?
I think it's more important to be "interested" than to try to be "interesting." I've always remained interested and curious and I've always been a student as well as a teacher, so I think that's key.
Also being intentional ... living an intentional life ... thinking about who you are, how you affect other people, how you are perceived in the world and how you can change that to be more positive -- instead of sort of just drifting along like a leaf in the river, being really intentional about how you live.
When you do yoga, you can do the poses thinking about the grocery shopping or what you are going to do tomorrow, or you can be intentional ... in the moment, being present in what you are doing. That's how to get the most out of life and learning. That has been very important to me.