“He’s very hot, and the workouts were really great and hot, and so I thought that would be a good background,” she says.

Own your age.

Speaking of Luda—he, like Supernatural creator Chris Milk, told Fonda he’d grown up watching his mom do her workouts. For some people this could be deflating, but Fonda took it as a point of pride.

“He said it was surreal for him to be actually doing a workout alongside me,” Fonda says. “That didn’t make me feel old. It made me feel really good. This guy that I’m boxing with was a little infant when he was watching me. But I’m still with you, kiddo.”

In other words, getting older isn’t something to be ashamed of, even in the fitness space, which, let’s be honest, tends to skew younger. Instead, Fonda now considers it motivation to keep moving.

“You want to remain independent, get in and out of cars without help, pick up your grandkids and all of that,” she says. “Staying strong is really important.”

Continue the workouts that make you feel good—but always modify as needed.

Fonda says she does essentially the same workouts she used to do, just at a more relaxed pace. This holds true both for her cardio and for strength training, both of which remain vital parts of her routine.

“It’s kind of like sex—slow is better,” she says. In fact, if she could go back and rerecord her earlier videos, she’d want to keep that nugget of advice in mind: Fonda says she probably would slow the movements down, so the broader population could follow along better and get the full benefits of each move.

While Fonda used to be a runner, she now walks or hikes instead for her cardio, preferably outdoors. On the days when her schedule allows, she meets with an “extremely nice and good” trainer for strength training. Each session lasts up to a full hour, and alternates among upper-body, lower-body, and combo days. “We make sure I work every muscle group,” Fonda says.

Doing all that on the regular left her fit enough that she didn’t have to do any kind of ramp up to lead the Supernatural classes. But she did choose a lower-intensity level of the class to coach, especially since she recently had shoulder replacement surgery. (Users are also encouraged to modify the experience in other ways that feel better for their bodies, including by removing lower-body movements or taking out turns.) Contrast that to her original workout, where Fonda can be seen doing moves like splits and seated stretches leaning all the way over her toes, while mentioning modifications for the less flexible in the voiceover.

Understand how physical strength contributes to personal (and collective!) power.

From the time she released her first videos, Fonda knew she was helping women build confidence that translated to other areas of their lives. She recalls a letter she once received from a woman who’d done her tapes.