Forget longevity buzzwords like Zone 2 and VO2 max, a top personal trainer says. Focus on this simple metric.

Harley Pasternak, a celebrity trainer, has worked with clients including Rihanna.

Emma McIntyre/Getty Images for Alo Yoga Tracking metrics like VO2 max and Zone 2 cardio is going mainstream via the longevity crowd.

Harley Pasternak, a top trainer, said most of us don't need to track them to improve our health.

Tracking your daily step count can be a good way to make sure you're moving enough.

What do the terms Zone 2 and VO2 max have in common? According to the celebrity personal trainer Harley Pasternak , they are irrelevant to the majority of people, the health-conscious among us included.

If your goal is to be healthy physically and mentally, you are far better off focusing on a simple metric, such as daily step count, than a set of hyper-specific terms peddled by health influencers, Pasternak told Business Insider.

"We've overcomplicated our approach to health and physical activity," Pastnerak, who has worked with the likes of Rihanna and has a Master's degree in exercise science from the University of Toronto, said.

"I want to wake up pain-free.

I want to be physically healthy.

I want to live a long time.

I want to be able to play with my kids.

I don't know why my VO2 max is relevant for that." Zone 2 refers to exercise done at around 60 to 70% of your maximum heart rate, and VO2 max is a measure of how much oxygen the body can use during intense exercise.

These metrics indicate a person's endurance, and evidence suggests that improving them could help you live longer .

With the rise of longevity and health optimization culture , buzzy terms like these have entered the mainstream.