Fitness is the friend you want for life.

And you can achieve that with the right exercise.

Let’s work backwards, addressing fitness from 65 to 90 years old.

Yes, 90!

San Antonio’s Synergy Studio was made famous by 90-year-old Esther Vexler, a yoga teacher. Today, Adele Brewer owns the studio, and at 60, she is as agile and supple as a 20-year-old.

“Mobility, movement, and breath, is so important for the longevity of the body,” she says. Her 65+ clients flock to her low-impact Pilates, yoga, African Dance, and Nia classes. “I am stronger and more fit than when I began … 16 years ago. I can get up and down, off of the floor,” says Trish Simonite, a retired Trinity University professor, in her 70s.

82-year-old Penny Wiederhold sports a slim, strong figure. A skier, she does the studio’s Strength and Healing Through Movement class, to heal from hip replacement surgery. “And it is a place where people talk, who feel the same way about things as you. Yesterday somebody left to go skiing, and they all went out to lunch!”

78-year-old Judith Schroeder says after 23 years of dance and yoga, her doctor visits are extraordinarily dull. “My tests turn out well, my bone density is young, and I have energy and joy. And it is the joy that gets you here.”

All three women are devoted to Nia, a combination of martial arts, dance, and yoga, that is strong on muscle tone, but easy on the joints. They swear, they are aging, in reverse.

Can one become fit, after a lifetime of not exercising?

Trainer Caroline McMillian says, yes! She leads the TriPoint YMCA Silver Sneakers program.“You are apt to have less injury than if you started earlier. Me doing it for 37 years, versus someone just exercising for 20 …” means fewer years, in which to get injured, McMillan says.

Silver Sneakers focus on form and strength, and on building a rock-solid core for balance, which is critical as one gets older. “They are doing strength training, with weights. They are using a band and a ball for mobility.”

Women in their 30s to 50s may spend long hours in front of an office computer. “We don’t move like we need to, so we tend to get tight in the knees and hips,” says fitness trainer Macos Hernandez, a “Flexologist” with Stretch Lab Dominion. “We do one-on-one assistance stretching. We help you get into a greater range of motion than what you can do, yourself.”

Stretch Lab is out of California, where stretching has been elevated from a couple of minutes before a workout to being a fitness routine, in its own right.“You lay on the table, and we move your body for you. We hold you, then you engage and contract the muscle.”

How’s that for an exercise class?

Walking around the compact gym of Quarry Village Orange Theory Fitness is a DJ. Headset on, he barks encouraging words over hip-hop music, while clients sweat, jump, and pump it, bathed in orange light.

The franchise attracts the 30s and 40-year-olds, on-the-go types, who pop in and out for a quick work-out. This age group is into data. Fitness is quantified, systematized, evaluated, and calibrated.

Regional Fitness Director Spenser Thomas recommends rowing for them. “We incorporate running and jogging. We also have water rowers. If you have had a lot of injuries because you played sports or have orthopedic issues, it is super low-impact. It is the No. 2 calorie-burning exercise” (No.1 is cross country skiing), “and you work about 85% of the muscles in your body.”

Co-worker Ana Maria Ramirez says Orange Theory Fitness members demand convenience. “In your 30s and 40s, you get hectic lives, being married, children, multiple events going on.”

Apps now match the music to the work-out.“If it is a strength workout, it is this kind of music, a power work-out, it is that kind of music, an endurance workout, it is something slower,and longer,” says Thomas.

And: “Younger generations are attached to their phones,” says Synergy’s Adelle Brewer. “So, the brain is losing out. They have to really work it, to fire up those neurons.”

Exercise also trains our brains, strengthening neural pathways, aiding in brain plasticity.

Remember on “Seinfeld” where the gym was often portrayed as a pick-up joint? Fitness experts say that today, exercise class is a place to make friends. Women are seeking a sense of community, sharing not only fitness goals, but life goals, as well.

By Berit Mason