(Image credit: Ramona Braganza/Lucy Miller/Tom's Guide)

At 64, celebrity trainer Ramona Braganza is seriously inspiring and strong. Scroll through her Instagram, and you’ll find her lifting weights, practicing pull-ups, hiking through Beverly Hills and generally doing all the things I hope I’m still doing 20 years from now.

Braganza has spent decades training some of Hollywood’s biggest names, including Jessica Alba, Halle Berry and Zac Efron, but these days, her own training has a slightly different focus: longevity.

“Never underestimate the power of a strong body to help build a strong life,” says Braganza, who once graced the cover of Muscle & Fitness magazine and regularly shares her own workouts alongside training her 91-year-old mum and clients.

Which brings me to Braganza's three simple tests of strength, balance and functional fitness. No fancy equipment, lab testing, or expensive longevity assessment is involved.…