The 80-year-old Ironman triathlon finisher who isn't slowing down: 'This is my passion'

Natalie Grabow became the oldest woman ever to finish the grueling, 140.6-mile Ironman World Championship triathlon last month. She's already planning more races.

At 60, she's reversed her biological age to 21 – these 5 fitness habits made it happen

Two decades after being told she had 'five good years left', Leslie Kenny has completely transformed her health ...

79-year-old Canadian grandmother shares the secrets behind her stunning fitness transformation

A 79-year-old grandmother, Joan MacDonald, transformed her health at 70. She embraced strength training and balanced meals.

79-year-old Canadian grandmother who started gym at 70 shares diet and fitness secrets: 'Eat protein with every meal'

Joan MacDonald, 79, is a fitness inspiration. The septuagenarian shares her journey to a healthier lifestyle, proving it's never too late to start.

80-year-old becomes oldest women to complete an Ironman triathlon

Natalie Grabow is the oldest woman to complete an Ironman triathlon. NBC News' Tom Llamas sits down with Grabow to talk about ...