Crossfit is a relatively new movement in fitness training. It was created in 2000 as a physical exercise training philosophy, and also as a competitive sport. You may well have seen people performing Crossfit classes or routines in your own gym.
Crossfit, as the name implies, mixes a wide variety of techniques from different disciplines to create its overall effect. Some of the areas of work are high-intensity interval training, weightlifting, powerlifting, gymnastics, plyometrics among others. While it is not without its critics, looking at this extremely fit woman in her 60's - and she only took it up in her 60's - it would appear to be a quite effective way of achieving and maintaining a high level of strength and fitness if you put the work in and if it's done correctly.
What is inspiring is her desire to be a role model and example for older adults of the level of conditioning that is achievable, and to show how that conditioning not only helps with your sports but also has life benefits as well. She says in the interview that she feels she has achieved the strength that she had in her twenties and thirties, which is truly admirable. As someone who has been involved in sports medicine and exercise physiology she is an advocate of exercise even - or especially - for those with orthopaedic conditions, endurance issues etc and is of the opinion that these are not a barrier to improved fitness.
So, as they say, don't try this at home, but if you are impressed with what this woman has done for herself, maybe find a qualified Crossfit instructor and give it a go.