Build ‘exercise’ into the rest of your activities, in easy ways, that you can continue … for the rest of your life.
Like park your car at the farthest part of the parking lot (where there are lots of spaces, and nobody is likely to park alongside and ding your car). Use stairs instead of elevators if it’s only a couple of floors. Get off the bus at the stop before your workplace, and walk that last block. Replace your expensive gas-powered lawnmower with a push reel one. Rake leaves by hand instead of using a leaf blower. Etc.
Find small changes like this that you can make in your routine life, that involve more exercise and will make you feel better each time you do them.
I have been using it and it works amazing well - my gym does 60 min HIIT workouts every Sunday. It also really compliments the MetCon workouts from every other day of the week.