JJ Virgin recommends doing HIIT twice a week if you're over 40, aiming for 4-8 minutes of hard effort per session. Use short bursts of maximal intensity followed by recovery periods roughly twice as long, like 30-60 seconds hard and double-time easy, or Tabata's 10 seconds on/20 seconds off.
high-intensity interval training. You're going to want to be doing some cardio every week, but when you're doing your cardio training, see if 2 times a week you can do that cardio training as high-intensity interval training. And what that means is, let's say that you started out on a bike. You would pedal, and then you would pedal super hard for 30 to 60 seconds, then you recover for twice as long by just pedaling, and then you hit it hard again. And you do this to accumulate 4 to 8 total minutes of HIIT. You can do this in a variety of different phases. You can do that Tabata training of 10 seconds on, 20 seconds off. You can do 1 minute hard, 1 minute easy, but it's just really hard and recover and hard and recover is the idea of high-intensity interval training.
