Strange Loops wrote:
Hate to sidetrack from new advice, but wanted to say thanks for the previous advice. I've been doing HIIT instead of most jogging now, and it feels great (though my heart almost exploded a few times and I lost vision...oops). I might be doing it wrong though. I do 30 seconds sprinting, then walk (or sit if my heart is thumping so hard I can't walk) for 30-60 seconds, then sprint 30 seconds, and repeat. I do 5 or so iterations, really giving each sprint my all. Is that too few? At that point my heart needs a break and I can't keep iterating. Am I sprinting too hard? Should I just go for higher intensity jogging, but not a full-on sprint? Or should I just take a longer rest after 5 iterations, then go again?
5 iterations is fine. And you're not sprinting too hard. When doing HIIT, it is by definition impossible to sprint too hard. If you can sprint any harder, you're not sprinting hard enough. If you want to do more iterations, that's fine too. If the HIIT portion of your workout lasts longer than 20 minutes, you're probably not going hard enough.
Glad it's working out for you. 
