HIIT question

  • I've recently started my own version of C25K. My treadmill cycles through speed, distance, time and calories to it is hard to watch for the intervals. Plus, since I am usually either engrossed in the MP3 or something on tv I don't usually watch the second hand on the clock either. I'll start my warm up around 3mph and then do the intervals at 4.5 and walking 3.3 or so. I just run until I can't run anymore, typically about 60-90 seconds. I can answer a question if one of the kids asks me something but usually no more than a few words.

    I bought a heart rate monitor last week. I bought the Omron HR 100C.

    I used it for the first time yesterday. I am 32 years old so that puts my max heart rate at 188. When I was running at 4.5mph I was at about 175 which is 93%. Walking at 3.3mph was around 155 which is about 82%. If I drop down to 4mph I can last about 2.5 minutes but not sure of my heart rate is as I was doing that before I bought my HRM.

    Here is where I am clueless. This seems high to me because when I was a member of Curves they stressed the 60-70% zone for maximum weight loss.

    Anyone have any idea of what I should be aiming for?
  • If you're training for intervals, you can really push it. You want to go as hard and fast as possible during the fast interval--getting your heart up above 85% or so if you can, then slow it down until your HR lowers, then jack it up again. I believe Jillian Michaels says that even Steady-State cardio should be done at 80% or above for maximum fat loss potential. Apparently the "fat burning zone" is an outdated way of thinking. Hard and fast is the way to do it You want to burn as much DURING the session as you can (and hard and fast burns more calories than a lower heart rate), and create enough metabolic disturbance (this is where intervals are great!) to create "afterburn"--in other words, so you'll burn calories even after you stop exercising.

    I'd say you're doing fine. I frequently hit peaks of about 90% of my MHR when I'm doing intervals or doing an intense cardio workout (like cardio kickboxing class at my gym).
  • One more question. I've been doing 30 minutes 3 days a week. Will it hurt to do it 5 days a week or should the other days be slightly slower? I've been searching the archives and haven't found that answer yet.
  • I think it depends on what else you're doing. Most full-body lifting programs I've read and done suggest 3 days a week of full-body lifting sessions with 3 HIIT sessions. I think the issue with 5 times a week of HIIT is that you can burn out--HIIT is HARD and it's taxing to create that metabolic disturbance I mentioned before. I think 3 days of HIIT is good, and if you want to do something the other two days a week, maybe do some less intense cardio. Take a walk, do some yoga, or something to that effect.

    That's my take on it, anyway. There are other more experienced people (who are at their goals!) who could probably chime in here. Depalma, Meg and a few others are very knowledgeable.
  • I wish I had the equipment or money to lift right now. I really think before I get started lifting I better see about a trainer and that is totally out of the budget right now. Hopefully someday soon though.

    I followed a bunch of links in the archives and found a lot of helpful information about heart rates. After all the reading tonight I am confident that my body does know what it is doing and will tell me when I have done to much.

    I was needlessly concerned before I bought the HRM about how hard I was working out. It never seemed like it was hard enough but the numbers in front of me assured me I was. Then I started second guessing myself and started thinking maybe I was overdoing things. I know when I get finished I look like I've been run over by a bus but I feel great.

    Thanks for your help.