Just from a scientific background: there is no such thing as a purely aerobic or anaerobic activity. Both systems contribute from their metabolic pathways relative to the activity being performed whether it is of high intensity/low intensity or short duration/long duration. You'd also be surprised how much aerobic metabolism contributes to anaerobic activites (like all out sprinting).
As for HIIT, The best means of performing these exercises is with the use of a HR monitor. That way, as you become fitter and adapt cardiovascularly you will still be exercising in at an appropriate speed. Normally, 65% of maxHR is considered the minimum working level to elicit the responses we're looking for in HIIT and would be considered moderate intensity. High intensity is 85% of maxHR. I'd say aim for around 85% of maxHR while performing HIIT intervals. Ideally you want your HR to return to at least 60% before tackling the next work interval; normally when it takes longer than two minutes for the HR to return to below 60% it's a sign that enough sets have been done.
Those are just general outlines used in exercise physiology. It's particularly important that people make sure they are in good cardiovascular health before using exercises like these.
Just adding in:
Aerobic metabolism is fueled by both fat and glycogen whereas anaerobic metabolism relies only on glycogen/glucose for energy substrate. Just because glycogen is the energy substrate does not mean that it is anaerobic.
Last edited by Jenn Equestrian : 03-26-2008 at 08:45 PM.
Reason: Editing to add about glycogen
|