Originally Posted by
Buffalobiian
You're right about HIIT.
I'll illustrate my point with some examples:
Background: jogging and running lands with either healstrike, midfoot or toe strike. It depends on the runner, if they wear shoes and the speed with which they run. Sprinting uses a toe (forefoot) strike due to the speed and the amount of lean you have when you run.
Your muscles also work on aerobic/anaerobic systems. The anaerobic one can be used for perhaps up to a 30 second burst of intense work. The fuel for that requires something like 5 minutes to rebuild in the body after you deplete it.
You require your anaerobic fuel if you wish to sprint at full speed.
Scenarios:
Sprint training with 5 minute breaks (like they do for track training):
I give my body enough time between sprints to rebuild my anaerobic capacity. I can utilise that system when I do my sprint, which will be as fast as my body can go. I will still accumulate muscle microtrauma, but I should not be hindered by a lack of anaerobic fuel. In this state, I can run in excess of 20km/hr at least for part of the track. This speed requires me to use a forefoot strike. It may be worth my while to use the sprinting form in order to increase my speed.
Someone training for track sprints would do this, but it doesn't mean they don't or can't choose to train with some aerobic capacity built in like below.
HIIT with 1 minute breaks
I will not have enough time to build my anaerobic capacity back up. During my run, I will be more tired and rely more on my aerobic capcity. Without the anaerobic fuel aid, I will probably only be able to run at 14km/hr. At that speed, I may comfortably run with a mid/heal stroke, especially when my speed drops lower by the 10th HIIT burst.
This is more in line with regular HIIT runs.
The above is HIIT, but by the latter stages you should be so tired that you're not even sprinting, but barely able to run hard. Even though you're running hard, you're not running all that fast. I was tossing up about which form would be ideal (both for performance and injury reduction) in this case.