The FastDay Forum

The HIIT gives improvements in insulin resistance, blood glucose levels and VO2max, but the latter only if you are a responder. It does improve heart health and had been tested for use in patients with heart disease. It does not give fat burning effects because at high intensity you are burning glycogen not fat.

Isn't there some sort of 6-12 hour elevated metabolism/fat-burning thing that happens after an effective HIIT workout? Not during the workout itself, but the 'after burn' effect.

[carorees]

It probably depends on how long the workout is! I wouldn't put too much faith in a 20 secs x 3 workout as having much carry-over! But if it does it's a bonus!

Isn't there some sort of 6-12 hour elevated metabolism/fat-burning thing that happens after an effective HIIT workout? Not during the workout itself, but the 'after burn' effect.

From what I remember the weekly weight / fat loss from HIIT was at least as good as from extended cardio.

EPOC - Excess post-exercise oxygen consumption - would be part of that I guess.

http://jap.physiology.org/content/102/4/1439.long said "In summary, seven sessions of HIIT over 2 wk induced marked increases in whole body and skeletal muscle capacity for fatty acid oxidation during exercise in moderately active women."

I've been using the eight week programme here for the past four weeks.

http://www.bodybuilding.com/fun/ultimat ... ogram.html

It is broken down into two week period and so far i have done weeks, one and two for three weeks and then moved onto week four.

I use it in conjunction with a hiit timer app called gymboss.

[carorees]

Isn't there some sort of 6-12 hour elevated metabolism/fat-burning thing that happens after an effective HIIT workout? Not during the workout itself, but the 'after burn' effect.

From what I remember the weekly weight / fat loss from HIIT was at least as good as from extended cardio.

EPOC - Excess post-exercise oxygen consumption - would be part of that I guess.

http://jap.physiology.org/content/102/4/1439.long said "In summary, seven sessions of HIIT over 2 wk induced marked increases in whole body and skeletal muscle capacity for fatty acid oxidation during exercise in moderately active women."

This HIIT schedule was much longer than the minimum 3 x 20 secs advocated by DrM.

Each session consisted of ten 4-min bouts at ∼90% V̇o2 peak with 2 min of rest between intervals

so whether the minimal HIIT has much carry over is still unknown.

Hi Caroline,

"This HIIT schedule was much longer than the minimum 3 x 20 secs advocated by DrM."

http://jap.physiology.org/content/102/4/1439.long

Yep, this paper seems to be using "4-min bouts at ∼90% V̇O2"

Is this really "HIIT" as popularly interpreted? ie all-out, total efforts, sustainable for a short period (measured in seconds) or is this moderate/hard aerobic exercise (I note that the title of the paper is high intensity aerobic exercise)? I thought that HIIT was short anaerobic sessions ie. HR at at nearly Max (and which is only sustainable for short periods as you are way above lactate threshold working anaerobically).

Perhaps the issue is that 90% of VO2 max is possibly not the same as 90% of max HR?

"a 60-min cycling trial at ∼60% V̇O2 peak before and after training."

So plus 2 hours of lower intensity aerobic training as well (which off course could account for the improvement anyhow). Maybe they needed a control group that did this but without the HIAIT (hey a new acronym!).

Try this one for intensity http://jp.physoc.org/content/575/3/901.full

Each session consisted of either four to six repeats of 30 s ‘all out’ cycling at ∼250% VO2max with 4 min recovery (SIT) or 90–120 min continuous cycling at ∼65% VO2max (ET). Training time commitment over 2 weeks was ∼2.5 h for SIT and ∼10.5 h for ET, and total training volume was ∼90% lower for SIT versus ET (∼630 versus ∼6500 kJ)

bigger fat loss (by skin fold measurement) from half the energy expenditure ? http://www.colorado.edu/intphys/Class/I ... emblay.pdf

http://www.shapesense.com/fitness-exerc ... lator.aspx

Found that converter... Not sure what 250% vo2 means?

250% VO2 max is presumably 2.5 times the power output that you achieve at VO2max by adding anaerobic effort and running up an oxygen deficiency for a short period.

Carorees' example above reminded me of these two interval workouts:

http://www.runnersworld.com/race-training/yasso-800s

http://www.runnersworld.com/running-tip ... ur-max-vo2

Still higher intensity, but not all-out sprinting, for 2-4 minutes at a time with 2-4 minutes jog or walk in between intervals, repeat 6-10 times.

You HIITers might be interested in this: http://well.blogs.nytimes.com/2013/05/0 ... ef=general

Thanks MaryAnn and Phil, that looks like a good one. After each 30-second exercise you rest for 10 seconds (for some reason this is not stated in the article). That makes 470 seconds in all which is near enough 8 minutes not 7. How much time do they think we've got?

Lol yeah and you end on a side plank where you'll need to do 30 more seconds on the other side or you'll be unbalanced in your post-HIIT puking!