Share your HIIT workouts!

cwolfman13 wrote: »

20/40s on my indoor bike trainer...it's tough, and it's intervals, but I don't know that it's HIIT, even though that sounds really cool...HR usually up around 155 for the 20s. The 40s are at a typical ride pace so still working Total time is 20 minutes...there's a two minute actual recovery about half way through.

Definitely HIIT assuming you're hitting it with some gusto. If the 20s don't get REALLY painful by the end, maybe not hard enough to be HIIT.

If you're utilizing glycolysis or Kerb Cycle as the metabolic pathway to generate the primary source of energy during your work period, it not HIIT. Why 20-30 seconds, because energy directly available via the phosphagen system is limited to less than 10 seconds of maximal effort while re-phosphorylation of ADP provides enough for about 25 seconds total.

Studies by Gibala and others trying to find equivalency by replacing lower intensity work periods are looking at overall fitness adaptation. HIIT is designed to sharpen the upper band and the fact it also improve lower bounds does not mean the protocols and goals are the same.

L_Master wrote: »

Most HIIT isn't just 20 to 30 seconds. It's 20-30s with a very short rest, repeated many times. After even a few repeats, you are predominately using aerobic pathways; and have even gone past the point of relying primarily on anaerobic glycolysis.

30 seconds per interval. Work intensity for Tabata's 1E1 protocol is 20 seconds of work at 170% of VO2 Max and 90 rpm with 10 seconds of rest. Gibala's comparison is at 150% VO2 Max (with continued downed grade to 120% as effort to find false equivalency). Both called for an intensity above anaerobic capacity (non-aerobic glycolysis). NOTE: workout is terminated if intensity cannot be maintained. Peter Coe regimen throws a curve as the intensity is not defined (power measurement wasn't available and even now it's in beta) repeated fast 200 meter runs with only 30 seconds recovery between each fast run. As the grandfather of all, Peter Coe regimen is only that falls short in the specification but he was training Olympic champions.

L_Master wrote: »

CrP system, once depleted, takes at a minimum 2-3 minutes to regenerate. If you blast our of the gate with all out 20s of activity, CrP is already depleted. If you take a 10s rest...it's still depleted. Where do you go for energy? Anerobic glycolysis. You'll burn through that over the next 2-6 repeats, and at that point you'll be getting ATP almost exclusively from aerobic pathways.

Re-phosphorylation, ADP -> ATP? Tabata's and Gibala's test subjects did just fine. Are you referring to tau? W'bal recovery relates to non-aerobic glycolysis. Completely different energy system.

L_Master wrote: »

f you wanted the primary source of energy generation to be from CrP, then you need short, maximal efforts with moderate recoveries. Think 10-15s sprints with 2-5 minutes of recovery between each one.

Classic AC intervals (from standing or from slow roll?). Not HIIT.

kcjchang wrote: »

L_Master wrote: »

Most HIIT isn't just 20 to 30 seconds. It's 20-30s with a very short rest, repeated many times. After even a few repeats, you are predominately using aerobic pathways; and have even gone past the point of relying primarily on anaerobic glycolysis.

30 seconds per interval. Work intensity for Tabata's 1E1 protocol is 20 seconds of work at 170% of VO2 Max and 90 rpm with 10 seconds of rest. Gibala's comparison is at 150% VO2 Max (with continued downed grade to 120% as effort to find false equivalency). Both called for an intensity above anaerobic capacity (non-aerobic glycolysis). NOTE: workout is terminated if intensity cannot be maintained.

An intensity above anaerobic capacity? Perhaps you're using anaerobic capacity the same way in a similar or identical matter to anaerobic threshold. I.e. maximum aerobic steady point. At easy exercise, aerobic glycolysis/kreb's can fuel all neccessary energy. It can do so up until a point that is commonly called by many names (threshold, FTP, anaerobic threshold, etc.). At intensities below this point, anaerobic glycolysis (anaerobic pathways) make almost no meaningful contribution to the generation of power.

As you begin to move to power higher than FTP, increasing more demand is placed on anaerobic systems (anaerobic glycolysis) to supply additional energy. If you have a threshold of 300w, and ride at 400w, then 100w will have to be generated anaerobically (i.e. using W'/FRC), the remaining 300w will of course be generated aerobically via krebs/aerobic glycolysis.

Going back to your comment with some clarification on terminology, of course both those protocols call for efforts above anaerobic threshold. 20s at threshold with 10s rest would be a very easy workout. Certainly not high intensity. Moreover, by definition VO2 max is already above anaerobic threshold, so 170% of VO2 max is dramatically about threshold by default.

My understanding of tabata is, as you said, 20s on, 10s off. However, I hadn't heard to stop when power drops. I've always heard do 5', 10' or even 20' continuous of tabata. If you use 170% of VO2 as a target, power is going to drop, dramatically, after just four or five intervals. Nobody out there is doing more than 6 repeats of tabata at 170% max, even if they stand or coast between reps.

Peter Coe regimen throws a curve as the intensity is not defined (power measurement wasn't available and even now it's in beta) repeated fast 200 meter runs with only 30 seconds recovery between each fast run. As the grandfather of all, Peter Coe regimen is only that falls short in the specification but he was training Olympic champions.

Not sure why you discuss this. I don't know Coe's regimen, and I'm not sure how it related into discussion of HITT training.

L_Master wrote: »

CrP system, once depleted, takes at a minimum 2-3 minutes to regenerate. If you blast our of the gate with all out 20s of activity, CrP is already depleted. If you take a 10s rest...it's still depleted. Where do you go for energy? Anerobic glycolysis. You'll burn through that over the next 2-6 repeats, and at that point you'll be getting ATP almost exclusively from aerobic pathways.

Re-phosphorylation, ADP -> ATP? Tabata's and Gibala's test subjects did just fine. Are you referring to tau? W'bal recovery relates to non-aerobic glycolysis. Completely different energy system.

W' refers to non-aerobic glycolysis, absolutely.

I wasn't talking about W' however. I said CrP. CrP is creatine phosphate system. It's what is used for short initial bursts of power. It's what you use to power a 5RM squat set, a 100m sprint, or any very short duration activity. It is NOT an aerobic pathway, and it is NOT W'/Anaerobic glycolsis/FRC.

I don't think you understood my post at all. My point is breaking down the energy system usage if you do 20s @ 170% VO2 followed by 10s of rest. The first repeat is power by CrP system. W' is unchanged. Basically CrP system is just creatine with an extra phosphate that can quickly recharge local ATP. As you mention, in order to reconstitute the phosphate on creatine to use again you need to synthesize ADP->ATP which can only happen with excess oxygen.

So, you use CrP up in first 20s repeat of tabata. The rest is not long enough to recover from oxygen debt, let alone recharge CrP, so CrP is done. You have another repeat to go, and you need to get energy for that. Where do you go? Well, you're aerobic system is kicking in now and your getting some from that, but most of it still has to come from anaerobic glycolysis, so you begin depleting W'. You get 10s rest and recovery a little W' but not much and go into the third repeat. Still 170%VO2, so you need alot of that to come from W', which depletes it further. After rep 4 or 5 W' becomes fully depleted. What can you do for power now? Well you can do aerobic power + whatever W' you can reconstitute in each 10" of recovery. Experience suggests this might run down to approximately 90-100% of VO2, but either way, it's going to be primarily aerobic at that point with only a small percentage (maximum of 10-20% of power) coming from W'/anaerobic glycolysis and the rest coming from aerobic system.

L_Master wrote: »

f you wanted the primary source of energy generation to be from CrP, then you need short, maximal efforts with moderate recoveries. Think 10-15s sprints with 2-5 minutes of recovery between each one.

Classic AC intervals (from standing or from slow roll?). [/quote]

No. What is described above is absolutely NOT AC intervals. Too short by a long shot. The repeats described about are maximum power intervals, performed to increase peak sprint power. If done for 15-20s there can be some carryover to sprint endurance (not the same thing as AC).

10-15s sprint w/2-5' recovery. Not HIIT.

Correct.