I've done some intervals yesterday.

Here's a sample of the workout:

...
450w x 1 min
210w x 1 min
300w x 1 min
210w x 1 min
400w x 1 min
...

When working at 450w, heart rate peaks at around 172bmp at the end of the minute. My max heart rate is around 183bpm.

I then slow down to 210w for a minute, but hr stays high at around 160 at the end of the minute.

Next interval was at 300w, so a fair bit higher but the heart rate stays flat at 160bpm.

Next interval at 210w, hr was still at 160bpm during the entire minute.

My hr go up to 170 during the 400w interval.

My question: is there a method/way of training to recover better after hard effort ? I expected to get a good recovery at 210w but it is not better than the 300w interval. Not sure if I explain it clearly...

Thanks.

Yes. You're doing it.

That is, the best way to train recovery is to do VO2max intervals with short rest periods so that you're forced to go hard again without being fully recovered from the prior interval.

Thanks caloso, when you say "short rest period", is there a rule of thumb regarding duration of the rest ? Is lowering HR by 10-12 bpm enough and considered a rest period ?

I don't know. I would say a minute or less is a short rest period. I wear a HR strap and collect the data, but I don't base my intervals on them. For example, last week I did a set of 6x5' @ 105%, with 1' rest (just coasting or softpedaling). On the 5th interval, I peaked at 181 and then dropped to 153 at the end of the minute rest. That's below my LTHR, but not fully recovered.

And with shorter, even harder intervals, your HR may not come down much, if any. Like with Tabatas, for example. That's 20"on/10"off. When I've done them, my HR basically pegs.

Not sure where you got the workout from or what your FTP is but normally workouts are structured to target a specific system for improvement with an intensity factor (IF) somewhere around 1.0 depending on session length.

If these are meant to be VO2Max type intervals you don't want, or expect, to fully recover after the hard efforts. Take the first two intervals, for example, at 450 and 210W that's an average of 330W. If your FTP is below 330W that level of effort won't be sustainable for very long.

I know this tread is a few weeks old, but I was looking around for info and saw it. I found the following formula based on heart rate which is what I think my heart monitor uses (at least similar - it does not figure differently male to female).
[h=3]Equations for Determination of Calorie Burn if VO2max is Unknown[/h]

• Male: ((-55.0969 + (0.6309 x HR) + (0.1988 x W) + (0.2017 x A))/4.184) x 60 x T
• Female: ((-20.4022 + (0.4472 x HR) - (0.1263 x W) + (0.074 x A))/4.184) x 60 x T

where

HR = Heart rate (in beats/minute)
W = Weight (in kilograms)
A = Age (in years)
T = Exercise duration time (in hours)

MeThinks that the question is more complicated than that. There are multiple systems involved in HIIT training -- so the type of HIIT needs to be tuned to which system(s) are being trained/emphasized....
.
For myself, I do not believe that short intervals where heart rate does not come down are truly HIIT training. Rather, they are just hard workouts with periodic breathers.
.
For myself: I favor 4 minute intervals: 4 minutes at 95% MaxHR followed by 4 minutes where the HR drops to 80%. Admittedly, while I keep the intense interval at a consistent 95%, the rest interval is more "U" shaped as the heart rate spends a minute dropping, 2 minutes resting followed by a minute rising back up to 95%.
... But, my goal is to train the cardio-pulmonary system rather than the metabolic system.

it really depends on what you want to do. I would probably have a longer rest interval at lower wattage and increase the wattage of your power segment. Or keep the power segment as is and extend its time. So many possible combinations and it depends on what specific training effect you are trying for. Do you want to work the lactic acid system or the ATP/CP system? Or perhaps you are interested in increasing your steady state.

This is a weird workout.

What are you trying to achieve?