Yep, I’ve found my vo2max zone to be higher than what is calculated from my ftp. The options are to either bump your ftp (and having a terrible time with any threshold/sweetspot workouts), raise intensity every workout, or just don’t use erg mode and go by feel. I’ve found that to be more realistic for anything with sprints or hard starts, keeping the cadence steady just isn’t what I’d do outside. Plus you can actually just go as hard as you can for the sprints.
Hi all. Lots of interesting stuff on here. I LOVE rattlesnake…Well I hate it but I love it if that makes sense! If we assume that 90% max HR corresponds to v02 work (reasonable if not totally safe bet) then often takes me most of the first set of rattlesnake to reach 90% max HR (say 9 mins of the 12)…but with the 2nd and 3rd intervals I’m at 90%max HR after about 2 mins and say over that for the remaining 10 mins per interval…so loads time over 90% HR over whole workout.
Wanted to pick brains about today’s workout…I did Mattes +1 last week (3 sets of 3x3mins at 115% ftp with 4 mins between work). Was v hard but did it with 90% max HR after about 60-90 secs of each. So all good.
Today I tried Mattes +2 which is 3 sets of 3x3.5 mins at 112%ftp with only 2.5 mins between work. Seemed MUCH harder (but then again I’m in week 7 of general build so wheels starting to come off in style!).
Basically on the last 2 sets (so for intervals 4-9) hit 90%max HR after 60-90 secs (my max is about 193 so 90% is about 173/174). Then rose to high 170s/low 180s and stabilised over the remainder of the interval even though power dropped off, often below 110%ftp (nearer 105% ftp for last 75secs or so of each interval).
I guess I want to know was this worth it - I.e. am I getting the v02 work benefits from these intervals since power dropping below the usual cut off of 110% BUT HR well above 90% max and certainly not falling…RPE etc felt v hard.
I’m 37yr old male, 164lb, ftp of 307W. Max HR of about 193.
Interesting, today I just touched 90% at the end of the first 60 second hard start and stayed there the whole of the first set!
Ouch! I’ve done rattlesnake several times and usually takes me at least half of 1st set to reach 90% HR max…but then teaching v quickly on 2nd and 3rd set.
I’d like to say I was obviously getting better training stimulus, but since I gave up halfway through the third set… maybe not 
Still calibrating my legs to these short /shorts tbh as last time I did them I was a couple of weeks from a 20w ftp jump so they felt good!
You are totally in my gang. 
You have to remember that VO2max is NOT a power target, it is a physiological process. Power numbers are almost non-essential, they merely give us something to aim for (e.g. how do you know YOUR cut-off is 110% FTP?).
That said, without lab testing your physiology and armed with only a HRM and PM, it’s going to be a pretty generalized VO2max stimulation. But, for most of us it’s all we have and it’s better than nothing.
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Great response and hard to comprehend until a person really gets to know the workout over time. The recovery intensity and duration has a significant part in these 30/15 VO2 type intervals too. I recall Chad mentioning in a podcast that up to a 10% change in intensity might be required to achieve the desired result based on a persons makeup (in these VO2 sessions).
FWIW after trial and error I perform 30/15’s with a 40 second hardstart at 138% then the remaining 30 sec “ons” are at 130% with the 15 sec. “off” at 63%. I was similar to others where the 120% just didn’t to get me in the desired “zone” for long enough.
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Yep, agreed…it certainly ‘felt’ like v02 and RPE and HR would say V02…Just power not much above ftp. However i guess high power to GET to high V02 state…Then easier to stay in that physical state despite power dropping steadily.