This answers my question. Thanks!
Would this be acute or chronic metabolic response ? Assuming acute, is there a lab instrument that could determine this, such as a met cart?
If oxygen consumption rate correlates with acute metabolic strain, then perhaps increased breathing rate during steady state exercise in a fixed body position would increase as metabolic stress increases.
My layman brain wonders if breathing rate (measured by some newer heart rate chest straps) could be used during erg rides to gage when I’m pushing longer than I should. I have a fairly high suffering threshold so I tend to over do a single session if I’m not careful.
I’m sure my logic is flawed, probably in the first two sentences 
Good point. I didn’t mean to suggest I didn’t drift. I started out at about 149 BPM in the first 30 min interval, and I was bumping over 160 BPM by the end of the 3rd. AND I would say that my RPE was generally rising in relation to my HR … i.e. while I could have pushed myself to go longer, I was pretty damn excited that it was over.
I used to (and sometimes still do) ride myself straight off the bike by pushing it too hard too often. Then my overall plan/fitness suffers. So I’m constantly in search of balance … as are we all.
If I do 3x30 at SS (and I’ll call SS 88%+ of FTP) I’ll feel pretty burned the next day, and if I don’t, I’ll definitely feel burned in a day or two … which I think is appropriate given my age (49) and training history (<6 years of structured endurance training).
But if I do 3x30 at the “right” tempo pace, I’ve been able to do 3x30 2-3x per week and never really fall into a hole. If I don’t fall into a hole, I can do more work and get faster in the long run.
At least that’s what I tell myself.
EDIT:
This is what my drift looked like, on average, across all 3 intervals. These numbers are a bit skewed by the fact that I stand for 1 minute out of every 5 mins of the interval, so there is some intra-interval HR spiking.
3 Likes
FWIW, Balance Point Racing coaches (Ways, Sellars) now use Moxy for determining lactate balance point and for intensity control during intervals. I’m pretty sure Steven would have athletes use a Moxy for these sessions for instant intensity control.
I was looking at the Moxy yesterday … I only dug into it for ~10 mins, so I don’t have a comprehensive understanding, but from what I gathered it looked like it only measured blood/oxygen levels, right? Not lactate? Was I reading the wrong stuff?
No, that’s it. Lactate is a proxy for intensity. Muscle oxygen saturation (SmO2) and the slope (rising/fallling) can also be a proxy for the same thing. One time cost and you can use it every day for the intervals. Cheaper and easier than lactate tasting over the long term.
I haven’t bought one because $1000 is a bit out of reach for a gadget that will probably not add 50 watts to me FTP. 
It HAS to be lol … I keep thinking about bringing my lactate meter out and doing another test, but performing that test on yourself while putting out damn near max effort on the bike and with the fans blowing and alcohol swabs set up and sweat, etc., it’s just a mess. I guess you get better with experience. Or if you worked in a lab and did this all the time.
I’d pay someone $50 to come over to my house every couple of months and do this for me. I definitely don’t want to spend $1k … and I doubt I’d ever use it for real-time monitoring. I think one reading every 6-8 weeks is enough.
1 Like
I asked Jem Arnold (Canadian NIRS researcher) if it was worth it for daily use and he said probably not. He said that you could use it for a week and figure out your intensity ranges.
I do like the concept of real time feedback and calibrating your interval intensity on the fly.
Buy it and rent it out to your riding buddies! A mini biz on the side.
5-6 of use should just go in on one and mail it around as needed. 
FWIW here is last night’s “tempo workout” from a Coggan 0.85-0.95 IF point-of-view:
Yellow is the 0.76 to 0.9 level 3 / tempo power zone. That was 46 minutes with an IF of 0.89, and no decoupling.
You can see where I dropped off the group, at that point we were doing 30mph in a light tailwind, and coming up to a hard left turn and the absolute worst 2.1 miles of road. I was pushing 350-500W to stay on wheels. Die another day.
A ‘cleaner’ version is the time before getting dropped, which was about 27 minutes (ends just after the 1:00:00 mark on that chart). And negative decoupling of -5% LOL.
For the entire ride, Garmin said this:
108 TSS for the 103 minute ride.
Those have been really potent rides to develop both fitness and pack riding skills.
1 Like
When placed over a muscle, the NIRS signal arises from both hemoglobin (blood) and myoglobin (muscle), with the relative contribution of each still being a bit uncertain. For the most part, though, you are measuring oxy/deoxyhemoglobin in capillary blood.
1 Like
Did a 30 min Z3 attempt ( not my first off course 
) to dial in a little bit power/heart rate.
230W (86% indoor ftp) and avg bpm was 134 (max 139).
If you look at 139bpm that is only 76-77% of my max heart rate.
So maybe I should go a little higher to more sweetspot zone 88-90%, that will get my heart rate up.
Read the Fasttalk topic I posted. More is not better. Top of the HR range is not the goal. The more you chase watts, the more fatigue you end up with. Short of being able to do the testing (moxy, lactate, met cart) just stay conservative IMO. Going for 5 more bpm is not going to make you 10% faster in the end.
BTW, Steve says the HR cap is 78-83%. He throws out a lot of different numbers because if he was working with an athlete he’d customize everything for them.
1 Like
Sounds like a good plan. But I have a lactate meter. Should I use it? And how? Look for LBP? Or just skip the effort and concentrate on the Z3 rides.
Read the link I sent you earlier in this thread … it explains the LBP testing protocol… also called a FAcT test.
You essentially perform a ramp test to (near) failure, then recover at ~40% FTP for something like 10 mins … then every 5 mins you raise your BPM a certain amount and record your BPM and take a lactate reading. When your lactate readings start to rise again, that is your LBP as well as associated HR.
In the absence of that, listen to @AJS914 … the goal isn’t to work at and the brink of 83% HRmax. The goal would be to be able to do 60 - 90 (or much, much more) mins of tempo work while keeping your HR below that. Then the goal would be to do multiple days of this extended work without a disruptive accumulation of fatigue. So if you account for HR drift, you’ll want to start well below 83%.
Also, I’ll just note that the “smallest” dose of this exercise Steve ever prescribed for me as my primary workout for the week was 4x20 … I know he has given others 3x20, and mentioned that on podcasts, but for me it was 4x20. When we started “stacking” days, my primary workout might be 2x48, and then he might give me a smaller dose the next day, like 1x30, 1x45, etc., but I don’t know that 1x30 at tempo is going to tell you a whole lot about where what your HR is going to do, or if it is a terribly effective expression of this type of work, if you’re going to do a steady diet of it.
I’ll caveat all of the above with: I’m unable to defend my above position due to my lack of technical or practical expertise in these matters over a broad range of years and athletes. Take it all as a N=1 and my narrow interpretation of my own experience.
Hope some of this is helpful to someone.
EDIT:
The goal isn’t to get your HR up with power. The goal is to keep it as low as possible while extending time-in-zone. My 2c would be that if you can do 90 mins nonstop tempo work at keep your HR below 75% +/- the entire time, then I might raise the power … and at that point I would go back to 3 or 4x20 and build back out.
Also, don’t listen to me because I’m not an expert🤘
EDIT #2:
I just did a quick browse of my calendar and I was wrong, the smallest he ever prescribed me was 2x30. But the point kinda stands, I think it was an hour of total work. Your age, experience, fitness, etc., would likely affect all of this … if I was right off the couch he may have given me 3x10, I honestly don’t know.
6 Likes
For anyone interested in an illustration of this (and if you’re reading this thread, you likely are), below is a screenshot of the “biggest” workout I’ve ever done in relation to this type of training in Jan ‘20 …. and it still stands as my all-time power record for 3:30 (by a lot!)
As you can see, I started leaking the 2nd half of the second interval. But, if I use the first 90 min interval as a reference … I started riding at 80% HRmax and at the end of those 90 mins, I was at 82% HRmax. Very little drift at all for 242 watts, I think. Also, at the time I was working off of a relatively recent LBP test, and not using HR to guide me.
As a corollary, doing 3x30 at this exact same power yesterday, I was at about ~80% HRmax once is settled in to the first interval, but by the end of the 3rd I was at 89% HRmax … and that was with 3 five minute breaks in between intervals.
Moral of the story: I would have f#cking KILLED IT if all my races that spring weren’t canceled due to the pandemic. Sigh. 
2 Likes
Do you ride those in ERG mode?
Nope. Never.
Steve hates ERG mode
(At least with me he did …)
EDIT:
Also, I should probably clarify something. Steve didn’t prescribe this workout for me … I did this on my own. Honestly, looking back … I think 2x90 is overkill. I don’t know if anyone is ever going to be able to do 2x90 at tempo without a lot of HR drift if they’re only training ~10-12 hours per week.
Going forward, I would probably max out at 1x90 or 2x60 as my ceiling before bumping up the power. If I could do 2x60 two or three times a week and not be destroyed … that’s pretty good fitness, and maybe sign that “tempo” isn’t tempo anymore … ?
1 Like
Nice!
I consider these two of my longest tempo workouts, where you can clearly see a lot of yellow (power zone3 / tempo) in the top graph of each ride:
- 1st push at .83 IF for 88 minutes
- 2nd push at .84 IF for 73 minutes
- 3rd push at .82 IF for 82 minutes
- final push back home at .71 IF for 80 minutes
and another one 2 weeks before it
- 1st push at .84 IF for 89 minutes
- 2nd push at .87 IF for 74 minutes
- 3rd push at .85 IF for 55 minutes
- final push at .71 IF for 120 minutes
both are tied for my best 4-hour average power.
ERG MODE FOR THE WIN 
just kidding
2 Likes