The discussion on VO2 max last week got me a bit curious….
My sis is entering the PT doctorate program this fall at Oakland U here in Michigan. In the ST DIY spirit, I asked her last week if she knew how to do VO2 max testing or had run any tests herself. She did, but has been busy getting ready for school, so she loaned me one of her undergrad books: “Exercise Testing and Prescription” 4th ed by David C Neiman.
Chapter 4 on cardiorespiratory fitness was interesting.
VO2 max testing in a lab is expensive, but from reading you can approximate it pretty darn close on your own…
P 88 Researchers from U of Georgia have developed a generalized equation for prediction of VO2 max in ml · kg^ -1 · min ^ -1 for males and females between 8 and 25.
The error of estimate is 4.8.
The regression equation for prediction of VO2 max from the 1-mile run time (MRT) is
VO2 max ml · kg^ -1 · min ^ -1 =
(-8.4 x MRT) + (0.34 x MRT^2) + (0.21 x age x sex) – (0.84 x BMI) + 108.94
Where: MRT = 1-mile run time in minutes; sex = 0 for F, 1 for M;
BMI = body mass index in kg/m^2
Ex) Subject is 15 y/o M w/ BMI =21 and can run mile in 6.5 min.
Insert info in equation and answer is… 54.2
Text also had a section on treadmill versus cycle ergometer testing. It stated that subjects reach higher VO2 max values during treadmill tests than with cycle ergometers. VO2 max values are usually 5-25% lower w/ cycle tests than treadmills depending on conditioning and leg strength. However, only elite cyclists can achieve VO2 max values on cycles that equal treadmill values.
I had part of a table from the book that would predict Equivalent Performances for Various Distances too as part of my post, but it went to crap when I pasted it in.
It showed that running a 6:01 mile required the same V02 max (56) to run a 21:23 5k.
There are a numer of ways to estimate VO2 max that can be reasonably accurate for most adult athletes with a few years of serious training under their belts. These formulas can be terribly inaccurate for adolescents and athletes relatively new to a sport.
When you consider the cost/value of VO2 max testing though, remember that of all the data derived from a well run test, VO2 max is the least useful. I test aerobic threshold, lactate threshold, and HR, speed, and wattage at 90-95% VO2 max. With these figures, we can generate very precise intensity zones based on each athlete’s unique physiology - which makes for more efficient training.
The test also measures economy. How many watts do you produce or how fast do you run per liter of oxygen consumed.
We also measure fat and carbohydrate burning. The test reveals respiratory exchange ratio (RER) at each wattage or running speed. This is very useful for ironman distance training, since burning less carboihydrate at ironman race pace is a primary goal of training.
Personally, I don’t really care what your VO2 max is. It is kind of cool to know and you can brag about it to your friends (or shamefully not tell anyone), but the test has much greater value if conducted, analyzed, and explained by a qualified technician.
Funny you mention this text. Got it right here- we used it as well in my ExRx class.
This is a pretty good field test, but take it with a grain of salt. Remember that there are HUNDREDS of different metabolic/CV tests (field and lab) which can estimate VO2, peakVO2, maxVO2 (and VVO2- there should be a little “dot” above that first “v”), LT, estLT, and so on.
For 99% of the tri-geeks, find a field test that works best for you, and reproduce it as accurately as possible. Never ceases to amaze me that when conducting lab tests, you could have “ideal” lab ranges for an athlete to use for HR, RPE, time, and power, but then hit the open road and end up adjusting +/- 5-10 BPM based on “real world” situations and training outdoors b/c those same values are not realistic when the terrain and wind hits you in the face. Guess what? The “real world” situation is very close to the results from the field test…
BUT…damn if it’s not cool to go all out on a treadmill hooked up to a metabolic cart and see the entire printout. Make you feel like a superstar!
I posted it for those who are curious enough and want to approximate what they have. From what I’ve read in the book and elsewhere, I agree it’s pretty much only something fun to know.
I realize you were saying this, I’m saying that there are many other field tests as well, and that the choices are plentiful. I’m in no way saying don’t bother with it, because I think field tests are great. Have fun with it.
The only reason I posted the info about VO2 is because it helps to have some interpretation with the text. I have seen a few isolated times when a person gets their hands on a Phys text, uses a test, and then interprets the information for incorrect training guidelines (like using a VO2 test for LT with no blood draw). The Nieman text is a undergrad text, so there is many more tests available.
Like everything in this sport, take it with a grain of salt and have fun.
Right I think it would be interesting to try a few of the different field and lab tests…on a track, treadmill, bike, walking, whatever and compare the results just for curiosity.
I think field testing and lab testing have entirely different benefits. I test athletes in the lab to determine appropriate training intensities … to learn how hard they should train, not how hard they can go.
Almost every athlete I have worked with initially overestimates both aerobic threshold and lactate threshold. Training with intensity just slightly too high for zone 2 and zone 4 workouts drastically reduces the volume that an athlete can absorb.
Generally, I find that a well trained athlete’s CP60 will be 3-5% above LT. The difference tends to be smaller for elites and higher for slower athletes.
I had my VO2 test today. I was a little disappointed by the cycling-specific knowledge of the Dr. and PT that administered it (the clinic where I went is primarily a rehabilitation clinic). Because I wanted to use my own bicycle instead of their ergo, there was some discussion about the actual protocol between the two. We ended up using my PowerTap, starting at 100W and raising every 25W. My bike was on a Cateye Cyclosimulator, which is by far the best feeling trainer that exists (very loud though).
Anyway, we did 3 minutes of me just sitting on the bike (not spinning), and then started. Went something like this:
Min Watt HR VO2
1 - 100 - 122 - 26.6
2 - 125 - 131 - 31.5
3 - 150 - 133 - 34.6
4 - 175 - 145 - 40.5
5 - 200 - 150 - 43.2
6 - 225 - 159 - 48.3
7 - 250 - 164 - 51.1
8 - 275 - 172 - 55.1
9 - 300 - 178 - 58.2
10 - 325 - 183 - 61.9
11 - 350 - 187 - 65.0
I only made it 15s past the 350W level, which was actually pretty generous of the administrator. I was pretty disappointed by that because I felt like going to the end of 350 that I had some chance of completing the 375 level, but it killed me to drag my watts up to that level. I shifted to a bigger gear to try and bring it up, which ended up being a bad idea, but I don’t know if that affected me.
So, I’d really appreciate any feedback from anyone who knows what this stuff means. In addition to getting my VO2max, I was really hoping to get my watts at VO2max. Unfortunately, just based on some stuff I’ve read on the internet, I’m not sure these 1 minute steps were ideal for capturing either VO2max or watts @ VO2max. I didn’t feel like I was in a situation to dictate the protocol though, since I’m not any sort of expert.
Long question short . . . do I consider 350 my watts @ VO2max?
325 would be your VO2 max wattage, since you couldn’t complete a full minute. Do you have the results with RER/RQ and ventilation for each stage? That data is needed to generate a full set of training zones. Also, do you have the PT file. Your aim on the Cateye isn’t perfect, so you may not have averaged 325 watts during that stage. I use a CompuTrainer so the testee can just pedal. Also, 25 watts is a large increment for power increases. Any results will be to the nearest 25W. I prefer to sue 5-10 watt increments near the thresholds to provide more precise results. Ken
Thanks for the reply. I finished the 350 level okay. I made it 15s into the 375 level. So anywhere between 325 and 350? I knew that before the test. Oh well. I was able to keep it pretty smooth in terms of watts until the 350 level where I couldn’t seem to dial in very well.
I will have the file when I can make it home to download it . . . probably a few days. They will e-mail the other stuff, but I do have a printout. My RER went like this:
Min - Watts - RER
9.5 - 325W - 1.12
10 - 325W - 1.15
10.5 - 350W - 1.19
11 - 350W - 1.19
11.5 - 375W - 1.20 (finish 15s).
There is no column labeled RQ on this chart. The administrator mentioned the RER as an indicator of how hard you worked and said mine was a pretty good effort, but then again he hasn’t done a lot of really competitive athletes.
You need to post the values for RER less than 1.0 (i.e. all the time intervals). FYI, the RQ and RER are typically used interchangably, so, if you see RER on a print out, you won’t see RQ, they are referring to the same thing. RQ is actually incorrect in the context though, it’s just used incorrectly alot.
With all due respect Ken, we really can’t define his LT since we don’t have any blood/plasma lactate values. I’d agree, it likely occurs somewhere around the 250 mark (it’d be nice to have smaller increments), but without blood can’t say. This discussion has come up before about individuals who have gone in to a facility to have a VO2max/LT test done, and have only had respiratory gases collected. It is not possible to say what an individuals LT is from respiratory gases. It would be okay if someone said, “from this data, I would expect your LT to occur approximately at ____”. Alternatively, one could state," your AT occurs between 250 and 275, or using given criteria, that it occurs at 250, or at 275", but that’s a little different. Also, I’d be interested to know what criteria you are using to determine AeT at 150.
If it matters . . . I can do 270-275 for about 20 minutes. I can do 250 for more than an hour. I do a lot of AT training, so I feel like I have a pretty good grasp on this number. I really wanted my watts at VO2max to get an idea on how much head room I had to improve my AT.
If you say my wVO2 is 337.5 (splitting difference between 325 and 350 – reasonable?) and my AT is 262.5 (again splitting the difference). Then my AT is just under 78% of wVO2. Given my obsession with doing AT intervals this seems very low. I know that some freaks can get up near 90%, but where does the average rider get cut off?
I’ve also wondered what type of training improves wVO2. Is it VO2/Friel Zone 5 intervals, or is it bunches of miles to improve economy?
275 for a CP20 sounds about right for a 250 LT. A well trained athlete can sustain LT for about 75 minutes.
I would test CP6 and use that instead of the test results in this case. Again, 25 watts is a large jump, you only made 15 sec of the final stage, and the wattage numbers are rough estimates since you were on the Cateye with rider-controlled wattage, so field testing is going to produce more reliable and precise data.
All training will increase VO2 wattage, but aerobic capacity training, which targets the aerobic capabilities of the fast twitch fibers - Friel’s zone 5b - is the type of training specifically designed for this.
LT is generally 80% of max, plus or minus, based on the rider’s level and style.
Again, almost every rider overestimates LT. You can hold 270 for a relatively long time because lactate (and associated toxins) is accumulating slowly. I believe that the best way for you to get strionger at 270 is to spend a huge amount of time at 250, and some at CP6. The recovery cost of the extra 20 watts is not worth the additional gains. Better to spend twice as much time at 250 and recover. Ken
I think it would be interesting to try a few of the different field and lab tests…on a track, treadmill, bike, walking, whatever and compare the results just for curiosity.