I�m doing a VO2max test in hospital on a cycle ergometer tomorrow and I was wondering if anyone could help with a couple of questions:
First question is about the ramping protocol. The physiologist generally likes to get at least 10min of data before hitting maximal exercise. He uses a continuous ramping protocol, which increases the load by x watts per min. Most of the patients who are tested in this lab never get near 200W at maximum, and quite often they use a 5W/min ramp, so I�m not sure if the physiologist will be used to testing someone who cycles a bit. I�ve done an all-out 8min at 380W on my SRM, so what ramping rate should I suggest? I was thinking 30-40W/min, but maybe that�s too aggressive. I�m also conscious of the fact that I did my 8min piece on my bike, whereas this is going to be on what looks like a basic stationary bike at the gym � not sure if that will significantly limit my power output. Just for fun, any predictions on VO2max and peak power output? I�m actually a bit nervous about the test � I suppose I�m afraid I�ll be disappointed by the numbers. I�m 73kg and I�d estimate FTP at 325W and the 8min @ 380W was from a couple of weeks ago.
Take your bike and a trainer, why would you get tested on there equi if you have your own power meter? And at 73k and ftp of 325 what are you nervous about that is only 15-25watts of top pros. I don’t know muck about vo2max but my guess is that yours is between 72-74.I would guess CP6 would be 390-400. And who cares about the number that is all it is.
cheers
If he uses the same protocol for you as he does for patients that achieve max at ~ 200 watts, you’ll be on there too long to get a valid VO2max. So, you could simply have him double the rate for the protocol that he would use for someone who maxes at 200. Alternatively, it’s a good bet you’ll be close to 400, likely over, so, he could use that as a reference to back calculate his ramp rate to have you max at the appropriate time. This is all assuming his Monarck (I presume) and your SRM are calibrated properly.
If s/he insists on equal increments in power throughout the test, I’d go for 30 W/min max…40 W/min would be a bit too steep.
As for your final power, I’m guessing something just north of 400 W, with a VO2max of 70-72 mL/min/kg.
Assuming both devices measure power accurately, the only difference between their ergometer and your bike will be one of comfort…which IMO is really irrelevant during such a short test.
My internet searching frenzies have typically found that these tests are as such…
25w/min ramps for amateurs.
20w/min ramps for elite/pros.
If that 380w for 8min was truly all-out, and was truly 380w on the nose, and your FTP really is 325w, then a 25w/min ramp test should see you completing a minute of 450w then dying pretty quickly when ramping towards 475w.
Then again, it could go differently! Not a big fan of stationary trainers, take your bike if they allow for it.
I’m actually doing the test as a bit of a favour to help one of the doctors practice using the equipment generally and using acetylene gas to estimate cardiac output. They’re estimating cardiac output at a variety of work intensities. The bike is electronically braked and is controlled by the same computer that gathers data from the gas exchange gear, so I don’t really have a choice to bring in my own gear.
As for why I’m nervous, I guess I’m worried that my VO2max will be low and that I’ll come away feeling like I don’t have much potential to improve further.
Your concern is not uncommon. However, it’s just a number. If it was “low”, would you not want to continue doing the sport? If you never took the test, you’d likely keep training/pushing your goals anyway. It’s interesting but keep it in perspective.
In the mid 70’s, the USCF started doing VO2 measurements of cyclists as well as muscle fiber typing. They gathered up the national team members as well as several groups of “up and comers” in Squaw Valley. The number thing really psyched out some guys. “Does this mean that Joe will always be faster than be?” “Should I forget being a pro?” “Does this mean I’m really a sprinter?”
you really should think about bringing your bike and trainer, especially if it’s a tri bike. You can manually up the wattage (also very easy on a computrainer or tacx) when the computer does as well.
And what you really ought to ask for is your Lactic Threshold (and wattage) based on the gasses… that would be more useful than knowing your VO2 Max.
I have the same VO2 Max as Frank Shorter, and I can barely run and he was an Olympic champion or something… knowing your VO2 can only make you feel bad about yourself.
As best I understand, national institutes and pro teams use protocols with small increments (15-25W) and long durations for each workload (2.5-4 min). Those that have rapid/continuous rises over short duration are for non-athletes who will struggle to stay on the bike before reaching max if go too long. If you use longer workloads you can get additional somewhat useful data (eg reach steady state before next workload). Well trained people (eg you) should be able to get pretty damn close to max even with long protocols. Also, the max power output that you reach is highly dependant on the protocol you use, so something to consider…
My predictions (am going to put it on the line give specifics!!) are based on a protocol (that comes highly recommended): start at a bit over 3w/kg - eg for you would just go ~225W after an easy warmup. Go up 25W every 2.5 min. Final power (peak power) is the last workload completed plus fraction of the last remaining workload. If you can hold 325W for ~1 hour, I estimate that this would be ~80% of the peak power you would get in the test described above (if you have quite good ‘threshold’). This correlates strongly and linearly with absolute VO2. Using appropriate formula, I estimate your peak power would be ~406W (ie complete 36 sec of 425W workload), and VO2peak to be, according to the formula, 5.07 L/min (+/- ~100 ml/min), or for you at 73kg, ~69.5 ml/kg/min (range 68.1 - 70.8).
I’m actually doing the test as a bit of a favour to help one of the doctors practice using the equipment generally and using acetylene gas to estimate cardiac output.
Ooo, acetylene rebreathing…enjoy the burn!
Thanks. I think the gear they’re using is made by Sensormedics - are you familiar with the brand and is the power measurement likely to be accurate?
Sensormedics is one of the biggest players in this area. I wouldn’t stake my reputation on the accuracy of one of their metabolic carts w/o testing it, but I also wouldn’t question the accuracy of one just because of who made it.
Similarly, you can probably trust the power data from one of their ergometers as little/much as most of the others out on the market…
The headline results were 68ml/kg/min and 421W at maximum, 310-320W at AT (depending on method used to measure). Now for the excuses…
We used a 25W/min ramp, as the custom ramp function on the machine wasn’t working and 25 is the highest on the machine’s pre-set drop-down menu. This meant that I did 16:50 of exercise, which the physiologist suggested was a bit too long. He prefers to keep the tests <12min. Anyone have any guesses as to how much of a difference it would have made if I’d done a 30W ramp?
Because the load on the electronically braked bike is only accurate at cadences <80rpm, I had to pedal at 70-80 rather than my natural 90-100 cadence. Subjectively I felt that I quit because my legs weren’t strong enough to turn the cranks, but they weren’t as pumped and burning as they sometimes get when going all-out on my bike. I hit an RQ of 1.14, which looks to be on the low side of the normal range (1.1-1.3)…interpretation?
The acetylene didn’t quite pan out the way we thought it would. You probably know all this, but the test requires maximal expiration, maximal inspiration of the gas mixture (we had methane, carbon monoxide and acetylene in there) and then a controlled, constant-rate expiration. This works great at rest or submax exercise, but the doctor I was working with was hoping we could do it at maximal exercise. Let me tell you, there’s no way a controlled, constant-rate expiration is happening at 400W+!
Thanks for asking. I guess it went pretty well. I wasn’t too unhappy with the result, and it hasn’t made me think all this training is a waste of time…so all in all the psychology side of things turned out okay.
This meant that I did 16:50 of exercise, which the physiologist suggested was a bit too long. He prefers to keep the tests <12min. Anyone have any guesses as to how much of a difference it would have made if I’d done a 30W ramp?
Because the load on the electronically braked bike is only accurate at cadences <80rpm, I had to pedal at 70-80 rather than my natural 90-100 cadence. Subjectively I felt that I quit because my legs weren’t strong enough to turn the cranks, but they weren’t as pumped and burning as they sometimes get when going all-out on my bike. I hit an RQ of 1.14, which looks to be on the low side of the normal range (1.1-1.3)…interpretation?
does the physiologist have any experience with doing these tests on very well trained athletes?
Probably is a good chance the cadence screwed you up a little, and gives a good indicator to the answer to the Q above.
I stand by my estimates above! You would be very close to ~405W with 2.5min ramps.
don’t worry about RQ (or preferred, RER, unless you had lines in femoral artery and vein). Without going into detail, some well trained athletes finish these tests completely blown at ~1.05, and is also highly dependant on nutrition. RER at max/peak is not worth much more than novelty value.
T… load on the electronically braked bike is only accurate at cadences <80rpm, I had to pedal at 70-80 rather than my natural 90-100 cadence.
Funny, all the labs I have gone to make me pedal faster than 80rpm. Optimum for me mid season is between 72-80rpm The power increments on the three different labs/machines I have tested on use 35w per 1 minute and start at 70w. That gives you 10-12 minutes unless you are a strong pro, then you end up around 14 minutes if they do not adjust the incremental amount of power.
The headline results were 68ml/kg/min and 421W at maximum, 310-320W at AT (depending on method used to measure). Now for the excuses…
We used a 25W/min ramp, as the custom ramp function on the machine wasn’t working and 25 is the highest on the machine’s pre-set drop-down menu. This meant that I did 16:50 of exercise, which the physiologist suggested was a bit too long. He prefers to keep the tests <12min. Anyone have any guesses as to how much of a difference it would have made if I’d done a 30W ramp?
Because the load on the electronically braked bike is only accurate at cadences <80rpm, I had to pedal at 70-80 rather than my natural 90-100 cadence. Subjectively I felt that I quit because my legs weren’t strong enough to turn the cranks, but they weren’t as pumped and burning as they sometimes get when going all-out on my bike. I hit an RQ of 1.14, which looks to be on the low side of the normal range (1.1-1.3)…interpretation?
Good work Don
I did a VO2 max test back in September, where I had to pedal at 70rpm (it was standardised as part of a study), and they used 34-35w jumps every 2 min, starting from 100w if I remember right. I’ve since done other ramp tests on the same equipment, but without clipless pedals and again at 70rpm, and I’d say that as long as you’ve got clipless pedals it won’t make too much of a difference. Recently I did 1min ramps at 34-35w and hit 470something watts, the test back in September was again >470w but obviously twice as long. It’s just that at low cadences it becomes more of an issue at the dead spot, and straps and trainers make it a bit hard! So I wouldn’t have thought the numbers would be too different at 70rpm vs. 90rpm, you did appear to reach VO2 max after all
Most important thing I would have thought would be to make sure that any subsequent tests you do use the exact same protocol?
The power increments on the three different labs/machines I have tested on use 35w per 1 minute and start at 70w. That gives you 10-12 minutes unless you are a strong pro, then you end up around 14 minutes if they do not adjust the incremental amount of power.