tallmantim

I have been following through the energy transfer chemistry that occurs when exercising and realised that you could calculate out a weight of O2 burnt while doing a particular effort based upon this.

See the attached spreadsheet and you can enter your own details (over on the right hand side) and get a figure for VO2Max - which may or may not be accurate to any degree but I think the math works out at least and the numbers it comes up with look sort of right.

I have put some figures up there for Lance and it comes through with 83ml/kg/min - which is pretty darn close to the 85 touted for him.

https://spreadsheets.google.com/ccc?...thkey=CM25-NgD

Issues:

• Only deals with aerobic energy from glucose (ie. 100% glucose for energy)
• States that the energy generated by 1 mole of glucose is 2880kJ, however 1 mole of carbohydrate should equal 3024kJ by normal calculations for energy (180g x 4cal/g x 4.2kJ/cal)
• Probably someone will come up with some other issues I haven't thought of!

Anyway, let me know your thoughts.

Racer Ex 

"The page isn't redirecting properly

Firefox has detected that the server is redirecting the request for this address in a way that will never complete"

I think BF will allow you to upload a zip or straight XLS.

tallmantim

Hmmm - that's odd. I'm using Chrome so it works OK for me (as you'd expect!).

Unfortunately I can't upload to BF - proxy blocks the upload function.

Jancouver

Your 1' power is only 447? Just asking since you said your FTP was around 360? That would be kind of low 1 min power IMO for 360FTP.

tallmantim

1 minute effort @ VO2Max - so the top of your aerobic range.

If you just plug in your max 1' power you are using too much (ie. mostly) of your anaerobic power and not doing oxygen conversion.

Just had a look at the results from my last MAP test in September and that gives 1' maximal power @564W - which I think may be a better number but gives me a stupidly large VO2Max result.

MAP or RAMP test protocol was to start at 200W and increase and hold power by 25W per minute - I finished after 13 minutes which took me up to 500W - so you are aerobic only by that point essentially, but for some reason I have an minute maximal power (MMP) listed as 564.

Hmmm - so now not sure whether I should use 447 (121% of FTP), 500 (MAP figure) or 564 (MMP).

Oh well.

Racer Ex 

75

tallmantim

hi rx

I imagine you have done the test - is it close to reality?

Racer Ex 

I haven't done the test. It's kind of a lab rat number that if I was 20 would be something I'd want to know, but wasn't worth the money to test otherwise. That said it would seem to be in the ballpark given where I fall on performance/Ewang thing.

I used Explorer to get the link to work. Might have to give Chrome a shot.

ridethecliche

Do you think the glucose energetics number is 'off' to account for inefficiency?

tallmantim

No - we are only 20-25% efficient as a rule and the figure of 2880 vs less than 5% off (rather than 75%).

I think that 1g glucose = 4 cal is just a convenient shorthand approximation, where it actually equals 3.81cal/g. Not usually an issue as if you are cal counting you will get most of your information from the nutritional information on the packet. Have looked at other sources, and the 2880 figure is the correct one.

Interestingly, if you look up sugar some use this figure to show energy:

https://www.calorieking.com.au/foods/...k9c3VnYXI.html

whereas some company sites use the larger approximation:

https://www.csrsugar.com.au/Everyday/White-Sugar.aspx

carbs are spot on 16kJ per gram (and there are 4.2kJ per Calorie).

tallmantim

Cool - what figure did you use? MMP, high MAP, 121% FTP or other?

Thanks

Racer Ex 

121 % FTP and weight from my best numbers in '09. I never got as light as I wanted this year.

tallmantim

One other interesting point (for me at least!) is that if you burn through 180g of glucose you will generate about 108g of water in your body (108mL).

High intensity work could see you burn through this in an hour or less and the average person sweats 0.8 - 1.4L/hour while exercising - so you will likely sweat out 8-14 times the volume of water under normal circumstances, however we would be somewhat closer to balance when doing a hard workout in very cold conditions.

SalsaPodio

I just did a VO2 max test for a study and got 62.8. Your spreadsheet gets pretty damn close to that for me

tallmantim

Excellent. What figure did you use? (121% FTP, MAP, MMP, etc)

Thanks

Nate552

This does not bode well for me......

SpongeDad

Other than approximations based on some fraction/multiple of another (FTP, MAP, ...), what interval would best approximate your VO2 max power? 6 minutes?

FormerRower

80 for me... with my racing weight from this year. About right maybe a little low.

echappist

i'll have to enter the data when i'm up to doing some CP6 min tests. When i got tested in June (before my crash, so at a possibly higher fitness level), i got 69mL/kg/min. I was producing 360W, for how long, i'm not sure.

Even when i enter 360W, i had to use 21% efficiency in order to get to 69mL/kg/min. This is probably the case as i was sweating so uncontrollably that the electrodes were falling off. Too bad my body temperature wasn't measured, so i can't be sure.

Ygduf

just saw this. my numbers calced to 67. I tested last month at 70.

tallmantim

I think an actual test for this would probably be a MAP (AKA a RAMP test) test - ie, the best average power you can get to and hold for a minute - there are various protocols out there, but it should last 10-15 minutes or so (ie, for mine, you need to average 200W for the first minute, 225 for the second etc and the biggest minute you can fully complete at that average power or higher is your MAP number). The MAP number could then be used in here I think.



That's huge. No wonder they liked you on the rowing team! Is that based off FTP?

LOL - efficiency sounds about right then!

Based off FTP?

Grumpy McTrumpy

I put mine in as well, but I think it would be far more accurate if you used 5 minute records. my best 1 minute is firmly in the anaerobic range, and gives me VO2max of 87. No friggin way.

Grumpy McTrumpy

figuring for my 5 minute record, it was 63

tallmantim

Grumpy, was that one minute in the aerobic range? (ie, after burning off your anaerobic power) - that's what the MAP test is designed to do, so definitely not just your 1 minute power as that is firmly in the anaerobic range.

For me, max 5 minute average power is about the same as my MAP test though, so 5 minute max average power may be about right - but is dependent upon what sort of anaerobic ability someone has though (ie, it would skew results between someone who could stay in the anaerobic zone for 2 minutes rather than 45 seconds with similar FTP's).

ericm979

Using my 5 min record (which is very close to FTP *1.21) I get 60. Polar's estimation for me is 55 or 58.