question for your testers like Jtupper etc...

bump

Typically VO2peak is lower on a cycle ergometer than a treadmill. If you were tested with the old-school incremental cycling protocol, the W's bumped up say 30W/minute until exhaustion, it is doubtful that that 71 ml/kg value is your true cycling VO2peak anyway.

In cycling you would score even higher with a constant power protocol, working at say 80% Wpeak from the incremental (in your case ~350W); this intensity (~half way between VT and incremental peak power, allows a very large slow component VO2 to manifest. The steady state cost of exercise for a given power or velocity is actually a myth.

Note that I use VO2peak rather than max because all oxygen uptake measurements vary widely depending on the protocol and exercise modality.

Now the bad news is that cycling VO2peak is higher for heavier subjects. And thus you have an advantage over the 140 lb runner on the bike. This advantage disappears when the body weight must be supported in running. While you may be able to hit 71ml/kg on a running or walking protocol

(with incline), what matters more is the velocity attained at end-exercise. Thats why the old standard, "VO2max" is not such a great predictor of endurance performance whereas peak W cycling, or peak velocity attained in a running protocol, is a great predictor for those sports.

If you were going to match the 71/ml/kg 140 pounder in running, thats much more likely to happen in durations < 6' or so. It is not that unusual to see heavier 800/1500 runners but is rare to see a heavy 5000m star. Aoutia and

Scott are good examples of this. Both ran ~346 for the mile, but Aouita ran much faster in 5k, despite doing much less training volume. Size matters.

to continue with the question say both runners are one and the same person(not me) :-). Lets say 5 foot10.

then at 140 lbs and 180 lbs. Now the absolute vo2max would increase more then a litre to keep relative vo2max the same.

Wouldnt the runner become actually more efficient in that case. Say he needed 4000 ml to run 3 minutes 20 seconds per kilometer. (I did 4200 for that speed in my last test at 74 kilograms). Wouldnt his relative vo2max requirement to run certain speeds get less in such big cases? I know it wont stay at 4000 ml for our runner but say it wouldnt nearly go up a litre as well would it?

bump

On the bike, once the road started to increase in grade the smaller person would have a decisive advantage.

Also, running and cycling are different.

The bike value will be lower only if the person is not cycling trained.