Somebody must have done the research. And, that is probably where all this "can't pull up" nonsense comes from. Without the power meter, let's try some estimates.

Say a rider weighs 180 lbs (82 kilos), then that more or less limits the downward force that one can apply to the pedals by simply standing to the 180 lbs, 82 kilos. The only way to increase force is to pull up with the arms and legs.

So one adds whatever downward pressure one can generate with the arms, say an additional 20 lbs.

Plus double the upward pressure one gets with one's legs, say an additional 40 lbs.

That gives one the equivalent of about 180+20+(2*40) = 280 lbs of downward force on the pedals (127 kilos). Not too bad, and potentially over a 50% increase in power over simply standing on flats. Say one can do it at 50 RPM. But, it comes at a HUGE PHYSICAL COST and makes a rider tired very quickly.

Now, the sprinter above was generating about 60 kilos downward force + 5 kilos upward = 65 kilos total force (143 lbs) on the pedals at 120 RPM. This effort also wouldn't be easy either, and was only held for 20 seconds in the study (all I have is the chart, and the link to the original paper wasn't posted).

One can probably just multiply the numbers together to get an estimate of who is putting more power to the rear wheel.

(280 lbs)*(50 rpm) = 14000
(143 lbs)*(120 rpm) = 17160

Now, this isn't a true power estimate which depends on the crank length, and power through the entire stroke, not just the peak force, but just looking at the numbers, the spinner may well win over the masher. And, with the estimated forces above, the only way the masher may be able to effectively increase power may be to drop down in the gears and spin faster. Doing so, however, may decrease the force function. That, or figure out how to pull up harder, but there is a limit, and as some people have pointed out, one naturally has difficulty pulling up with significant force.

And, of course, there are some BIG ESTIMATES in the calculations.

No doubt one could calculate the peak power standing, and the peak power spinning, as well as how much power can be maintained over a period of time, say 1 minute, 10 minutes, or 30 minutes.

From my experience, it seems that watts power may be the limiting factor. Say one rides a 10 MPH hill either mashing or spinning, one still gets to the top at about 10 MPH. That is actually an easy enough test one can do with a $10 speedo and no fancy equipment.

Anyway, pulling up certainly isn't impossible as there are many riders that do it, especially on standing hill climbs. The big question is whether or not it is more or less efficient (for all riders).