Thursday, February 28, 2013

Stair Torture Machine Threshold Test

Per the PT, I got to start off with 20 min of 30 sec run/30 sec walk.  Manna from heaven.   :)

Then, a 45 min ramp-up through threshold on the Draconian Stair Torture machine, 30 min of elliptical, and 30 min of swim.  Moderation is for other people. 

The stair torture machine has a wattage readout, and just for the sheer geekiness of it, I recorded my wattages and heart rates for the ascending 5 minute intervals.  Here's the data, which corresponds pretty well to a lactate threshold/VO2max test:

Presumably, the machine's wattage algorithm is fairly accurate.  Power is force times velocity, which in this case would be:

Power = Mass x acceleration x upward velocity

Mass (weight) was entered to the nearest pound.  The machine measured upward velocity, and acceleration is your standard acceleration due to gravity.  It's calculating force against gravity at a known upward velocity (assuming one doesn't hold onto the railings), and asks for my weight to the nearest pound. 

One year ago when I tested LTHR for bike, it was 147.  Power at this HR was about 315W.  Run LTHR is 155, with a power output of about 330W.  This corresponds to a threshold power/weight ratio of either 3.7W/kg or 3.9W/kg depending on which threshold value I use.  The correlation with bike power is unlikely to be perfect, but hopefully it's pretty good, as it indicates some improvement over my test from a year ago (285W).

Not bad for a big 'ol fella who busted his hip less than 3 mo ago.

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