In case my newfound e-bike fandom didn't give it away, I made a quick trip to Washington D.C., last week. We hit the Smithsonian museums hard, and it was worth every minute. But the most entertaining elements for me by far were the pedal powered equipment. Here's the bicycle ergometer from Skylab:
You know this is my personal photo by the fuzziness and poor composition.
https://www.flickr.com/photos/nasa2explore/11456762794
http://spaceref.com/nasa-hack-space/skylab-shoe-fashion---with-duct-tape.html
I can't embed the video here, but take another look at Pete's mounting of the bike. He clearly works to get his feet situated in some kind of clip or strap before he starts pedaling. I tried to find schematics, but I can't find the contractor for the bike. The orbital workshop itself was built by McDonnell Douglas (right):
And while there were early, proto-clipless pedals around for cycling, this was at least a decade before Look pedals debuted at the Tour de France (see Greg winning Worlds in Look clipless below in 1989; Sean Kelly and Dimitri Konyshev are still rocking clips and straps):
https://www.cxmagazine.com/greg-lemond-echelon-dirt-gran-fondo-hood-river
https://starchild.gsfc.nasa.gov/docs/StarChild/space_level2/conrad_bicycle.html
Look at those handlebars!
Astronauts Charles C. "Pete" Conrad Jr. (seen space-cycling above), Paul J. Weitz, Joseph Kerwin, (Scientist; I love that Skylab missions included people simply and officially dubbed "Scientists."), Alan L. Bean, Jack R. Lousma, Owen K. Garriott (Scientist), Gerald P. Carr, William R. Pogue, and Edward G. Gibson (Scientist) undoubtedly knocked out some Zwift-style mileage on that baby.
Legend has it that the bike was rated to 300 watts, but it could really only get to about 270 watts reliably. I have no idea why. But 270 W is no joke.
All the exercise was intended to prevent muscle atrophy. Since astronauts are in microgravity, their muscles don't get the same routine, day-by-day work that yours get just in the process of sitting and standing. The data that came back from Skylab was fascinating: cardiac output was down 30% (mostly from a 50% reduction in stroke volume; heart rates actually went up) upon the astronauts' return to earth. Peripheral vascular resistance was up, presumably to keep the blood pressure up with such a big drop in output (mean arterial pressure didn't change). No matter how long the astronauts stayed on Skylab (approximately 1 month, 2 months, or 3 months), they returned to normal within 30 days of landing.
I wondered if the same shoes that allowed them to clip into the floor allowed them to clip into the pedals. Skylab had a bungee cord system that was designed to strap the astronauts down. Here it is being used with the "treadmill" (really just a piece of teflon-coated metal) on the third mission (left).
But Pete's not wearing the bungee harness in the photo, so he must be clipped in. I can't find a good source, but the shoes were definitely up to the challenge, even if it took a little duct tape:
https://lsda.jsc.nasa.gov/Mission/miss/40
Even though I'm not much of a runner myself, I'll admit that the bike looks like less fun than Skylab's famous "exercise wheel," or as I prefer to call it, the "Zero Gravity Stripper Pole":