It's a bit retro, but prior to the Air Force's 1st PT Renaissance, all they did was an 'ergo bike test' once a year. That shit was on its way out when I hit operational side in '03. Got to do it once and the euphoria of not having to do PT after finishing tech school lasted mere months. Damned Indian givers. But I digress. Supposedly, this magical stationary bike was able to measure a person's overall fitness by varying the resistance while monitoring heart rate. If an increase in resistance didn't cause a massive jump in heart rate you passed. Im oversimplifying as it took a good 15min of work on the bike with resistance going all over the place and the whole magic show basically killed 2hrs of your day.
The punch line... Damn thing didn't work. Air Force people aren't stupid and any magical measurement device with career ramifications will be hacked within a month. Never underestimate the ingenuity of a fat NCO with car payments and a mortgage, facing early separation.
The first sign of weakness was an early batch of marathon runners, century cyclists etc. failing the test and having to do 'alternate assessments,' i.e. do an actual PT test. Turns out, those people had resting heart rates one click up from dead. When the bike resisted, their bodies would jump up to a workout heart rate well above baseline established when the bike had 0 resistance.
The dirt bag E5s and above were aware of the situation and being briefed on the regular about paperwork required when an obviously fit subordinate failed the bike test. When it was their turn, they would spend the day of the test chugging coffee and smoking cigarettes. Before going in they would finish off a pack. Once on the bike, they were already half a notch down from a full on heart attack. Stereotypical, potbellied NCOs with a coffee cup in one hand and a lit cig in the other were passing with flying colors while former track stars and people recently reclassed out of PJ, TAC-P and combat controller pipelines were bombing out hard.
Cross into the blue, where everything is backward.