I'm trying to pinpoint why on some days I can cycle on the same stationary bike, with the same settings (saddle @ "E", handlebars height at "7"), for 20 minutes, while other days I can only cycle for 7 minutes before I have to stop due to muscle aches in my thighs.
I've been tracking variables like,
- sleep - same amount, including deep sleep; sometimes I can cycle for 20 minutes on only 4 hours of sleep, other days I have to quit after 7 minutes despite 7 hours of sleep (in both cases the deep sleep was about 50 - 60 minutes)
- food intake - both types of days, after dinner, which includes some carbs (though I haven't tracked the amount of carbs very precises). I could also do 20 minutes on an empty stomach in the morning
- time of day - early afternoon, early evening or late evening don't seem to make a difference
- hydration - did ~20 minutes while pretty dehydrated
What else could I track more precisely?
Note that I don't have sore legs afterwards, and on the days I can cycle for 20 minutes, I don't really stop due to muscle pain, but rather due to running out of breath or just beating my PR by 1 minute.
I cycle every other day, so I don't think there's risk of overtraining.