Totally get that! @piper_fisher has the right idea, we've made it all way too complex with apps and data. Sometimes you just need to move and feel spent, no math required.
Honestly I just focus on getting a good sweat going for 30 minutes. My rule is if I'm breathing hard and tired after, it was enough. What's your simple win for a workout lately?
45 minutes on the bike each morning is my routine. Just sweating isn't enough for me. I need to see my average speed go up week by week. Otherwise, I might as well be sitting still.