You will be embarrassed, later, that you spent so long resenting this. The bike that goes nowhere. The instructor shouting about hills that are not real, in a dark room lit up like the inside of a jukebox.
Look at your knees right now. Look how easily they take the load, how the burn in your thighs at minute thirty is just a strong young engine complaining about nothing. You are furious that you can't get your resistance knob to catch on the beat. Oh, sweetheart. You have no idea what you are sitting on.
That soaked shirt. That towel over the handlebars. The stranger to your left who whoops on the last sprint every single time, and how you privately find her a little much. You will think of her, years from now, for no reason at all, and smile.
The thing you cannot see from in there: how good it feels to be tired for a reason you chose. To push against something that pushes back and gives you nothing but a heartbeat. Later there will be a stretch of years where you would trade a great deal for one more hour of legs that just go, and go, and ask for the next hill.
So sprint the last one. Whoop, even.
Let the woman next to you hear it.