Fine Stationary Does The Resistence On A Stationary Bike Make That Much Of A Difference?

Does the resistence on a stationary bike make that much of a difference? - fine stationary

I have a stationary bike in my attempt to restore health. I had a very high resistance, unconscious, and it took me 30 minutes by bike 10 miles. I then pulled the resistance, and I shaved 10 minutes of my time. This may sound stupid, but what I'm trying to continue to act for 30 minutes or 10 not in 20 perfect?