I started working out again a couple months ago (although I only seriously started trying to lose weight two weeks ago), and today I discovered my usual arc trainer program was too easy! Like, I was barely even breathing hard. Also, when I started, my heart rate would get up to about 170 after I had been working hard for a while, and now it stays around 140!
As you can tell, I'm very excited about this! It certainly makes me want to stick with it.