Flashcards and Elliptical

Today I did the elliptical for 45 minutes without music (the battery on my ipod died). Instead I went through my flashcards for the medical college admissions test which made me feel doubly productive. Surprisingly, I really wasn't tired afterwards or even during and I kept it at the same intensity and speed as last time. This just goes to show I am building my endurance and can still function without the motivation of my music.