One of my favorite short 45 minute aerobic workouts, is to do a 3k lap up and around our ski hill with a stop to do ten laps up "Buried Treasure," a 30 foot 5.2 at the NCS crag. The music comes from the movie "The English Patient." (As always, click on the video to start it, and then click on it again to be transferred to the larger You Tube site.)