PopSci 5-Minute Project video: CD dumbbell

Trash those CDs? Never! Let Bjorn and his 5-minute dumbbells pump you up.
A man in blue Popular Science coveralls holding a dumbbell made out of old CDs, pointing at the camera, and yelling.
Lift, bro.

In the age of MP3s, most people have a lot of old CDs lying around. Instead of throwing them in the trash, though, you can put them to use in a way that’s both eco-friendly and healthy. Thread the discs onto the ends of a thin metal rod and secure them in place with bolts to make a usable (and cool-looking) dumbbell. Tape up the middle of the rod to provide a comfortable grip, and you’ll be all set for a workout.