How to perform
Set a bench to roughly 45 to 60 degrees and sit back against it.
Let your arms hang straight down behind your torso, dumbbells in each hand.
Curl one or both dumbbells up without letting your elbows travel forward.
Lower all the way back to the stretched position.
The behind-the-body arm position loads the biceps in a lengthened position, which makes this one of the more productive curl variations.
Common mistakes: letting the elbows swing forward, and cutting the stretch short at the bottom.