These trainers are simple to use. You wear a waist belt, and shoe attachments, and you pick a resistance band that connects between the two. The resistance band Find helpful customer reviews and review ratings for SKLZ Hopz Vertical Jump Trainer with Free SKLZ Carry Bag at Amazon.com. Read honest and unbiased I do hill sprints on my non-lifting days. you could use something like this instead, but I find the hill sprint also help with getting up and down the court