Mac McClung on Instagram: "I’m super excited to announce the Mac McClung dunk program ! Ever since I was a little kid I was obsessed with dunking. I can’t wait to show everyone step by step how I increased my vertical jump and explosiveness ! To make sure you get the best possible results, I partnered with Vertical Jump Scientist and NBA trainer @pjfperformance to provide proper progressions through every stage of the program. Real world results, backed by science. It’s time to transform your at