: 🏋🏽 'Post 60' #Fitness - #Ab #Crunches Using A #Dumbbell. The swinging of any #weight will allow your #arms' swinging momentum to assist in working your #abs. Your Lats and upper arm contract to swing your arms towards your knees (much like a Lat Pullover #exercise) to make it easier for people to get #gains & #strength in their #core. (try it out - it works even if you haven't done or been able to do a crunch in years!)