@thegravgear: There is no better way to build super strong hamstrings than the Nordic Hamstring Curl. How many reps can you perform in one go? #calisthenics #calisthenicsworkout #calisthenicsmovement #calisthenicstraining #calisthenicscommunity #calisthenicsworldwide #calisthenicsgermany #calisthenicsworkouts #calisthenicsaustralia #calisthenicsbody #gravgear #workoutaddict #workoutdaily #workoutchallenge #workouthard #workoutcomplete #workoutmode #workoutday #workoutgoals #workouttips #workoutideas #workoutsession #workouteveryday #workoutgear