<iframe width="580" height="385" src="https://www.youtube.com/embed/FldHbMDgwO4" frameborder="0" allowfullscreen></iframe> <br>A strong core = better performance & injury prevention! Here's a quick Core Compilation: ✔️ Russian Twist ✔️ Superman ... <br><a href="https://www.youtube.com/watch?v=FldHbMDgwO4">source</a>