The muscles of the core are heavily involved in all endurance activities, even though it might not seem so initially. Swimming involves rotation from side-to-side that is initiated from the hips and the core. Cycling requires a strong core, especially when pedaling hard, to effectively transfer power from the upper body through to the lower body and into the pedals. When running, a strong core contributes to a more efficient run technique and helps to avoid fatigue in the upper body during long-distance running events. Check out the video above for a 10-minute core routine that you can do with nothing more than your own body-weight and a mat (or a soft surface)! This routine focuses on the musculature that makes up the "core", including the abdominals, lower back, obliques, hip flexors, and glutes! Give it a try, and incorporate it into your week on 2-3 days each week for better core endurance.
Happy training and racing!
-Ryan Eckert, MS, CSCS