By Runner’s World x Slendertone on
Train your midriff muscles to conquer some of the world’s greatest races.
This content has been created in collaboration with Slendertone.
Although the distances vary, the landscapes are vast and the challenges unique, the one thing that unites these four RW race picks is the demand for unstoppable core strength. Crucial for torso stability, stride efficiency and acceleration, your abs should never be ...