Bicycle crunches are a great exercise for building core strength in runners – and are harder than they look. The exercise is a variation of an ab crunch, where one leg flexes while the other ...

White shared that seated Russian twists, chair dips, seated leg lifts, chair squats, seated cat-cow stretch, and seated bicycle crunches are some of the best options.

Bicycle crunches are a great exercise for building core strength in runners – and are harder than they look. The exercise is a variation of an ab crunch, where one leg flexes while the other extends.