Running may seem like a total lower-body activity ... Then repeat on opposite side. Why it works: This exercise can power your arm swing by strengthening the shoulder and upper-back muscles ...

The obliques, which you might have heard being called "side abs ... This single-arm variation adds an element of anti-rotation, leaning on your obliques to keep your torso upright and balanced.

Keep the rod against the lead side of the torso until the hands are outside ... Slowly ramp up to a normal speed and try to ...

While running may seem like a total lower body activity ... Repeat on opposite side. Berdan notes that this exercise can power your arm swing by strengthening the shoulder and upper back muscles ...