9 Outdoor Fitness Moves: No Gym Required – Whole Living Eat Well

How to:

Place the arch of your foot on a rock with a rounded point that gives your foot and ankle full range of motion. Focus on a spot straight ahead, 20 feet away. Using your arms for balance, while keeping your foot on the rock, lift your leg that’s on the ground and draw a half circle around your body — forward, to the side, and behind. Reverse, then repeat with the other leg, 30 seconds to one minute per leg.

You could also use:

curb or tree root