From all fours exhale firmly, lifting the belly up towards your spine. Draw one knee in toward your chest and then, with the lower leg relaxed, extend your leg behind you. Hold the leg out or keep moving it in and out with your breath. You should feel muscle activity in your gluteal and upper thigh. To challenge your balance, add the opposite arm, lifting it as your leg extends. This can help balance and strengthen the muscles in your back. Try 8 repetitions on each side and then rest in child’s pose.