Although this looks like a relaxing runner's lunge stretch, I assure you this pose is all about strengthening your thighs. As a bonus, you'll also get a nice stretch in the front of your hips.
- From Down Dog, inhale to step your right foot forward between your hands, as if coming into Warrior 1. Lower your torso and reach your right arm underneath your bent right knee. Interlace both hands in front of your right ankle. Keep all the weight in your legs, resisting the urge to lean into your hands. If this is too intense for your thigh muscle to hold (it's a killer move!), then rest one or both hands on the floor.
- Breathe deeply in this low lunge for five breaths. Then release your hands to the floor, step your right foot back, take a vinyasa (Four-Limbed Staff to Upward Facing Dog to Down Dog), step your left foot forward, and repeat this pose on the left side. Come to Down Dog after five breaths.