Yin Yoga does not focus on strengthening the muscles (and this is a Yin Yoga forum): for that you will need to look at any of the several applicable yang yoga practices: standing poses like Warrior 1 and 2, Chair Pose, Goddess, lunges and Triangle can all help to strengthen the major muscles used in running. But most runners are seeking not greater strength, but enhanced length. Running can take its toll and tighten the hips and lower back as well as shortening the long leg muscles, contract the hip flexors and hip rotators. Yin Yoga can be very good at regaining lost range of motion in these areas. If you want to focus on mobilizing your hips, see the flow in YinSights for the hips
. If you want to stretch out tight hamstrings and lengthen your spine, see the flow in YinSights for the spine
. You can also find a video sequence for these in the playlists on my YouTube channel
. If you feel your IT band is overly tight, try postures like Bananasana, or Reclining Twists such as Twisted Roots (these are explained in the Yin Asana tab to the left of this page.)
Regarding your question of lifting yourself off the ground in locust posture, it may be weaker muscles preventing your lift off: the best way to prepare for this pose is to do this pose. Just go slowly and work to lift just your chest of the floor for a few seconds at a time. Later, add the legs. Later add the arms. Don’t try for great height: go for strength and endurance not range of movement. Good luck.