In order to be come a more efficient runner, you need to work on improving your running form and posture all the time. The iKinesis wearable can help. It is a smart wearable device that analyzes your 3D movement in real-time. It takes into account center of gravity oscillation, impact force, and food placement to give you feedback.
The iKinesis Kapsule combines with your smartphone to give you a running profile based on your stride. It lasts up to 6 hours on battery and is IP68 rated. The companion app gives you feedback via audio and vibration. Expected to ship in October.[where to get it]