I was trying to be!Ha! I don't know about energy efficient! Nothing felt remotely energy efficient as this old man struggled to hang on to the pack. As we got to the end of the lap i had to get out of the saddle to generate enough power to stay with you guys which is never a good sign.
Its funny, looking the video i thought you raced really well, just inside the pack, not straying to the front or towards the back, suggesting you were being energy efficient.