Running Off the Edge of the Cliff

Last week, I went out on the track to run a workout that combines 800s and 200s. The workout looked like this:
2×800 RI 1.5″
2×200 RI Jog 200
2×800 RI 1.5″
2×200 RI Jog 200
800 RI 1.5″
200 RI Jog 200
As I moved my way through the workout, I was recording lap times on my watch and feeling like my times were so dismal. In previous years, I had been able to run 800s and 200s so much faster than that morning, but for some reason I just could not make those speeds in recent weeks. I tried cycling my legs faster, but this just made me hit my aerobic limit that much faster and I risked flaming out before I could hit the end of an interval.
Then towards the last few intervals, I remembered that body positioning can enhance speed. If I lean too far back, I need to exert more energy in my legs to drive my body forward. Leaning forward by bending at the waist puts me off balance which is bad also, and I waste energy trying to maintain my balance. But leaning forward while upright, presenting chest, with shoulders slightly back and head upright as well, then gravity can add its acceleration to the body and create forward speed without expending muscle energy.
On every 200, I was running them at 43-45 seconds. Then on the 2nd to last 200, I decided to run it with more aggressive body lean forward. Unbelievably, I hit 41 seconds, and without addition of effort. I then ran the next 800 and it was faster than any preceding 800.
On the last 200, I maintained not only aggressive forward lean, but also cycled my legs a bit faster, pushing my aerobic capacity. I made it to 200 in only 39 seconds!!
But the whole time I was leaning my body forward in that upright manner, and leaning as far as I could, feeling like my upper body was pushing forward beyond my cycling legs, it felt like my body was sliding off my hips/legs and about to fall off a cliff the entire time I was running – what a weird sensation this was!
Now I will strive to maintain that “upper body is flying off a cliff” feeling during running, which I know is giving me free, effortless speed that requires minimal leg energy. It does give me an immense mental challenge, however; for some reason, focusing on keeping my body in that position is mentally taxing. With training, I know I can increase my mental endurance on maintaining optimal body lean over race distance.