Long story short, after working closely with a coach since Sunday, we've verified that I practically run on my toes. My forefoot strike is extreme and the angle of my foot coming down is too extreme and needs to be leveled out a bit. I'm putting tremendous pressure on my Achilles tendon and plantar muscle. What's amazing is that I haven't injured myself but I do have Achilles pain right after a hard run but it goes away within hours. However, since working on a transition to a mid-foot strike, I have no pain after I run and I'm running faster times with less effort.
I think one of mentors was right when he said it takes 3 years of consistent running, then at that point, you start to learn how to run. In the last 2 months, I've identified this issue and the fact that I wasn't running straight, balanced and aligned which I've fixed and it had a major impact on improving my running (although I didn't exhibit good alignment at the 5k race this past Saturday).
This article by Steve Magness really got my attention: http://www.scienceofrunning.com/2010/08/how-to-run-running-with-proper.html.
I've gone back to really working on my core and hip extensions. On my run yesterday and today, I could already feel my stride lengthen while still landing balanced and under the body. The trick is finding the optimal balance of vertical and horizontal lift coming off the ground, in the air, and landing.
The removing a tremendous amount of stress and pressure by transitioning to more of a mid-foot landing. I use the terms "forefoot," "mid-foot," and "ball of foot," a bit loosely because I think those terms cause incredible confusion in the running community. And, in many circumstances, we are talking about small degrees like landing on the front of the ball of foot, middle of the ball of foot of near the rear of the ball of foot (I'll stop b/c even that can be confusing). Ultimately, for me, I'm landing on the ball of foot with the slightest amount of space before my heel comes down as opposed to a more severe forefoot landing where my heel had a long way to come down and/or didn't touch the ground at all.
I'm not saying a forefoot landing is bad as I don't know that much about bio-mechanics but I'll say this. As a 41 yr. old runner who only started running at 38 yrs. of age, it may be too much to ask to move to a severe forefoot landing . . . it may be too big of an adjustment after 38 yrs. of abusing my body in bad shoes.
I'm still amazed that I've run this way without major injury for over 1 yr. but now that I'm trying to increase performance, speed and efficiency, it's really cool finding all these areas where you can continue to improve.