As my running onboard ship was a bit "difficult" ( too many old F***s strolling around hand in hand!! ) - I did a bit of reading. I reread the Chi-Running book and re-watched the video and tried to do some practices.
I have always believed ( after watching some short videos of myself running) , that I run too "upright" . But this is what many/most books say to do - however when I watch other better runners than me , I can see that they have a forward lean and heels that "kick up" behind them. I have also read that the fastest way to run is not to increase the stride forewards ahead of you - but to increase the length of the stride AFTER you!! I have also been suffering a bit of calf muscle tightness ( after 2 years of running ) -- actually , a LOT of calf muscle tightness. So whilst onboard ship, I have tried just a little to "lean forward" as I ran - and my calf muscles immediately stopped complaining and I could feel my pace speed up considerably . - but this was only over VERY short distances!!!
I have tried this before - but found it to feel "unnatural" and "uncomfortable" but I am now thinking that practicing it would be very good!!! Basically you are using the force of gravity to propel you forwards rather than muscle strength - your legs only support you and stop you from falling face into the ground. Your forward speed depends only on your angle of lean and your body centre of gravity position determines your speed across the ground - your legs only keep up with your body!!
I am going to play around with this more