Lots of good advice here.
Lots of good advice here. There are just two additions I want to throw in the pot.
Fahrtlek runs are great. When I was a young Army Captain, the instructor at a school I attended asked all of us in the class to give up running except for Fahrtlek runs 3 times a week. In two months, I dropped a minute per mile off of my average time doing only these. The principle behind them is to sprint all out (90%, as Abide has wisely noted; only go to 100% if it will make you faster than your buddy while outrunning a bear) for a stretch (usually between 50 and 200 yards, with the longer distances earlier in your run) and drive your heart rate up and hold it there for a brief time. Then you slow back to a trot until your heart rate returns to normal mild exercise level, at which point you sprint again. We were doing this for about 30 minutes or until we thought we were going to die. You might try a little shorter distances or a shorter period, or even doing several of these sprints followed by a longer period of slower, steady running. The interval training process, which pushes your heart rate up for brief sustained periods, is what provides the most rapid increases in heart strength.
The other note actually comes from Rex Hall, whom I met here at US Forces Command last year as I was just beginning to transition from traditional running to BFR. I was (and frankly, still am a bit) dismayed at the loss of speed and at the potential prospects for regaining any speed at all, much less back to my 6:15/mile traditional running pace. I ran with him to have him watch my form in person and help me improve it. While running, I asked him how one might go about increasing one's BFR speed. A quick check of the math works out like this: in traditional heel-striking form, I was making 54-inch (4.5-foot) strides at a cadence of 188 steps/minute, or 1,173 steps per mile, resulting in a 6:15/mile pace. The BF math is as follows: 32-inch (2.67-foot) strides at a cadence of 233 steps per minute, or 1,977 steps per mile, resulting in a 8:30/mile pace. So by decreasing my stride length by almost half and increasing my cadence by 24%, I've been able to add 2:15/mile with no difficulty at all. The problem is that I'm pretty much maxed out at that cadence, and my soles are pretty much maxed out at that pace (unless I'm on dirt or grass that don't abrade like concrete does, giving me some room to allow more friction as I speed up). Rex Hall's theory was that to increase speed BF, rather than significantly lengthening your stride, which will increase the friction your feet experience due to push-off and braking effects, you should simply hold your feet up in the air for a longer time. This sounds like what Master Abide is advocating from a different angle now that I've read what he says above about " high knees and butt kickers." But my experience is that to get any significant increase and still keep my feet landing under my center of gravity, I've got to lean forward more with my hips at the same time to provide the forward motion without the push-off and braking effects coming into play. The biggest downside to this is that while holding your feet up for a longer time before setting them down, you get more impact on each foot plant due to gravity's pull effectively increasing as you increase the time above dirt. This is a recipe for stress fractures if you don't gradually work up to it. Since my initial stress fracture 7 months ago, I've not even begun to attempt this again yet, and probably won't until this summer (and then, only on dirt, and VERY SLOWLY).
Just more food for thought. As Davy Crockett said, "Make sure you're right, then go ahead." Fahrtlek runs now are a great idea, tailored to your ability; just keep the sprinting focused on getting your heart rate up (again by using Abide's "high knees and butt kicks" rather than forward speed as your means for raising the heart rate).
http://www.scienceofrunning.com/2010/08/how-to-run-running-with-proper.html
