Today's workout was 7 miles with 8 x 100M strides:
- I did 2 miles slowly speeding up to 8 min pace
- At about 2 miles (well, at 17:00 to be exact) I pushed the "12 mph" button and ran for 20 seconds. At 20 seconds I pushed the 7 mph button and then would gradually speed back up to 8 min pace (7.5 mph)
- I did that every four minutes. That is, I'd do the stride, slow down to an 8:34/min pace, then speed back up to a 8:00 min pace and do that until the next four minute mark. That meant: 17/21/25/29/33/37/41/45 were the times. It dispersed the strides "fartlek like" through my 7 mile run at 8 min pace
- I figured that I'm supposed to accelerate through 100 meters or so, and Usain Bolt runs 100 meters in 10 seconds, so 20 is probably correct
- of course I also calculated that if 80 meters were at the top end of the pace, that would take 15 seconds at a 5:00/mile pace, and the machine takes 3-4 seconds to go from 7.5 MPH to 12 MPH, so I'm probably doing them right
That's a common workout in most marathon programs so I've read up on it and this is a short summary on this element of training. The more I read about them, the more I realized that I'd been doing them for years. When I ran cross country at TPHS back in the 70s we'd finish all our runs by doing these. We'd do eight of them..the classic "run the straights, jog the ends" on an oval or whatever circuit you run laps of. (We had no track as the school was new, so we ran around something the size of a soccer field.) We did them easily at the beginning of the run, and we always ended with them.
From Runner's world:
...the volume and intensity of German's hard training days were just what I expected of a runner of his caliber. But the way he finished every easy run came as a total surprise to me: He'd always finish with 8 to 10 fast strides.
Strides are those 60- to 100-meter "pickups" that runners typically do just before speedwork or races. In these instances, they generally warm up well, stretch, and then use strides as a finishing touch to ease into fast-running mode. The reasons for doing strides before a bout of fast running are multiple: muscles need to be flooded with blood, fast-twitch muscle fibers need to be recruited, and race pace must be briefly simulated to get the body and mind ready to run fast.
But why do strides at the end of an easy run? One answer can be found at the finish line of almost any race: People like to run fast at the end of races. We all do it, both the first-place runner turning on his kick in the Olympic 10,000-meter final, or the 450th-place runner sprinting to out-lean the 451st at a local Haul Around the Mall 5-K. Easy-day strides will improve that finishing kick.
Strides also improve your neuromuscular coordination, as the bursts of speed stimulate neural pathways. Just as a pianist's fingers fly over scales that have been practiced repeatedly, your coordination and form become more fluid from these short but frequent doses of speed tacked onto the ends of easy runs. Result: You become faster.