Dr. Pepper wrote:
Do some type of speed every day (may be something as simple as 8 * 15 seconds on the 1:00 during a run). One day of dedicated interval work - get used to running faster. Build up to 20*200 with a 200 jog -run them at mile pace. At 100 miles a week, everything else should fall into place.
This is one of the things about LR that is bad: generalized advice given to make the poster feel better/smarter.
He's running 100mpw and he has yet to break 18:30, do you think he is ready to "Do some type of speed every day"?
Do you think that he could run 20x200 w/200j when he has "only" run 18:30? That is 20 laps of the track? YES, I realize he is running 100mpw or so he says, but I bet it is at 8:00-9:00 pace.
He's not ready for those kind of workouts. I was ready for that when I could run 5:00 or under for 1600m. Even at mile pace that workout will crush most runners at his level.
Additionally, he doesn't need "speed" training to run faster than 18:30, he needs VO2max training. Most simply this is best done as 2-4 min intervals at about 4k race pace. John Kellogg has a brilliant article on it on this site.
Not even really sure he needs VO2max training if he is that slim and is still running 18:30. Not everyone needs intervals. The longer the event and the slower you are the less you "need" them. But I guess if he hasn't gotten faster with his current regimen he should try the classic 5k training.
800s, 1200s, 600s , 1000s. You can do 3-5 x 1600m but do them slower at 5k pace or if you do a lot, 8k pace. We used to do classic HR-recovery intervals :
Run the reps at whatever pace you could race 4 X the rep dist (i.e. 800 rep at 3200 pace), then rest until HR drops to 120. It is self-regulating and keeps the pressure on MAXIMUM O2 UPTAKE.
I.E.-
An 18:30 5ker is at 3:42 pace per 1000m. So it follows that he could run 3:35-3:38 for a 4k race.
So if he is doing 1k reps, do them at 3:38 to start and then "squeeze them down" to 3:35 and then a little faster for the last 1-2.
6 X 1k at 3:38, 3:38, 3:36, 3:36, 3:34, 3:32 rest until HR drops to 120, or jog a 400 or 500m.
If you aren't recovering enough to keep the pace ... you aren't in that shape you thought you were.
And keep in mind, it is not the only way, or the best way, it is just ONE WAY.