what it means

Pace Intervals (PI): Relatively lengthy repetitions at your goal half-marathon per-mile pace to build endurance and develop pace judgment. Note: All numbers in parentheses above denote distance of recovery jog.

Cruise Intervals (CI): Run at 10-K race pace to promote stamina and the ability to run strong when tired. for 7:00 half-marathon goal pace (1:31:46), run 6:40 for 1-mile, 5:00 (1200), 3:20 (800)

Speed Intervals (SI): Run at 5-K race pace to promote relaxed speed and a sense of comfort at your considerably slower half-marathon pace. for 7:00 half-marathon pace, run 3:09 (800), 1:35 (400), 0:48 (200)

Strides (S): Over 100 meters, gradually accelerate to 90 percent of all-out, hold it for 5 seconds, then decelerate. Walk to full recovery after each.

Total Uphill Time (TUT): Work the uphill sections during your run, at something near a strong 10-K effort in the total time called for.

Race Day Rules: To warm up, jog just 800 meters, then do a few fast strides. That's it. Keep your glycogen tanks topped off and your legs fresh. Divide your half like this: 10-mile run, 5-K race. Run the first mile just slower than goal pace, then work into a rhythm and run just below your lactate threshold level so you don't implode an hour out. And draft off other runners to conserve energy. Do all these things, and you'll be fine.

Intermediate

Profile
You have a solid aerobic base. You have been running consistently for several years, tried various kinds of speed training, average 25 to 30 miles a week, and may even have finished a half-marathon. But now you want to race a half. That is, you have a specific finishing time in mind, and you're willing to train hard to achieve it.

Schedule Tips
"Intermediate runners have enough experience and strength to support some faster running--but within the context of increased weekly mileage and an adequate long run, which remains the key to improvement at this level," says Anaerobic Management coach Jon Sinclair (anaerobic.net). "So be careful when you add speed, because what we're after here is greater endurance, the ability to run longer at race pace." That's the crux of the Intermediate plan. To that end, Sinclair also suggests "adding some tempo to at least some of the long runs when they're maybe going just a bit faster over the final 10 to 15 minutes." That's a bit faster, okay? No bug-eyed straining.

"I would also include some interval miles at faster than projected race pace," Sinclair adds. "Interval tempo here should be challenging, but not too crazy. And the recovery should be enough to support the effort--down to a 120 heart rate, 400-meter jog, whatever it takes. If the rest isn't long enough, you can't maintain the quality."