Coach Culpepper: Shifting Your Half Marathon Training

A solid half marathon is the result of timely preparation (Photo:

Learn how to shift the focus of your half-marathon training.

Over the course of a 12-week half-marathon training program for experienced runners, the focus of your workouts (or “priorities”) should shift as you progress. The emphasis during the first four weeks of the plan will look different compared to the last four weeks. Slight adjustments to your workouts—not massive swings in methodology—can lead to relatively big changes on race day.

Imagine you were to see a 3 percent improvement come race day. If you’ve run 1:45 for a half marathon, which is an average of 8 minutes per mile, that would translate to shaving almost 3:30 off your time! Most people would be thrilled with that kind of improvement.

Here’s how to adjust your priorities during your training program while bearing in mind that slight adjustments can have very impactful results.

Workout Components

Training stimulus can be broken down into four categories:

1. Volume: This is your standard weekly mileage, comprised primarily of your long run and comfortable, easy runs.

2. Speed: Workouts that include paces faster than your goal half-marathon race pace; 5K race pace is a good gauge for most speed workouts and these workouts—commonly referred to as VO2 max workouts—should include intervals in the range of 30 seconds to 3 minutes.

3. Race Pace: This is the goal pace you’re preparing to run on race day; these tempo workouts (longer sustained efforts) vary in length from 10 to 40 minutes.

4. Threshold: In these workouts you are working hard but can sustain the effort for intervals that range from 4 to 8 minutes in length; 10K race effort is the best way to describe the intensity of these workouts.

Phase 1:

During the first four weeks of a 12-week training program, your priority should primarily be building your overall weekly mileage and the length of your long run. Don’t neglect doing faster workouts during this period—a weekly speed session and tempo run are perfect during this phase—but there should be less focus on more intense threshold workouts.

Breakdown of emphasis:

65% on increasing volume

15% on speed

15% on race pace

5% on threshold

Phase 2:

During the middle four weeks, your priorities should shift toward more sub-race pace work, with less focus on mileage. Doing workouts at 5K pace will really help your ability to maintain your goal pace during your half-marathon race. Tempo runs should still be included, as should harder threshold workouts, but the focus should be on maintaining good, consistent mileage with workouts below race pace.

Breakdown of emphasis:

50% on volume

20% on speed

15% on race pace

15% on threshold

Phase 3:

During the last four weeks of a 12-week training program, put your emphasis on race-pace work and threshold work. Your weekly mileage will begin to drop as you taper off maintenance miles and include more critical work at race pace and just below it at 10K-race effort. During this phase, the goal is to transition all that nice efficiency you gained during Phase 2 to your goal race-pace workouts and threshold workouts.

Breakdown of emphasis:

35% on volume

10% on speed

30% on race pace

25% on threshold

This piece first appeared in the July 2014 issue of Competitor magazine. 


About The Author:

Two-time U.S. Olympian Alan Culpepper helps runners of all abilities via his website at

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