The Coach: Joe Rubio of the Asics Aggies Training Group, San Luis Obispo, Calif.

The Athlete: Sergio Reyes, 2010 U.S. marathon champion

When They Did It: Training for the 2012 edition of the Rock ’n’ Roll San Jose Half Marathon, where Reyes finished second overall in a new PR of 1:03:30.

Why They Did It: According to Rubio, this workout “teaches athletes to better utilize lactate as a fuel by forcing the recoveries to be maintained at a solid effort between the more traditional harder mile repeats.” In other words, this is a continuous workout and better simulates a race, which affords runners no time to jog or recover.

“The volume of the workout lends itself to be most beneficial to 10K, half-marathon and marathon runners,” Rubio says.

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How They Did It: The In/Out Miles workout should be run on the track. The session consists of alternating 1,600 meters or 1 mile (four laps) run at goal 10K pace with 1600m or 1-mile run 60 seconds slower. During his training for the half-marathon, Reyes typically ran four “fast miles” out of 7-12 miles total. For a 40-minute 10K athlete, an appropriate workout would be running a mile at 6:27 followed by a mile at 7:27, back and forth in this fashion for 7-12 miles total, not counting the warmup or cool down.

How You Can Apply The Workout: The key to this workout is to know how fast you should be running your “In” and “Out” miles. If you are at the beginning of your training cycle, err on the side of conservative. Beginners should start out with a four-mile session that includes two “In” miles and two “Out” miles. Gradually increase the total amount of faster miles and duration of the workout from week to week, working up to an eight-mile session that includes four fast miles two weeks before your goal race.