Workout of the Week: Sarah Brown’s Hammer Intervals

This interval session from one of the America's top middle-distance runners alternates paces to help you get race-ready.

At last Saturday’s Prefontaine Classic, 28-year-old Sarah Brown shined in the women’s 1,500 meters, crossing the finish line sixth in a new personal best of 4 minutes, 3.20 seconds—a full two seconds faster than her previous PB—giving her a huge confidence boost heading into the U.S Track & Field Championships later this month.

The New Balance-sponsored Brown, who represented the U.S. in the 1,500m at the 2013 World Championships and, most recently, ran on the world-record-setting distance medley relay team at the 2015 New Balance Indoor Grand Prix, lives and trains in Solana Beach, Calif., where she is coached by her husband Darren Brown, a sub-4 minute miler in his own right.

One of the 28-year-old’s favorite speed workouts she does throughout the year is a session called “Hammer Intervals.” When she’s in the middle of racing season, the workout—most often done on a 400m track—consists of twelve 300-meter repeats run at Brown’s current mile race pace with a slow 100-meter jog for recovery between reps. The catch? She “hammers” every third 300m interval at her current 800m race pace before settling back down to mile pace. For Brown, the workout totals eight 300m reps run in the range of 48-49 seconds—her current 1-mile or 1500m race pace—while the four “hammers” come in closer to 45 seconds.

“I like how this workout takes you out of your comfort zone during the hammer intervals,” Sarah Brown says. “The hammer intervals wake up your legs. They do leave you gasping for air a bit and feeling the burn in your legs, but if you can stay calm and relaxed, then they allow for the slower paced intervals to feel easy and smooth in comparison. By the end of this workout, you really have to focus on pace and form to ensure that you hit the assigned efforts.”

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Darren Brown says that physiologically, the workout closely mimics the demands of a 1,500m race, while the short recoveries allow the athlete to run more than 1,500m worth of volume at race pace or faster. Additionally, he says, the “hammer” intervals mimic the surges that occur in a tactical middle distance race.

“The hammer intervals rapidly increase fatigue and lactate accumulation,” explains Brown. “By returning to mile race pace for two intervals in between, it teaches the athletes to run smooth under duress by forcing the body to flush the system.”

Not a miler? No worries. Brown says this workout can be adjusted to work for runners focusing on longer distances too, and doesn’t always have to be done on a track. For example, during the winter base-building phase, Sarah Brown will do more reps (up to 18) at slower paces, often alternating 3K pace for the slower reps with mile pace for the “hammers.” Also, when it’s not racing season, Brown usually does this workout on a grass field or similar soft surface, which adds an additional strength element and can be easier on her body.

Half marathoners and marathoners can manipulate the length of the intervals to suit their needs, Darren Brown says, alternating 1-mile reps at 10K to half-marathon pace with a 400-meter “hammer” run at 5K pace or faster every third interval. “They will gain many of the same benefits that a middle distance runner does, but the stimulus will be much more specific to their physiological needs,” he explains.