Workout of the Day: 25 x 400m
25 x 400m
Intensity — 10,000m pace
Recovery — 100m-200m jog/float after each rep
Exertion — 8/10
Context & Details
I like this workout because it is straightforward, simple, and effective.
The 10K is 25 laps around the track and this session readies the athlete for the mental and physical grind of such an endurance contest. The yardstick for progress is not an acceleration of the 400m reps, but the quickening of the time for 100m-200m floats. The first run of this session is usually with a 1:1.0-1.5 work:rest ratio. As fitness improves this ratio become 1:1/2.
Seb Coe’s coach, Peter Coe said, “The runner who buffers best will beat the rest.” He was referring to lactate. Buffering, or clearing, efficacy of lactate from the bloodstream to muscle tissues is a key biomarker of success in endurance running. Lactate is super fuel, but if our bodies produce more than can be used it becomes acidosis and slows us down.
This workout, with a focus on sustaining the speed of the 400s at 10K pace but shortening the recovery intervals between, seeks to advance this buffering ability.
It is one of those year-round workouts in my book. It’s moderate frequency serves as a benchmark of progress, but doesn’t lead to undue burnout. My 10K runners visit it about once a month year-round, save the months in which they’re racing a top flight 10K race.