Sprint Training Program: Korfist and Fichter

Based on Episode 38 of the Just Fly Performance Podcast, a conversation between host Joel Smith and coaches Chris Korfist and Dan Fichter.

The sprint training program Chris Korfist and Dan Fichter built does not run on sets and reps; it runs on drop-offs. Both are longtime track and football coaches, and in the early 2000s they spent years trading emails with the anonymous author behind the InnoSport system, known as DB Hammer, until they had reverse-engineered a way to program speed around one question: how much can an athlete do today before the workout stops paying off? The answer changes every session, every athlete, and every week, and that is exactly the point.

Key Takeaways

• Drop-offs replace sets and reps. An athlete keeps working until performance falls a set percentage, then stops, so every session is auto-regulated.
• Volume is individual. Read the numbers long enough and some athletes turn out to need one hard day a week, not five.
• Two fatigue brackets organize the week. Pure neural work lives under nine seconds; anaerobic reserve work runs beyond it, and both matter.
• Rest until you are fresh. Max-speed reps get eight to twelve minutes so fatigue never contaminates the quality.
• Train the quality the athlete lacks. Find where they sit between pure speed and pure strength, then train the opposite end.

Drop-offs replace sets and reps

The engine of the whole program is autoregulation, which the InnoSport material shortened to drop-offs. Instead of prescribing three sets of ten, the coach sets a percentage and lets performance decide when the athlete is done. Fichter describes how it worked with a jumper.

We would sprint and jump to an autoregulation of one to three percent, depending on how many days a week we were training. Once they reached that percentage of drop-off, you knew they were done, because now you’re not working maximally anymore.

Korfist’s case for it is that a fixed set-and-rep plan leaves you blind to what the athlete can absorb, while a drop-off tells you in real time.

If you go in and say, all right, we’re doing three sets of ten, you didn’t know what those kids were going to come back like in a day or two for the next workout. But when you autoregulate, kids came back and they got better every workout. You didn’t have beat-up kids throughout the week.

None of it works by eye, and both coaches are emphatic that you need timing equipment to see a three percent change. The drop-off is only as good as the number you are reading it from.

Volume is individual, sometimes radically so

Because the program reads each athlete instead of imposing a template, it will occasionally tell you something that sounds absurd. Korfist’s favorite example is a sprinter whose numbers only improved on a schedule almost no coach would prescribe.

This kid did the best if he only trained one day a week. If we trained twice a week, his numbers dropped off and he wasn’t hitting his numbers. If we went to one day a week, he was improving every week. So based on autoregulation, I knew this was a once-a-week kid.

The larger principle is that better athletes can spread their work out. As an athlete’s capacity grows, the same total volume gets distributed across more days at smaller drop-offs, and at the far end a mature athlete can train nearly every day by only ever dipping one or two percent below their best.

Two brackets organize the week

The program sorts everything into two fatigue brackets, and the split governs how a training week is laid out. Korfist lays out the boundary.

He has two brackets for fatigue. One takes you up to nine seconds, and one takes you over nine seconds up to fifty seconds. When you’re less than nine seconds, it was more pure neural drive, explosion-type stuff.

In practice that becomes a repeatable weekly shape: a max-speed day, a second day for acceleration or strength work, and a third day in the longer anaerobic-reserve bracket.

We had a fly day, and then a second day which would be acceleration or strength work, and then that third day without a meet, it was an anaerobic-reserve day, which for me turned into twenty-three-second runs.

Rest until the athlete is fresh

Because the pure-speed bracket is about top-end neural output, Korfist refuses to let fatigue leak into it. The rest interval is not a fixed clock; it is however long it takes to be ready for another personal best.

With the shorter sprints, I want them to rest when they think they can run their next best ten-meter fly. For some kids that’s seven minutes, for some that’s twelve. You’re looking at top-end peak neural output, and I don’t want fatigue to be part of it.

Fatigue still has a place in the system, but it belongs to the anaerobic-reserve bracket, not the speed day. Mixing the two is how coaches accidentally turn a speed session into conditioning.

Train the quality the athlete lacks

For all its detail, the program reduces to a single diagnostic. Fichter draws a line with pure speed at one end and pure strength at the other, and coaches to the gap.

I’ll put neural rate on one side and neural duration on the other. Neural rate meaning pure speed, neural duration meaning pure strength, and right in the middle is neural magnitude. Where does your athlete fall on that spectrum? Wherever he falls, train him on the other end of it, and he’s going to be a better athlete.

Asked for the methods they still reach for out of the system, both land on the same one. Oscillatory isometrics, contracting and relaxing rhythmically against a load, is the tool Fichter says he puts into nearly every athlete’s program, and Korfist still governs almost everything he does, now with a 1080 Sprint, by the same drop-offs that started it all.

Frequently asked questions

What is drop-off training?
It is a way of ending a workout based on performance rather than a set count. The coach picks a percentage, and the athlete keeps working until their output falls that far below their best of the day, at which point the session stops because further reps would train fatigue rather than speed or power.

How many sprints should an athlete do in a session?
As many as it takes to reach the drop-off, which is different for every athlete and every day. Korfist and Fichter argue the honest answer is not a number you set in advance; you read it from timing data, and it can range from a couple of reps to more than a dozen.

What are the two fatigue brackets?
The InnoSport system splits work into efforts under nine seconds, which are pure neural and explosive, and efforts from roughly nine to fifty seconds, called anaerobic reserve, which build capacity. A well-organized sprint week touches both, on separate days, rather than blending them.

How much rest goes between maximum-speed sprints?
Enough to run another personal best, which Korfist puts at seven to twelve minutes for short flying sprints. The goal of the speed bracket is top-end neural output, so any fatigue that bleeds into the next rep defeats the purpose.

What are oscillatory isometrics?
They are isometric holds performed with small, rhythmic contract-and-relax pulses against a load rather than a single static push. Fichter names them as his most-used method from the system, valuing them for training the nervous system’s ability to produce and release tension quickly.

About the authors

Chris Korfist is a longtime high school track and football coach in Illinois, the founder of Slow Guy Speed School, and a co-founder of the Track Football Consortium. He is known for applied speed training and early, hands-on use of training technology such as the 1080 Sprint and Freelap timing.

Dan Fichter is the owner of Wannagetfast Power/Sport Training near Rochester, New York, a strength and speed coach who works across sports with a strong emphasis on the nervous system and reflexive, neurally driven performance.

Joel Smith is the host of the Just Fly Performance Podcast and the founder of Just Fly Sports, a former collegiate strength and track and field coach focused on speed, power, and athletic development. Listen to the full episode with Chris Korfist and Dan Fichter on Just Fly Sports.