Individualized Training: The Henk Kraaijenhof Approach

Based on Episode 20 of the Just Fly Performance Podcast, a conversation between host Joel Smith and elite sprint coach Henk Kraaijenhof.

Few coaches have made a stronger case for individualized training than Henk Kraaijenhof. The Dutch sprint coach, who has guided some of the fastest athletes in the world, keeps returning to one idea: the athlete in front of you is not the average athlete in a study, so stop coaching them like one. Across this conversation he applies that lens to everything, from sprint technique and muscle fiber type to brain chemistry, competition nerves, and the limits of sports science itself. What follows is less a set of drills than a way of seeing each athlete as their own experiment.

Key Takeaways

• Coach the athlete, not the average. Kraaijenhof’s whole method is reading the individual instead of applying a generic template.
• There is no one perfect sprint technique. Over-cueing backfires, because “when you can think, you are running too slow.”
• You can read fiber type without a biopsy. Watch how much an athlete’s times or jumps decay across repeated efforts.
• Bounding is potent but injury-prone. Dose it “as much as necessary, not as much as possible,” to the individual’s tolerance.
• Sports science is built on averages. Use it, but apply it to the individual, because the outliers defy the group data.

There is no perfect sprint technique

Kraaijenhof’s guiding phrase for technique work is deliberately balanced: “as much as necessary, as little as possible.” He does not chase a textbook model, because he does not believe one exists.

There is no perfect running model for everybody. If you look at a nail and a hammer, and you hammer the nail, every time you hit it in a different way. It seems there’s a different solution to the problem of going from A to B all the time. Otherwise long jump would be easy. Everybody would always hit the board.

People run the way they do for anatomical reasons, he says, and fixing what is not broken often just creates compensation or a slower athlete. He keeps cueing to a minimum, reserving it for clear biomechanical faults, because the act of thinking about technique is itself a brake.

One of my athletes once said, “I don’t think while running, because if you can think, you’re running too slow.” I think he was absolutely right. The feedback system is much faster, so when you interfere with cognitive thoughts about how your arms should be, you’re running slower.

Matching jump tests to the phases of the sprint

Where Kraaijenhof does get precise is in testing. By testing many athletes, he found specific jump tests that track specific phases of the 100 meters, which lets a coach see where an athlete is strong or weak.

I found a relationship between the block start and the squat jump, jumping from a 90 to 100 degree angle, isometric to concentric, the same thing you do in the start. The acceleration phase related to the countermovement jump. For maximum speed we used the reactivity test, the highest jump with the shortest possible contact time. And for the endurance phase, the repeated countermovement jump over 15 seconds.

Each test mirrors the demand of its phase: the near-isometric squat jump for the block, the eccentric-to-concentric countermovement jump for acceleration, the stiff-legged reactivity jump for top speed, and the fading repeated jump for the run-in. He credits the framework to his mentor, the Italian physiologist Carmelo Bosco, whose work on explosive strength he considers groundbreaking and underused.

Reading muscle fiber type without a biopsy

The same decay that shows up in a repeated jump is how Kraaijenhof reads an athlete’s fiber type, no needle required. He simply watches how the numbers fall apart across repeated efforts.

You make him run five times 300 meters. If he starts in 38 and ends up in 41, he’s probably a fast type. If he starts at 38 and ends up in 36, he’s probably a slow type. The fast type starts off very fast but lacks endurance, so the decline is much stronger.

The training implication follows directly from the physiology. Fast-fiber athletes handle high intensity but need low volume and more recovery, while their slower counterparts tolerate larger workloads. He learned the cost of ignoring that the hard way, trying to build endurance into a very fast athlete.

The last part of the race they improved one or two tenths, but the first part they lost three or four tenths, because the dominance of the slow fibers slowed down the contraction speed of the fast fibers. After a couple of months it started to work out in a negative way.

He is careful not to overclaim: fiber type is not destiny, because technique and the efficiency of using energy matter too. As he puts it, you can have a car with a huge engine, but if the wheel is turned the wrong way you go nowhere.

Brain types and how you cue the athlete

Kraaijenhof extends the same individualizing logic to the nervous system, arguing the brain, not the muscle, is the real performance organ. He has profiled athletes by neurotransmitter tendency (dopamine, acetylcholine, GABA, serotonin) and brain-hemisphere orientation, using tools like the EEG and Eric Braverman’s framework.

Everybody has a different brain. Not everybody looks at the track or looks at sports the same way you and I do. By understanding the brain you start to understand why some corrections work in one athlete and don’t hit home in another. We do a lot of work testing muscles, and everything apart from the brain, and that’s what I find surprising.

He is candid that these types are largely genetic and not something you change or that predict performance. Their value is in communication: knowing how an athlete is wired tells you how to coach, cue, and prepare that specific person.

Bounding: powerful, but dose it to the athlete

Bounding is where the individualizing really bites, because Kraaijenhof rates it both highly effective and genuinely dangerous. Some athletes tolerate huge volumes; others should barely touch it.

I have guys who are living kangaroos. They could jump over hurdles endlessly without Achilles or knee problems, so I love jumping for these kids. I also coached athletes who couldn’t jump at all. Why would I make them do a lot of jumping? Every exercise should be judged on the relationship between the training effect and the risk of injury.

The danger, he warns, is that bounding does not punish you in the moment. You are not out of breath after ten hurdles, so the joint and tendon load hides until it backfires later. His rule is the same one he applies everywhere: as much as necessary, not as much as possible.

People can bound 30 meters, do it five times, and you see the effect. Why would you do it 10 times, or 20? Just because you can? When you do more than necessary, you destroy the athlete. Injured athletes seldom win a medal.

He notes the calculus is different in a small country: a program with a hundred athletes can afford to break ninety-five and let the survivors win, but a coach with one national-level sprinter cannot afford to burn anyone.

Warrior versus worrier: coaching the athlete’s arousal

Even the warm-up gets individualized, because Kraaijenhof reads athletes by how they handle competitive arousal. He sorts them by what he calls being a bloomer or a breaker.

The bloomer is the one that blossoms under stress, the one that welcomes the stress. And the breaker, they always seem to crack under pressure, because they squeeze out too much adrenaline.

The warrior type welcomes a packed stadium as a great moment and functions optimally under pressure, so they tend to peak when it counts. The worrier performs best in the low-stress comfort of training and can shrink when a big competition pushes their arousal past its optimum. So he tailors the warm-up to move each athlete toward their own optimal adrenaline: the over-aroused athlete gets slow jogging, long calm stretching, and a steadying voice, while the under-aroused athlete gets strides, push-ups, and a sharper tempo to fire the system up. Reading the athlete correctly, and matching your own energy to what they need, is in his view the real point of a warm-up.

Why sports science built on averages fails your athlete

All of this rolls up into Kraaijenhof’s most pointed argument: science describes the average, and he does not coach average athletes. He values science, but he has seen where it breaks.

Science is always geared toward averaging, toward generalizing. I don’t work with average athletes and I don’t want average performances. Everything I learned based on tests done on average athletes or sports students didn’t apply to the genetic freaks I was coaching. How many Usain Bolts are there to do research on? There’s only one.

He compares the coach to a painter: Rembrandt knew nothing about the chemistry of his pigments, yet a chemist who knows every formula could not paint the Night Watch. Science gives the coach knowledge, but the craft is applying it to one person.

I’m not saying science is bad. We need science, and I use a lot of scientific knowledge, but then I try to apply it to my athlete. That’s the trick. How can I apply the knowledge from research on this particular individual athlete in front of me?

Frequently asked questions

What is individualized training?
In Kraaijenhof’s approach it is coaching each athlete according to their own anatomy, fiber type, brain wiring, and temperament, rather than applying a generic program built on group averages. Every training decision, from cueing to plyometric volume to warm-up, is adjusted to the specific person.

How do you know if an athlete is fast-twitch or slow-twitch without a biopsy?
Watch how much they fade across repeated maximal efforts. In five repeated 300-meter runs or a 30-second repeated jump test, a fast-twitch athlete starts high and drops off sharply, while a slow-twitch athlete holds up much better, so the decline itself reveals the type.

Which plyometric tests match the phases of a sprint?
Kraaijenhof pairs the squat jump with the block start, the countermovement jump with acceleration, the reactivity (short-contact) jump with maximum speed, and the repeated 15-second countermovement jump with the endurance phase of the race.

How much bounding should sprinters do?
Only as much as is necessary to get the effect, dosed to what the individual can tolerate without injury. Because bounding does not feel fatiguing in the moment, its joint and tendon cost is easy to overshoot, so athletes who tolerate it can do more and those who do not should do very little.

What is the difference between a warrior and a worrier athlete?
A warrior is energized by competitive pressure and tends to peak when it matters, while a worrier performs best in the low-stress comfort of training and can shrink under the arousal of a big event. Kraaijenhof coaches each type differently, especially in how he manages their warm-up and arousal.

About the authors

Henk Kraaijenhof is a Dutch elite sprint coach, researcher, and consultant regarded as one of the sharpest minds in speed and conditioning. He has coached some of the fastest sprinters in the world and advises coaches and sports federations across many disciplines, with a long-standing focus on building training around the individual athlete. He is the author of “What We Need Is Speed.”

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 Henk Kraaijenhof on Just Fly Sports.