The sprint is built

Here's what's in this week's edition.

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Bob Thurnhoffer, who coaches the jumps at Louisville, made a point on the Just Fly Performance podcast this month.

In acceleration, he said, every step feels like a build. You push hard and keep pushing. But once you're upright and at top speed, "the sprint is built. You're not building anymore." From there it's about rhythm, and every step should feel the same.

The mistake, as he sees it, is carrying the acceleration feeling into top speed. You think you have to keep building, so you push for too long and spend too much time on the ground.

I agree, with one thing added. Relaxed doesn't mean soft.

Faster sprinters push harder into the ground than slower ones. What you let go of is the tension in your face, shoulders and hands, and the urge to keep pushing, not the force.

Here's how I'd practise it.

Sprint-float-sprint. Accelerate for 30 metres (40 if you take longer to reach top speed), then float, holding your speed without trying to add to it, then sprint for another 20.

The whole rep is about 70 to 80 metres. On that last sprint, don't try harder. Think quicker steps, quicker arms, and keep your face loose.

Alternating flys. A fly is a sprint with a run-up, so you hit the timed part already at top speed. Run one fly at about 80% effort and the next one flat out, and film both. They should look the same. If the flat-out one looks tighter, that's what to work on.

Keep it to a few reps with full rest, because this only works when you're fresh. And don't expect the relaxed reps to feel fast. That's partly the point.

After the tempo edition in June, a reader wrote in to say that tempo "should not even exist in a sprinter program", because there's no meta-analysis showing it improves sprint performance.

They're right that the study doesn't exist. As far as I can find, there isn't a meta-analysis, or even a single controlled trial, testing this kind of tempo on sprinters' times.

But that doesn't mean tempo doesn't work. It means nobody has tested it.

One review of how elite sprinters train points out that most sprint-training studies are done on young team-sport players rather than sprinters, and that the methods top sprinters use have come from coaches' experience, not from sports science.

That's where coaching comes in. You can't wait for a study on everything. You watch what a session does to your athletes, and you adjust.

I also don't think tempo was ever meant to make anyone faster.

Charlie Francis kept it in his program all year round, at 65 to 75% of top speed. A 22-second 200 metre runner, he said, should never go faster than 30 seconds in tempo.

He used it to keep athletes fit, lean and in rhythm, and he warned that "some coaches spend too much time on tempo work! The priority requirement for sprinting is power."

Some good coaches don't use tempo at all. One has said he saw his sprinters improve when he dropped it. That's exactly the kind of judgement I mean, and I'd respect it. It just doesn't prove tempo is useless for everyone else.

So here's how I'd judge it. Tempo isn't speed work, and if it's taking anything away from the speed work, cut it.

The clearest risk is volume. Too much endurance work on top of strength training cuts into the power you get from the lifting, which I come back to in Game Speed below.

But for athletes who race on back-to-back days or run the 200 and 400, for younger athletes who need general fitness, and on days when the weather rules out anything fast, I'd keep it.

Keep it easy. Francis's version was 10 x 200 metres on grass at about 75%, walking 100 metres between reps, 2,000 metres in all. If the reps start creeping faster, it's stopped doing its job.

And watch your athletes. If they come into the next speed session fresh, it's earning its place. If their legs are heavy or their shins start to complain, do less.

Jack Grimes was Melbourne's pick 14 in the 2007 AFL draft and went on to co-captain the club. In a video this month, he looks back at how he trained as a teenager.

At 15 and 16 he was running 16 kilometres, sometimes 18 or 19, at least three times a week, timing each run and trying to beat it.

Along the way he had a stress fracture in his foot, then one in his back, and he barely played in his first year at Melbourne because of osteitis pubis, an overload injury around the groin.

He'd had "a lot of speed" and "a lot of power" as a kid. In his words, his body "slowly transformed into this slow one-paced player." Last year, at 36, he ran the fastest 20 metres of his life.

I'd be careful with the lesson here, because it isn't "don't get fit". Team sports need fitness, and a review of studies on young athletes found you can build fitness and power at the same time.

The problem is the kind of running. Across studies that add endurance work to strength training, the more often and the longer people did it, the less power they got out of the lifting.

And in one small study of teenage male athletes, mostly distance runners, those averaging more than 30 miles a week had about six times the odds of low bone density. Grimes's runs added up to about that, before any football.

If you're a teenager trying to get fitter for your sport, here's what I'd do instead.

Swap the long runs for short, hard intervals. A well-tested version is four efforts of four minutes close to your maximum heart rate, with three minutes of jogging between, twice a week.

In young soccer players it improved fitness without making them any slower. You can even do it with a ball.

Play small-sided games. The fewer players, the harder the work, and they improve fitness about as well as running drills do.

Sprint flat out twice a week. Short sprints of about 20 metres, with at least 90 seconds between them. There's also some evidence that players who regularly hit close to their top speed in training get injured less.

And don't write your speed off. Grimes found his best 20 metres at 36.

At the Tokyo Olympics in 2021, Su Bingtian ran 9.83 in the semi-final. It was an Asian record and made him the first Chinese man in an Olympic 100 metres final, where he finished sixth. He was 31.

He'd already broken 10 seconds in 2015 under his previous coach, Yuan Guoqiang. Randy Huntington took over at the end of 2017, when Su was 28.

What makes this a useful case is that Su helped write it up. He was the lead author of a 2019 paper on Chinese men's sprinting that sets out his own training under Huntington.

Huntington's diagnosis started with Su's build. His legs are short, and he was already taking over five steps a second.

His ground contacts were as short as 0.074 seconds, so brief, in Huntington's words, "that he didn't have enough time to develop stride length." There wasn't much more speed to find by moving his legs faster.

So they trained what was holding him back. Su's paper lists hamstring and ankle strength, how actively he drove his foot into the ground, and his start, meaning his block set-up and his first seven steps, which were too short.

The numbers in the paper show what changed in his first year or so under Huntington. His calf power on a Keiser resistance machine went from 900 to 2,050 watts. His power clean went from 100 to 115 kilos. His first seven steps went from 9.24 metres to 10.15.

But his average step over the whole race barely moved, from 2.08 metres to 2.09.

That last number is the interesting one. You'd expect the story to be "he got stronger and took longer steps." In those numbers, what mostly changed was the start.

And they didn't chase longer steps directly. Su has said his coach told him not to make his steps bigger on purpose, but to get stronger in normal training and let them grow on their own.

Before Tokyo, they also spent about a year getting back some of the step frequency he'd lost.

So is "find your weakness and train it" the answer? I think it's the right way to think, but I wouldn't oversell it.

Training built around each athlete's individual profile hasn't consistently beaten standard programs when it's been tested. And Su had a full support team and changes we can't separate out.

What I would copy is the process. Measure, find the gap, train it, and measure again. You don't need a lab for that.

Time your splits. Time 0 to 10, 10 to 20 and 20 to 30 metres, and a flying 30. Two athletes with the same 30 metre time can lose it in different places, and they need different work.

Film your first steps. Put tape marks every metre over the first 10 metres, film side-on, and measure your first few steps. That's the part of Su's race that changed most.

Retest every few weeks. If the number you're training isn't moving, or it moves and your times don't, change something.

If there's something you'd like me to cover, just reply to this email.

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