Bend running isn't a fitness quality

This is a follow-up to a newsletter I sent about a month ago, which made the case that the bend is somewhere to run rather than somewhere to rest. If you're newer here or you missed it, it's worth a skim first.

What it didn't get into is where bend running actually sits in a training week. That's what I want to cover here.

Start with a mismatch that's easy to miss.

On a standard outdoor track the bend accounts for roughly 115 metres of the 200, whichever lane you're in. That's 58 per cent of the race, and the whole acceleration phase happens on it.

You leave the blocks on a curve, you build to top speed on a curve, and more than half the race is behind you before the track straightens out.

Now think about where your fast running actually happens across a normal week. If most of it is on the back straight, that's understandable. That's where the wickets go, where the timing gates go, and where you can see what you're doing.

Here's where it gets interesting, because the obvious fix is the wrong one. The obvious fix is more curve running. Some curve tempo, Saturday's session round the top bend, a bit more exposure. I don't think that does much, and the reason is worth spelling out.

Bend running isn't a fitness quality. There's no bend energy system, and no general curve fitness waiting to be developed underneath your bend performance.

What you're training is narrower than that. It's tolerance for a fairly strange force environment.

Here's what makes it strange. Sprinting on a curve, your two legs stop doing the same job as each other. Peak vertical force through the inside leg drops by around a third of your body weight compared with straight line sprinting, while the outside leg carries on more or less unaffected.

Some athletes actually produce more force through the outside leg on a bend than they do on the straight. One leg does the turning, the other does the driving, and nothing in a straight line session rehearses that.

The same group put the implication carefully, and they're explicit that it's speculation. Their suggestion is that an athlete's main way of learning to tolerate these forces is by sprinting on the bend at high velocities.

That constrains things in both directions. It says bend running is trainable, and it says the training has to be genuinely fast, because you can't build tolerance for high forces at speeds that never generate them. Curve tempo doesn't produce those forces, so it doesn't buy you the adaptation.

The study behind that suggestion has a nice piece of evidence in it that this is a trainable skill rather than a fixed mechanical tax. Nine sprinters, most of them with 200m bests between 21.1 and 22.6 seconds, were tested in lanes eight, five and two.

Average velocity dropped as the bend got tighter, which is unsurprising. What happened to the spread between them is more interesting.

As the radius tightened, the athletes became more different from each other, not less. If the bend were a toll everybody paid at the same rate, they'd have stayed about as bunched as they started.

Instead they fanned out, which is what you'd expect if some of them were simply better at running bends.

So why not put everything on the curve?

Because you can't reach your top speed there. Maximal sprinting on a bend comes out around 4.7 per cent slower than the same effort on the straight.

A session whose whole purpose is exposing you to the highest velocity you're capable of producing can't sensibly be run on a curve. That's the real constraint.

Which brings me to the part that's actually useful. The tidy answer is to sort your training by session type. Speed endurance goes on the curve, max velocity stays on the straight. It's clean, and it sounds right.

It also isn't what the best programmes do. Go through a full elite 200m season and you find genuine speed work on the bend, including short reps run flat out. What you don't find is peak velocity work through the tight middle of the curve.

So the division isn't by session at all. It's by which part of the bend you're on. The exit tolerates speed, because a rep that starts late spends its fastest metres coming off the curve and onto the straight, where the constraint lifts.

The tight middle doesn't. And the entry, meaning the first few steps out of the blocks, is a separate skill that belongs with your start work.

The vocabulary is worth borrowing. A full bend rep starts at the 200 start and runs the lot. A half bend rep starts 150 metres from the finish, which puts you about halfway round the curve. An off bend rep starts 120 out, so it only catches the last part of it.

The seasonal shape falls out of this on its own.

Through general preparation, the base phase early in the season, there's no bend running on the track at all. Everything fast is straight. It turns up as competition approaches, and it arrives first as short off bend reps inside a technical session rather than as conditioning.

Sixty, seventy five and ninety metres, long recoveries, catching only the end of the curve.

From there it lengthens into race-shaped work, half bend and full bend 150s. Then through the sharpest weeks it goes back to being short again, with the primary speed session a set of ninety metre off bend reps.

Starts are the exception, in that they move onto the curve earlier than the rest of your bend work and then stay there. Clyde Hart's progression is still the cleanest I know.

Put a marker in the lane at 30 metres and take four to six starts to it, then move it out to 40, and keep moving it out until you've run starts through the first 60.

That leaves two things, and they're the two easiest to get wrong even once you're training the bend on purpose.

The first is where the rep ends.

If your bend running stops as the track straightens, you've trained everything except the part where the race gets decided.

The transition runs from the curve into the straight, and it's the moment you unwind a lean while still running close to top speed.

Across that elite season, off bend reps outnumber full bend reps through the entire competition period. At the top of the sport the exit isn't the forgotten part of bend training. It's most of it.

The second is your lane. The standard advice is to train in lane one because it's the tightest, and I think that's aimed at the wrong end of the track.

When those nine sprinters were tested, almost all the velocity they lost came between lane eight and lane five. From lane five down to lane two, the further drop was negligible.

So the cost isn't waiting for you in lane one. Most of it has been paid by the time you reach the middle of the track.

The mistake isn't neglecting lane one, it's doing all your bend work in lanes six to eight, where the track is empty and the curve is kindest, and never running where the penalty actually lands.

The bend does tax everybody. But the spread widens as it tightens, and that's the argument for training it properly. Some people are better at this than others, and being better at it is something you can go and get.