How far apart should starting blocks be?

Start from your leg length. Set the front block about 50–55% of that distance behind the start line and the rear block about 45% of leg length behind the front block. In a 2023 study, front-block distances closer to 50% of leg length produced better starts than longer ones. Fine-tune by timing 10m.

Which foot goes in the front block?

Most athletes put the leg they prefer to push from in the front block. If you're unsure, try both setups over a few sessions and keep the one that gives you the faster 10m time.

Do you have to use blocks in the 400m?

Yes. Under World Athletics rules, a crouch start and starting blocks are compulsory in all races up to and including 400m, including the first leg of the 4 × 400m relay.

What is the false start rule?

When a certified start information system is used, a reaction time under 0.100 seconds after the gun signals a possible false start. Outside combined events, an athlete responsible for a false start is disqualified.

How do I practice starts without blocks?

Use crouch or three-point starts, falling starts and push-up-start accelerations over 10–20m, which train the same low, forceful push. The Sprint University system starts athletes from a crouch and introduces blocks later.

Why do my toes drag on the track in the first steps?

A light scrape in the first two or three steps can be a side effect of a low, forward first step, with the foot recovering close to the ground before it punches back down. The cue "trim the grass with your toes" asks for that low path, so if your 10m times are good and you aren't catching the track, leave it alone. Coach it when the toe catches hard enough to trip you or cut your step short, or when the foot trails far behind you: cue a quicker knee drive forward, and time 10m before and after to check the change helped.

Block start: setup, positions and cues for a faster start

By the Sprint University coaching team

Set your blocks so both legs can push hard. In the set position, stay still with both legs loaded, then push violently and come out low with quick, powerful first steps. Most athletes underrate how much the rear leg and hip contribute.

World Athletics rules require blocks in every race up to 400m, so if you sprint on the track, this setup is part of every race you run.

The rules you are starting under

World Athletics Technical Rule 16 sets out how a sprint start works.

Races up to and including 400m use a crouch start and starting blocks. The commands are “On your marks” and “Set”.
On your marks, you may not touch the start line or the track in front of it. Both hands and at least one knee touch the ground, and both feet are in contact with the block foot plates.
At “Set”, you rise straight to your final position with hands on the ground and feet on the blocks, and hold still.
Where a start information system is used, a reaction under 0.100 seconds after the gun flags a possible false start, and outside combined events a false start means disqualification.

How to set your blocks

Block spacing varies from athlete to athlete, and research gives you a place to start. A 2023 study of 36 sprinters set the front block between 50% and 70% of each athlete's leg length behind the line, with the rear block 45% of leg length behind the front. The shorter front distances, toward 50%, produced better starts in both trained and untrained sprinters, mainly through more force from the rear block.

Measure your leg length, standing, from the bony point on the side of your hip to the floor.
Set the front block at about 50–55% of that distance behind the start line.
Set the rear block about 45% of leg length behind the front block.
Time a few 10m starts, change one thing at a time, and keep whatever is fastest.

Don't chase one ideal setup. A review of sprint start biomechanics found that sprinters at every level use a wide range of set positions, and those differences were not directly tied to block performance. The force you put into the blocks counts for more than the exact position.

On your marks

Back into the blocks, front foot first and then rear foot, with your toes just touching the track.
Put your rear knee down and your hands just behind the line, a little wider than shoulder width.
Keep your arms straight, with thumbs and fingers forming a bridge and your shoulders over or slightly ahead of your hands.
Hold your head neutral with your eyes down, then breathe and settle.

Set

Raise your hips to slightly above shoulder height in one smooth movement.
Shift your weight forward onto your hands until you feel pressure in both blocks.
Bend the front knee clearly and keep the rear knee more open, with both legs loaded.
Hold completely still and wait for the gun.

The push and the first steps

Studies of the first second of a race point to four priorities.

Push hard against both blocks. Greater average force against the blocks, especially from the rear leg and particularly at the hip, is linked to a better block phase.
Get back to the ground low and fast. Better sprinters spend less time in the air after leaving the blocks and longer on the ground in their first step, which gives them more time to push.
Keep the ankle firm and the knee extending. A stiff ankle and a knee that keeps extending through the first contact go with faster starts.
Keep the force pointed forward. In acceleration, faster sprinters keep more of their force horizontal as speed builds, so rise gradually instead of popping upright.

Your arms work hard too. Punch the arm opposite your front leg forward, big and fast, and drive the other one back. One cue for the first steps from the elite sprint literature is “trim the grass with your toes,” meaning keep your feet low and quick.

The Sprint University app

See your start show up in your 100m time

Sprint University pairs start work with acceleration, top-speed and strength sessions, and it retests your 100m every few weeks.

Get Sprint University

A block start session

In the Sprint University catalog, the block start block is four reps at 95–100% with 3 minutes of rest. A full session can look like this:

A full warm-up, including 2–3 build-ups. See the sprint warm-up.
A primer of 3 standing broad jumps or a short sled push.
4–6 × 10m block starts, walking back, with 2–3 minutes of rest. Focus on the push.
3–4 × 20–30m block starts with 3–4 minutes of rest. Focus on rising gradually.
End the session as soon as your starts get sloppy or slower.

In the Sprint University system, athletes build acceleration from crouch starts first and add blocks later. The day before a race is a full warm-up, two or three short starts and a warm-down. The acceleration that follows the start is covered in acceleration drills, and posture beyond the first steps in sprint form.

Common mistakes

Blocks set too long: A very stretched setup weakens the rear-leg push. Move the front block closer to the line and time it.
Standing straight up: Popping up in the first two steps costs you horizontal force. Let your body angle rise gradually over the first 20–30m.
Reaching with the first step: A long, floating first step lands in front of you and brakes. Drive the knee forward and punch the foot back down under you.
Rocking or rolling the start: Movement in the set position risks a false start. Hold still, then react.
Only the front leg pushing: Feel both blocks loaded in the set position, since rear-block force is linked to a better start.