How to time athletes and record split times

You click the stopwatch, shout the time, and by the third runner you've forgotten the first. The fix is simple: run one clock for everyone, press Lap as each runner's torso crosses the line, and write down both the lap time and the running total. A few more habits make your splits far more useful to the people you coach.

In short

A lap split is the time for one lap. A cumulative split is the total time so far. Record both if you can.

Start on a visible signal and stop as the runner's torso crosses the line, the way officials do.

For a group, time one clock for everyone and write down finishing order with numbers. Don't try to run ten stopwatches.

1. What is a split time?

A split is a time taken partway through a run.

There are two kinds, and mixing them up causes most confusion:

Lap split: the time for that lap or section only. "That lap was 1:52."
Cumulative split: the total time since the start. "You're at 5:41."

Most stopwatches show both when you press Lap: the lap time and the running total. Write down which is which.

For pacing, lap splits are usually more useful. They show whether a runner is speeding up or slowing down.

2. How do I hand time accurately?

UK athletics officials follow a simple routine, and it works just as well at a club session.

From Welsh Athletics' reference cards for officials:

Start the watch on the flash of the gun, not the sound. Sound travels slower than light, so starting on the bang makes times late.
Stop the watch when the athlete's torso reaches the finish line. Not the head, arm or foot.
Don't anticipate. Their advice: see it, do it.

At a club session without a gun, use a visible start: a dropped arm or a flag. If you're standing at the finish and someone else shouts "go" from 200 metres away, you'll start late.

3. How should I round hand times?

Officials round up, never down.

For track races, Welsh Athletics' cards say hand times are rounded up to the next tenth of a second:

10.01 becomes 10.1
10.10 stays 10.1
11.97 becomes 12.0

For races wholly or partly outside the stadium, such as road races, times are rounded up to the next full second.

You don't have to follow these rules at a club session. But rounding up is a good habit: it means nobody's personal best is flattered by a fast thumb.

4. What if two people time the same runner?

Officials have a rule for that too. From the same reference cards:

Three timekeepers, two agree: that's the time.
Three timekeepers, all different: take the middle time.
Two timekeepers: take the slower time.

For a time trial that matters to your athletes, two timers on the same runner is a cheap way to catch mistakes.

5. How do I time a whole group at once?

Don't run one stopwatch per runner. You'll miss presses and lose track.

Instead:

Start one clock for everyone at the same time.
Give each runner a number, or use their names if the group is small.
As each runner finishes, press Lap and write their number next to the lap count. Or have a helper write the numbers down in order while you press.
Afterwards, match the order of numbers to the order of times.

For lap splits on a track with several runners, stand at the line and call out the running time as each person passes. Runners remember their own times better than you can. Welsh Athletics' cards note that timekeepers call lap times to athletes in races of 800 m and over.

6. How do I work out target splits?

Divide the target time by the number of laps or kilometres.

Here are some even-pace splits for a 5 km run:

5 km target	Per km	Per 400 m lap
20:00	4:00	1:36
22:30	4:30	1:48
25:00	5:00	2:00
27:30	5:30	2:12
30:00	6:00	2:24

A 400 m lap is 0.4 of a kilometre, so multiply the per-km pace by 0.4.

Give runners their target lap split before the session. Then each time they pass, you can tell them "on pace", "3 seconds up" or "2 down".

7. How do I time repeats like 6 × 400 m?

Repeats need two clocks in your head: the rep time and the recovery time. A rolling clock makes this easier.

Start the stopwatch at the first "go" and don't stop it until the session ends.
Press Lap as the runner finishes each rep. That lap is their rep time.
Press Lap again when they start the next rep. That lap is their recovery.
Read the list afterwards. Odd laps are reps, even laps are recoveries.

If you're timing a group doing repeats, set everyone off together on a fixed cycle instead, such as "go every 3 minutes". Each runner's rep time is then whatever the clock says when they finish, and their recovery is whatever's left of the 3 minutes.

8. What should I record after a session?

Keep it simple, but keep it. Over time, your records tell you who's improving and who's overdoing it.

For each athlete, write down:

Date and session (for example, "6 × 400 m, 90 s jog recovery")
Each lap split
Recovery time between reps
Conditions: wind, rain, heat, track or grass
How it felt, in a word or two

Watch for patterns. If a runner's splits get much slower over a session, the reps may be too fast or the recovery too short.

9. How do I make timing accessible for everyone?

Shouting splits only works if runners can hear you. Wind, traffic, other groups and breathing all get in the way, and some of your athletes may be deaf or hard of hearing.

Try:

Hold up fingers for seconds up or down on pace.
A small whiteboard with the running time, held up as they pass.
A big screen timer at the line, visible from the bend.
Agree signals before the session: thumbs up for on pace, flat hand for "ease off".

Do I need an app for this?

A good stopwatch is all you need to start.

The Clock app on iPhone has a stopwatch with a Lap button. Apple's guide notes that it keeps running if you switch apps or your iPhone sleeps.
A sports stopwatch with a lap memory is hardy and works in the rain.
A notebook for numbers and splits. Still the most reliable back-up.

How Reptyl helps

Reptyl Coach is a stopwatch for timing other people, one athlete or a whole group.

Reps, laps or a race. Time reps with a rest between, laps for one runner, or a group race on one clock.
Taking turns. Several athletes run one after another, one, two or three at a time, and the app keeps the order.
Rest if you want it. The rest counts down between reps. Turn it off and the app just shows who's next.
To the thousandth. Rep times show milliseconds, for short sprints. (Remember a thumb is never that accurate.)
Athletes and squads. Keep your athletes, put them in squads, and see PBs and a leaderboard for each distance.
Share cards. Send a session, a PB or a squad board as a picture.

It's a one-off purchase with no subscription, no account and no adverts, and your data stays on your phone. The Coach page has the details.

For speed work, read how to coach sprint sessions. For group sessions with stations, see how to run a circuit class.

Quick answers

What's the difference between a split and a lap?

A lap time is the time for one lap. A split is any time taken partway through. It can be a lap split (that section only) or a cumulative split (total time so far).

Should I stop the watch on the runner's foot or chest?

The chest, or more exactly the torso. UK officials stop the watch when the torso reaches the finish line, not the head, arms or feet.

Should I round hand times up or down?

Up. In track races, UK officials round hand times up to the next tenth of a second. Outside the stadium, they round up to the next full second.

How do I time several runners with one stopwatch?

Start one clock for everyone. Press Lap as each runner finishes, and write down their numbers in finishing order. Match the two lists afterwards.

Want every rep timed and saved? See Reptyl Coach