Race Directors click here SpacerSpacerSpacerSpacerSpacer AIMS Members click here
Home Page Marathon History About Us Contact Us Calendar Directory Results Partners

Event Manual
Course Measurement
AIMS Congress

Race Timing

The basic reason most people enter a race is to record a definite time to cover a definite distance. An official, correct, time is recognition of a runner’s performance. If you give the runner an incorrect time, it gives a very bad impression.

Timing a small race of less than 100 people poses entirely different problems to one in which tens of thousands participate. The budgetary constraints and the equipment and personnel available will also be quite different. You need to design your own timing system with the equipment and personnel you have available. There is no "best" system, merely systems that are most appropriate to requirements.

The main types of timing systems available are:

1) Those assigning transponders (“active” or “passive) to runners so that finishing times are registered electronically onto a computer system as runners cross the finish line. This is definitely the most efficient method of timing races, and any race with more than 1500 runners will most likely find some version of a transponder system within the constraints of their budget. Results (after appropriate checking by human agency) can be directly outputted for press, TV and to the race website.

2) Manual printer-timers, where a timekeeper depresses the key on a hand-held printer-timer each time a runner crosses the finish line. Runners then have to queue up in their finishing order so that their running number can be checked against their finishing position. There are various ways in which this can be done to render the processing and eventual output of results easier. An independent check must be made from time to time, where a runner is selected whose number is noted directly alongside the finishing time (usually on the printout) so that the two lists remain synchronised.

3) Hand-held stopwatches, where timekeepers call out a time as each runner crosses the finish line and this time is written down by someone else on a pre-prepared sheet. Runner numbers must also be matched with their finishing positions as in (2) above, and the same occasional cross checks need to be made. This method can only cope with relatively small size races, with no more than a few hundred runners. It is nearly always used as an additional method to time the first few finishers in a race (see below)

In all cases a back-up system will be required in case of the breakdown of the primary system. In most cases such backup can be achieved simply by continuously filming the finish line with a video camera as runners pass through, and keeping the race clock in view. Even if the race clock breaks down the clock operating within the camera can be checked against the time elapsed in the race.

Additionally, it is strongly advised that the traditional hand-held stopwatch method [(3) above] be used for the top finishers in any race. Apart from acting as an independent backup system, this is the only practical method of timing for road races which yields results eligible for record ratification (requiring "three stopped watches"- further discussion of this point <here>).

Transponder timing

IAAF rule 165.24 permits the use of transponder timing systems in road races.

Transponder systems can deliver accurate results almost instantaneously. They have the capacity to handle runners finishing in far greater numbers than traditional systems could cope with. For races of more than 1500 runners, the use of a transponder system should be economically feasible.

They are also secure. The only back up required would be manual timing for the race winners (in case of records being set) and a video camera trained on runners finishing with the finish clock also visible. This is a failsafe against the overall breakdown of the system, although the chances of this are very small. Chip timing systems are always operated with a back-up line at the finish and data is buffered on several levels. Video camera evidence will resolve any questions, if they arise, of who was wearing which chip.

The system times each individual runner as they pass any specified point along the course and can be activated either by the starting gun (for "gun" times) or when the individual runner passes over antenna mats laid at the start line (for "net" times). A runner's net time is the time taken between crossing the start line and the finish line. A gun time is the time taken from the starting signal until the runner crosses the finish line. Official results must be based upon gun times.

The "chip" itself is a miniature transponder in a plastic casing. This device contains a chip in combination with an energising coil. These elements are encased in a waterproof glass capsule so that the chip can be used in all conditions: hot or cold, wet or dry.

This sort of chip contains no batteries. The transponder is "passive". Only when moved into a magnetic field generated by a send antenna will the energising coil produce an electric current to power the chip. The transponder then transmits its unique identification number to a receive antenna. Both send and receive antennae are cast within thin tartan mats laid over the road surface. The send-receive process takes about 60 milliseconds and is repeated continuously as long as the chip continues to move within the magnetic field generated.

The mats are connected to small boxes placed at either side of the road, which contain electronics and batteries. As each athlete crosses the mats and the chip ID is transmitted, this number and the corresponding time is stored to a timing computer for further processing.

There are other systems on the market. The main technical difference between them is whether they rely upon "passive" or "active" transponders. Active transponders are those that incorporate a battery within the casing, which powers the chip without the need for the mats laid over the roadway to generate a magnetic field for the chip ID to be registered.

The main practical differences between active and passive transponder systems are:

i) Active transponders are much more expensive (active chips cost about five times as much as passive transponders).

ii) Active transponders can transmit information as runners pass over a wire loop. Such a loop could be merely taped to the road surface. No heavy matting is required and costs for transport of equipment and time for set up are much reduced.

In either case the transponders are relatively valuable items that race organisers must retrieve from their race entrants, unless they charge them a deposit for "rental" which will cover the cost incurred by possible loss of the chip. "Chip retrieval" is a specific function that must be considered and carefully planned out in any finish line set-up where transponder timing is used.

Passive transponders are most usually distributed at the race registration and collected at the finish line. The timing company charges a rental for providing the chips and race organisers should also be prepared to pay for the cost of lost chips. If the chip retrieval process is efficient, then this is a very cost-effective system.
Disposable transponders have been developed for use very recently. This is a slightly more expensive option, but it has several advantages. The shape has room for branding, and leaves the athlete with a very nice souvenir. Disposable chips are easy to use in parallel with runner-owned chips, and there is no need to retrieve the chips after the race.

All transponder systems offer significant advantages:

- fast and accurate results for each individual participant
- "net" times and split times can be made available to participants
- split times can be fed to press, TV and Internet
- there is no back-up of runners at the finishing line
- less build-up and break-down of material at the finish line
- automated checkpoints along the course to safeguard against cheating

The chip is usually worn on the shoe in order to be close to the magnetic field generated by the mats, or so that the active transponder does not need to transmit very far to register a signal. That the timing point is the foot (and only one of them at that) rather than the torso is one reason why IAAF do not accept transponder timings for world record purposes.


When problems occur with these systems it is usually because operators do not understand all set up and software issues. Either employ a dedicated timing company or, if you are renting or purchasing the equipment yourself, make sure that your entire team are thoroughly briefed by the distributor before you use the system in a real race.

Note the difference between 'gun times' (brutto) and 'chip times' (netto) and the consequences of using either or both. IAAF recognises only 'gun times', the time elapsed from when the timing system is activated by a starting signal to when the finish system picks up a signal from runner's transponder. All official results should be reported with gun times, and rounded up to the nearest whole second.

IAAF Rule 165.24 includes the following technical specifications:

a) none of the equipment used at the start, along the course or at the finish line constitutes a significant obstacle or barrier to the progress of the runner

b) the weight of the transponder and its housing carried on the runners' uniform, race number or shoe is not significant.

c) the system is started by the Starter's gun or approved starting apparatus. The official time is that elapsed between the start signal and the runner reaching the finish line. The time elapsed between a runner crossing the start and the finish line can be made known to the runner, although it will not be considered the official time.

d) the system requires no action by the runner during the competition, at the finish line or at any stage in the results processing

e) the resolution is 0.1 seconds (i.e. it can separate runners finishing 0.1 seconds apart)


Asics Marathon-Photos Konica-Minolta Citizen Attica 1000km Productions VisitGreece

AIMS Sponsors