The timer starts at the athlete's first movement and stops when the athlete crosses the 40 yard mark. If using a stopwatch, start the timer when the athlete moves, and stop when they cross the finish. If using timing gates, space them 40 yards apart. Have the athlete start as close to the first gate as possible without triggering it to get the most accurate time possible.

THE START

Use a three-point start. It is what NFL athletes use.

A three-point start places the athlete lower, allowing them to apply force horizontally rather than straight down. Horizontal force is what accelerates you, so a three-point start produces faster times than a standing start.

The athlete starts on their own time. The clock starts when they move or when they break the first gate, depending on your setup.

RUN THROUGH THE LINE

Athletes lose real time by decelerating before they reach 40 yards. Easing up in the last few yards can cost close to half a yard.

Tell them the finish is five yards past the line and let them run through it.

HOW MANY REPS

Two or three.

Research on 40-yard testing suggests performance starts to decline after the third or fourth rep, even with rest in between.

Watch the times as you go. When they start falling off, extend the rest or stop. Pushing through a session where every rep is slower than the last does not build speed, and it raises injury risk for nothing.

Athletes should be fresh going in. Testing at the end of a hard practice measures fatigue, not speed.

SURFACE

The NFL combine runs on turf, and turf is what most published times are compared against. A track is faster.

Whichever you use, note it down. A turf time and a track time are not the same measurement.

TIMING IT

If you are using a stopwatch, your times run about two tenths of a second fast. The timer starts late because they are reacting to movement, and stops early because they anticipate the finish.

The bigger problem is that the error is not consistent. The same coach timing the same athlete twice will not be off by the same amount both times. So when an athlete runs a tenth faster than last month, you cannot tell whether they got faster or whether you were quicker on the button.

Electronic timing removes the reaction time on both ends. For reference, elite athletes run the 40 in roughly 4.5 to 5.5 seconds, and meaningful improvement at the high school level often shows up in hundredths. If you do not have the funds for timing gates, you can apply here.

RECORD THE CONDITIONS

Write down the surface, the footwear, and where in the session you tested, alongside the time. A number on its own is not much use three months later.