Why Is Reaction Time Important in Sport? Football, Netball, Sprinting & More

Reaction time is the time between a stimulus and the start of your response. In sport the stimulus can be visual (the ball, an opponent’s movement), auditory (the starting gun, a whistle, a teammate’s call) or even touch (a push in a scrum or a clinch).

• Reaction time — stimulus to first movement.
• Movement time — first movement to completing the action, such as the full dive or the full swing.
• Response time — the two added together. This is what decides whether you get there in time.

There are also two kinds of reaction. Simple reaction means one stimulus and one planned response, like a sprinter reacting to the gun. Choice reaction means picking the right response among several, like a defender deciding which way a dribbler will go. Choice reaction is slower, and it slows more with age (Der & Deary (2006)). Most team sports are full of choice reactions.

For scale: the average adult simple reaction to a light, measured on a screen like a browser test, is about 231 ms, or roughly a quarter of a second (Woods et al. (2015)).

The clearest example is the penalty kick. The penalty mark is 11 metres (12 yards) from goal (IFAB Laws of the Game, Law 1), and the goalkeeper must stay on the goal line until the ball is kicked (IFAB Laws of the Game, Law 14). A ball struck at 100 km/h covers those 11 metres in about 0.4 seconds (simple arithmetic: 11 m at 27.8 m/s).

Now subtract a typical reaction of about a quarter of a second before the keeper even starts to move. More than half the ball’s flight is gone, and the dive itself still has to happen. That is why goalkeepers do not wait to see the ball: they read the kicker’s run-up, hips and standing foot, and start moving as the ball is struck. Reaction time still matters, but anticipation is what buys the time to use it.

When is reaction time used in football?

• Goalkeepers: penalties, close-range shots, deflections and crosses that change direction late.
• Defenders: reacting to a dribbler’s feint, a through ball or a sudden change of pace. These are choice reactions, the slower kind.
• Attackers: reacting first to a rebound, a loose ball or a defender’s mistake. Many goals come from being a fraction quicker to a ball nobody expected.
• Everyone: reacting to a deflection, a bad bounce, or a teammate’s shout. Sound helps here, because people react faster to sound than to light (Jain et al. (2015)).

A useful way to answer this, and a common exam question, is to ask who starts the action.

• Externally paced sports force you to respond to something you do not control: an opponent, a ball, a gun. Boxing, football, netball, tennis, badminton and sprint starts all depend heavily on reaction time.
• Self-paced sports let the athlete decide when to start. Weightlifting, golf, archery and long-distance running rely far less on reaction time.

So if you are asked whether reaction time is crucial for weightlifting, chess, boxing or golf, the answer is boxing. Chess is about decisions over seconds or minutes, not split-second reactions.

Partly, and the most trainable part is not raw speed.

• Stay active. Physically active students reacted faster to both light and sound than inactive ones (Jain et al. (2015)).
• Practise the real situation. Repeating the same stimulus and response makes it more automatic, which is why sport-specific drills beat generic ones.
• Train anticipation. Learning to read cues, such as a kicker’s hips or a server’s toss, starts your response earlier. This is where elite players gain the most.
• Sleep. Short-term sleep loss hits simple attention and reaction tasks harder than almost anything else it affects (Lim & Dinges (2010)).