Agility Training: Improving Sporting Reaction Times

How visual acuity and auditory signals can affect your performance in sport.

Article at a glance

  • The relationship between race length, previous experience and auditory reaction times in sprinters is explained;
  • Research is presented identifying the necessary skills and behaviours for superior visual reaction times in field and racket sports;
  • Training drills and equipment that can improve reaction times are described.

There aren’t many sports where having split second reactions isn’t an advantage. However, as John Shepherd explains, rapid reactions depend on numerous factors such as the auditory and visual senses, specific sports skill and experience. The good news is that while this aspect of sports performance is perhaps not fully appreciated, it can be specifically trained

Athletes who have the fastest reactions have more ‘thinking time’ to perform their specific sports’ skills and achieve winning performance. An obvious example is the 100m-sprinter, who gains a metre seemingly before the others have moved from their blocks when reacting to the gun. However, moving in the blink of an eye is just as important for footballers or racket sports players and in numerous other sports. For instance, footballers that can gain a split second through their quick reactions will often find that they can tackle or shoot for goal more effectively. In this article, reaction time is assessed in the context of responses to auditory and visual cues, and drills and practices are described that can enhance reaction times are presented.

Reacting to an auditory signal

As indicated (see box, below left), the IAAF has in place a sprint start rule that warns/disqualifies athletes if they achieve a starting reaction faster than one tenth of a second. However, some researchers believe that reaction times of less than one tenth of a second are achievable and new British research conducted at the University of Loughborough appears to confirm this(1).

Sports reaction times

Sprinting
The International Association of Athletics Federations (IAAF) believes that a human takes at least a tenth of a second to react to the start line gun; any faster implies cheating. However, not all would agree (more later)! The fastest ever legal reaction time (by IAAF criteria) was the 0.101-second reaction achieved by Canadian Bruny Surin in the 1999 world championships 100m semi-final.

Racket sports
Badminton requires faster reaction times than tennis and squash, although table tennis may require even faster reaction times. The fastest reactions in badminton are required in men’s doubles, where returning smashes can reach 200mph as the returning player is often in closer proximity to the smash compared to singles. In table tennis, with smashes in excess of 60mph, a player typically has only 0.3 seconds to react as the ball travels the length of the table (2.74m/9 feet).

Cricket
22 yards gives the batsman about half a second to react to a ball delivered at 95mph.

Football
A goalkeeper has just 0.3 seconds to react to a penalty struck at 80mph from the penalty spot, 12 yards out from the goal.

Reaction time figures from: www.gresham.ac.uk/event.asp?PageId=45&EventId=352

The reaction times of nine athletes performing sprint starts were considered in which the starting blocks used had force plates, akin to those used in competition. These measure the slightest levels of exerted force (it’s pressure on the blocks that sets off the false start signal to the starter in the case of a race, or the researchers in this case). In this study, it was shown that five sprinters had legal mean reaction times of less than one tenth of a second.

The theory was that this was possible because the brain could get a signal to the reacting muscles and begin the process of muscle firing before the tenth of a second had elapsed. This was substantiated by the measurement of EMG activity during the start, which measured the electrical impulses received in the muscles involved and discovered that they could be initiated in less than a tenth of a second. The researchers went on to conclude that, ‘ … the neuromuscular-physiological component of simple auditory reaction times can be under 85 milliseconds…’

Jargonbuster

EMG (Electromyography)
The amount of electrical activity in a muscle created by muscle contraction/stimulus

Before starting blocks were designed with force plates, sprinters often attempted to anticipate the ‘bang’ to get away quicker and some highly interesting research from France has arisen out of this(2). In fact, these research finding might indicate why over the shortest of sprint distances very quick reactions are achievable that could beat the IAAF limit.

The French study involved male 100 to 400m sprinters and what makes it particularly valuable is the fact that all the athletes reached the final of a sprint event at world championship or Olympic level. Analysis indicated that reaction time to the starting shot played a significant role in the athletes’ races. The team discovered three characteristics:

  1. The longer the sprint, the longer the reaction time ie 60m reaction times were quicker than 100, 200 and 400m times;
  2. Reaction times were seen to be a function of race length, ie the reaction time of the first leg runner in the sprint relay was no different from that of a 400-m sprinter. Also the reaction time of the lead-off sprinter in the a 4 x 400m was slower than that for individual one-lap races;
  3. Reaction time was found to decrease from the heats to the final. Interestingly the team discovered that this phenomenon was not observable in less experienced sprinters through the qualifying rounds (junior 18/19-year-old sprinters taking part in their own world championships).

These very interesting findings led the researchers to postulate that reaction time is a skill, which is influenced by experience and learning, and crucially is also associated with race length. As sprinters place more emphasis on a quicker reaction in the short sprints, they are able to get faster starts. This behaviour results from the factors identified, but also they believe from the ‘allocation of concentration resources and expenditure’. Basically they argue that fostering greater concentration (coupled with experience) will lead to faster reactions for the shortest sprints.

Visual reaction

In field and racket sports, the athlete has to respond to a moving object or other players. How the player reacts can have a highly significant influence on the success of their particular reaction-based sports skill/skills. Elite football goalkeepers exemplify quick reactions.

A team of researchers specifically looked at keepers’ reactions and penalty saving in a novel way(3). The Dutch team used a film-based test of ‘anticipation skill’. The test required the keepers to move a joystick in response to penalty kick situations presented on a large screen. The proportion of penalties saved was assessed, as well as the frequency and time of initiation of joystick reactions. Visual search behaviour was examined using a portable eye movement registration system (basically, eye movements were tracked).

The team found from this test that the quicker keepers and best penalty savers were more accurate in predicting the height and direction of the penalty kick, waited longer before initiating a response and appeared to spend longer periods of time focusing on the non-kicking leg of the penalty taker.

‘The best penalty savers were more accurate in predicting the height and direction of the penalty kick, waited longer before initiating a response and appeared to spend longer periods of time focusing on the non-kicking leg of the penalty taker’

Let’s continue with football and move to outfield players; what visual factors can improve their reactions? British researchers from Liverpool investigated skill-based differences in anticipation and visual search strategies in open-play(4). Fifteen experienced and 15 inexperienced subjects were required to anticipate pass destination from filmed football sequences viewed on a large 3m x 3m video projection screen.

It was discovered that the experienced players demonstrated superior anticipatory and reaction performance. Experienced players fixated on peripheral aspects of the display, such as the positions and movements of other players across significantly more locations than their inexperienced counterparts, and the better players were also able to look at different areas of the field of play on the screen more frequently. Consequentially they were processing more information, more rapidly and accurately. This led the researchers to conclude that: ‘The increased frequency of eye fixations was regarded as being more advantageous for anticipating pass destination during open play in football.’

Similar findings were made by researchers from the same city almost a decade later(5). This team first showed skilled and less skilled football players footage of match situations and found that the former were also able to react and analyse the situations more effectively than the latter group. However, they went a stage further than their predecessors and analysed the speed and accuracy of pattern recognition skills in a non-football visual way. The players were required to analyse patterns, which used coloured dots (pin light forms) displayed on a screen. These patterns reflected football sequences. It was again discovered that the skilled players were better able to react to and correctly identify the various scenarios. The researchers attributed this to the players’ ability to read the sequences, the way they looked (ie took in visual information) and finally their playing experience.

Research from other sports has provided similar conclusions. For example, Texan researchers looked at reactions to visual cues in 13 skilled and 12 novice tennis players(6). One test condition required the players to anticipate the type of stroke and the direction in which the ball would travel. Both groups of players correctly anticipated at greater than ‘chance levels’. However, the skilled players were significantly more accurate than novices with live and video displays but not with point-light displays (unlike the footballers). Crucially in the light of the subject matter of this article it was discovered that the reactions of 10 expert performers were significantly faster when they returned balls hit by a real opponent, than when they returned balls projected from a cloaked ball machine. This led the researchers to conclude that: ‘The findings indicate that experts are able to use movement-pattern information [in their opponents] to determine shot selection and to use that information to significantly reduce their response delay times.’ So again we have an example of ‘better’ sports participants being able to read match play in a superior manner with consequent benefits for reaction time.

Researchers from Brisbane in Australia considered cricket(7) and drew conclusions very much in agreement with those considered to date, and those from other sports not previously considered, such as squash(8). It seems that superior performers possess a greater ability to read an opponent’s actions which reduces their reaction time and therefore makes them much more likely to select the appropriate sports skill response. The researchers concluded that, ‘… highly skilled cricket players demonstrated the additional, unique capability to pick up advance information from some specific early cues (especially bowling hand and arm cues) to which the less skilled players were not attuned.’

So in terms of improving reaction time in field and racket sports it’s clear that sight is crucial if a player is to read a visual or numerous visual cues. This impacts on all aspects of vision. Sports scientists specifically refer to ‘visual acuity’ in this respect (see box, right). Basically, visual acuity refers to the ability of a player to see and react to movement correctly and as swiftly as possible. More specifically, for example, it considers eye fixation points and length of focus on these and different types of acuity, such as contrast sensitivity, more of which later.

Training to improve reaction time and visual acuity – practices

As I have indicated ‘reading’ a sporting situation correctly will allow for a quicker reaction. This has led to the development of various innovative practices. The football research quoted above used pin-lights to assess the reading of sports situations and reactions to them. Videos of real match situations were also used, to which players had to react. Players and teams in training from a number of sports have used these methods in recent years in an attempt to improve reaction through vision.

On a more basic, but potentially just as effective, level small items of kit such as ‘visual acuity rings’ have been produced by specialist speed training companies, such as SAQ (SAQ stands for speed, agility and quickness). The visual acuity ring has three different coloured fixed balls on its perimeter. The ring is thrown to a player and a colour called out, the player has to catch the ring at the appropriate place. The aim is to train the players’ reactions and sports ‘reading’ abilities.

In terms of improving reaction times, numerous ball-type gadgets exist that are designed to bounce in highly unpredictable directions. As the player’s ability to anticipate spin or the likely angle of deviation off the ground is significantly reduced, they primarily have to respond when attempting to catch the balls by reaction only (ie not by ‘reading’ the movement patterns of an opponent).

Figure 1: A Snellen visual acuity chart

What is visual acuity?

Visual acuity often is referred to as ‘Snellen’ acuity, so-called because of the 19th-century Dutch ophthalmologist called Snellen who created charts as a test of visual acuity (see figure 1). Visual acuity refers to the clarity of vision – a measure of how well a person sees.

Someone with ‘20/20 vision’ (visual acuity) is just able to decipher a letter that subtends a visual angle of 5 minutes of arc (written 5’) at the eye (5’ of arc is 5/60 of a degree, because there are 60’ of arc in 1 degree.) What this means is that if you draw a line from the top of a 20/20 letter to the eye and another line from the bottom of the letter to the eye, the size of the angle at the intersection of these two lines at the eye is 5’ of arc. The distance from the eye to the object observed is irrelevant; if it subtends an angle of 5’ of arc at the eye, then a person with 20/20 visual acuity will just be able to determine what it is.

Although 20/20 is considered as ‘normal’ visual acuity for most people, it is possible to have better than 20/20 visual acuity, and many people do in fact have better than 20/20 vision – ie they can determine objects that subtend an angle of less than 5’ at the eye. For instance, many people have 20/15 visual acuity, which means that they can stand 20 feet away from an object and see it as well as a person with 20/20 acuity moving up to 15 feet away from the object to view it.

Visual acuity specialists

There has been a growing trend in the use of visual acuity specialists in the sports arena. These specialists perform tests to discover the visual strengths and weaknesses of players with regard to different types of ‘visual acuity’ and implement remedial action.

The US ski team has been using specific visual acuity analysis and training for over a decade(9). In a sport that requires great eyesight and reactive ability, researchers discovered that nearly 40% of team skiers failed to attain 20/20 vision (a visual acuity considered as normal and not even optimum). Prescription goggles or contact lenses were then prescribed to correct this obvious hindrance and a rigorous policy of analytical and corrective measures were also put in place to improve the visual acuity of team members.

Contrast sensitivity

Contrast sensitivity refers to the ability to visually discriminate between shades of gray and black from white and the ability to see under variable lighting conditions. This type of vision affects reaction time response in players who play in changeable lighting conditions, for example, a day/night cricket match. Contrast sensitivity can be tested using special ophthalmic equipment. If the athlete does not fully respond when prescribed lenses to achieve 20/20 vision then sports sunglasses to improve vision in varying light conditions can be used, for example glasses that darken with increased lighting intensity (photochromic glasses).

Summary

Reaction time depends on numerous factors. The athlete has to process what is seen and/or heard and then select the most appropriate and speedy response in order to set their muscles into motion. As we have seen, more proficient sportsmen and women seem to be able to react more quickly and appropriately than the less proficient (a consequence of their superior playing ability and experience). However, it appears that reaction times can be enhanced by appropriate training. Depending on the athlete’s sport there are various conditioning drills, kit and visual acuity analyses and remedies that can enhance this most vital sporting requirement.

John Shepherd MA is a specialist health, sport and fitness writer and a former  international long jumper

References

  1. J Sports Sci 2007; 1;25(1):79-86
  2. Percept Mot Skills 1999; 88(1):65-75
  3. Ergonomics 2005; 48(11-14):1686-97
  4. Res Q Exerc Sport 1994; 65(2):127-35
  5. Perception 2006; 35(3):317-32
  6. J Mot Behav 2005; 37(2):164-75
  7. Q J Exp Psychol (Colchester) 2006;59(12):2162-86
  8. J Sports Sci 1990; 8(1):17-34
  9. www.visualfitness.com/ski/ski_team.html

 

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