Curtin home > Health Sciences > Physiotherapy > Resources > Educational Resources > Exercise Physiology Educational Resources > Exercise Physiology Educational Resources 1998 > Netball

Netball

Fitness Testing Assignment: Hockey - by Tania Ashfield

Introduction
Characteristics of Successful Athletes
Energy Requirements
Fitness Assessments - A Review of the Literature
Fitness Testing Procedures
Conclusion
References

Introduction

Fitness testing in netball is essential to enable effective assessment of conditioning programs and assist with talent identification. Netball is the most popular team based sport in Australia, played predominantly by females of all ages and fitness levels with mixed and male competitions increasing in popularity. Despite the popularity of netball and publicity concerning abundant injuries, research into fitness testing, training variables and body composition characteristics of successful athletes is incredibly scarce (McGrath and Ozanne-Smith 1998).

A report recently released by Monash University reviews the literature concerning netball injuries. The report recommends simple fitness testing prior to competition however fails to present literature suggesting the types of tests to be conducted. Anthropometric research on a wide range of players with age and skill variation is recommended to establish a screening and intervention program (McGrath and Ozanne-Smith 1998).

Several physical parameters and characteristics of the game require testing. These include strength, speed, power, agility, muscular endurance, aerobic condition, flexibility and body composition (McGrath and Ozanne-Smith 1998). Netball has been described as a game reliant on rapid acceleration to "break free" from an opponent, sudden and rapid changes in direction in combination with leaps to receive a pass, intercept a ball or rebound after attempting to goal (Otago 1983).

Characteristics of Successful Athletes

Anthropometric data is limited. Bale and Hunt (1986) investigated anthropometric variables in relation to playing standard and playing position. Position was divided into three sub-groups including 1) attacking players, goal shooter (GS) and goal attack (GA), 2) centre court players, wing attack (WA), centre (C) and wing defence(WD), and 3) defenders, goal defence (GD) and goal keeper (GK).

Most elite netball players have tall, powerful, balanced physiques, high in lean body weight but low in adipose tissue. Position specific trends are apparent in netball. Since basketball is relatively similar to netball, research on basketball is often considered comparable, however the positions allocated to basketball players are not as specific as those for netball players and therefore extrapolation of results is problematic. The tallest, heaviest players in netball are the attackers and defenders. The centre court players are significantly shorter and lighter with the lowest levels of adiposity, lower bone widths and lower limb circumferences (Bale and Hunt 1986). The centres in basketball play nearer the basket where size, strength and jumping ability is advantageous. Often the tallest and heaviest female basketball players are the centres whereas the shortest and lightest are the guards. The centres in netball have responsibilities similar to the guards in basketball. WD (the tallest of the centre court players) stops and defends the ball and WA feeds the ball to the circle. Centre court players cover more ground in netball and therefore their slimmer physique is advantageous for stamina and agility. Fitness testing may identify characteristics of players suited to netball and specific positions and clearly should not rely on data obtained from studies investigating basketball (Bale and Hunt 1986).

The mean height of elite netball players was found to be 172.9 cm's (Bale and Hunt 1986). This is comparable to results of other studies (Elliot and Smith 1983). The mean height and weight of 16 elite netballers tested in the Australian Institute's Sports Science Laboratory was 173.6 cm (range 161.8-182.4) and 64.6 kg (range 61-71.7) respectively. Telford et al (1984) found the mean sum of seven skinfold measurements was approximately 87 mm (range 60-115) . It is suggested that elite netball players like top class basketballers have larger muscle mass but lower adiposity levels in relation to height. Mean percent fat of 24.5% was calculated for all netballers. This value was lower than values obtained from studies with lower subject numbers, and higher than values from studies using hydrostatic weighing (Elliot and Smith 1983, Withers and Roberts 1981). Elite netball players have significantly smaller femur bone widths than good players, and netball players like female basketball players were found to be predominantly meso-endomorphs (Bale and Hunt 1986, Elliot and Smith 1983).

Elliot and Smith (1983) investigated the relationship between netball shooting accuracy and selected anthropometric and biomechanical factors. The taller, less mesomorphic individuals with a higher percentage of body fat were more accurate goal shooters. They were also stronger in knee extension and elbow extension. Additional factors affecting one-handed netball shot accuracy were wrist flexibility, relative sitting height and upper limb length (Elliot and Smith 1983).

Elite netballers train and play matches significantly more often than good players. Elite players concentrate upon improving their overall fitness and strength by including sprint and distance training, bounding and weight training in weekly program schedules. Good players rely more on ball skill practice and match play to improve performance. Over two thirds of elite netball players run between 3-10 kilometres per week (Woodford et al 1993). Hopper et al (1995) found that athletes with better anaerobic fitness and jumping ability were at a lower risk of injury thereby indicating the usefulness of these tests for fitness examination and pre-participation screening.

Energy Requirements

Studies have investigated the physical capacities of skilled netball players in relation to playing position, the energy requirements of positional play during match play and training, and movement patterns related to playing position. These studies have marked limitations as analysis has mostly taken place over one match and matches were arranged. These circumstances may differ to conditions of competition (Otago 1983).

Netball is confined to a small court (15.25m by 30.5m) with 14 players constantly involved in offensive/defensive manoeuvres for four 15 minute quarters. Allison (1978) and Otago (1983) have identified fundamental characteristics of netball play including typical body movements, duration of work periods and work to rest ratios, indicating the nature of effort involved. Netball is an interval type game involving a combination of short work intervals of sprints, jumps and shuffling movements interspersed with rest-relief periods of slow jogging, goal shooting and passive defence. Players are generally involved in work periods of less than 15 seconds before any recovery is allowed or a series of short sprints interspersed with short recovery periods. This interval game involves aerobic and anaerobic energy sources (Allison 1978).

Otago (1983) found the majority of work periods in netball were less than 10 seconds after which time players recovered for at least three times the duration of the work period (work-to-rest ratio of 1:3). Allison (1978) found the average sprint time of a player during a game ranged from 1.43-1.84 seconds. When the average time spent per activity was analysed all movement patterns were less than five seconds (Steele and Chad 1992). The predominant energy source for short bursts of maximal effort lasting 8-10 seconds is from ATP and CP already stored in muscle. The high energy phosphate system provides available energy without the need for oxygen. ATP and CP stores depleted following maximal efforts are rapidly replenished during recovery periods with 50% available for use 30 seconds following effort. Therefore, repeated short bursts of movement are completed without exhaustion. The game is sustained for 15 minute quarters and therefore muscular endurance is also demanded (Woolford and Angrove 1991).

Anaerobic energy sources are rapidly replenished in the recovery period. This taxes the ability of the player to supply oxygen or aerobic energy. The more intense the work period and the shorter the recovery period the greater the responsibility of the oxygen energy system to maintain performance at a high level (Allison 1978). Allison (1978) documented the sprint efforts of netball players according to playing position. The GS and GK spent 4.1% of the time sprinting with 82 sprint efforts, GA and GD spent 5.9% of the time sprinting with 148 sprint efforts. Centre had 232 sprint efforts spending 11.8% of the time sprinting. In contrast, WA and WD had the greatest endurance/oxygen requirement with 16.3% of the time spent sprinting, 336 sprint efforts and less recovery time.

Table 1. Percentage of playing time spent in each intensity zone.
	Wing Attack	Goal Attack	Centre	Wing Defence
Zone 1	0	54	25	10
Zone 2	45	39	44	63
Zone 3	32	6	9	22
Zone 4	3	0	22	5

The energy demands specific to player position were also highlighted by Woolford and Angove (1991). Their study aimed to determine if intensities experienced during training matched game intensities. Incremental treadmill tests were used to determine each player's maximal heart rate (max HR). From these results four intensity zones were calculated for each player. These included:

Zone 1 greater than 95% max HR (to improve aerobic power)
Zone 2 between 85% and 95% max HR (for anaerobic endurance)
Zone 3 between 75% and 85% max HR (for aerobic endurance)
Zone 4 less than 75% max HR (for recovery and regeneration)

These zones relate to each individuals lactate threshold (LT) and individual anaerobic threshold (AT). The LT refers to the point of increase in blood lactate above resting baseline levels, and AT is the highest metabolic rate at which blood lactate concentrations are maintained at a steady state during prolonged exercise. It has been demonstrated at the South Australian Sports Institute that LT occurs at approximately 75% max HR and AT between 85-92% max HR. Blood lactate is being produced and removed from the body at all times however, when exercise intensities increase above approximately 75% max HR the production of lactate exceeds elimination from the body. Heart rates above 95% max HR are indicative of maximal oxygen consumption. It should be noted that a mix of energy systems are used throughout game play (Woolford and Angove 1991).

Woolford and Angove (1991) found a lot more time was spent in zones 3 and 4 during training than games. The implications of these findings for the coach are that training programs must incorporate drills designed around the specific demands of the position using appropriate intensities depending on the stage of training. Appropriate pre-season fitness testing could provide base values for regular monitoring of exercise intensity throughout training and games. The four positions monitored GA, WA, WD and C all required a high level of aerobic fitness, therefore these players should be stressed in the top three intensity zones with zone four used for recovery. Conditioning should initially start at zone 3, building up gradually (Woolford and Angrove 1991).

The limitations of using HR as an indication of exercise intensity include psychological influences such as precompetition elevations in state anxiety, HR and adrenalin levels, and cardiovascular drift during the course of a game due to environmental factors such as heat stress. This causes the changes during prolonged exercise such as constant cardiac output, increased HR and decreased stroke volume to be exaggerated. HR is not a good indicator of anaerobic metabolism due to the slow response time of the heart to exercise (Woolford and Angrove 1991).

As an extension of the study Woolford and Angrove (1992) investigated further, the position specific trends in netball. GA was found to spend very little time in zone 4 and was therefore continuously accumulating blood lactate above resting levels until quarter breaks where levels declined. In contrast, C spent 22% of playing time in zone 4 in addition to quarter breaks, and therefore eliminated lactate faster than its production. The significance of lactate production is that it causes fatigue. With appropriate training, tolerance to blood lactate can improve thus delaying fatigue. Results of time periods spent in each zone indicate that all of the players tested (GA, WA, C and WD) required high levels of aerobic fitness. GA and C spent the majority of play time in zones 1 and 2. Woolford and Angrove (1992) felt results indicated high aerobic power and anaerobic endurance requirements. GA was found to spend 54% of time in zone 1 and 39% in zone 2. The longest time period spent in zone 1 for GA was 5 minutes, 30 seconds with an average of 1 minute, 23 seconds and zone 2 was 4 minutes, 45 seconds with an average of 59 seconds. C spent 25% of time in zone 1 and 44% in zone 2. The longest period spent in zone 1 was 8 minutes, 15 seconds with an average of 59 seconds and zone 2 was 7 minutes, 15 seconds with an average of 32 seconds. These values may be overestimated as only three subjects were tested for GA and four for C. The authors concluded that aerobic conditioning was of prime importance in elite netball players. Characteristics of match play are summarised in table 1.

Steele and Chad (1992) quantified the movement patterns demonstrated during match play by each of the seven playing positions in netball. The study highlights major differences between playing positions indicating the need for each position to be trained specifically to requirements. Shooters (GA and GS) were found to spend a high percentage of time catching and rebounding the ball. Centre court players (C, WA and WD) spent a high percentage of time jogging, running and shuffling with less time available for rest-relief. WD also spent a considerable amount of time jumping. The circle defence (GD and GK) were mostly involved in jumping, rebounding and guarding.

Recognition of these energy requirements enables fitness tests to be devised appropriately and specific to playing position. For example, the circle defence would be expected to perform well during the vertical jump test and centre court players should obtain high levels for the shuttle run test.

Muscular strength is also very important. Upper limb strength facilitates gripping the netball after a rebound or catch. Power of the upper and lower limbs is important to facilitate performance during characteristic short bursts of speed when leaping for a high pass, rebounding a goal, intercepting a pass or breaking free. The agility requirement of netball is evident in match play with stops and pivots executed frequently. The agility requirement is tested via batteries of skill tests. The flexibility component is assessed by tests such as the sit and reach test (Allison 1978, Barham and Wilson 1981).

Fitness Assessments - A Review of the Literature

Despite the popularity of netball there are no standardised tests available for the evaluation of skill achievement or physical and motor fitness skills. Attempts to establish tests have been scarce. Davey (1968) established achievement tests for netball related to particular netball skills required throughout the game. These included stationary throwing and catching over a short distance, one handed shoulder accuracy passes over a short distance, jumping for height, and moving at speed with changes in direction. Since these tests were devised, the skills demanded have changed to include throwing whilst moving to a moving target, throwing over longer distances and pivot turn and throw (Barham and Wilson 1981).

Barham and Wilson (1981) established a reliable and practical battery of tests in response to outdated tests. The tests are used to compare individuals, establish performance levels for specific groups from national teams to schools, to gauge an individual's progress, to provide a criteria for team selection at various levels and to provide incentives for practice and motivation for improvement. The tests were developed via analysis of game characteristics. The frequency of jumping of centre-thirds and goal-thirds, the number of stops and pivots executed and the number of times players received and passed the ball on the run were recorded based on an international netball match. Analysis of more than one game would have given the tests more strength. Tests included, throwing for speed and accuracy, reaction movement, throwing for accuracy over distance, and pivoting and throwing skill (Barham and Wilson 1981).

Validity was established by correlating the ranking of 24 players results with the ranking assessment of four expert judges. All tests produced high correlation coefficients at p=0.01 level of significance except the long throwing test with a moderate correlation coefficient at the p=0.05 level. These validity measures would have greater strength had a larger number of raters been used. Reliability was determined by repeating the tests for 15 of the players (r=0.63 to r=0.82) (Barham and Wilson 1981). Normative data was established from a random sample of 120 netball players from all levels of competition. Percentile scores were established for skills tests and a battery of fitness tests which were chosen for their applicability to the fitness requirement for netball with validation in earlier studies (Barham and Wilson 1981). The battery of fitness tests chosen was practical and easily administered to large groups. It included, a five minute modified Harvard step test to determine cardiovascular fitness, flexed arm hang, vertical jump, grip strength, sit-ups, trunk flexion using the sit-reach test, and trunk extension (Barham and Wilson 1981).

Barham and Wilson (1981) established these tests to enable players and coaches to measure their functional fitness. More recently Chad and Steele (1990) compared the percentile scores of Barham and Wilson (1981) with vertical jump scores. Players performed within the 95 th percentile. Chad and Steele (1990) considered these scores representative of explosive leg power. Data is presented in table 2.

Table 2. Percentile scores for the vertical jump.
Percentile	Vertical Jump Height (cm)
95	42.4
90	40.2
85	38.7
80	37.5
75	36.5
70	35.6
65	34.7
60	33.9
55	33.2
50	32.4
45	31.6
40	30.9
35	30.1
30	29.2
25	28.3
20	27.3
15	26.1
10	24.6
5	22.4

(from Barham and Wilson 1981).

The vertical jump is designed to test the power of the extensor muscles of the hips, knees and ankles. It has been considered part of a battery of tests of muscular strength, power and endurance. Normative data with the categories high performance to very poor have been formulated, however interpretation of data is limited as values have not been divided by body mass and are therefore not normalised (Barham and Wilson 1981).

The vertical jump test is designed to measure leg power although there is speculation concerning whether it achieves this goal. The brief period of power generation in propelling the body occurs only when the feet are in contact with the ground. This period may be insufficient to evaluate the ATP-CP capacity. No relationship has been found between jump test scores and ATP-CP levels or depletion patterns. The reactions to power the performance are isolated within the specific muscles activated by the exercise which requires neurologic or skill components. The vertical jump may be used to effectively demonstrate changes in an athletes performance resulting from specific training whether in the mode of a jumping task or a specific strengthening exercise (McKardle et al 1991).

Woolford and Angrove (1992) tested max HR to monitor exercise intensities throughout training and games. Max HR should be determined on the exercise mode specific to the sport. For netball this is running. The authors described a test for coaches similar to the Shuttle run test (SRT) which is practical and easy to administer. It is recommended that HR max be determined at the start of the training year and at intervals throughout the year to detect variations (Woolford and Angove 1991).

The 20 metre SRT is a simple field test providing an estimation of VO_{2 max}. Ramsbottom et al (1988) examined the validity of using the SRT to estimate maximal oxygen uptake. The correlation between VO_{2 max} determined via treadmill running and shuttle level was 0.92 suggesting the SRT provides a valid estimate. Levels attained on the SRT for young physically trained females were 9.6±1.8. A table of VO_{2 max} values together with the appropriate shuttle run performance was prepared from the results obtained in the study. This is presented in table 3. Normative data is yet to be established for elite netballers. A treadmill test would be the ideal method for determining a players aerobic capacity, however this method is time consuming, difficult for coaches to organise and expensive (Kyle 1991).

Table 3. Table of predicted maximal oxygen uptake values for the progressive 20m shuttle run test.

Level	Shuttle	Predicted VO_{2 max}
4	2	26.8
4	4	27.6
4	6	28.3
4	9	29.5

5	2	30.2
5	4	31.0
5	6	31.8
5	9	32.9

6	2	33.6
6	4	34.3
6	6	35.0
6	8	35.7
6	10	36.4

7	2	37.1
7	4	37.8
7	6	38.5
7	8	39.2
7	10	39.9

8	2	40.5
8	4	41.1
8	6	41.8
8	8	42.8
8	11	43.3
9	2	43.9
9	4	44.5
9	6	45.2
9	8	45.8
9	11	46.8

10	2	47.2
10	4	48.0
10	6	48.7
10	8	49.3
10	11	50.2

Level	Shuttle	Predicted VO_{2 max}
11	2	50.8
11	4	51.4
11	6	51.9
11	8	52.5
11	10	53.1
11	12	53.7

12	2	54.3
12	4	54.8
12	6	55.4
12	8	56.0
12	10	56.5
12	12	57.1

13	2	57.6
13	4	58.2
13	6	58.7
13	8	59.3
13	10	59.8
13	13	60.6

14	2	61.1
14	4	61.7
14	6	62.2
14	8	62.7
14	10	63.2
14	13	64.0
15	2	64.6
15	4	65.1
15	6	65.6
15	8	66.2
15	10	66.7
15	13	67.5

Level	Shuttle	Predicted VO_{2 max}
16	2	68.0
16	4	68.5
16	6	69.0
16	8	69.5
16	10	69.9
16	12	70.5
16	14	70.9

17	2	71.4
17	4	71.9
17	6	72.4
17	8	72.9
17	10	73.4
17	12	73.9
17	14	74.4

18	2	74.8
18	4	75.3
18	6	75.8
18	8	76.2
18	10	76.7
18	12	77.2
18	15	77.9

19	2	78.3
19	4	78.8
19	6	79.2
19	8	79.7
19	10	80.2
19	12	80.6
19	15	81.3

20	2	81.8
20	4	82.2
20	6	82.6
20	8	83.0
20	10	83.5
20	12	83.9
20	16	84.8

Otago et al (1994) used a 20 metre SRT to exhaustion to test netball umpires fitness levels. The SRT is thought to be a reliable and efficient means of testing maximal oxygen uptake outside the laboratory (Paliczka et al 1987). Kyle (1991) reported that the constant stopping and changing of direction throughout the shuttle test makes it highly appropriate for games players especially in games where endurance is vital but short bursts of speed and quick directional changes are essential. In particular it mimics the movements of centre court players (Otago et al 1994).

To test netball fitness of the anaerobic energy system, Withers and Roberts (1981) evaluated anaerobic alactic power output by using the Margana stair climb test. Stair sprinting tests must be interpreted cautiously as outcomes are not adjusted for weight. The test may be more suited in the evaluation of individuals with similar body mass or to monitor pre/post training changes. High correlation has been found between stair sprinting power tests and sprint running tests which require a less elaborate set-up and are probably more appropriate (McArdle et al 1991). More recently, anaerobic capacity tested over 10 seconds has been used to determine the alactic power and work index (Telford et al 1987) for state league netball players from the Illawarra Academy of Sport (Chad and Steele 1990). In this study the centre court players demonstrated the highest degree of alactic work (99.49±16.23 J/kg) and peak power (12.47±1.68 W/kg) when compared to either the shooters alactic work (89.73±17.09 J/kg) and peak power (11.2±1.72 W/kg) or the defenders alactic work (84.05±15.66 J/kg) and peak power (10.71±1.61 W/kg). Assessment of anaerobic capacity is important especially at elite levels where netball is a game of great skill, speed and complexity (Chad and Steele 1990).

Assessment of body composition is an important component of an athletes physiological preparation. Methods available include hydrostatic weighing, total body water, ultrasound, spectroscopy and electrical impedance. These techniques are complex and impractical. A simpler and more expedient measure is anthropometric measurement of skin-fold thickness which is routinely used (Woolford et al 1993). Excess body fat increases the body's mass thereby decreasing acceleration (Newton's second law). Greater demand is placed on the aerobic energy system with increased body mass as more energy is required to initiate and sustain movement of a larger mass. Excess of body fat will generally lead to earlier onset of fatigue. Additional fat mass also reduces the ratio of surface area to body mass reducing the capacity to dissipate heat efficiently. The amount of heat energy required to raise the temperature of fat tissue by a given amount is less than that of the fat free mass and therefore body temperature increases more. Alternatively, if fat mass is too low the athlete is predisposed to poorer performances and increased susceptibility to illness (Woolford et al 1993). Recommendations for body fat assessment by skinfold thickness are found in the test methods manual (Draper et al 1992).

Fitness Testing Procedures

The battery of tests used at the Australian Institute of Sport (AIS) for evaluation of the Australian Netball team includes the SRT, vertical jump, 5x 20 metre sprint tests, the sit and reach test, and skin fold assessments (Tweede 1998). The West Australian Institute of Sport (WAIS) uses variations of these tests. The principle difference is the sprint tests described to follow (Bishop 1998).

Field tests should be performed in a standardised order with anthropometry performed on day 1. On day 2 sprint tests should be performed first followed by the vertical jump and SRT (Lawrence 1998).

Anthropometry

Equipment required includes a balanced scale accurate to±0.1 kg, a stadiometer mounted on the wall, hapenden skinfold calipers, anthropometric tape and a marking pen.

The measurements required include:

Standing height without shoes to the nearest mm.
Body mass with minimal clothing (shorts and singlet) to the nearest 0.1 kg.
Sum of skinfolds at seven sites.

Expected test scores and ranges are presented in Table 4. Values from WAIS February 1998 can be found in Table 5.

Table 4. Body composition results (sum of 7 skinfolds) for female netballers from South Australian Sports Institute.
	Mean (cm)	STD (cm)	Range(cm)
Senior	83.4	17.3	51.5-124.0
U/21	97.9	29.3	56.6-168.4
U/19	92.6	24.9	49.4-187.4
U/17	87.6	18.9	49.7-132.1

(Woolford et al 1993).

Table 5. Summary of WAIS netballers testing results from February 1998.
	Weight (kg)	Sum of 7 Skinfolds (mm)	5m Sprint Time (s)	10m Sprint Time (s)	Vertical Jump Height (cm)	20m Shuttle Run (Level and Shuttle)
	Anthropometric Tests		Anaerobic Tests			Aerobic Test
Subject 1	73.35	74.7	1.21	2.06	4446	12.1
Subject 2	72.60	106.2	1.26	2.16	46	10.2
Subject 3	79.25	76.5	1.20	2.07	45	10.4
Subject 4	69.10	85.3	1.30	2.10	55	10.6
Subject 5	65.05	93.5	1.28	2.10	42	11.5
Subject 6	69.50	86.0	1.29	2.14	43	11.7
Subject 7	67.90	82.5	1.26	2.12	48	11.9
Subject 8	69.55	82.2	1.12	1.93	53	13.2
Subject 9	65.00	93.5	1.23	2.09	41	11.2
Subject 10	66.85	70.1	1.22	2.11	42	10.6
Subject 11	56.05	58.6	1.14	1.95	52	10.8
Subject 12	65.80	84.8	1.29	2.06	47	12.2
Subject 13	74.95	85.1	1.14	1.94	51	8.7
Subject 14	65.55	110.5	1.28	2.12	53	11.2
Subject 15	71.00	92.1	1.23	2.16	37	-
Mean	68.77	85.4	1.23	2.07	46.6	11.16
Minimum	56.05	58.6	1.12	1.93	37	8.7
Maximum	79.25	110.5	1.30	2.16	55	13.2

Sprints

A warm up period consisting of 5-6 minutes of low intensity jogging followed by stretching should occur prior to the physiological tests.

For this test a stopwatch, measuring tape or cones and marking tape are required.

A start gate is positioned on the start line with gates also set at 5 and 10 metres from the start line. Athletes position themselves in a side-on position with the preferred foot touching the start line and weight on the back foot. The front foot is not allowed to leave the ground. In their own time, athletes sprint through and past the 10 metre line. The time taken to reach the 5 and 10 metre gates is recorded. A minimum of three trials should be given with at least two minutes rest between trials. This test was devised by WAIS and is not documented in the literature.

Results from WAIS are presented in Table 5. It should be noted that results are comparable to observations by Allison (1978) mentioned previously concerning the average time spent sprinting during game play (ranging from 1.43-1.84 seconds).

Vertical Jump Test

Equipment required includes a vertical board marked in cm, chalk for finger tips and a board cleaner.

Three attempts are allowed due to the skill involved in the test thereby enabling the player to achieve their best jump. A warm-up should be provided. The subject stands sideways against a surface allowing the distance jumped to be measured. Either the left or right side is permitted. Chalk is placed on the subjects fingertips. The player then reaches up with the hand closest to the surface touching as high as possible and leaving a mark. The feet should be flat on the floor with the body close to the wall and the shoulder elevated to stretch out the arm and hand as much as possible. The initial mark is recorded. The subject may then take a step backwards and must go into a crouch to the depth the player wishes. The arms must be outstretched behind the body. The player brings both feet together from this stationary position and leaps up as high as possible. The arms are brought forward with the inner arm touching the surface as high as possible. The distance between the initial mark and the highest jump of the three trials is recorded as the vertical jump distance.

It is the tester's responsibility to ensure the initial height before the jump was the highest possible, the subject starts from a crouched stationary position, repeated arm swing does not occur prior to jumping, the up-stretched inner arm touches the wall, and the subject has touched the surface at the greatest height.

Limitations include the skill required to perform the test consistently and touch the board at the peak of the jump, the ability of players to cleverly disguise their standing reach height and the possibility of the jump board/surface inhibiting jump performance.

Results from WAIS are presented in Table 5.

The 20 metre shuttle run test

Equipment required for the test includes, a flat, non-slippery surface of at least 22 metres in length; a stopwatch; measuring tape; marker cones; cassette player; and a shuttle run testing tape.

The SRT is a maximal aerobic test. The procedure begins with players lined up at one end of the 20 metre shuttle course. The players are instructed to run continuously following the progressively increasing running pace signalled by the beep sounds emitted from the tape over the 20 metre course for as long as possible. The pace increases every minute. The athlete should have reached one of the end lines of the course at every beep of the cassette player. One foot should be placed either on or behind the 20 metre mark at the end of each shuttle. Players should wait for a beep before resuming the run if they arrive at the end of the shuttle before the beep sounds. Termination of the test occurs when a player is unable to reach within 2 strides of the line for two successive beeps hence, pace is not maintained. The player is asked to withdraw and the stage is recorded. Only one attempt is allowed. The duration of the test depends on the players aerobic capacity and lasts for a maximum of 20 minutes. The average time taken is usually much less.

Once the subject stops, a lap score indicated by the tape is recorded. The score corresponds to a maximum oxygen uptake.

The SRT is effort dependent and relies on a maximal effort from subjects. This limitation is lessened if the player is highly motivated and provided with team support and urging. The SRT is assumed to be a reliable means of determining HR max.

Advantages of the SRT include the simplicity of testing. The only equipment required is a tape player with the appropriate tape, a stop watch and a twenty metre flat surface either indoors or outdoors. Large numbers of players can be tested together saving considerable time and creating a highly motivating and competitive situation. The initial slow running speed offers a good warm up built into the test. Constant stopping and changing of direction is highly appropriate for netball players as it simulates the short bursts of speed and quick directional changes required. Tables provided with the test kit allow comparison of test scores. By comparing scores of individuals, different levels of aerobic fitness are noted within the team. It appears from previous research that aerobic fitness is most important for centre court players (Woolford and Angrove 1992).