The Shuttle Run An Endurance Test for Hockey Referees
Experiences and Results of the first Test Series
Krista Gruss / IMSB / Vienna / AUT
The performance of hockey referees during a game does not only depend on the
referees exact knowledge of the rules. The physical capacity as well as the ability
to concentrate also are of great importance.
INTRODUCTION
Being in good physical condition is one of the requirements for a success performance
as a referee. A referee’s performance should be constantly high throughout a hockey
game and shouldn’t decline because of lack of fitness. Although up to a certain league
this could be compensated by the referee’s experience at an international level
compensating lack of fitness is no longer possible.
The endurance capacity had been previously evaluated by using the Cooper Test. The
IHF-PRC had set limits for assessing the performance. The disadvantage of the Cooper
Test lies in the fact that it does not provide information about the muscle’s metabolism
which is an important biochemical requirement of any endurance performance.
For this reason the Cooper Test was replaced by a Shuttle Run. The results of the
Shuttle Run give information about the individual demand of the metabolism in the
muscles and the change of heart rates due to varying intensity of strain. Because of the
correlation between intensity of loads (km/h), metabolism in the muscles (lactat in
mmol/l) and heart rate (bpm) this test enables us to recommend individual heart rates
for endurance training to each referee.
The Shuttle Run was carried out for the first time at the men’s World Championship
1995 in Iceland. Many hockey referees had already shown a considerable deficiency
of endurance. Since then the Shuttle Run has been carried out at all international
championships (European and World Championships). The testing team could thus
follow the development of the endurance level of each referee. In addition to carrying
out the test Hans Holdhaus (Director of the Institute for Sportsmedicine and Science,
IHF/ MC-Member) recommended methods of basic endurance training during the
referee courses held at these events, in order to motivate the referees to perform
regular endurance training. At the same time Mr. Holdhaus stressed that just training
the Shuttle Run itself would neither improve the endurance level nor the results of the
test.
At the World Championship in Iceland 1995 blood samples were taken to evaluate the
lactat value of the referees during the games in addition to the Shuttle Run. An average
lactat level of 3,0 mmol/l was determined. This means that the referee’s activity takes
place between the aerobic and the anaerobic threshold. It is therefore absolutely
essential for international referees to function at this metabolic level as well as possible
so that the metabolic system can cope quickly with a short sudden burst of speed.
Even at the end of the game quick decisions should not prove to be a problem and
should be made with full attention and concentration.
The goal of the Shuttle Run lies therefore in testing the basic endurance level of the
referees. If required the referees are provided with recommendations for improving of
their physical fitness to support their performance during the games (international limits
for participation in the World Championship in Kumamoto/Japan have been established
by the PRC). At the same time the awareness of general well-being and a healthy body
should be improved.
During EHF events in May and December 1996 each referee was tested with the
Shuttle Run at the beginning of the championships. In addition height, weight and
bodyfat (for determination of the body composition) were determined at IHF events in
1995. Additionally muscle functions (determination of shortened and weakened main
muscle groups to determine a muscular disbalance), the ability to react and co-ordinate,
strength of legs and arms were determined to put a value on the general fitness level.
METHOD OF TESTING
At the World Championship in Iceland (May 1995), in Vienna (December 1995) and at
the European Championship in Sevilla (May 1996) the test began with 8 km/h and
ended after four levels (11 km/h). At the European Championship in Copenhagen
(December 1996) the test began for the first time with 7 km/h and consisted of four to
five levels. The reason for this change in the test was to ascertain the aerobic threshold
(running speed at 2 mmol/l) of all referees, which was not possible at a starting level of
8 km/h. However the frequently reached maximum strain level of the test persons
should be avoided because the test does not aim to establish a persons maximum
strain level. This adjustment of the Shuttle Run has proved to be successful.
Goal of the Test:
With this progressive, accumulative running test the basic endurance, the aerobic and
anaerobic threshold and the corresponding heart rates to each level are determined.
Material needed for the test:
λ=20 metres distance for running
λ=Heart rate monitors for each
person taking part in the test
λ=Implements for measuring lactat .
λ=Audio cassette or computer programme for giving the right speed at the test: The
advantage of an audio cassette is that it can be used very easily at different venues,
you only need a cassette player. The disadvantage is that the tape can stretch and then
become inaccurate, though an adaptation of the running distance is possible. The
advantage of a computer programme is the very high accuracy.
Test procedure:
After having done all the preparations (putting on the heart rate monitors, warming up,
preparing for taking blood samples) the first level starts at a speed of 7 km/h, the tested
persons cover the distance of 20 metres at an even speed. At the end of the 20 metre
zone one foot should be placed on or behind the 20 metre mark when turning around.
Each level lasts 3 minutes. A blood sample is taken from the earlobe, the heart rate is
registered. After a rest of 1,5 minutes the next level (8 km/h) begins. This sequence
must be completed 4-5 times depending on the condition of the tested person. 4 levels
are necessary for a representative lactat-performance-diagram, the fifth level is only
necessary if the anaerobic threshold is not reached after the fourth level. The test
shouldn’t be a maximal load test.
Valuation of the tests:
The anaerobic threshold (4 mmol/l) indicates the endurance level. Small blood samples
are taken from the earlobe at the end of each level and also if the last level cannot be
completed entirely, to determine the lactat values. These values are shown in a
diagram.
Graph 1 – Lactat Performance Diagram of a Shuttle Run
Lactat Performance Diagram of a Shuttle Run
Lactat in mmol/l
8
6
4
2
0
7 km/h
8 km/h
9 km/h
10 km/h
11 km/h
Level
Chart 1 – The Most Important DAta of the test at one Glance
Level
Running
Speed
Duration of Duration of Repetitions Running Time
each Level
Rest
of Running
over 20 m
Distance
min
sec
20 m
sec
3
1,5
17,5
10,3
1
km/h
7
2
8
3
1,5
20,0
9,0
3
9
3
1,5
22,5
8,0
4
10
3
1,5
25,0
7,2
5
11
3
1,5
27,5
6,5
SHUTTLE RUN AT EHF / IHF EVENTS
The described test was performed two days before the start of the games at the
European or World Championships. The 20 referees were divided into two groups of
seven and one group of six. The groups had to be so small because, during the rest
period between two levels (1,5 minutes), blood had to be extracted from the earlobe
from each of the test persons to determine lactat levels and the heart rate had to be
registered. The size of the group depends on the available number of testing persons,
since in this short time one person can extract blood from only 4 people.
In Sevilla at the Men’s European Championship and in Copenhagen at the Women’s
European Championship 39 referees were tested in total (20 pairs, one referee was
injured and could not participate in the test at the European Championship in
Copenhagen). One pair was present in Sevilla as well as in Copenhagen, for this
reason only 37 persons were included in the evaluation of the test in order to have no
duplications.
Results
With few exceptions the physical performance of the referees can generally be rated as
average to low. The endurance level of some of the referees must even be classified as
very low.
The average value of lactat at the various levels is 1,99 mmol/l at 7 km/h (Copenhagen)
and rises to 2,58 mmol/l at 8 km/h, to 4,14 mmol/l at 9 km/h and to 6,30 mmol/l at 10
km/h. The average value at 11 km/h lies at 8,85 mmol/l. The mean performance at the
aerobic threshold rates 8,04 km/h and 9,1 km/h at the anaerobic threshold.
Chart 2 - Average Values of Lactat at the Different Levels and
Average Running Speed at the Aerobic and Anaerobic Threshold
n=39
7 km/h
(n=19)
mmol/l
8 km/h
9 km/h
10 km/h
11 km/h
mmol/l
Aerobic
Threshold
km/h
Anaerobic
Threshold
km/h
mmol/l
mmol/l
mmol/l
Mean Value
1,99
2,58
4,14
6,30
8,85
8,0
9,1
Standard
Deviation
Minimum
0,68
0,94
1,55
2,18
2,36
0,6
0,8
1,2
1,1
1,3
1,8
4
7,3
7,1
Maximum
3,9
5,5
8,1
11,2
12,9
10,1
11,0
The smallest and highest values of lactat at the various testing levels offer information
about the different endurance levels of the referees. Up to 10 km/h the smallest value
lies under 2 mmol/l. A value in this range points to a very good basic endurance level
because no lactat has accumulated at this work load. With such an endurance level the
running speed can be varied around the aerobic threshold without causing any major
changes in the metabolism. Therefore a hockey game would not put the referee under
great strain. On the other hand the highest value of 5,5 mmol/l at 8 km/h lies clearly
above the anaerobic threshold. Even though only a few referees reach such high values
this would be an alarmingly low endurance level because an oxygen defeciency
already occurs at a very low speed. This would not only influence the willingness to
perform physically but after a period of time the mental agility also deteriorates.
Chart 2 shows that the lowest value at the anaerobic threshold occurs at a lower speed
than the lowest value at the aerobic threshold. The reason for this fact is that due to his
low basic endurance a referee with a low value at the anaerobic threshold has no lactat
under 2 mmol/l and therefore cannot be included in the calculations for the mean
aerobic threshold.
At the European Championship in Sevilla only 8 out of 20 referees could achieve an
aerobic threshold. Due to the developed testing method 15 out of 19 referees reached
an aerobic threshold in Copenhagen. Accordingly the basic endurance level could be
assessed more accurately and recommendations for endurance training could be
established. At the same time in Copenhagen no near maximum strain values were
registered. Only 6 referees had to run the fifth level, though the necessity for a higher
level indicates a better endurance level.
Comparing the two groups (Sevilla, Copenhagen) the average lactat values of the first
three levels drawn in Sevilla are lower. The values of the fourth level (11 km/h) were
higher in Copenhagen. The differences at 8 km/h and 11 km/h are not statistically
significant. The difference between 9 km/h and 10 km/h is significant (p=0,05).
Graph 2 - Comparison of the Average Lactat Levels at the ECh in
Sevilla and Copenhagen
Vergleich der durchschnittlichen Höhe
fff des Laktats bei der
EM in Sevilla und in Kopenhagen
10,00
Sevilla 23.05.1996
Copenhagen 04.12.1996
9,00
8,00
mmol/l
7,00
6,00
5,00
4,00
3,00
2,00
1,00
0,00
7km/h
8km/h
9km/h
10km/h
11km/h
After the tests the referees were given training recommendations providing them with
information indicating which heart rate to maintain to train their endurance. Since 79 %
of the EHF-referees (n = 30) had already been tested in the Shuttle Run before the
European Championship changes and efforts towards the improvement of the
endurance capacity could be seen: 47,4% (n=18) of the referees executed (more
intensive) endurance training and were able to improve their endurance level at the next
test. The endurance level of 5,3% (n=2) of the referees did not change and 26,2%
(n=10) of the referees had a lower endurance level than before. The remaining 21%
(n=8) performed the Shuttle Run in Sevilla or Copenhagen for the first time and did not
provide the testing persons with previous values.
Graph 3 - Average Change in Performance of Referees
at the Anaerobic Threshold from the 1st to the 2nd Test
Average Change of Performance of Referees at the Anaerobic Threshold from the First to
the Second Test
km/h
10,5
10
First Test
9,5
Second Test
9
8,5
8
7,5
7
Referees who improved (n=18)
Referees who worsened (n=10)
Referees who remained unchanged
(n=2)
The difference in the performance at the anaerobic threshold between the two tests is
significant (p=0,01) for those referees who improved as well as for those whose
performance declined. The main reason for the positive change was a regular
endurance training, the main reason for the decline was lack of training. However the
composition and frequency of training was not questioned.
Considering the changes of the referee pairs, both referees of seven pairs (almost half
of the tested persons) could improve their performance at the anaerobic threshold. With
four pairs one referee improved and one worsened the performance and only with two
pairs both referees worsened their performance. With two pairs one worsened his
performance and the other did not change at all. It can be assumed therefore that two
referees consider themselves to be a team and so train for a mutual goal. This
assumption has not as yet been questioned .
For the World Championship in Kumamoto/Japan limits for the Shuttle Run have been
established (9,0 km/h at the anaerobic threshold). 21 of the 38 referees (55%)
refereeing at the 1996 European Championships would have achieved this limit at their
last test. The other 17 range more or less below.
Graph 4 - Performance at the Anaerobic Threshold with the Limit for
the World Championship in Kumamoto in May 1997 (9km/h)
Performance at the Anaerobic Threshold with the Limit for the World Championship in
Kumamoto in May 1997 (9 km/h)
km/h at the Anaerobic Threshold
13
11
9
37
35
33
31
29
27
25
23
21
19
17
15
13
11
9
7
5
3
1
7
Referees in Order of Rank of Performance at the Anaerobic Threshold
CONCLUSION
In the future it would be recommendable that the national federations tested their
referees with the Shuttle Run regularly, provided them with training
recommendations and hence supported the development of performance of
referees on the national but especially on the international level. The national
federations should be able to perform the Shuttle Run independently. It would
then be possible in the future for the national federations to optimally prepare
their referees for important events. Regarding training recommendations it is
most important that the referees are provided with instructions stressing the
method of correct endurance training. This could be done by a professional
chosen by each national federation.
The training recommendations were focused on the basic endurance, not only to
improve the performance but also to achieve a positive change of the body
composition as to the percentage of body fat. This goal is a result of determining
the percentage of body fat during IHF events.
Testing referees at international meetings by means of the Shuttle Run has so far
proved to be very important for the development of the performance level of the
referees. For the Men’s World Championship in Kumamoto/Japan it is planned to
test not only at the venue of the event but to start the test series in the countries
of the individual referees weeks beforehand. In the future this would be
recommendable for all events. Before the start of the championship in question
the nominated referees have to reach the PRC-limits at the venue, in order to be
admitted to the championship. All referees were informed accordingly of this and
were provided with training recommendation in order to pursue these limits.
SUMMARY
Since the World Championship in Iceland the basic endurance of the referees
present has been tested by means of a Shuttle Run. Last year this test method
also was used at the European Championship in Sevilla/Spain and in
Copenhagen/Denmark. After the test each referee was supplied with training
recommendations to enable him to improve his level of basic endurance. The first
positive results have already been observed.
In the future the level of physical capacity of the referees is to be raised by
introducing limits; being in better physical shape would support their physical
performance while in action during games. The national federations should
prepare the referees from their countries independently and should also run the
tests on their own.
THE AUTHOR
Krista Gruss is a graduate of the Institute of Sports Science at the University of Vienna.
Since 1995 she has been with the Institute for Sportsmedicine and Science in Maria
Enzersdorf / Austria working in the field of performance diagnosis (field tests) and
training recommendations. Since the women’s World Championship in Vienna in 1995
she has been responsible for executing the Shuttle Run with the international referees
and has been involved in the further development and standardization of this test.