In a scientific paper presented to the
1st World Congress of Science and Racket Sports Professor Craig Sharp outlines The
Formula for Racket Sports Fitness concentrating particularly on squash.
The Fitness Formula for Squash and racket sports
of a number of items:
- Muscle endurance, a combination of
the ability to deliver appropriate anaerobic and aerobic power together with the ability
to recover (mainly anaerobic recovery);
- Muscle strength, which is more important in
tennis than the other racket sports;
- Muscle speed, an important component of power in
all the racket sports;
- Low percentage body fat.
Squash is a game which may last from 6 minutes to 2 hours
48 minutes. One rally may last one stroke and 1.5 seconds, or 400 strokes and 10 minutes.
More usually for training purposes rallies can be categorised into three
populations, those lasting <5 seconds, those between 6-20 seconds, and a small but
important number which last upwards of 20, but not usually longer than 60 seconds. There
are approximately 7 seconds between rallies, which are played at a rate of up to 40
strokes per minute.
The heart rate rises in the first few minutes of play to
80-85% of maximum, which is maintained throughout the match. Body temperature may rise by
20C in the first 40 minutes, thereafter more slowly. Male players may lose up to 2.0
litres/hour of sweat, and women approximately half this rate. Systolic blood pressure
rises by up to 30% in the first five minutes, but thereafter falls linearly to pre-match
levels after 30-40 minutes. Diastolic blood pressure tends to fall by about 10mmHG or more
according to standard throughout the game. Oxygen consumption ranges from 2.0 to 3.5
litres/minute (40ml/kg/min men, 32 ml/kg/min women), with energy expenditures of 10 to 18
kcals (42-75kJ)/min. Lactic acid level after 30-40 minutes play ranges from 3.5
to10.0mmol/l, and may be reduced during play by exploitation of suitable tactics. Lactate
levels may also be reduced by 4 to 8 weeks of suitably phased interval
shadow-training or ghosting. Such interval-training regimes are surprisingly
specific in their application to individual players. In players of all standards, a poor
tactical sense may surface as an apparent lack of physical fitness.
Top class male players tend to have maximum oxygen uptakes
in the mid-60s and upwards, high anaerobic thresholds (60->80% VO2 max) and body
fat percentages between 7% and 12%. On the Wingate anaerobic test they tend to have leg
peak powers of 12.5-13.5w/Kg, a fatigue index of between 10 and 15 W/sec, and
a recovery index (on a repeat test 4 minutes later) of 95-98%. They tend to
have hand-grip strengths of 45-60kg.
Female players tend to have a VO2 (max) in the low to
mid-50s, with similarly high anaerobic thresholds, and body fat percentages in the
18 to 25% range. Their anaerobic leg peak powers tend to be around 7.5-8.0 w/kg, and their
fatigue indices tend to be between 8 and 15 W/sec, with recovery
indices of 94-100%, and grip strengths of 30-45kg. Within limits the amount of force
required to hold a racket tends to vary inversely with the diameter of the grip.
On time-lapse cinephotographical analysis, players of
county-standard and upwards tend to markedly deviate through the T on moving from
the front to the rear (or vice versa) of the court; club and recreational players tend to
have a more random movement pattern around the court. The Physics Department of Birmingham
University has timed national standard players to hit the ball at upwards of 70m/sec
(>156mph), and club players at 40m/sec (90mph). Due to the coefficient of restitution
of the squash ball being set at around 20%, the front wall rebound speeds are of the order
of 14 and 8m/sec, (31 and 18mph) respectively. It is this disparity of rebound speed which
Players of both sexes tend to have better-than-average
simple and complex reflex response times, and to have good dynamic balance at upwards of
20 sec out of 30 sec at 5 degrees from horizontal stabilometer displacement.
A good pre-season physical training programme will
incorporate the triple strands off
- aerobic/cardiorespiratory training;
- lactate/glycolytic training (for both anaerobic power and recovery); and
- phosphagen/speed training. (Some of the last two elements may be incorporated into
on-court pressure training.) The physical programme will have an appropriate in-season
maintenance component and an appropriate series of phased macro-cycles to peak for the
highlighted tournaments and championships.
The physical programme will, of course, be fully
complemented with solo and pairs practices, practice and conditioned games, and games
against opponents selected to probe particular technical, tactical or physical weaknesses.
Squash players are not alone among racket players in too often wishing to train their
strengths rather than their weaknesses, whether in skills or physical attributes, and
whether on or off the court.
Squash as a sport needs a mix of both types of fitness - we
know that it needs the anaerobic component because if we measure the lactic acid (the
waste product which indicates that anaerobic work has been going on) level at the end of a
game and it is high - say about 50% of maximum. (It could be 10 mmols, in the units in
which lactic acid is measured, as opposed to 20 mmols, which is the human maximum.) At the
end of a 400 metre race runners would measure 20. They generate this in 44 seconds.)
In squash where players play for an hour they have say 7-10
mmols - but this is a huge amount of lactic acid to tolerate for that amount of time.
Marathon runners have about 1.5 mmols when they finish the race. This is a real aerobic
sport - but squash fitness requires a mix. When squash players are training for local
muscle endurance they are doing two things. Firstly they are training the ability to
produce anaerobic energy, and secondly they are training the ability of the muscle and the
body to remove the lactic acid that is its fatiguing by-product. Lactic acid training is
always two things, one to increase the anaerobic power and the other to remove faster more
lactic acid. Shadow training and ghosting intervals are the basic training methods.
Balksby, BA, Eliott, BC, Davis, KH and Mercer, MD. Blood pressure and rectal
temperature responses of middle-aged sedentary, middle-aged active and A grade
competitive male squash players. Br. J. Sports Med 14: 133-138. 1980.
Hammond, M.O. An investigation into the anaerobic aspects of the game of squash rackets.
MA Dissertation, Department of PE and Sports\Science, University of Birmingham, 1984.
McKenzie,I. The Squash Workshop, Marlborough, Wiltshire: The Crowood Press.
Montpetit, R. Applied Physiology of Squash. Sports Medicine 10 (1) 31041. 1990.
Reilly, T. The racquet sports, in Physiology of Sports, edited by Reilly T and
Williams C. London, E and T.N. Spon. pp337-369. 1990.