CHAPTER 89 • SOCCER 527PHYSICAL DEMANDS OF SOCCER
- The American Academy of Pediatrics classifies
Soccer as a contact sport. - The 26th Bethesda Conference classifies soccer as a
low static: high dynamic sport. - Soccer demands physical strength through the trunk
and lower extremity. - The aerobic challenges of soccer mesh the endurance
requirements of a distance runner with the abrupt accel-
eration demands of a sprinter. The average distance
covered by an elite midfield male player is in the 10-km
range, with the strikers, and fullbacks and centre-backs
covering respectively less. Sprinting comprises 10% of
the total distance covered (Reilly and Thomas, 1976). - Agility and proprioception skills are essential to com-
plete soccer’s sport specific tasks to make quick
changes in direction and jumps in the air. - The physiologic demands of soccer require proper
nutrition and hydration. The wet bulb globe tempera-
ture(WBGT) and both exercise duration and the
intensity will dictate individual requirements for opti-
mal fluid consumption and frequency. The American
College of Sports Medicine recommends activities be
halted when WBGTs exceed 82oF (28oC) (Elias,
Roberts, and Thorson, 1991).
•Young competitors dehydrated as little as 2% will not
only have impairments in performance but have a
diminished ability to dissipate heat and are more
prone to heat related injury. A 5% drop in body weight
during or following a soccer match or practice should
sideline that athlete for 24 hours to recuperate fluid
losses and to identify an intrinsic etiology such as
poor acclimatization, ergogenics, or illness (Elias,
Roberts, and Thorson, 1991; Saltin and Costill, 1998)
(level of evidence C, expert/concensus opinion). - It has been demonstrated that carbohydrate ingestion
in the fluids before and during soccer activity can
delay muscle glycogen depletion (Leatt and Jacobs,
1989) (level of evidence A, randomized controlled
trial). In a study by Foster and coworkers, they demon-
strated that indoor soccer athletes who drank a glucose
polymer enhanced work output and increased time to
exhaustion when compared to controls (Foster et al,
1986) (level of evidence A, randomized trial). - The recommended amount of carbohydrate to maintain
glucose levels and spare muscle glycogen is 30 to 60 g/h.
SOCCER INJURY RATES
- The overall injury incidence in soccer is favorable. In
comparison with American football, youth athletes
playing soccer sustain two to five times fewer injuries
(Sullivan et al, 1980).- Injury rates within the sport of soccer increase with
participant age and correlate with the increased inten-
sity of the match. More injuries occur during com-
petitive games than during practice. When a
correction is incorporated for exposure rates, senior
athletes (age >18) sustain 15 to 30 times as many
injuries as youths (Keller, Noyes, and Buncher,
1987). - Female youths have injury rates over twice as high as
male youths. Engstrom and colleagues reported an
incidence per 1000 player hours of 12 for girls versus
5 for boys (Engstrom, Johanoson, and Tornkvist,
1991). Schmidt-Olson reported an incidence per 1000
player hours of 17.6 for girls versus 7.4 for boys
(Schmidt-Olsen et al, 1991). - In most studies, ankle sprain is the most common
injury type in male and female soccer players
(Sullivan et al, 1980; Albert, 1983; Nilsson and Roaas,
1978; National Collegiate Athletic Association,
2000); however, Ekstrand in his study of 256 soccer
injuries in senior players found knee injuries in 20%
of his athletes and ankle injuries in 17% (Ekstrand and
Gillquist, 1983). The difference here possibly reflects
self-selection as players who sustained ankle injuries
as youth could have left the sport or played with ankle
braces as adults. Or, the style of play could follow the
finding that 50% of knee injuries are attributed to
tackling maneuvers (Nielsen and Yde, 1989) and
those players/opponents involved in this high-risk
exchange were more commonplace in Ekstrand’s
study of senior athletes. - Ankle sprain is implicated as a reinjury 56% of the
time (Soderman, 2001). - Soccer injury rates reported by the National Collegiate
Athletic Association (NCAA) use an established injury
surveillance system to follow male and female colle-
giate injuries (Putukian, Mandelbaum, and Brown,
2002). - Head injuries account for 1.2 to 8% of all injuries,
depending on the study. Youth soccer participants
suffer more head injuries than adults and this is
thought to be attributed to underdeveloped neck mus-
cles to absorb the impact shock, increased ball-weight:
head-weight ratio, and, more importantly, improper
head ball technique (Keller, Noyes, and Buncher,
1987). - Injury type follows gender differences. Women soccer
players suffer more concussions than men at a ratio
4.3:1 and more anterior cruciate ligament (ACL)
injuries 1.8:1 (practice) and 5.78:1 (games) (Putukian,
Mandelbaum, and Brown, 2002). - Indoor versus outdoor soccer injury rates are similar
in severity and type (Putukian et al, 1996). - Natural grass versus artificial surface soccer injury
rates reflect a higher injury incidence in games played
- Injury rates within the sport of soccer increase with