|
| ||||||||||||||||||||||||||||||||||||||||||||||||
PEDIATRICS Vol. 106 No. 1 July 2000, pp. 154-157
AMERICAN ACADEMY OF PEDIATRICS:
Intensive Training and Sports Specialization in Young Athletes
 |
ABSTRACT |
|---|
Top
Abstract
Recommendation
References
|
|---|
Children involved in sports should be encouraged to participate in a variety of different activities and develop a wide range of skills. Young athletes who specialize in just one sport may be denied the benefits of varied activity while facing additional physical, physiologic, and psychologic demands from intense training and competition.
This statement reviews the potential risks of high-intensity training and sports specialization in young athletes. Pediatricians who recognize these risks can have a key role in monitoring the health of these young athletes and helping reduce risks associated with high-level sports participation.
There appear to be increasing numbers of children who
specialize in a sport at an early age, train year-round for a sport, and/or compete on an "elite" level. Media coverage of national and
international competition in sports such as gymnastics, figure skating,
swimming, diving, and tennis has focused attention on a number of very
talented but very young competitors. The successes of young athletes
can serve as a powerful inducement for others to follow. Most Olympic
sports have selection processes that attempt to identify future
champions and initiate specialized training To be competitive at a high level requires training regimens for
children that could be considered extreme even for adults. The
ever-increasing requirements for success creates a constant pressure
for athletes to train longer, harder, more intelligently, and, in some
cases, at an earlier age. The unending efforts to outdo
predecessors and outperform contemporaries are the nature of
competitive sports. The necessary commitment and intensity of training
raises concerns about the sensibility and safety of high-level
athletics for any young person.
Adverse consequences from intense training and competition have been
reported in the lay and medical
literature.1,2 Many pediatricians can cite
examples of undesirable outcomes from sports participation
involving patients in their own practices. Unfortunately, anecdotal
reports and case studies are insufficient grounds for drawing
conclusions about the safety of intense training or high-level
competition.
The short-term and long-term health consequences of such training in
young athletes need to be further investigated. Physical, physiologic,
and psychologic tolerances to stress in children have been studied in
laboratory settings and can be defined by observing the threshold for
injury in clinical settings. Unfortunately, this information is
difficult to directly apply to the specific clinical scenarios of
concern to the pediatrician. Studying the risks of "specialized,"
"intensely trained," or "elite" athletes is hampered by the
lack of clear definitions of these at-risk populations. Even if a study
group could be defined, the level of variation between sports,
individuals, and training regimens creates further methodologic
challenges for investigators.
Despite recognized inadequacies of current information, pediatricians
can still help safeguard their young athletic patients by being aware
of potential problems associated with intense training. Because
pediatricians serve as the primary medical contact for most young
athletes, they may have the best opportunity to recognize, treat, and
monitor injuries or illnesses resulting from strenuous training. To
respond to parental concerns and to more effectively monitor the child
athlete engaged in intensive training, increased awareness of the
following issues is suggested.
Child athletes have superior cardiac functional capacity compared
with nonathletes. Nonetheless, there is some cause for caution. Data
obtained from studies using animals and humans indicate that myocardial
function can be depressed, at least transiently, after intense
exercise. Echocardiographic studies have indicated a transient decrease
in left ventricular contractility after extremes of athletic competition (ie, 24-hour ultramarathon runs).3
A limited number of studies have failed to identify an adverse effect
of intense endurance training on the heart of the child athlete. In
these investigations, no differences in resting echocardiograms or
electrocardiograms have been observed between trained prepubertal runners and nonathletes.4,5 Rost studied a group of young
swimmers longitudinally with echocardiograms over a 10-year period.
Cardiac volume and chamber size exceeded those of nonathletic children.6 The effects of sustained submaximal exercise on
cardiac function are similar in children and adults.7 Evaluation of cardiac function before and immediately after a 4-km road
race by echocardiograms in run-trained boys ages 9 to 14 years
showed no evidence of change in left ventricular
contractility.8
Based on these limited data, currently there is no indication that
intense athletic training of the child athlete results in injury to the
heart. However, closer study of the cardiac characteristics of children
training at elite levels is necessary before this conclusion can be
verified. Careful assessment of cardiovascular status (heart murmurs,
abnormal rhythms) remains important in ongoing medical care of the
child athlete.
With low or absent physical activity, muscle tissue becomes
atrophic, and bone mineral content decreases. An increase in physical activity stimulates musculoskeletal growth and repetitive stress can
stimulate positive adaptive responses in musculoskeletal structures. However, excessive stress or overload can lead to tissue breakdown and
injury. To realize maximum gains, athletes must correctly identify and
train just below the threshold for injury.
Overuse injuries (tendinitis, apophysitis, stress fractures) can be
consequences of excessive sports training in child and adult athletes.
Certain aspects of the growing athlete may predispose the child and
adolescent to repetitive stress injuries such as traction apophysitis
(Osgood-Schlatter disease, Sever disease, medial epicondylitis [Little
League elbow]), injuries to developing joint surfaces (osteochondritis
dissecans), and/or injuries to the immature spine (spondylolysis,
spondylolisthesis, vertebral apophysitis).9
Because of the potential for long-term growth disturbances, injuries to
epiphyseal growth centers are a particular concern for young athletes.
Because the physeal plate may be weaker than surrounding ligamentous
structures, external stress may disrupt a growth plate rather than
damaging a ligament or related soft-tissue structure. Physeal fractures
can result in growth arrest or deformity of long bones. Fortunately,
there is no evidence that epiphyseal fractures or growth complications
caused by epiphyseal injuries are seen disproportionately in children
who participate in organized sports or higher levels of competition.
The long-term effects of repetitive microtrauma to the epiphysis is
still under investigation. Damage to the distal radial epiphysis with
subsequent alterations in radial-ulnar growth has been described in
highly competitive gymnasts.10 Epiphyseal injuries to the
long bones of prepubertal children involved in distance running and
other weight-bearing sports (that might potentially affect development
of stature) have not been described. Similarly, cross-sectional and
longitudinal studies describing growth in child athletes indicate that
size and rate of growth of athletes are not negatively influenced by
intensive training and competition.11 Short stature in
gymnasts has been considered most likely a consequence of genetic and
physique preselection rather than a result of training, although some
have concluded that training starting before and maintained throughout
puberty can alter growth rates.12
Proper nutrition is critical for both good health and optimal
sports performance. For child athletes, an adequate diet is critical
because nutritional needs are increased by both training and the growth
process. Young athletes and their parents are frequently unaware of the
appropriate components of a training diet. The following 4 areas are of
particular concern.
Total Caloric Intake
Athletic training creates a need for increased caloric intake, and
requirements relative to body size are higher in growing children and
adolescents than at any other time in life. In child athletes, the
energy intake must be increased beyond the needs of training to
maintain adequate growth. Children who engage in sports in which
slenderness is considered important for optimizing performance (ie,
gymnastics, ballet dancing) may be at risk for compromising their
growth. A risk for pathologic eating behaviors also may be increased in
children participating in sports where leanness is rewarded.
Balanced Diet
Balance, moderation, and a variety of food choices should be
promoted. The Food Guide Pyramid can be used to plan a diet that is
balanced and provides sufficient nutrients and calories for both growth
and training needs. Athletes who focus on particular dietary
constituents (such as carbohydrates) at the expense of a well-rounded
diet may potentially compromise their performance as well as their
health.
Iron
The body's requirement for iron is greater during the growing
years than at any other time in life. Adequate iron stores are important to the athlete to provide adequate oxygen transport (hemoglobin), muscle aerobic metabolism (Krebs' cycle enzymes), and
cognitive function. However, athletes often avoid eating red meat and
other iron-containing foods. Moreover, sports training itself may
increase body iron losses.
Calcium
Inadequate calcium intake is common in athletes, presumably
because of their concern about the fat content in dairy foods. Normal
bone growth, and possibly, prevention and healing of stress fractures,
are contingent on sufficient dietary calcium.
Athletic girls tends to experience menarche at a later age than
nonathletic girls, leading to concern that intensive sports training
might delay sexual maturation. The average age of menarche in healthy
North American girls is 12.3 to 12.8 years, while that of athletes in a
wide variety of sports is typically 1 to 2 years later. Undernutrition,
training stress, and low levels of body fat have been hypothesized to
account for this delay. Alternatively, it is possible that the later
age of menarche in athletes simply reflects a preselection
phenomenon.13 Girls who have narrow hips, slender
physiques, long legs, and low levels of body fat Secondary amenorrhea, or cessation of menstrual cycles after menarche,
can occur as a result of intense athletic training. Prolonged
amenorrhea may cause diminished bone mass from the associated decrease
in estrogen secretion, augmenting the risk for stress fractures and the
potential for osteoporosis in adulthood. Efforts to improve nutrition
or diminish training volume in these girls may permit resumption of
menses and diminish these risks.
Studies of males have indicated no evidence of an adverse effect on
sexual maturation related to sports training. Progression of Tanner
stages of pubertal development has not been observed to be retarded in
athletic compared with nonathletic adolescents.11
Considerable research has addressed anxiety and stress that affect
children who engage in competitive sports but little data exist about
the effects of more intense or sustained training on young athletes.
Anecdotal reports suggest risks of "burnout" from physical and
emotional stress, missed social and educational opportunities, and
disruptions of family life. Unrealistic parental expectations and/or
exploitation of young athletes for extrinsic gain can contribute to
negative psychological consequences for elite young athletes. Survey
studies suggest, however, that while such adverse effects occur, they
are experienced by only a small minority of intensely training
athletes.13 Most athletes find elite-level competition to
be a positive experience.
Research supports the recommendation that child athletes avoid early
sports specialization. Those who participate in a variety of sports and
specialize only after reaching the age of puberty tend to be more
consistent performers, have fewer injuries, and adhere to sports play
longer than those who specialize early.15
Child athletes differ from adults in their thermoregulatory
responses to exercise in the heat.16 They sweat less, create more heat per body mass, and acclimatize slower to warm environments. As a result, child athletes may be more at risk for
heat-related injuries in hot, humid conditions. It is particularly critical that coaches, parents, and young athletes are aware of signs
of heat injury. They also should be aware that limiting sports play and
training in hot, humid conditions and ensuring adequate fluid intake
can prevent heat injury.
Although many concerns surround intense sports competition in
children, little scientific information is available to support or
refute these risks. Nonetheless, it is important to make efforts to
assist young athletes in avoiding potential risks from early excessive
training and competition. The following guidelines are suggested
keeping in mind 1) the importance of assuring safe and healthy sports
play for children, 2) the need to provide practical and realistic
guidelines, and 3) the limited research basis for making such
recommendations.
often before the prospect
finishes elementary school. The lure of a college scholarship or a
professional career can also motivate athletes (and their parents) to
commit to specialized training regimens at an early age. The low
probability of reaching these lofty goals does not appear to discourage
many aspirants.
CARDIAC
MUSCULOSKELETAL INJURY AND GROWTH
NUTRITION
SEXUAL MATURATION
advantageous
characteristics in many girls' sportsare more likely to experience
later menarche regardless of sports participation.
PSYCHOSOCIAL DEVELOPMENT
HEAT STRESS
RECOMMENDATIONS
Top
Abstract
Recommendation
References
COMMITTEE ON SPORTS MEDICINE AND FITNESS, 1999-2000
Steven J. Anderson, MD, Chairperson
Bernard A. Griesemer, MD
Miriam D. Johnson, MD
Thomas J. Martin, MD
Larry G. McLain, MD
Thomas W. Rowland, MD
Eric Small, MD
LIAISON REPRESENTATIVES
Claire LeBlanc, MD
Canadian Paediatric Society
Robert Malina, PhD
Institute for the Study of Youth Sports
Carl Krein, ATc, PT
National Athletic Trainers Association
Judith C. Young, PhD
National Association for Sport and Physical Education
SECTION LIAISONS
Frederick E. Reed, MD
Section on Orthopaedics
Reginald L. Washington, MD
Section on Cardiology
CONSULTANT
Oded Bar-Or, MD
STAFF
Heather Newland
| |
FOOTNOTES |
|---|
The recommendations in this statement do not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate.
| |
REFERENCES |
|---|
|
Top
Abstract
Recommendation
References
|
|---|
- Ryan J. Little Girls in Pretty Boxes: The Making and Breaking of Elite Gymnasts and Figure Skaters. New York, NY: Warner Books; 1996
- Tofler IR, Stryer BK, Micheli LJ, Herman LR. Physical and emotional problems of elite female gymnasts. N Engl J Med. 1996;25:335:281-283
-
Niemela KO,
Palatski IJ,
Ikaheimo MJ,
Takkunen JT,
Vuori JJ
Evidence of impaired left ventricular performance after an uninterrupted competitive 24-hour run.
Circulation.
1984;
70:350-356
[Abstract/Free Full Text] -
Rowland TW,
Delaney BC,
Siconolfi SF
"Athlete's heart" in prepubertal children.
Pediatrics
1987;
79:800-804
[Abstract/Free Full Text] - Rowland TW, Unnithan VB, McFarlane NG, Gibson NG, Paton JY Clinical manifestations of the "athlete's heart" in prepubertal male runners. Int J Sports Med. 1994; 15:515-519 [Medline]
- Rost R. Athletics and the Heart. Chicago, IL: Yearbook Medical Publishers; 1987
- Rowland TW, Rimany TA Physiological responses to prolonged exercise in premenarcheal and adult females. Pediatr Exerc Science. 1995; 7:183-191
- Rowland TW, Goff D, Popowski B, DeLuca P. Cardiac effects of a competitive road race in trained child runners. Pediatrics. 1997;100(3). URL: http://www.pediatrics.org/cgi/content/full/100/3/e2
- Micheli LJ Overuse injuries in children's sports: the growth factor. Orthop Clin North Am. 1983; 14:337-349 [Medline]
- Caine DJ Growth plate injury and bone growth: an update. Pediatr Exerc Science. 1990; 2:209-229
- Malina RM Physical growth and biological maturation of young athletes. Exerc Sports Sci Rev. 1994; 22:389-434
- Thientz GE, Howald H, Weiss V, Sizonenko PC Evidence for a reduction of growth potential in adolescent female gymnasts. J Pediatr. 1993; 122:306-313 [Medline]
- Malina RM Menarche in athletes: a synthesis and hypothesis. Ann Hum Biol. 1983; 10:1-24 [CrossRef][Medline]
- Donnelly P. Problems associated with youth involvement in high-performance sport. In: Cahill BR, Pearl AJ. Intensive Participation in Children's Sports. Champaign, IL: Human Kinetics Publishers; 1993:95-126
- Bompa T. From Childhood to Champion Athlete. Toronto, Canada: Veritas Publishing, Inc; 1995
- Bar-Or O. Pediatric Sports Medicine for the Practitioner. New York, NY: Springer-Verlag; 1983
Pediatrics (ISSN 0031 4005). Copyright ©2000 by the American Academy of Pediatrics
Statement of reaffirmation:
- AAP Publications Retired and Reaffirmed
- American Academy of Pediatrics
Pediatrics 2006 117: 1846-1847.[Extract] [Full Text] [PDF]
This article has been cited by other articles:
 |
|
 |
|
  S. G. Rice and and the Council on Sports Medicine and Fitness Medical Conditions Affecting Sports Participation Pediatrics, April 1, 2008; 121(4): 841 - 848. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Brenner and and the Council on Sports Medicine and Fitness Overuse Injuries, Overtraining, and Burnout in Child and Adolescent Athletes Pediatrics, June 1, 2007; 119(6): 1242 - 1245. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. C. S. Mihata, A. I. Beutler, and B. P. Boden Comparing the Incidence of Anterior Cruciate Ligament Injury in Collegiate Lacrosse, Soccer, and Basketball Players: Implications for Anterior Cruciate Ligament Mechanism and Prevention Am. J. Sports Med., June 1, 2006; 34(6): 899 - 904. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C L Otis, M Crespo, C T Flygare, P R Johnston, A Keber, D Lloyd-Kolkin, J Loehr, K Martin, B M Pluim, A Quinn, et al. The Sony Ericsson WTA Tour 10 year age eligibility and professional development review * Commentary. Br. J. Sports Med., May 1, 2006; 40(5): 464 - 468. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Rosenfield The Use of Ergogenic Agents in High School Athletes The Journal of School Nursing, December 1, 2005; 21(6): 333 - 339. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||