Female athletes are often nutritionally vulnerable as they strive
for thinness and a lean physique in the belief that this will make them faster
& stronger and lead to an overall improvement in their sporting performance.
The female athlete triad was first
defined in 1992 by the American College of Sports Medicine (ACSM) and described
the interrelationship between disordered eating, amenorrhoea (cessation of
menstruation) and osteoporosis; an updated position was released in 2007 that
modified the components of the triad to energy availability, menstrual function
and bone mineral density (BMD) (George et
al., 2011).
Low energy intakes and disordered
eating affects body fat levels and menstrual function, leading to amenorrhea,
which, in-turn leads to the development of impaired bone health and subsequent
development of osteoporosis. Adolescents
and women training for sports in which low body weight is emphasised for
athletic activity or appearance are at greatest risk (Nattiv et al., 2007, George et al., 2011).
It is important, at this point, to distinguish the difference
between the terms “disordered eating” and “eating disorder”; disordered eating
refers to unhealthy and harmful eating behaviours that are used to achieve low
body weight and leanness, whereas an eating disorder refers to one of the three
clinical conditions, anorexia nervosa, bulimia nervosa or eating disorder not
otherwise specified (EDNOS), each diagnosable by a set of clinical criteria (Burke
& Deakin 2010).
Low or restricted energy intakes will ultimately lead to both
macro-nutrient (protein/fat & carbohydrate), micro-nutrient (vitamin &
mineral) deficiencies and low intakes of the essential fatty acids, omega 3
& 6, leaving the individual susceptible to fatigue, illness, infection and
possible risk of injury. As body fat is
reduced, hormonal imbalances are created and as levels of oestrogen,
follicle-stimulating hormone (FSH) and luteinising hormone (LH) decline, menstruation
may then cease; according to Frisch (2002) “a girl does not have her menstrual
period until she has a predictable minimum amount of body fat, and a grown
woman requires a larger minimum amount of fat to maintain ovulation and regular
menstrual cycles”. Oestrogen suppresses
osteoclast (cells that break down bone tissue) activity and therefore loss of
endogenous oestrogen leads to accelerated bone loss.
|
An athlete's condition moves along each spectrum at a different rate,
in one direction of the other, according to her diet and exercise habits
(American College of Sports Medicine) |
On a more positive note, if energy intake is increased to compensate
and accommodate for increased energy expenditure, hormonal balance and
menstrual function will usually return to normal; strenuous training alone is
not enough to disrupt menstrual function unless it is accompanied by dietary
restriction (George et al., 2011). However, as the number of missed menstrual
cycles accumulates, the loss of BMD may not be fully reversible and may
compromise the achievement of peak bone mass (the highest level of bone mass
achieved as a result of normal growth) (Thomas & Bishop 2007). “Studies
conducted with female athletes have shown that premature osteoporosis may occur
as a result of menstrual dysfunction and may be partially irreversible” (Burke
& Deakin 2010); low BMD also increases the risk of injury and stress
fractures.
Nutrition is pivotal to an athlete’s performance and the female
athlete triad demonstrates how severe under-nutrition can impair not only
overall health but also reproductive and skeletal health; “existence of one or
more components of the triad, alone or in combination, poses a health risk for
the physically active and athletic female” (Lanham-New et al., 2011).
Prevention, recognition and early intervention of the triad should
be a priority for all those who work with female athletes and education should
be at the forefront to ensure that all women are able to enjoy the benefits of
regular exercise & physical activity throughout the whole of their lives.
“I am building a fire, and every day I train, I add more fuel. At just the right moment, I light the match.” – Mia Hamm (Olympic gold medalist in women’s football)
Burke, L., Deakin, V. (2010) Clinical Sports Nutrition, 4th
Edition, Australia, McGraw-Hill Education (Australia) Pty Ltd
Frisch, R.E. (2002) Female Fertility and the Body Fat Connection,
London, The University of Chicago Press Ltd
George, C.A., Leonard, J.P.,
Hutchinson, M.R. (2011) The female
athlete triad: a current concepts review. South African Journal of Sports
Medicine, Vol 23, No.2, pp. 50-56
Lanham-New, A.A., Stear, S.J., Shirreffs,
S.M., Collins, A.L. (2011) Sport &
Exercise Nutrition, West Sussex, John Wiley & Sons Ltd
Nattiv, A., Loucks, A.B., Manore,
M.M., Sanborn, C.F., Sundgot-Borgen, J., Warren, M.P. (2007). The Female Athlete Triad. American College of Sports Medicine, Position
Stand, pp. 1867-1877
Thomas, B., Bishop, J. (2007) Manual
of Dietetic Practice, 4th Edition, Oxford, Blackwell Publishing
Ltd