This is an excerpt from Women's Guide to Triathlon, The by USA Triathlon.
The most challenging condition that differentiates female and male athletes is the female athlete triad. The triad consists of three primary components: disordered eating, menstrual dysfunction, and osteoporosis, which is decreased bone mineral density (Ivković et al. 2007). Reduced availability of energy intake with high levels of energy expenditure is the primary cause of injuries that characterize the triad (Ivković et al. 2007). When females restore adequate energy intake, bone-associated injuries decline and menstrual function resumes, resulting in improved training and performance (Ivković et al. 2007).
In a sport such as triathlon, in which athletes can benefit from being lighter and in which they compete in form-fitting or minimal clothing, intentional disordered eating is more prevalent than sports that are not highly weight dependent or have participants wear clothing that fully covers the body or that is not tightly fitted. Studies show the prevalence of disordered eating to range between 15 and 62 percent in groups of female athletes, which is significantly greater than the 1 percent identified in the general population (Migliorini 2011). Disordered eating can take on a variety of patterns, from intentional avoidance of food intake to poor food choices because the athlete has not been educated on how to eat for her training load.
When an athlete is not consuming adequate calories and will not intentionally increase food consumption, the disordered eating pattern is termed anorexia athletica . Anorexia athletica differs from anorexia nervosa in that the disordered eating patterns are a function of trying to achieve a performance goal rather than body image alone. Athletes willing to increase caloric density in order to achieve adequate caloric intake are not considered to have anorexia athletica.
Anorexia athletica is characterized by an inability of hormones to rise and fall properly in order for menstrual function and normal bone formation to occur. When a female's menstrual cycle is absent for a period of 90 days or more, she is considered to have amenorrhea, which is characterized by low estrogen levels. As a result of these low estrogen levels, bone density is immediately affected, and injury most likely will eventually result. When estrogen levels are too low, osteoclasts within the bone live longer and resorb more of the bone, thus inhibiting the daily rebuilding of bone tissue. Should this occur for a prolonged period of time, the third component of the female athlete triad, osteoporosis - a skeletal disorder resulting in severe decreases in bone strength and density - is the end result. In addition to amenorrhea and decreased bone density, psychological disturbance is also observed in anorexia athletica and includes obsessive food behavior, anxiety, depression, and severe mood swings. Along with food restriction, anorexia athletica may include episodes of binging and purging and increased levels of exercise, especially after consumption of any form of food.
With a lack of appropriate caloric density, athletes with any form of disordered eating also lack nutrient density sufficient to sustain energy metabolism. As a result, stores of critical nutrients such as iron, B6, B12, folate, vitamin D, calcium, and electrolytes become depleted, resulting in a malnourished state. With declines in nutrients such as iron, B6, B12, and folate, the formation of hemoglobin and red blood cells is compromised, which eventually results in anemia and a reduced ability to transport oxygen. Thus, one of the primary indicators of insufficient caloric and nutrient density is a continuous decline in training capacity and performance. In addition to anemia, athletes may also present with decreased stores of vitamin D and calcium, which impairs bone remodeling and leads to increased incidence of bone-related injuries.
Preventing anorexia athletica, disordered eating, and the rest of the female athlete triad is not only about nutrition education. It also revolves around the environment, including whom athletes choose as coaches, friends, training partners, and family, as well as the mental outlook athletes have on performance and life. Coaches should help focus their athletes on measures of performance rather than body weight or body composition. Friends, training partners, and family should lend support to optimizing nutrition for performance. Ultimately, an athlete's mindset toward performance will determine her ability to choose the right foods and use them to enhance training and succeed in competition.
Training to Prevent Injury
Preventing injury depends heavily on understanding how to place a training load safely on the body and maintain the body's overall athleticism. The training load can be considered the total amount of stress placed on an athlete's body. Athleticism is the ability of the body to optimize the innate sport characteristics of flexibility, strength, endurance, agility, and explosiveness.
Overloading the body with a higher training load is one of the fundamental principles for improving performance. In the sport of triathlon, when three sports must be improved, too often the load can become too high and injury results. Keys to ensuring that an overtraining injury does not result include improving one sport discipline at a time, using perception of effort to guide training intensity, and manipulating only one of three factors - frequency, intensity, or duration - in the process of loading the body.
Determining the most effective training load on the body is best facilitated through the use of physiological monitoring tools such as power meters and GPS (Global Positioning System) or heart rate monitors in conjunction with a psychobiological assessment such as rate of perceived effort (RPE; table 12.1). In addition, the overall feeling of recovery should be monitored each day to enable full understanding of the impact of training (table 12.2). Together, these methods can then be used with software systems such as TrainingPeaks and Training Load to calculate and monitor a training load or stress score.