Regardless of gender, benefits of exercise to improve fitness and sports performance are well known and documented. Response to exercise is mostly the same for both genders with minor differences.
Body size and composition is one of the major differences between men and women. During pre-puberty years, there is no significant difference in height, weight, and body size. During puberty, estrogen secretion increases in women, this increases fat deposition and breast development. In men, an increase in testosterone secretion increases bone formation and protein synthesis (1,3). This is when significant differences in body size and composition become more evident. As far as body composition goes, women possess higher body fat than men. To summarize the differences in body size and composition, women on the average are (6):
- 13 cm / 5 in shorter,
- 14 kg to 18 kg / 30lbs to 40 lbs. lighter,
- 18 kg to 22 kg lighter in fat-free mass,
- 3 kg to 6 kg heavier in fat mass, and
- 6% to 10% higher in relative body fat
In terms of absolute strength, females tend to have two-thirds the strength of men (60 to 63.5%). Upper body strength levels tend to be around 55% of that of males, while lower body strength tend to be around 72%. However, when relative strength is considered, the differences in strength tend to lessen. Relative strength is defined as the absolute strength divided by the body weight or fat free mass. (3)
As far as training response is concerned, there is also little difference between the two genders. In both strength and endurance exercise response, both respond similarly. Major cardiovascular and respiratory adaptations to exercise are not gender specific. On the average, women experience the same relative increase VO2max as compared to men, about 15% to 20% . Women can experience also the same increases in strength as men with an average increase of about 20% to 40%. Therefore, there is little reason to advocate different training or conditioning programs based on gender. (1, 3, 4, 6)
However, for strength training and conditioning for sports for women there are a few considerations. One of the things to watch out for in female athletes is the warning signs of the female athletic triad.
The female athletic triad starts with eating disorders. This followed by secondary amenorrhea, and finally bone disorders.
When it comes to losing weight, most people resort to diets. Diets do work, but in conjunction with exercise. In sports where weight plays a major role, this can become a problem. The athlete may develop eating disorders. Eating disorders refers to a spectrum of behaviors, core attitudes, coping strategies, and conditions that share an emotionally based, inordinate, and often pathological preoccupation with body weight and shape (4).
Eating disorders must meet a specific criteria set by the American Psychiatric Association 6. The two most common eating disorders are Anorexia Nervosa and Bulimia Nervosa (1, 4, 6). Eating disorders among women became prominent in the 1980s, with men constituting about 10% of those cases. Anorexia has been recognized as a clinical syndrome since the 19th century. Bulimia, on the other hand was first described in 1976. (6)
Anorexia nervosa is characterized by the following: (1, 4, 6)
- Refusal to maintain more than the minimal normal weight based on age and height.
- Distorted body image
- Intense fear of fatness or gaining weight
- Amenorrhea
- Restricting type: Does not regularly engage in binge eating or purging behavior.
- Binge eating purging type: Regularly engages in binge eating purging behavior.
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| Distorted body image is on of the signs of Aneroxia Nervosa |
Bulimia nervosa, on the other hand, is characterized by: (6)
- Recurrent episodes of binge eating
- A feeling of a lack of control during these binges
- Purging behavior, which includes the use of self-induced vomiting, laxatives and diuretic use.
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| Purging Behavior is one of the signs of Bulimia |
Below is a short list of warning signs for anorexia and bulimia nervosa. A more comprehensive list can be found in Mcardle, Katch and Katch’s Exercise Physiology text book: (6)
Anorexia Nervosa Warning Signs:
- Dramatic loss in weight
- A preoccupation with food, calories, and weight
- Wearing baggy or layered clothing
- Relentless excessive exercise
- Mood swings
- Avoiding food-related social activities
Bulimia Nervosa Warning Signs:
- A noticeable weight loss or gain
- Excessive concern about food
- Bathroom visits after meals
- Depressed mood
- Strict dieting followed by eating binges
- Increased criticisms of one’s body.
The NSCA also includes a list of warning signs for both disorders: (2)
- Complaining frequently of constipation or stomach aches
- Mood swings
- Social withdrawal
- Relentless, excessive exercise
- Excessive concern about weight
- Strict dieting
- Increased criticism of one’s body
- Strong denial that a problem exists even when confronted with hard evidence.
Anorexia athletica, or eating disorders among athletes, is usually observed during the competitive season. It usually ends after the season ends. This does not really reflect a true pathologic eating disorder, but a desire to achieve optimum performance. However, some athletes, the season may never end and may develop into a true eating disorder. (4)
There are certain sports, which are more prone to eating disorders, and thus the triad, than others are. Endurance, weight classification, and appearance sports (bodybuilding, ballet, diving, figure skating, gymnastics, cheerleading) athletes are prone to eating disorders. About 25% to 60% of the athletes, less than 5% of the general population, exhibit some form eating disorder. (4, 6)
When the warning signs for eating disorders are recognized, it would best for the athletic trainer, strength and conditioning coach, or whoever is in charge, to report the problem immediately to the team doctor or psychologist. As mentioned earlier, eating disorders are a psychological problem and must be dealt with by qualified personnel.
Menstrual dysfunction is the second warning sign in the female athletic triad. Menarche is the term used to describe the first occurrence of menstruation. If the female has regular normal menstrual function, the term used is eumenorrhea. The term used to describe an irregular menstrual cycle is oligomenorrhea. Dysmenorrhea is painful menstruation. Amenorrhea is used to describe the absence of menstruation. Primary amenorrhea refers to the absence of menarche in women 16 years or older. These women never began menstruating. Athletes with previous normal menstrual function have sometimes reported the absence of menstruation for 180 days or more. This is referred to as secondary amenorrhea.
Secondary amenorrhea can occur in about 4% to 5% of the female population. In athletic groups, the figure is about 40%. When secondary amenorrhea occurs in athletic groups, it is sometimes referred to as athletic amenorrhea. There are currently two existing hypothesis on the menstrual irregularity when it comes to athletes. Exercise stress and the energy availability. (4)
The exercise stress theory states that the hypothalamic-pituitary-adrenal axis may be disrupted thus modifying the output of the gonadotropic-releasing hormone 4. Current evidence shows that the alternative theory, energy availability, is more likely the cause. As per Wilmore et al, studies have shown that inadequate caloric intake, when the intake of calories does not match the caloric expenditure, is the primary cause of secondary amenorrhea (6).
A well balanced diet reverses and prevents athletic amenorrhea. This can be done even without reducing the intensity or volume (4). A qualified licensed nutritionist should be able to create such a dietary plan with consultations with the athlete.
Secondary amenorrhea is also related to third sign of the triad, bone disorders. Specifically, osteoporosis. As we age, bone density decreases with aging. This normal occurrence is termed as osteopenia. Osteoporosis, on the other hand, is a more sever loss of bone mass. The microarchitecture of the bone deteriorates and leading to fragile porous bones. The injury rate due to bone fracture increases. These changes start to occur after the age of 30. Typically, in post-menopausal women, the injury rate due to fractures increases by about five times. Men also experience osteoporosis, but to a lesser degree. Bone mineral loss is slower in males. (6)
Wilmore et al lists three major contributing factors to osteoporosis common to post-menopausal women: (6)
- Estrogen deficiency
- Inadequate calcium intake
- Inadequate physical activity
Bone density remains closely related to menstrual regularity and the total number of menstrual cycles. Women who are amenorrhic tend to also have low serum estrogen. Estrogen has a protective effect on bone. The premature cessation of menstruation removes the protective effect of estrogen on bone. Persistent amenorrhea tends to negate the effect of exercise on bone mass. As per Mcardle et al, a 5% decrease in bone mass may lead to a 40% increase risk of fractures. (4)
Inadequate calcium intake can be best addresses by a sound balanced diet. Increasing calcium intake to about 1,200 mg to 1,500 mg daily has been proposed for decreasing the risk of osteoporosis (6).
Mcardle et al suggests a four phase plan in reducing athletic amenorrhea: (4)
- Reduce training levels by 10% to 20%
- Gradually increase total energy intake
- Increase the body weight by about 2% to 3%
- Maintain calcium intake by about 1,500 mg daily.
Bibliography:
1. Baechle, Thomas R. and Roger W. Earle “Essentials of Strength Training and Conditioning 3rd edition” 2008
2. Baechle, Thomas R. and Roger W. Earle “Essentials of Personal Training” 2004
3. Fleck, Steven J. and William J. Kraemer “Designing Resistance Training Programs 3rd edition” 2004
4. Mcardle William D. Frank I. Katch, And Victor L. Katch “Exercise Physiology: Energy, Nutrition, and Human
Performance 7th edition” 2010
5. Wilmore, Jack M. and David L. Costill “Training for Sport and Activity: The Physiological Basis of the
Conditioning Process” 1988
6. Wilmore, Jack M., David L. Costill and W. Larry Kenney “Physiology of Sport and Exercise 4th edition” 2008
