Energy and nutrient status of amenorrheic athletes participating in a diet and exercise training intervention program.

Chronic energy deficit is one of the strongest factors contributors to exercise-induced menstrual dysfunction. In such cases, macro- and micronutrient intakes may also be low. This study presents the results of a diet and exercise training intervention program. designed to reverse athletic amenorrhea, on improving energy balance and nutritional status in 4 amenorrheic athletes. The 20-week program provided a daily sport nutrition supplement and 1 day of rest/week. The program increased protein intakes for the 3 athletes with a protein deficit to within the recommended levels for active individuals. Micronutrient intakes increased, as did serum concentrations of vitamin B12, folate, zinc, iron, and ferritin. These results indicate that some amenorrheic athletes have poor nutritional status due to restricted EIs and poor food selections. A sport nutrition supplement may improve energy balance and nutritional status in active amenorrheic women.

Blood redistribution and circulatory responses to submaximal arm exercise in persons with spinal cord injury.

The purpose of this study was to evaluate responses to submaximal arm exercise (20%, 40%, and 60% of peak power output) using four conditions to support the circulatory redistribution in persons with spinal cord injury (SCI). Five males with tetraplegia (TP) and four males with paraplegia (PR) exercised 1) sitting, 2) supine, and 3) sitting with the addition of a) an anti-gravity suit (anti-G), b) elastic stockings and abdominal binder, and c) functional electrical stimulation of the leg muscles. Compared to sitting, the following significant changes were observed: in the supine position, heart rate (HR) decreased (PR: 104 vs 118 b/min, TP: 76 vs 92 b/min) and stroke volume (SV) increased (PR: 132 vs 116 ml, TP: 96 vs 83 ml). The anti-G suit induced a decrease in heart rate (PR: 104 vs 118 b/min, TP: 87 vs 92 b/min) and a decrease in oxygen uptake (VO2) in PR. Stockings only affected TP, i.e. a decrease in heart rate with 5 b/min and an increase in stroke volume with 13 ml/beat. Functional electrical stimulation produced an increase in VO2 (PR: 1.00 vs 0.95 l/min, TP: 0.68 vs 0.53 l/min) and a rise in stroke volume in TP. Results indicate that the methods employed to support the circulatory redistribution have different working mechanisms and, in addition, that the effects are different for TP and PR probably because of differences in active muscle mass, sympathetic impairment and blood pressure values.

Limits to maximal performance in individuals with spinal cord injury.

The purpose of this study was to examine the effect of four conditions that might improve oxygen transport and/or utilization during maximal exercise performance in individuals with spinal cord injury (SCI). Five males with tetraplegia (TP) and four males with paraplegia (PR) performed maximal arm cranking exercise in the following positions: 1) sitting; 2) supine; and 3) sitting with the addition of a) anti-gravity suit (anit-G), b) elastic stockings and abdominal binder, and c) functional electrical stimulation (FES) of the paralysed leg muscles. Peak power output (PO peak), peak oxygen uptake (VO2peak), peak heart rate (HR peak) and maximal systolic blood pressure were significantly lower in TP compared to PR for all conditions. A significant decrease in HR peak for PR, and a significant increase in VO2peak/kg for TP was seen during the supine compared to sitting condition. Respiratory exchange ratio (R) decreased significantly during the FES compared to the sitting condition in TP. No other changes were observed for any of the other conditions in either group. Improvements in central circulation previously reported during submaximal exercise for these four conditions did not result in a concomitant rise in maximal exercise performance. The results of this study suggest that the limitation in VO2peak for individuals with SCI is located peripherally (small active muscle mass) rather than centrally (heart or lungs).

Adiposity, plasma leptin concentration and reproductive function in active and sedentary females.

OBJECTIVE: Circulating leptin has recently been proposed as the peripheral signal indicating the adequacy of nutritional status for reproductive function. To test whether low plasma leptin concentration for a given degree of adiposity is associated with menstrual dysfunction, we measured plasma leptin concentration and body composition in young premenopausal women with normal or abnormal reproductive function. DESIGN: Fasting plasma leptin concentration (ELISA), body composition (dual energy X-ray absorptiometry) and menstrual status (menstrual history and hormonal profile) were assessed in 34 premenopausal women characterized by different levels of physical activity. RESULTS: Body fat content and plasma leptin concentration were both reduced in women with impaired reproductive function (amenorrheic < anovulatory < eumenorrheic women). However, after adjusting plasma leptin concentration for percentage body fat, there was no independent association between leptin and menstrual function. CONCLUSION: Menstrual abnormalities in young premenopausal women seem to occur as a consequence of the linear decline in adiposity and plasma leptin concentration observed in response to inadequate nutritional status. Levels of adiposity below 15% and plasma leptin concentration below 3 ng/ml are more likely to be associated with impaired reproductive function.

Role of energy balance in athletic menstrual dysfunction.

The cessation of menstrual function in the female athlete may reflect her inability to adapt to the environmental and lifestyle stressors associated with training and competition. As society's emphasis on thinness, dieting, and exercise continues to increase, so will the incidence of menstrual dysfunction in active females. Unfortunately, some individuals view athletic menstrual dysfunction as a benign consequence of strenuous exercise. Conversely, it is most likely a strong indicator of overtraining and a marker for future decrements in performance, and it can have long-term health consequences. Thus, it is imperative that the active female be appropriately educated regarding the adverse consequences of menstrual dysfunction and the interventions available. This paper focuses on the most current information regarding athletic menstrual dysfunction and its multifactorial etiology, especially the role of energy drain. In addition, common misconceptions, adverse health and performance effects, and available treatment options are discussed.

Treatment of athletic amenorrhea with a diet and training intervention program.

The purpose of this study was to determine the effect of a 15-week diet and exercise intervention program on energy balance, hormonal profiles, body composition, and menstrual function of an amenorrheic endurance athlete. The intervention program reduced training 1 day/week and included the use of a sport nutrition beverage providing 360 kcal/day. Three eumenorrheic athletes served as a comparison group and were monitored over the same 15-week period. The amenorrheic athlete experienced a transition from negative to positive energy balance, increased body fat from 8.2 to 14.4%, increased fasting luteinizing hormone (LH) from 3.9 to 7.3 mIU/ml, and decreased fasting cortisol from 41.2 to 33.2 micrograms/dl. The eumenorrheic subjects showed a 0.4% reduction in body fat, a decrease in follicular phase levels of LH from 7.9 to 6.5 mIU/ml, and no change in cortisol. These results suggest that nonpharmacological treatment can contribute to reestablishing normal hormonal profiles and menstrual cyclicity in amenorrheic athletes.