RESUMEN
Amenorrheic athletes have been likened to postmenopausal women, with low estrogen levels and osteopenia. It has been suggested that estrogen exerts its antiresorptive actions on bone via a nitric oxide (NO)-dependent mechanism. This study investigated whether the mechanism of bone loss in amenorrheic athletes is similar to that of postmenopausal women with reduced NO levels and high bone turnover. Eleven amenorrheic athletes, 15 eumenorrheic athletes, and 10 sedentary controls were studied. Spine and hip bone mineral density was measured using dual-energy x-ray absorptiometry. Bone turnover was assessed by biochemical markers of formation (osteocalcin and bone-specific alkaline phosphatase) and resorption (deoxypyridinoline). NO metabolites were measured from 24-h urine samples using a chemiluminescence assay. Spine, but not hip, bone mineral density was reduced in the amenorrheic group, compared with the eumenorrheic (P = 0.0001) and control (P = 0.04) groups. Osteocalcin, bone-specific alkaline phosphatase, and deoxypyridinoline were similar in all groups. NO metabolites were lower in the amenorrheic group, compared with controls (P = 0.035), despite a higher dietary intake of nitrates. Unlike postmenopausal women, amenorrheic athletes do not have raised bone turnover but do have reduced NO metabolites and spinal osteopenia. The results show, however, that reduced NO production is a common denominator in both conditions and further support the importance of NO in estrogen-mediated protection of skeletal mass and strength.
Asunto(s)
Amenorrea/metabolismo , Enfermedades Óseas Metabólicas/metabolismo , Remodelación Ósea , Óxido Nítrico/orina , Enfermedades de la Columna Vertebral/metabolismo , Deportes , Adulto , Fosfatasa Alcalina/sangre , Amenorrea/etiología , Aminoácidos/orina , Densidad Ósea , Femenino , Humanos , Osteocalcina/sangre , PosmenopausiaRESUMEN
A growing number of reports of anabolic-androgenic streroid (AS) use in Great Britain (GB) among non-competitive groups have emerged since the beginning of 1990s. A study was commissioned by the Departments of Health for England, Scotland and Wales, to explore the extent and uses of AS from the public health point of view. As a part of a wider investigation into AS use, 21 gymnasia in England, Scotland and Wales were surveyed by questionnaire. The response rate was 59%. We found that of the 1667 participants, 9.1% of the men and 2.3% of the women had taken AS at some time and 6% of the men and 1.4% of the women were current users. Considerable variation in the prevalence of use was found, ranging from no reports in three of the gymnasia, up to 46%. We also investigated patterns of AS use and perceived side-effects in a wide-ranging group of AS users (n = 110), who were recruited through social networks. In-depth interviews with the users revealed that the 97 men (27+/-7 years) and 13 women (25+/-5 years) had been using AS regularly for 2.05+/-1.7 years and 1.9+/-2 years, respectively. Seventy-two injected AS. While most injected themselves, 25% were mainly injected by their friend. Up to 16 different drugs were taken by interviewees during the present or last cycle. Polydrug use was common and dosage taken exceeded therapeutic recommendations. Sixteen interviewees did not report side-effects, while the majority reported two or more. Many of these were cosmetic. Of the 97 men interviewed, 56% reported testicular atrophy, 52% gynaecomastia, 36% elevated blood pressure, 56% fluid retention, 26% injuries to tendons, 22% nosebleeds and 16% more frequent colds. Six men reported problems with kidney function and five with liver function. Problems with sleep were reported by 37%. Of the 13 women interviewed, eight reported menstrual irregularities, eight fluid retention, four clitoral enlargement, three decreased breast size and two elevated blood pressure. Four reported sleeplessness.
Asunto(s)
Anabolizantes/administración & dosificación , Doping en los Deportes/estadística & datos numéricos , Deportes/estadística & datos numéricos , Administración Oral , Adulto , Anabolizantes/efectos adversos , Atrofia , Actitud Frente a la Salud , Mama/efectos de los fármacos , Mama/patología , Clítoris/efectos de los fármacos , Clítoris/patología , Resfriado Común/epidemiología , Combinación de Medicamentos , Edema/epidemiología , Epistaxis/epidemiología , Femenino , Gimnasia/estadística & datos numéricos , Ginecomastia/epidemiología , Conocimientos, Actitudes y Práctica en Salud , Humanos , Hipertensión/epidemiología , Hipertrofia , Inyecciones , Enfermedades Renales/epidemiología , Hepatopatías/epidemiología , Masculino , Trastornos de la Menstruación/epidemiología , Prevalencia , Salud Pública , Trastornos del Sueño-Vigilia/epidemiología , Traumatismos de los Tendones/epidemiología , Testículo/efectos de los fármacos , Testículo/patología , Reino Unido/epidemiologíaRESUMEN
During the competitive season of 1990, 155 British triathletes whose competitive distances varied from sprint to full ironman, and who self-classified themselves as recreational, intermediate or élite, kept a training diary for an 8-week period. They gave details of injuries sustained while training for, or competing in, triathlons. The mean(s.d.) distances covered each week were: swimming, 4.2(2.6) km; cycling, 100.2(70.6) km; and running 23.4(15.2) km; mean(s.d.) training time was 7(3.4) h per week, and a mean(s.d.) of 7.9(3.4) training sessions were completed per week. At least one injury was reported by 37% of the participants. The most frequently affected sites were the ankle/foot, thigh, knee, lower leg and the back. Overuse was the reported cause in 41% of the injuries, two-thirds of which occurred during running. The likelihood of an injury was positively associated with experience in triathlon. Average injury rate was 5.4 injuries per 1000 h of training (95% confidence interval: 4-7.2) and 17.4 per 1000 h of competition (95% confidence interval: 10.9-27.9). Injury incidence was unrelated to the mean amount of weekly training or competition, intensity or frequency of training.
Asunto(s)
Ciclismo/lesiones , Ciclismo/estadística & datos numéricos , Carrera/lesiones , Carrera/estadística & datos numéricos , Natación/lesiones , Natación/estadística & datos numéricos , Adulto , Traumatismos del Tobillo/epidemiología , Traumatismos de la Espalda , Trastornos de Traumas Acumulados/epidemiología , Métodos Epidemiológicos , Femenino , Traumatismos de los Pies/epidemiología , Humanos , Incidencia , Traumatismos de la Rodilla/epidemiología , Traumatismos de la Pierna/epidemiología , Masculino , Registros Médicos , Desempeño Psicomotor , Esguinces y Distensiones/epidemiología , Muslo/lesiones , Factores de Tiempo , Reino Unido/epidemiologíaRESUMEN
Most studies of the triathlon have looked at male triathletes with respect to the longer distance events such as the Hawaii Ironman Triathlon. The purpose of this study was to investigate and compare the physiological characteristics and training protocols of elite and competitive (club) women triathletes who compete at Olympic distance (1.5 km swim, 40 km cycle, 10 km run) to examine the relationship between these factors and running performance in the triathlon. The elite triathletes (n = 10) had a lower body mass and BMI than club level triathletes (n = 9) as well as smaller girths at all measured sites although these differences were not significant. Sum of skinfold thickness measured at four sites was significantly smaller in the elite group (p = 0.05), yet, wide individual variations were found within each group. The amount of training undertaken by individuals in both groups varied markedly; however, overall the elite did more training in all disciplines. The VO2max measured on the treadmill was significantly higher (p = 0.03) in the elite women (65.6 +/- 6.0 ml.kg-1.min-1) as compared to the club level women (60.4 +/- 3.1 ml.kg-1.min-1). The elite triathletes were significantly more economical, showing a lowered relative oxygen consumption (% VO2max), (p = 0.008); lowered heart rate (p = 0.01) and lowered blood lactate values (p = 0.03) at 15 km.h-1. The elite group were also much more efficient runners at 15 km.h-1 when looking at VE/VO2 (p = 0.05). An association was found between run race time and %VO2max at 15 km.h-1 (p = 0.04). The results suggest that there is no ideal nor unique anthropometric profile that can be established for female triathletes especially with respect to running time and overall performance. The widespread differences in physiological variables found between the two groups confirms the important contribution factors such as these make to performance.