阿基里斯之痛

跟腱炎又叫阿基里斯腱炎。阿基里斯是希腊神话中海洋女神忒提斯与国王佩琉斯的儿子,他是所有英雄之中最耀眼的一位,也是战无不胜的。他的母亲忒提斯是不死的,所以她也希望自己的孩子不死。在阿基里斯出生后,     

Sarcoidosis presenting as Achilles tendinitis.

A case is described of sarcoidosis which presented with Achilles tendinitis. This association has not previously been reported.     

Contribution of creatine to protein homeostasis in athletes after endurance and sprint running

Purpose

Few studies have focused on the metabolic changes induced by creatine supplementation. This study investigated the effects of creatine supplementation on plasma and urinary metabolite changes of athletes after endurance and sprint running.

Methods

Twelve male athletes (20.3 ± 1.4 y) performed two identical (65–70 % maximum heart rate reserved) 60 min running exercises (endurance trial) before and after creatine supplementation (12 g creatine monohydrate/day for 15 days), followed by a 5-day washout period. Subsequently, they performed two identical 100 m sprint running exercises (power trial) before and after 15 days of creatine supplementation in accordance with the supplementary protocol of the endurance trial. Body composition measurements were performed during the entire study. Plasma samples were examined for the concentrations of glucose, lactate, branched-chain amino acids (BCAAs), free-tryptophan (f-TRP), glutamine, alanine, hypoxanthine, and uric acid. Urinary samples were examined for the concentrations of hydroxyproline, 3-methylhistidine, urea nitrogen, and creatinine.

Results

Creatine supplementation significantly increased body weights of the athletes of endurance trial. Plasma lactate concentration and ratio of f-TRP/BCAAs after recovery from endurance running were significantly decreased with creatine supplementation. Plasma purine metabolites (the sum of hypoxanthine and uric acid), glutamine, urinary 3-methylhistidine, and urea nitrogen concentrations tended to decrease before running in trials with creatine supplements. After running, urinary hydroxyproline concentration significantly increased in the power trial with creatine supplements.

Conclusions

The findings suggest that creatine supplementation tended to decrease muscle glycogen and protein degradation, especially after endurance exercise. However, creatine supplementation might induce collagen proteolysis in athletes after sprint running.     

Vitamin and mineral supplementation: effect on the running performance of trained athletes

There is limited scientific justification for the widespread use of vitamin and mineral supplements by athletes. We used a 9-mo, placebo-controlled crossover study design to determine whether a multivitamin and mineral supplement influenced the athletic performance of 30 competitive male athletes. At 0, 3, 6, and 9 mo the runners performed a progressive treadmill test to volitional exhaustion for measurement of maximal oxygen consumption, peak running speed, blood lactate turnpoint, and peak postexercise blood lactate level. Running time in a 15 km time trial was also measured. None of these variables was influenced by 3 mo of active supplementation. We conclude that 3 mo of multivitamin and mineral supplementation was without any measurable ergogenic effect.     

Thermoregulation in elite athletes

PURPOSE OF REVIEW: Exercise causes body temperature to rise and the resulting heat stored becomes a factor limiting exercise performance in hot conditions. Loss of heat by evaporative processes leads to hypohydration which itself can eventually impair performance. This review focuses on thermoregulatory and behavioural processes during sustained exercise in the heat. RECENT FINDINGS: Several studies have implicated cerebral mechanisms in eschewing fatigue due to heat stress. Acclimatization improves performance by affecting heat loss mechanisms, implicating peripheral and central processes. Pharmacological methods of increasing heat tolerance are unacceptable strategies for the athlete, but appropriate precooling measures are effective. SUMMARY: This review highlights the combination of physiological processes that converge in heat stress during extended exercise. Pharmacological ergogenic aids are discouraged due to likely side effects in cerebral function whereas behavioural measures, including precooling the body, have practical support.     

Discipline-specific insulin sensitivity in athletes

ObjectiveWeight status and abnormal liver function are the two factors that influence whole-body insulin sensitivity. The main goal of the study was to compare insulin sensitivity in athletes (n = 757) and physically active controls (n = 670) in relation to the two factors.MethodsHomeostatic metabolic assessment for insulin resistance (HOMA-IR), weight status, and abnormal liver function (alanine aminotransferase and aspartate aminotransferase) were determined from 33 sports disciplines under morning fasted condition. This study was initiated in autumn 2006 and repeated in autumn 2007 (n = 1508) to ensure consistency of all observations.ResultsIn general, HOMA-IR and blood pressure levels in athletes were significantly greater than those in physically active controls but varied widely with sport disciplines. Rowing and short-distance track athletes had significantly lower HOMA-IR values and archery and field-throwing athletes had significantly higher values than the control group. Intriguingly, athletes from 22 sports disciplines displayed significantly greater body mass index values above control values. Multiple regression analysis showed that, for non-athlete controls, body mass index was the only factor that contributed to the variations in HOMA-IR. For athletes, body mass index and alanine aminotransferase independently contributed to the variation of HOMA-IR.ConclusionThis is the first report documenting HOMA-IR values in athletes from a broad range of sport disciplines. Weight status and abnormal liver function levels appear to be the major contributors predicting insulin sensitivity for the physically active population.     

Bone disease in female athletes

Regular exercise and physical activity have many health benefits for both females and males. In particular, weight-bearing exercise has a protective effect on the skeleton, and can even be osteogenic (stimulating to bone formation). However, achievement of optimal bone mineral density and regulation of bone maintenance depend upon a combination of mechanical, hormonal and dietary factors. Adequate hormonal status (oestrogen and progesterone), and sufficient nutrition (calcium, protein, and other bone-building materials) are essential. For young women with components of the Female Athlete Triad (such as disordered eating, amenorrhea and other forms of menstrual dysfunction), one or more of these may be lacking, and decreased bone density can result. With an effort to maximize peak bone mineral density in the young athlete and to preserve or restore gonadal function during the reproductive years, the complications of altered bone mineral density and frank osteoporosis can be avoided.