Central aponeurosis tears of the rectus femoris: practical sonographic prognosis.

OBJECTIVE: This study is a statistical analysis to establish whether a correlation exists between the level and degree of rectus femoris (RF) central tendon injury and the amount of time that an athlete is unable to participate subsequently, referred to as "sports participation absence" (SPA). DESIGN: Causal-comparative study. PATIENTS: 35 players from two high-level Spanish soccer teams with an injury to the central tendon of the RF based on clinical and ultrasound criteria. MAIN OUTCOME MEASURE: Ultrasound examination was performed with an 8-2 MHz linear multifrequency transducer. All studies included both longitudinal and transverse RF sections. RESULTS: At the proximal level the SPA time is 45.1 days when the injury length is 4.0 cm. This value increases by 5.3 days with each 1 cm increase in the length of injury. In the case of distal level injury, SPA time is 32.9 days when the injury length is 3.9 cm. This value increases by 3.4 days with each 1 cm increase. In the total representative sample, SPA time when the injury length is 4.2 cm corresponds to 39.1 days. This value increases by 4.2 days per length unit. CONCLUSIONS: RF central tendon injury at the proximal level is associated with a greater SPA time than at the distal level. Patients with a grade II injury have an SPA time longer than those with a grade I injury whether the injury is located proximal or distal.

Fast and slow myosins as markers of muscle injury.

OBJECTIVE: The diagnosis of muscular lesions suffered by athletes is usually made by clinical criteria combined with imaging of the lesion (ultrasonography and/or magnetic resonance) and blood tests to detect the presence of non-specific muscle markers. This study was undertaken to evaluate injury to fast and slow-twitch fibres using specific muscle markers for these fibres. METHODS: Blood samples were obtained from 51 non-sports people and 38 sportsmen with skeletal muscle injury. Western blood analysis was performed to determine fast and slow myosin and creatine kinase (CK) levels. Skeletal muscle damage was diagnosed by physical examination, ultrasonography and magnetic resonance and biochemical markers. RESULTS: The imaging tests were found to be excellent for detecting and confirming grade II and III lesions. However, grade I lesions were often unconfirmed by these techniques. Grade I lesions have higher levels of fast myosin than slow myosin with a very small increase in CK levels. Grade II and III lesions have high values of both fast and slow myosin. CONCLUSIONS: The evaluation of fast and slow myosin in the blood 48 h after the lesion occurs is a useful aid for the detection of type I lesions in particular, since fast myosin is an exclusive skeletal muscle marker. The correct diagnosis of grade I lesions can prevent progression of the injury in athletes undergoing continual training sessions and competitions, thus aiding sports physicians in their decision making.

Endemic strongyloidiasis on the Spanish Mediterranean coast.

Diagnosis and treatment of Strongyloides stercoralis infection can be difficult, and a high degree of clinical suspicion in patients who have visited an endemic area is required. We describe the epidemiology and clinical features of 152 prospectively identified cases of strongyloidiasis in an European region, and identify risk factors for the development of severe forms of the disease. This was a prospective study of all patients admitted to a single institution over an 8-year period. Patients (n=152) were mainly elderly male farmers (79%) who had acquired the disease by working barefoot in contact with soil and ingesting non-drinking water. Eosinophilia was a sensitive marker for the infection (82%). Twenty patients (13%) developed severe forms of the illness and six patients (4%) died. A significant association was found between severe forms of strongyloidiasis and steroid usage (OR 9.0, 95%CI 2.1-37.6), immunodebilitating illness (OR 10.1, 95%CI 3.2-32.3) and other immunosuppressive therapy (OR 13.7, 95%CI 2.9-58.7), but by logistic regression analysis, only immunodebilitating disease was as a risk factor (OR 2.1, 95%CI 1.78-2.43). S. stercolaris infection is endemic in the Spanish Mediterranean coast. The frequent development of severe forms of the disease, with a high mortality, makes early recognition and treatment essential.

Differences between lactate concentration of samples from ear lobe and the finger tip.

Blood lactate concentrations in capillary samples obtained from the ear lobe or from the finger tip are used indistinctly, since they are considered equivalents. The aim of the study reported in this paper was to verify whether that assumption is valid due to the practical implications which any possible differences between these two sampling sites would have in the planning and assessing of an athletic training program. Twenty six healthy male athletes competing in different sports at the national level (9 rowers, 7 cyclists and 10 runners) were studied during the performance of a graded exercise test up to the point of exhaustion, on specific ergometers. In each group, capillary blood samples were obtained simultaneously from both the ear lobe and the finger tip at three different times during the test: 1) in resting conditions; 2) when exercising at a submaximal work load and 3) seven minutes after the point of exhaustion. Significant differences were found between the blood lactate concentrations of samples obtained from the ear lobe and from the finger tip (p < 0.001). The method error of repeated measurements for lactate concentrations from paired samples obtained in resting conditions was 27%, when exercising at a submaximal work load, 16% and at maximal work load, 3%. Capillary blood samples collected from the finger tip consistently showed higher values in lactate concentration than those obtained, at the same time, from the ear lobe.

Heritability of running economy: a study made on twin brothers.

Running economy (RE), defined as the steady-state of oxygen uptake (VO2) for a given running velocity, is a factor of sports performance the genetic component of which has seldom been reported to date. We studied this component using a heritability index (HI) in a group of 32 male twins, 8 monozygotic (MZ) and 8 dizygotic (DZ) pairs, all sportsmen with similar perinatal and environmental backgrounds. Zygocity was determined by the identity of erythrocytic antigenic, protein and enzymatic polymorphism, and human leucocyte antigen serologic types between co-twins. The subjects exercised twice on a treadmill, once until exhaustion and again at submaximal intensities. Pulmonary gas exchange was measured continuously using an automatic analyser system during both tests. Blood samples were obtained during the recovery period to determine lactate concentrations. No significant differences were observed between MZ and DZ, in respect of RE at any speed or in maximal VO2 relative to body mass. Nevertheless, significant HI (P < 0.05) was found in maximal lactate concentrations (HI=0.75) and in respiratory equivalent for oxygen at two speeds, 7 km x h(-1) HI=0.71) and 8 km x h(-1) (HI=0.79), differences which probably suggest that there are differences in RE. In conclusion, we did not detect a genetic component in RE or in maximal oxygen uptake, but a genetic component for markers of anaerobic metabolism was present.

Cardiorespiratory response to exercise in elite Sherpa climbers transferred to sea level.

Himalayan Sherpas are well known for their extraordinary adaptation to high altitude and some of them for their outstanding physical performance during ascents to the highest summits. To cast light on this subject, we evaluated the cardiorespiratory response during exercise at sea level of six of the most acknowledged Sherpa climbers, mean age (+/- SD) 37 (+/- 7) yr old. Continuous electrocardiogram and breath-by-breath pulmonary gas exchange until exhaustion were obtained by following the Bruce protocol. We detected a maximal oxygen uptake (VO2max) of 66.7 (+/- 3.7) mL-min-1.kg-1, maximal cardiac frequency of 199 (+/- 7) beats.min-1, and ventilatory anaerobic threshold at 62 (+/- 4) % of VO2max. These factors could help to explain the greater performance level shown by several elite climbers of this ethnic group. The high functional reserve demonstrated by this very select group of highlanders could be associated with natural selection and with special physiological adaptations probably induced by long-training in a hostile environment.

Exercise-induced asthma prophylaxis in athletes using inhaled nedocromil sodium.

This open labelled, group comparative, cross over study, was carried out to analyze the efficacy of two dosages of Nedocromil sodium (NS) in the prophylaxis of Exercise Induced Asthma (EIA). 13 athletes (6 males, 7 females), aged: 12-38 years, were studied measuring their EIA by forced spirometries prior and at 1, 3, 5, 10, 15 and 30 minutes post treadmill test. Four mg of NS were administered via inhalation chamber 30 minutes prior to the second test; prior to the third one;: NS at a dose of 4 mg every 8 hours during four weeks plus 4 mg of NS 30 minutes before it. In the baseline exercise test, a 33.6 +/- 10.5 percent decrease of FEV1 was observed; 12.6 +/- 11.4 in the second one, and 9.7 +/- 9.76 in the third test. A protection index higher than 30% was obtained in 9 cases of the second test (81.5 +/- 16.2%), and in 10 of the third one (77.2 +/- 15.3%). Nedocromil sodium (4 mg prior to exercise) is effective for EIA prophylaxis. Although no significant differences exist between both dosages, a greater protection index is reached after NS sustained administration.

Evaluation of erythropoietin in endurance runners.

To evaluate the role of erythropoietin (Epo) in the erythroid abnormalities often found in athletes, Epo was evaluated by radioimmunoassay in endurance runners (ER). In a first study, 46 experienced ER, 11 with iron deficiency (ID group), were studied during a training period. In ID and non-ID runners, serum Epo (SEpo) levels were similar to sedentary controls (ID = 19.1 +/- 4.9 U/L, non-ID = 19.7 +/- 5.5 U/L and controls 19.7 +/- 9.2 U/L). In a second study, serum and urine erythropoietin (UEpo) levels were evaluated in 17 ER during a 6-hour race. Samples were taken before the race (pre-race), immediately following (6-hour) and 4 days after (post-race). No differences were observed in SEpo levels (pre-race = 19.8 +/- 4.1 U/L, 6-hour = 21.2 +/- 4.9 U/L and post-race = 21 +/- 4 U/L), but UEpo increased following the race (pre-race = 15.4 +/- 9.6 U/L, 6-hour = 26.1 +/- 6.2 U/L and post-race = 14.1 +/- 6.5 U/L) (p < 0.0001) and this UEpo increase was related to urine creatinine changes (rs = 0.79, p < 0.00001). In conclusion, SEpo in ER does not differ from sedentary values and does not vary with competition; however, UEpo increases during a long-distance race. These data may be important for a correct evaluation of Epo abusers and sports anemia.

Effect of prior ingestion of glucose or fructose on the performance of exercise of intermediate duration.

The metabolic responses induced by the ingestion of a beverage containing glucose (G), fructose (F) or placebo (W) 30 min before exercise of high intensity and intermediate duration have been investigated; in these conditions the energy processes are mostly dependent on aerobic reactions. A group of 11 male recreational sportsmen ran on a treadmill, at an intensity corresponding to 82% of peak oxygen consumption, until exhaustion on three different occasions (after ingestion of a beverage containing 75 g of G, 75 g of F or W). Plasma glucose, insulin, and lactic acid concentrations were determined just prior to the ingestion of the beverages, 30 min afterwards and 10 and 30 min after completion of the exercise. The mean endurance time was 644 (SD 261) s after the ingestion of G, 611 (SD 227) s after the ingestion of F and 584 (SD 189) s after the ingestion of the W (P < 0.05 between G and W). No differences in the oxygen uptake, respiratory quotient or lactate concentrations between the three trials were observed. Both plasma glucose and insulin concentrations determined in samples obtained immediately before the onset of exercise were higher when G was ingested than when F (P < 0.05 and P < 0.05, respectively) or W (P < 0.001 and P < 0.005, respectively) were ingested. These findings would suggest that the ingestion of G prior to an effort of intermediate duration may improve physical performance.

[Hematologic changes induced by exertion during a long-distance race]. / Cambios hematológicos inducidos por el ejercicio durante una carrera de largas distancias.

PURPOSE: To evaluate the haematological changes induced by a long-distance race in well trained runners. PATIENTS AND METHODS: The haematological changes presented by 17 runners (15 men and 2 women) were assessed in a 6-hour race. For this purpose samples were examined before the race, 2 hours later, 4 hours later, at the end of the race, and 4 days after the trial. RESULTS: Haemoglobin rates, as well as leucocyte, neutrophil, monocyte and platelet counts were increased, probably due to decreased plasma volume. Haemolytic traits were seen as well, namely, increased reticulocyte count and decreased haptoglobin. High transferrin-transport capability and serum B12 levels were also present. Mild haematuria was found without any haemosiderinuria, siderinuria or haemoglobinuria. All these changes recovered in the post-race study. CONCLUSION: Changes in the major haematologic values are present during long-distance races, some of them due to haemoconcentration. Leucocytosis, haemolysis and haematuria are noteworthy, and these findings must be borne in mind when evaluating the health of runners.