Allergy and asthma in elite summer sport athletes

Exercise may increase ventilation up to 200 L/min for short periods of time in speed and power athletes, and for longer periods in endurance athletes, such as long-distance runners and swimmers. Therefore highly trained athletes are repeatedly and strongly exposed to cold air during winter training and to many pollen allergens in spring and summer. Competitive swimmers inhale and microaspirate large amounts of air that floats above the water surface, which means exposure to chlorine derivatives from swimming pool disinfectants. In the summer Olympic Games, 4% to 15% of the athletes showed evidence of asthma or used antiasthmatic medication. Asthma is most commonly found in endurance events, such as cycling, swimming, or long-distance running. The risk of asthma is especially increased among competitive swimmers, of which 36% to 79% show bronchial hyperresponsiveness to methacholine or histamine. The risk of asthma is closely associated with atopy and its severity among athletes. A few studies have investigated occurrence of exercise-induced bronchospasm among highly trained athletes. The occurrences of exercise-induced bronchospasm vary from 3% to 35% and depend on testing environment, type of exercise used, and athlete population tested. Mild eosinophilic airway inflammation has been shown to affect elite swimmers and cross-country skiers. This eosinophilic inflammation correlates with clinical parameters (ie, exercise-induced bronchial symptoms and bronchial hyperresponsiveness). Athletes commonly use antiasthmatic medication to treat their exercise-induced bronchial symptoms. However, controlled studies on their long-term effects on bronchial hyperresponsiveness and airway inflammation in the athletes are lacking. Follow-up studies on asthma in athletes are also lacking. What will happen to bronchial hyperresponsiveness and airway inflammation after discontinuation of competitional career is unclear. In the future, follow-up studies on bronchial responsiveness and airway inflammation, as well as controlled studies on both short- and long-term effects of antiasthmatic drugs in the athletes are needed.     

Jumping height in former elite athletes

To evaluate lower-limb explosive strength with respect to lifetime athletic activity, we measured vertical jumping height on a contact mat in former male runners (n?=?28), soccer players (n?=?31), weightlifters (n?=?29) and shooters (n?=?29) (age range 45–68 years). There were no statistically significant age-adjusted sport-group differences in jumping height, but differences by sport were evident among the subgroup of athletes without hip or knee osteoarthritis (n?=?65) (P?n?=?33) (P?相似文献   

Predictive value of allergy and pulmonary function tests for the diagnosis of asthma in elite athletes

BACKGROUND: Asthma is frequently found in athletes, often associated with rhinitis and allergy. AIM: To study the predictive value of allergy and pulmonary function tests for the diagnosis of asthma in athletes. SUBJECTS AND METHODS: Ninety-eight national preOlympic athletes underwent an accurate medical examination including a validated questionnaire for asthma and rhinitis, spirometric recordings and skin prick testing with a panel of the most frequent inhalant allergens. Bronchodilator and/or exercise challenge were also performed in asthmatic subjects. RESULTS: Clinical asthma was present in 20.4% of athletes, rhinitis in 35.3% (in 21.4% of cases alone and in 13.9% associated with asthma). Positive prick tests were recorded in 44.4% of athletes (in 60.5% of asthmatics, in 95.2% of rhinitics and in 21.0% of nonasthmatic - nonrhinitic subjects). Mean spirometric values and distribution of abnormal values were not different among asthmatics, rhinitics and nonasthmatics - nonrhinitic patients. Skin-tests positivity was not related to the abnormal spirometric data found in individual cases. Provocation tests with bronchodilators or exercise did not appear sensitive enough to diagnose mild forms of asthma in subjects with normal basal spirometric values. CONCLUSIONS: Allergy testing and spirometry should be performed routinely in athletes because of the high prevalence of allergy, rhinitis and asthma in this population. However, the predictive value of these tests and of the bronchial provocation tests performed in this study seems too low to document mild or subclinical asthma in athletes.     

Anxiety and performance in elite non-professional athletes

Anxiety is one of the main motivators with regards to performance of individuals in any given task, including sporting endeavours. Our study sought to assess state anxiety levels in elite non-professional sportsmen, and to investigate if anxiety correlated with sporting performance, the IDA-Q (irritability, depression & anxiety questionnaire) was used to assess 3 mental state variables in an inter-county hurling team as well as a matched non-sporting control group, and performance was judged by completion of a standard task in 2 different settings: a non-pressurised one and a highly pressurised setting. Subjects had significantly higher anxiety scores on the IDA-Q than the controls (p = 0.019). There were no significant differences and controls in the depression and irritability scales. There was a significantly negative correlation between anxiety scores and performance on the IDA-Q; spearman r = -0.57. High anxiety levels impair sporting performance.     

Living high-training low: tolerance and acclimatization in elite endurance athletes

The “living high-training low” (LHTL) model is frequently used to enhance aerobic performance. However, the clinical tolerance and acclimatization process to this intermittent exposure needs to be examined. Forty one athletes from three federations (cross-country skiers, n=11; swimmers, n=18; runners, n=12) separately performed a 13 to 18-day training at the altitude of 1,200 m, by sleeping either at 1,200 m (CON) or in hypoxic rooms (HYP), with an O₂ fraction corresponding to 2,500 m (5 nights for swimmers and 6 for skiers and runners), 3,000 m (6 nights for skiers, 8 for swimmers and 12 for runners) and 3,500 m (6 nights for skiers). Measurements performed before, 1 or 15 days after training were ventilatory response (HVRe) and desaturation (ΔSaO₂e) during hypoxic exercise, an evaluation of cardiac function by echocardiography, and leukocyte count. Lake Louise AMS score and arterial O₂ saturation during sleep were measured daily for HYP. Subjects did not develop symptoms of AMS. Mean nocturnal SaO₂ decreased with altitude down to 90% at 3,500 m and increased with acclimatization (except at 3,500 m). Leukocyte count was not affected except at 3,500 m. The heart function was not affected by LHTL. Signs of ventilatory acclimatization were present immediately after training (increased HVRe and decreased ΔSaO₂e) and had disappeared 15 days later. In conclusion, LHTL was well tolerated and compatible with aerobic training. Comparison of the three patterns of training suggests that a LHTL session should not exceed 3,000 m, for at least 18 days, with a minimum of 12 h day⁻¹ of exposure.     

REM sleep and catecholamine excretion: a study in elite athletes

We investigated the potential influence of catecholamines on sleep architecture in endurance-trained athletes. The hypothesis was that endogenous levels of aminergic neurotransmitters influence sleep architecture. Thirteen well-trained male street cyclists (all members of the German national amateur team, mean age 23.9 years, mean body mass index 21.9 kg/m²) completed the protocol. Each subject was studied during training after a race competition (C) and later in a recovery/rest period (R) with no training and no competition. Polysomnography (PSG) was performed for one night (C) and for a second night some weeks later (R). Urinary levels of catecholamines collected during the preceding day and over the night of PSG were used as an index of excretion rate of circulating adrenergic agonists. Nighttime and daytime excretion of epinephrine and norepinephrine was significantly elevated after exercise (C vs R; P<0.01). Rapid-eye-movement sleep (REM) onset latency was significantly increased (P=0.03) and REM was significantly decreased in the first half of the night in the training compared to the resting condition (C vs R, P=0.05). REM latency was correlated with increased epinephrine excretion on the day of exercise (C, r=0.63, P=0.02). The temporal appearance of REM during the night appears to be affected in part by the intense exercise associated with race competition, and urinary catecholamines are markers that are correlated with this alteration in REM appearance. Electronic Publication     

Airway injury as a mechanism for exercise-induced bronchoconstriction in elite athletes

Exercise-induced bronchoconstriction (EIB) is a consequence of evaporative water loss in conditioning the inspired air. The water loss causes cooling and dehydration of the airway surface. One acute effect of dehydration is the release of mediators, such as prostaglandins, leukotrienes, and histamine, that can stimulate smooth muscle, causing contraction and a change in vascular permeability. Inspiring cold air increases dehydration of the surface area and causes changes in bronchial blood flow. This article proposes that the pathogenesis of EIB in elite athletes relates to the epithelial injury arising from breathing poorly conditioned air at high flows for long periods of time or high volumes of irritant particles or gases. The evidence to support this proposal comes from many markers of injury. The restorative process after injury involves plasma exudation and movement of cells into the airways, a process repeated many times during a season of training. This process has the potential to expose smooth muscle to a wide variety of plasma- and cell-derived substances. The exposure to these substances over time can lead to an alteration in the contractile properties of the smooth muscle, making it more sensitive to mediators of bronchoconstriction. It is proposed that cold-weather athletes have airway hyperresponsiveness (AHR) to pharmacologic agents as a result of epithelial injury. In those who are allergic, AHR can also be expressed as EIB. The role of beta(2)-receptor agonists in inhibiting and enhancing the development of AHR and EIB is discussed.     

Plasma lecithin: cholesterol acyltransferase activity in elite athletes from selected sports

Summary The activity of lecithin: cholesterol acyltransferase (LCAT) and the plasma lipoprotein concentrations of elite athletes from 8 selected sports (volleyball, judo, sprinting, wrestling, throwing, cycling, water polo and tennis) were determined and compared with those of a sedentary control group. Plasma LCAT activity levels in the athletes were significantly 2.2–7.0 times higher than in the controls in most sports (p<0.01). Judo, sprinting, wrestling and throwing had comparable LCAT values while tennis, volleyball and cycling were considerably higher. HDL-C concentration was significantly higher than controls in the water polo (p<0.05), cycling and volleyball (P<0.01) groups. Percentage lipoprotein distribution in the athletes in all sports except tennis, throwing and wrestling were similar to the controls. The differences among groups in LCAT activity may be related to the effect of physical exercise and training adaptations to lipid metabolism. This may be of importance when judging the benefit of exercise for atherosclerosis protection.     

Beat-to-beat QRS amplitude variability in elite endurance athletes.

Results from variance electrocardiography, displaying the wide-band, phase-locked electrical micro-variability during the depolarization phase, was analysed versus clinical data, echocardiographic structural and functional variables and myocardial scintigraphic findings in 174 elite orienteers compared with 37 age-matched elite endurance athletes and 50 age-matched, healthy medical students. PCA analysis identified a subgroup of five orienteers deviating from the rest of the study group and both control groups with regard to their QRS amplitude variability. No correlations were found between pathology by medical history or any of the echocardiographic and scintigraphic variables or by the variance electrocardiographic aberrations in any of the groups studied.     

Functional torque-velocity and power-velocity characteristics of elite athletes

Summary Technical limitations of some isokinetic dynamometers have called into question the validity of some data on human muscle mechanics. The Biodex dynamometer has been shown to minimize the impact artefact while permitting automatic gravity correction. This dynamometer was used to study quadriceps muscle torque and power generation in elite power (n = 6) and elite endurance (n = 7) athletes over 12 randomly assigned isokinetic velocities from 30° · s^–1 to 300° · s^–1. The angle at peak torque varied as a negative, linear function of angular velocity, with the average angle across test velocities being 59.5° (SD 10.2°). Power athletes developed greater peak torque at each angular velocity (P < 0.05) and experienced a 39.7% decrement in torque over the velocity range tested. En-, durance athletes encountered a 38.8% decline in peak torque. Torques measured at 60° of knee flexion followed a similar trend in both groups; however the greatest torques were recorded at 60° s^–1 rather than at 30° · s^–1 Leg extensor muscle power increased monotonically with angular velocity in both power (r ² = 0.728) and endurance athletes (r ² = 0.839); however these curves diverged significantly so that the power athletes produced progressively more power with each velocity increment. These inter group differences probably reflected a combination of natural selection and training adaptation.     

Iron status in elite young athletes: gender-dependent influences of diet and exercise

Iron depletion seems to occur more frequently among athletes than in the general population and may affect performance capacity. Only little information is available about the prevalence of iron status abnormalities in young elite athletes and whether iron depletion is associated with gender, sport, age or nutrition- and exercise-related factors in this group. Hence, diet, exercise and haematological data from 193 elite athletes (96 males, 97 females; 16.2 ± 2.7 years) from 24 different sports were analyzed retrospectively. Most female athletes failed to meet the recommended daily allowance for iron, even though dietary iron density was higher than in males (5.75 ± 0.78 vs. 6.17 ± 0.98 mg/1,000 kcal; P = 0.001). Iron depletion (serum ferritin < 35 μg/L) occurred in 31% of male and 57% of female athletes (P < 0.001). Low haemoglobin (males: <13 g/dL; females: <12 g/dL) and haematocrit (males: <40%; females: <36%) values were equally prevalent in both genders [haemoglobin: 7.3% (males), 6.2% (females); haematocrit: 13.5% (males); 15.5% (females)]. In females, reduced ferritin levels were associated with a lower dietary iron density (5.9 ± 0.8 vs. 6.6 ± 1.1 mg/1,000 kcal; P = 0.002). Males with iron depletion had a significantly higher estimated energy expenditure (48.7 ± 7.0 vs. 44.4 ± 7.6 kcal/kg/day; P = 0.009).     

Skeletal muscle properties and performance in elite female track athletes

Summary Selected biochemical and physiological properties of skeletal muscle were studied in light of performance capabilities in 24 elite female track athletes. The feasibility of quantifying end point histochemistry and relating oxidative staining density (reduced nicotinomide adenine dinucleotide diaphorase: NADH-D) to whole body maximal oxygen consumption ( max) was also investigated, while muscle fiber types, classified according to alkaline APTase stains, were studied and related to muscle oxidative capacity (succinate dehydrogenase: SDH), max and “in vivo” torque-velocity properties. Muscle biopsies were taken from the vastus lateralis of each subject and maximal knee extensor torques were recorded at 30‡ from full extension at four selected velocities. While results confirm earlier reports on skeletal muscle properties and performance it was concluded that end point histochemistry could be reliably quantified and that an “oxidative” stain such as NADH-D correlates extremely well with max (r=0.86,p<0.001) whereas correlations between %slow twitch fibres (alkaline ATPase stain) and max were lower (r=0.44,p<0.05). Additionally, as knee extension velocity increased from 0–1.7 rad·s⁻¹ angle specific extensor torque production did not decline as observed in vitro and pentathletes displayed significantly larger torques at all velocities when compared to the other athletes. These data confirm that while myofibrillar ATPase staining correlates with force-velocity properties of muscle, max is better correlated with quantified oxidative staining. Supported in part by a Public Health Service Biomedical Research Support Grant to UCLA, Public Health Service Grant 10423 and by the National Aeronautics and Space Administration (NASA)     

Neuromuscular control adaptations in elite athletes: the case of top level karateka

This paper aimed at investigating the neuromuscular response of knee flexor and extensor muscles in elite karateka and karate amateurs (Amateurs) during isokinetic knee flexion/extensions and during the execution of a front kick (FK). Surface electromyograms (sEMG) were recorded from the right vastus lateralis (VL) and biceps femoris (BF) muscles with a four-array electrode during maximal isometric knee flexion and extension (maximal voluntary contraction), during isokinetic contractions (30°, 90°, 180°, 270°, 340°, 400°/s), and during the FK. The level of VL and BF agonist (ago) and antagonist (ant) activation during the isokinetic and FK protocols was quantified through normalized sEMG root mean square value (%RMS_{ago/ant-ISOK/FK}). VL and BF average muscle fiber conduction velocity (CV) was computed for isokinetic and FK. Isokinetic flexion and extension torques and knee angular velocity during FK were also assessed. Analysis of variance was used to test the effect of group, angular velocity, and task on the assessed variables (P < 0.05). Elite karateka showed higher isokinetic knee flexion torque when compared with Amateurs. For all angular velocities, VL and BF %RMS_{ant-isokinetic} were lower in elite karateka, while their BF-CV_isokinetic BF-CV_{front kick} and BF %RMS_{ant-front kick} values were higher. For VL and BF, %RMS_{ago-front kick} was lower than %RMS_{ago-isokinetic} in both groups. Elite karateka demonstrated a typical neuromuscular activation strategy that seems task and skill level dependent. Knee flexion torque and CV results suggest the presence of an improved ability of elite karateka to recruit fast MUs as a part of training induced neuromuscular adaptation.     

Lower white blood cell counts in elite athletes training for highly aerobic sports

White cell counts at rest might be lower in athletes participating in selected endurance-type sports. Here, we analysed blood tests of elite athletes collected over a 10-year period. Reference ranges were established for 14 female and 14 male sports involving 3,679 samples from 937 females and 4,654 samples from 1,310 males. Total white blood cell counts and counts of neutrophils, lymphocytes and monocytes were quantified. Each sport was scaled (1–5) for its perceived metabolic stress (aerobic–anaerobic) and mechanical stress (concentric–eccentric) by 13 sports physiologists. Substantially lower total white cell and neutrophil counts were observed in aerobic sports of cycling and triathlon (~16% of test results below the normal reference range) compared with team or skill-based sports such as water polo, cricket and volleyball. Mechanical stress of sports had less effect on the distribution of cell counts. The lower white cell counts in athletes in aerobic sports probably represent an adaptive response, not underlying pathology.     

Hormonal response to Taekwondo fighting simulation in elite adolescent athletes

Exercise training efficiency depends on the training load, as well as on the athlete’s ability to tolerate it. The aim of the present study was to evaluate the effect of fighting simulation (3 fights, 6 min each, 30 min rest between fights) on anabolic (IGF-I, LH, FSH, estradiol, and testosterone) and catabolic hormones (cortisol) in elite, male (n = 10) and female (n = 10) adolescent (12–17 years) Taekwondo fighters. Blood samples were collected before the first and immediately after the third fight. The fighting simulation practice led to significant (p < 0.05) decreases in IGF-I (males −27.1 ± 25.6, females −22.4 ± 36.3 ng/ml), LH (males −0.7 ± 1.2, females −2.3 ± 3.3 U/L), and FSH (males −0.9 ± 0.5, females −1.5 ± 1.1 U/L), and to a significant increase (p < 0.05) in cortisol (males 141.9 ± 30.1, females 64.1 ± 30.6 mcg/dL) in both genders. Fighting simulation decreases in testosterone (males −1.9 ± 1.6, females −0.02 ± 0.06 ng/mL), and free androgen index (males −20.1 ± 21.5, females −0.3 ± 0.5) were significant (p < 0.05) only in male fighters. Exercise had no significant effect on estradiol, sex-hormone-binding globulins or thyroid function tests. Our data demonstrate that the physiologic and psychologic strain of a Taekwondo fighting simulation day led to a catabolic-type circulating hormonal response.