Do inhaled beta(2)-agonists have an ergogenic potential in non-asthmatic competitive athletes?

The prevalence of asthma is higher in elite athletes than in the general population. The risk of developing asthmatic symptoms is the highest in endurance athletes and swimmers. Asthma seems particularly widespread in winter-sport athletes such as cross-country skiers. Asthmatic athletes commonly use inhaled beta(2)-agonists to prevent and treat asthmatic symptoms. However, beta(2)-agonists are prohibited according to the Prohibited List of the World Anti-Doping Agency. An exception can be made only for the substances formoterol, salbutamol, salmeterol and terbutaline by inhalation, as long as a therapeutic use exemption has been applied for and granted. In this context, the question arises of whether beta(2)-agonists have ergogenic benefits justifying the prohibition of these substances.In 17 of 19 randomised placebo-controlled trials in non-asthmatic competitive athletes, performance-enhancing effects of the inhaled beta(2)-agonists formoterol, salbutamol, salmeterol and terbutaline could not be proved. This is particularly true for endurance performance, anaerobic power and strength performance. In three of four studies, even supratherapeutic doses of salbutamol (800-1200 microg) had no ergogenic effect. In contrast to inhaled beta(2)-agonists, oral administration of salbutamol seems to be able to improve the muscle strength and the endurance performance. There appears to be no justification to prohibit inhaled beta(2)-agonists from the point of view of the ergogenic effects.     

Ergogenic effect of inhaled beta 2-agonists in asthmatics

To investigate the effect of beta 2-agonists on exercise performance, eight asthmatics performed an incremental exercise test on a treadmill. Five minutes before the start of the exercise, they were treated with inhaled salbutamol or placebo in a double-blind manner. The exercise started at a low intensity (2 mph, 10% inclination), and every 3 min the speed was increased by 0.5 mph at the same inclination until the subjects were exhausted. Every minute peak expiratory flow, heart rate, blood lactate concentration, and rating of perceived exertion were measured. The same parameters were also measured following the completion of the exercise. No significant difference was seen in total working time, maximal lactate concentration, heart rate, or rating of perceived exertion, whereas the decrease in peak expiratory flow was reduced following pretreatment with salbutamol. It is concluded that the release of inhaled beta 2-agonists for use in competitive events is justified as no ergogenic effect was seen.     

Pharmaceutical treatment of asthma symptoms in elite athletes – doping or therapy?

Asthma, exercise-induced bronchoconstriction, and airway hyper-responsiveness are often found in elite athletes, perhaps as a consequence of their sport or maybe because asthma is a common disorder in young adults. Inhaled beta2-agonists (IBA) are frequently used in elite athletes, but due to regulations introduced by the International Olympic Committee, the use of anti-asthmatic therapy might change. Drugs that make ergogenic effect persist are prohibited in all athletes, whether or not they take part in competitions and systemic steroids and beta2-agonists are among such drugs. On the other hand, opinion is more divided about the use of inhaled corticosteroids (ICS) and IBA. In humans, no effect has been found on the oxygen uptake, performance or distance run with therapeutic doses of IBA, either in asthmatics or non-asthmatics, whereas others report an ergogenic effect and better lung function of high doses of a beta2-agonist in non-asthmatics. Anti-asthmatic treatment is necessary for asthmatics, but should not be used by non-asthmatic elite athletes due to both possible systemic effects and furthermore, side effects of both ICS and IBA.     

The effect of salbutamol on performance in elite nonasthmatic athletes.

The effect of salbutamol on performance was studied in seven male nonasthmatic highly trained (VO2max > or = 60 ml.kg-1 x min-1) cyclists. Salbutamol (S = 2 puffs = 200 micrograms) or placebo (P) was administered by metered-dose inhaler, through a spacer device, 20 min prior to testing in a double-blind, randomized cross-over design. Testing sessions on a cycle ergometer included the measurement of maximal oxygen uptake (VO2max), peak power, maximal heart rate, and pulmonary function. A timed sprint to exhaustion was performed after 45 min of exercise at 70% of VO2max, and a Wingate anaerobic test was used to measure total work and peak power. There was a nonsignificant decrease in VO2max (P = 63.5 +/- 3.2; S = 62.6 +/- 3.3 ml.kg-1 x min-1). No difference was found in peak power, maximum heart rate, endurance sprint time, Wingate peak power, or total work. After an anticipated baseline increase was taken into account, the pattern of change in FEV1 over time did not differ between salbutamol and placebo. It was concluded that a therapeutic dose of aerosol salbutamol does not have an ergogenic effect in elite nonasthmatic athletes, and it is therefore recommended that inhaled salbutamol continue to be permitted in international competition for individuals with exercise induced bronchospasm.     

Salbutamol and high-intensity treadmill running in nonasthmatic highly conditioned athletes

Salbutamol is a widely used drug among elite athletes. We wanted to provide more information on the effects of salbutamol in nonasthmatic athletes. Seventeen highly conditioned male athletes (Vo_2max > 70 ml · kg⁻¹· min⁻¹) participated in a randomized, double-blind and placebo-controlled cross-over study. Nebulized salbutamol (0.05 mg/kg) or placebo was inhaled prior to a high intensity (110% of Vo_2max) treadmill run to exhaustion. The measured variables included endurance time, oxygen uptake, ventilation, breathing rate, heart rate, and oxygen saturation. Lung function was measured as forced expiratory volume in the first second (FEV₁) before and after medication, and during the recovery from the run. The high intensity runs led to total exhaustion after 4–10 min. A close-to-significant shortening in endurance time was found when salbutamol was given. During the running (0–4 min) the oxygen uptake was slightly lower and the heart rate was slightly higher when salbutamol was given. No differences were found in peak oxygen uptake, peak heart rate, ventilation, breathing rate or oxygen saturation. FEV₁ reflected an increase in airway caliber after the inhalation of salbutamol. These changes were still present in the recovery from the test run with the exception of the measurement immediately after the exercise. Although evidence for β-adrenergic stimulation was found, it was concluded that a therapeutic dose of nebulized salbutamol does not improve performance in highly trained athletes during a high-intensity run to exhaustion.     

β₂-Agonists and physical performance: a systematic review and meta-analysis of randomized controlled trials

Inhaled β?-agonists are commonly used as bronchodilators in the treatment of asthma. Their use in athletes, however, is restricted by anti-doping regulations. Controversies remain as to whether healthy elite athletes who use bronchodilators may gain a competitive advantage. The aim of this systematic review and meta-analysis is to assess the effects of inhaled and systemic β?-agonists on physical performance in healthy, non-asthmatic subjects. To this end, MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched up to August 2009. Reference lists were searched for additional relevant studies. The search criteria were for randomized controlled trials examining the effect of inhaled or systemic β?-agonists on physical performance in healthy, non-asthmatic subjects. Two authors independently performed the selection of studies, data extraction and risk of bias assessment. Parallel-group and crossover trials were analysed separately. Mean difference (MD) and 95% confidence intervals were calculated for continuous data and, where possible, data were pooled using a fixed effects model. Twenty-six studies involving 403 participants (age range 7-30 years) compared inhaled β?-agonists with placebo. No significant effect could be detected for inhaled β?-agonists on maximal oxygen consumption (VO?(max)) [MD -0.14?mL?·?kg?1?·?min?1; 95% CI -1.07, 0.78; 16 studies], endurance time to exhaustion at 105-110% VO?(max) (MD -1.5 s; 95% CI -15.6, 12.6; four studies), 20-km time trial duration (MD -4.4 s; 95% CI -23.5, 14.7; two studies), peak power (MD -0.14 W?·?kg?1; 95% CI -0.54, 0.27; four studies) and total work during a 30-second Wingate test (MD 0.80 J?·?kg?1; 95% CI -2.44, 4.05; five studies). Thirteen studies involving 172 participants (age range 7-22 years) compared systemic β?-agonists with placebo, with 12 studies involving oral and one study involving intravenous salbutamol. A significant effect was detected for systemic β?-agonists on endurance time to exhaustion at 80-85% VO?(max) (MD 402 s; 95% CI 34, 770; two studies), but not for VO?(max) (placebo 42.5?±?1.7?mL?·?kg?1?·?min?1, salbutamol 42.1?±?2.9?mL?·?kg?1?·?min?1, one study), endurance time to exhaustion at 70% VO?(max) (MD 400 s; 95% CI -408, 1208; one study) or power output at 90% VO?(max) (placebo 234.9?±?16 W, salbutamol 235.5?±?18.1 W, one study). A significant effect was shown for systemic β?-agonists on peak power (MD 0.91 W?·?kg?1; 95% CI 0.25, 1.57; four studies), but not on total work (MD 7.8 J?·?kg?1; 95% CI -3.3, 18.9; four studies) during a 30-second Wingate test. There were no randomized controlled trials assessing the effects of systemic formoterol, salmeterol or terbutaline on physical performance. In conclusion, no significant effects were detected for inhaled β?-agonists on endurance, strength or sprint performance in healthy athletes. There is some evidence indicating that systemic β?-agonists may have a positive effect on physical performance in healthy subjects, but the evidence base is weak.     

Inhaled salbutamol and endurance cycling performance in non-asthmatic athletes

Beta(2)-adrenergic agonists are important therapeutic agents for the prevention and treatment of (exercise-induced) asthma in athletes, but may have ergogenic effects. In this study we investigated whether inhalation of a supra-therapeutic dose of 800 microg salbutamol before exercise affects endurance performance during a cycling trial in non-asthmatic athletes. In a double-blind, randomized cross-over study, 16 athletes performed two trials, where they had to perform a certain amount of work as fast as possible on a cycle ergometer, 30 minutes after inhalation of 800 micro g salbutamol or placebo. Peak expiratory flow (PEF), forced vital capacity (FVC), and forced expiratory volume in 1 second (FEV(1)) were measured before and after exercise and blood samples were obtained before and during exercise. Cycling performance time was 4010.2 +/- 327.7 s after placebo inhalation and 3927.6 +/- 231.3 s after inhalation salbutamol (p < 0.05). Although salbutamol inhalation increased plasma free fatty acids, glycerol and lactate concentrations and decreased plasma potassium concentrations at rest, no differences between placebo and salbutamol in these variables were found during exercise. PEF and FEV(1) were increased after salbutamol inhalation at rest compared with placebo, but the difference between placebo and salbutamol after exercise was no longer significant. Inhalation of a supratherapeutic dose of 800 micro g salbutamol improved endurance cycling performance by 1.9 +/- 1.8 % in non-asthmatic athletes, which indicates that this route of administration does not exclude the possibility of an ergogenic effect of beta(2)-adrenergic agents in athletes. The increase in performance was not explained by changes in plasma concentrations of free fatty acids, glycerol, lactate, and potassium during exercise or by changes in ventilatory parameters at rest and after exercise. Therefore, the mechanism of the increase in performance remains to be determined.     

Acute formoterol administration has no ergogenic effect in nonasthmatic athletes

PURPOSE: To determine the effect of formoterol (formoterol fumarate dihydrate) on the aerobic and anaerobic capacities of highly trained athletes. METHODS: 10 male athletes (age = 26.2 +/- 0.9, VO(2max) = 65.6 +/- 2.4 mL x kg(-1) x min(-1)) with minimal bronchial reactivity to aerosols (i.e., negative methacholine challenge test) completed three identical exercise sessions differing only by the medication administered. Formoterol (F) a long-acting beta(2)-agonist, presently not approved for international competition by the I.O.C. Medical committee, was compared with salbutamol (S), an accepted bronchodilator, and a placebo (P). Formoterol (12 microg), salbutamol (400 microg), or placebo was administered by a Turbuhaler, 10 min before exercise testing in a double-blind, randomized, three-way crossover design. Testing sessions included a Wingate anaerobic test followed 15 min later by an incremental cycle ergometer test to exhaustion. RESULTS: There were no significant differences between the groups in VO(2max) (F = 66.5 +/- 2.7; S = 67.8 +/- 2.5; P = 67.5 +/- 2.1 mL x kg(-1) x min(-1)) or Wingate peak power (F = 885 +/- 40; S = 877 +/- 40; P = 885 +/- 44 W) values. During the maximal aerobic test, no differences were observed in maximum minute ventilation, respiratory exchange ratio, heart rate, or work between the three experimental conditions. Also, there were no differences in the Wingate anaerobic test variables, total work, or fatigue index. CONCLUSION: Formoterol, administered in one aerosolized therapeutic dose, does not have an ergogenic effect in elite athletes without asthma.     

Effect of a long- and short-acting beta2-agonist on exercise-induced arterial hypoxemia

PURPOSE: determine the effect of formoterol and salbutamol on the arterial oxygen saturation (SaO(2)) of highly trained nonasthmatic athletes with exercise-induced arterial hypoxemia (EIAH). METHODS: Ten male athletes (age = 27.1 +/- 0.7, [OV0312]O(2max) = 65.2 +/- 2.5 mL.kg-1.min-1, SaO(2min) = 91.0 +/- 2.1%) with minimal bronchial reactivity to aerosols (i.e., negative methacholine challenge test) completed three identical exercise sessions differing only by the medication administered. Formoterol (F), a long-acting beta-2 agonist, was compared with salbutamol (S) and a placebo (P). F (12 microg), S (400 microg), or P was administered by a Turbuhaler, 10 min before exercise testing in a double-blind, randomized, three-way crossover design. Testing sessions included an incremental cycle ergometer test to exhaustion, while monitoring SaO(2) and ventilation, and a pre- and postexercise pulmonary function test. RESULTS: There were no significant differences between the groups in SaO(2) nadir with exercise (F = 92.0 +/- 1.0; S = 92.0 +/- 1.0; P = 91.0 +/- 0.7%). During the maximal incremental test, no differences were observed in SaO(2) or minute ventilation between the three experimental conditions. Pulmonary function tests revealed a significant increase in FEV(1) and FEV(1)/FVC after exercise in all conditions. Drug administration increased FEV(1)/FVC postexercise compared with placebo (F = 87.9 +/- 2.3, S = 87.6 +/- 1.7 > P = 85.6 +/- 2.1%; P < 0.05). CONCLUSION: An acute, inhaled, therapeutic dose of formoterol or salbutamol did not affect SaO(2) nadir or ventilation kinetics in a group of highly trained nonasthmatic athletes with EIAH.     

Effects of formoterol on endurance performance in athletes at an ambient temperature of -20 degrees C

The use of inhaled beta2-agonists is restricted in sports. No benefit of inhaled formoterol upon performance was found in healthy athletes under normal climatic conditions, but it has not been investigated whether formoterol improves performance in athletes during exposure to cold. To investigate the effect of inhaled formoterol vs placebo upon performance and lung function at -20 degrees C in 20 healthy male athletes. We used a randomized double-blind, placebo-controlled, cross-over design. The subjects performed a run until exhaustion after inhaled study drug. The speed was 95% of the predetermined maximal oxygen uptake (VO2 max) the first minute and increased to 107% of VO2 max for the remaining part of the test. Time until exhaustion, ventilation (VE), VO2, respiratory rate (RR), tidal volume (VT), heart rate (HR) and arterial oxyhemoglobin saturation (SPO2) were recorded during exercise. Lung function was measured before inhaling, after inhaling the study drug and after the treadmill run. Inhaled formoterol did not improve endurance performance in cold environments compared with placebo, although formoterol significantly improved lung function (FEV1, FEF50 and PEF) and HR 4 min after the start of the exercise. Inhaled formoterol did not improve endurance performance in healthy, well-trained athletes exposed to cold.     

The effect of inhaled salbutamol and salmeterol on lung fuction and endurance performance in healthy well-trained athletes

The present randomized, double-blind placebo-controlled study aimed at investigating the possible improvement in endurance performance caused by inhaled salmeterol (long-acting β₂-agonist) and salbutamol (short-acting) compared to placebo in 18 healthy well-trained athletes, aged 17–30 years old. Lung function (flow-volume loops) was measured before and after each inhaled study drug and after run to exhaustion. After inhalation of study drug and 10 min warm-up, anaerobic threshold was measured; thereafter maximum oxygen uptake, peak ventilation and running time until exhaustion during a brief graded exercise were measured. No significant differences were found for ventilation, oxygen uptake or heart rate at anaerobic threshold or at maximum performance between placebo and the β₂-agonists. Lung function increased significantly after exercise, but without differences between the β₂-agonists and placebo. Running time till exhaustion was significantly reduced after both the long-and the short-acting β₂-agonist compared to the placebo.     

The effect of formoterol inhalation on endurance performance in hypobaric conditions

INTRODUCTION: Inhaled beta2-agonists are important therapeutic agents for the treatment of exercise-induced asthma in athletes but are restricted by international antidoping regulations. PURPOSE: To investigate whether 18 mug of inhaled formoterol affects endurance performance during running at high altitudes until exhaustion among 20 nonasthmatic male athletes aged 21-35 yr. METHODS:: In a randomized, double-blind, placebo-controlled crossover study, the athletes performed one screening test and two similar performance tests. Each performance test consisted of 20 min of warm-up and a running test until exhaustion, which lasted 210-300 s in hypobaric conditions equal to 2000 m above sea level. Maximal oxygen consumption (VO2max) and peak ventilation (VEpeak) were measured during running, and pulmonary function was measured before and after exercise. The screening test was used to determine running speed on days 2 and 3, with inhaled formoterol or placebo in a randomized manner before exercise. VO2, VE, arterial oxyhemoglobin saturation (SPO2), and heart rate (HR) were measured during exercise, and maximum plasma lactate concentration was measured after exercise. RESULTS: Inhaled formoterol did not improve running time to exhaustion, VO2, VE, SPO2, or HR (P > 0.05) in hypobaric conditions compared with placebo, although formoterol significantly improved lung function (FEV1 and FEF50) 15 and 30 min before exercise and 3, 6, 10, and 15 min after exercise. CONCLUSIONS: Inhaled formoterol did not improve endurance performance in healthy nonasthmatic athletes at hypobaric conditions equal to 2000 m above sea level. Inhaled formoterol can thus be used by asthmatic athletes in sports under extreme conditions.     

Bronchodilating effect and anabolic effect of inhaled procaterol

While the use of oral beta (2)-agonists by athletes is prohibited because of their anabolic effects, some inhaled beta (2)-agonists can be used in accordance with the World Anti-Doping Agency regulations. We examined the dose disparity between the bronchodilating effect and anabolic effect of inhaled procaterol, a selective beta (2)-agonist, to determine if the drug might be effective for athletes with asthma. Intact rats were given nebulized procaterol at 0.001, 0.01, 0.1 and 1 mg/mL by inhalation, and its inhibitory effect on carbachol-induced bronchoconstriction was evaluated. Castrated rats were given nebulized procaterol at 0.03, 0.1, 0.3 and 1 mg/mL by inhalation 3 times a day for 14 days, and anabolic markers (body weight gain, weight of the levator ani muscle and gastrocnemius muscle) were measured. At 0.01 mg/mL and higher, procaterol dose-dependently inhibited carbachol-induced bronchoconstriction with a significant effect. At doses of up to 0.3 mg/mL, there were no signs indicating an anabolic effect of procaterol. At 1 mg/mL, however, a slight but statistically significant increase in the weight of the levator ani muscle was observed with no significant changes in other anabolic markers. It was suggested that inhaled procaterol might be useful for athletes with asthma because of the big dose disparity between its bronchodilating effect and anabolic effect in rats.     

Dose response of inhaled salbutamol on exercise performance and urine concentrations

PURPOSE: This study determined the dose-response effects of inhaled salbutamol (SAL) on time-trial performance and urine concentrations of SAL (cSAL). METHODS: Nonasthmatic, trained male cyclists and triathletes (N = 37) were studied. Day 1 consisted of screening for airway hyperresponsiveness, using a eucapnic voluntary hyperpnea test (EVH), followed by an incremental exercise test to determine V O 2max and peak power (P max). On days 2-5, athletes performed a 20-km time trial 15 min after inhalation (PI) of placebo, 200 microg (D2), 400 microg (D4), or 800 microg (D8) of SAL. At 60 min PI, urine samples were provided. All conditions were randomized and double blinded, with repeated-measures ANOVA used to determine effects of dose. Post hoc analysis was done with Tukey's HSD test. RESULTS: Seven subjects had positive responses to the EVH test, resulting in a 19% incidence within this sample; they were excluded from further participation in this study. The remaining subjects (N = 30) had a V O 2max of 67.1 (4.3) mL x kg(-1) x min(-1) and Pmax of 457 (31) W (W). There was no effect of dose on completion time (P > 0.05), mean power (P > 0.05), or mean heart rate (P > 0.05). Similarly, SAL had no effect on any metabolic or ventilatory parameters (P > 0.05). Urine cSAL increased with dose and was highly variable, with the peak value observed being 831 ng x mL(-1) after a dose of 800 microg. Moderate but significant correlations were noted between cSAL and urine specific gravity at higher doses (D4, r = 0.42; D8, r = 0.37). CONCLUSIONS: These findings suggest that inhaled SAL does not enhance time-trial performance, regardless of dose, and that urine cSAL after exercise is related to dose, demonstrates high variability, and is partially related to hydration status.     

Effect of salbutamol on muscle strength and endurance performance in nonasthmatic men

PURPOSE: The ergogenic effect of acute beta2-adrenergic agonist administration in nonasthmatic individuals has not been clearly demonstrated. Therefore, the acute effects of oral administration of the beta2-adrenergic agonist salbutamol (4 mg) on muscle strength and endurance performance were studied in 16 nonasthmatic men in a double-blind randomized cross-over study. METHODS: Peak expiratory flow (Mini Wright Peakflowmeter), isokinetic strength of the knee extensors and knee flexors at four angular velocities (Cybex II dynamometer), and endurance performance in a cycle ergometer test until exhaustion at 70% of maximal workload were measured. RESULTs: Peak expiratory flow increased from 601 +/- 67 L x min(-1) to 629 +/- 64 L x min(-1) after salbutamol (P < 0.05). Peak torque was higher after salbutamol than after placebo (4.4% for the knee extensors, 4.9% for the knee flexors) (P < 0.05). Mean endurance time increased from 3,039 +/- 1,031 s after placebo to 3,439 +/- 1,287 s after salbutamol (P = 0.19). When four subjects complaining about adverse side effects were excluded from the analysis, the increase in endurance time (729 +/- 1,007 s or 29%) was statistically significant (P <-0.05). Salbutamol did not affect VO2, respiratory exchange ratio, heart rate, and plasma free fatty acid and glycerol concentration during exercise; plasma lactate and potassium concentrations were increased (P < 0.05). CONCLUSIONS: Under the conditions of this study, oral salbutamol appears to be an effective ergogenic aid in nonasthmatic individuals not experiencing adverse side effects.     

The lactate minimum test protocol provides valid measures of cycle ergometer VO(2)peak

AIM: The aim of the present study was to investigate the validity of the Lactate Minimum Test (LMT) for the determination of peak VO(2) on a cycle ergometer and to determine the submaximal oxygen uptake (VO(2)) and pulmonary ventilation (VE) responses in an incremental exercise test when it is preceded by high intensity exercise (i.e., during a LMT). METHODS: Ten trained male athletes (triathletes and cyclists) performed 2 exercise tests in random order on an electromagnetic cycle ergometer: 1). Control Test (CT): an incremental test with an initial work rate of 100 W, and with 25 W increments at 3-min intervals, until voluntary exhaustion; 2). LMT: an incremental test identical to the CT, except that it was preceded by 2 supramaximal bouts of 30-sec (approximately 120% VO(2)peak) with a 30-sec rest to induce lactic acidosis. This test started 8 min after the induction of acidosis. RESULTS: There was no significant difference in peak VO(2) (65.6+/-7.4 ml x kg(-1) x min(-1); 63.8 +/- 7.5 ml x kg(-1) x min(-1) to CT and LMT, respectively). However, the maximal power output (POmax) reached was significantly higher in CT (300.6+/-15.7 W) than in the LMT (283.2+/-16.0 W). VO(2) and VE were significantly increased at initial power outputs in LMT. CONCLUSION: Although the LMT alters the submaximal physiological responses during the incremental phase (greater initial metabolic cost), this protocol is valid to evaluate peak VO(2), although the POmax reached is also reduced.     

Urine concentrations of repetitive doses of inhaled salbutamol

We examined blood and urine concentrations of repetitive doses of inhaled salbutamol in relation to the existing cut-off value used in routine doping control. We compared the concentrations in asthmatics with regular use of beta2-agonists prior to study and healthy controls with no previous use of beta2-agonists. We enrolled 10 asthmatics and 10 controls in an open-label study in which subjects inhaled repetitive doses of 400 microgram salbutamol every second hour (total 1600 microgram), which is the permitted daily dose by the World Anti-Doping Agency (WADA). Blood samples were collected at baseline, 30 min, 1, 2, 3, 4, and 6 h after the first inhalations. Urine samples were collected at baseline, 0-4 h, 4-8 h, and 8-12 h after the first inhalations. Median urine concentrations peaked in the period 4-8 h after the first inhalations in the asthmatics and between 8-12 h in controls and the median ranged from 268 to 611 ng×mL (-1). No samples exceeded the WADA threshold value of 1000 ng×mL (-1) when corrected for the urine specific gravity. When not corrected one sample exceeded the cut-off value with urine concentration of 1082 ng×mL (-1). In conclusion we found no differences in blood and urine concentrations between asthmatic and healthy subjects. We found high variability in urine concentrations between subjects in both groups. The variability between subjects was still present after the samples were corrected for urine specific gravity.     

Influence of chronic supplementation of arginine aspartate in endurance athletes on performance and substrate metabolism - a randomized, double-blind, placebo-controlled study

The intake of arginine aspartate has been shown to increase anabolic hormones like human growth hormone (hGH) and glucagon. The aim of our study was to investigate whether daily intake of two different dosages of arginine asparate during four weeks affects selected parameters of overtraining syndrome like performance, metabolic and endocrine parameters. Thirty male endurance-trained athletes were included in a randomized, double-blind, placebo-controlled study and divided into three groups. During four weeks, they ingested either arginine aspartate with a high concentration (H) of 5.7 g arginine and 8.7 g aspartate, with a low concentration (L) of 2.8 g arginine and 2.2 g aspartate or placebo (P).VO(2)peak and time to exhaustion were determined on a cycling ergometer in an incremental exercise test before and after supplementation. Before and after each incremental exercise test, concentrations of hGH, glucagon, testosterone, cortisol, ferritine, lactate, and urea were measured. Compared to placebo, no significant differences on endurance performance (VO(2)peak, time to exhaustion), endocrine (concentration of hGH, glucagon, cortisol, and testosterone) and metabolic parameters (concentration of lactate, ferritine, and urea) were found after chronic arginine aspartate supplementation. The chronic intake of arginine asparate during four weeks by male endurance athletes showed independent of dosage no influence on performance, selected metabolic or endocrine parameters. Consequently, there seems to be no apparent reason why the supplementation of arginine aspartate should be an effective ergogenic aid. The practice of using arginine aspartate as potential ergogenics should be critically reevaluated. Further investigations with higher dosage and extended supplementation periods should be performed.     

Effect of prolonged exercise on arterial oxygen saturation in athletes susceptible to exercise-induced hypoxemia

This study examined the effect of prolonged endurance exercise on the development of exercise-induced hypoxemia (EIH) in athletes who had previously displayed EIH during an incremental maximal exercise test. Five male and three female endurance-trained athletes participated. Susceptibility to EIH was confirmed through a maximal incremental exercise test and defined as a reduction in the saturation of arterial oxygen (SpO(2)) of >/=4% from rest. Sixty minutes of running was conducted, on a separate day, at an oxygen consumption corresponding to 95% of ventilatory threshold. Immediately following the 60 min exercise bout, athletes commenced a time trial to exhaustion at 95% maximal oxygen consumption (VO(2max)). The reduction in SpO(2) was significantly greater during the maximal incremental test, than during the 60 min, or time trial to exhaustion (-8.8+/-1.4%, -3.3+/-1.1%, and -4.1+/-2.3%, P<0.05, respectively). The degree of desaturation during the 60 min was significantly related to the relative intensity of exercise at 95% ventilatory threshold (adjusted r(2)=0.54, P=0.02). In conclusion, athletes who did not exercise at greater than 73% VO(2max) during 60 min of endurance exercise did not display EIH, despite being previously susceptible during an incremental maximal test.     

Ergogenic Aids What Athletes Are Using—and Why

Athletes at all levels explore ergogenic aids. Testosterone and growth hormone are still abused and difficult to detect. Single doses of albuterol or salmeterol do not seem ergogenic, but questions remain about prolonged dosing and about other beta2 agonists. Caffeine can be ergogenic for prolonged or brief exertion. Creatine supplementation is legal and in vogue among strength and power athletes. Not all studies agree, but creatine seems ergogenic for repeated brief bouts of intense exercise. Ergogenic aids pose vexing questions for athletes, physicians, and society.