A field tool for the aerobic power evaluation of middle-aged female recreational runners.

This study used time to exhaustion (TTE) to predict V̇O2max in female recreational master runners. Forty-two middle-aged women (mean = 40.5 ± 5.9 years) who had trained for recreational running performed two Université de Montréal Track Tests in the facilities of the University of Barcelona (Spain). The first was performed on a treadmill (t), the second, on an athletics track (field: f). After measuring TTE and V̇O2max on the treadmill, a first-order equation was obtained to estimate fV̇O2max from fTTE. No significant difference was observed between the estimated fV̇O2max (46.5 ± 2.9 mL·kg-1·min-1) and the measured tV̇O2max (46.2 ± 5.3), with a mean value of the absolute differences of less than 8% of the tV̇O2max average. High agreement between the two V̇O2max values was also evident, as shown by the low bias of the differences and the Bland-Altman plot. The equation obtained is of interest to evaluate performance in middle-aged female recreational runners. It will allow coaches and runners to set running paces for training and could be used in training routines to determine improvements after a training program. Moreover, these tools could be used in the field to assess the physical fitness of middle-aged women, in efforts to preserve their health and physical function.

Changes in dietary intake, plasma carotenoids and erythrocyte membrane fatty acids in breast cancer survivors after a lifestyle intervention: results from a single-arm trial.

BACKGROUND: The influence of nutrition on breast cancer prognosis is still inconclusive and therefore dietary interventions incorporating dietary biomarkers are needed to confirm compliance with dietary goals and clarify biological mechanisms. The present study assessed whether a lifestyle intervention in breast cancer survivors could affect dietary biomarkers of fruit and vegetables and fatty acids. METHODS: In this phase II single-arm trial, 37 overweight/obese early stage breast cancer patients completed a 12-week diet and exercise intervention. The intervention involved 1-h weekly diet sessions delivered by a dietician and 75-min bi-weekly physical activity sessions of moderate-to-high intensity led by trained monitors. Before and after the intervention, three 24-h dietary recalls were carried out to calculate nutrient intakes and, in addition, blood samples were taken to measure plasma carotenoids, vitamin E and retinol concentrations and erythrocyte membrane fatty acid (EFA) composition. Wilcoxon signed rank tests were used to assess changes in dietary and biomarkers measurements over the intervention period. RESULTS: After the intervention, there was a significant increase in the intake of dietary carotenoids (+15.1% compared to baseline) but not plasma carotenoids levels (+6.3%). Regarding the EFA levels, we observed a significant decrease in percentage of saturated fatty acids (-1.4%) and n-6 polyunsaturated fatty acids (-2.9%) and an increase in monounsaturated fatty acids (1.7%) and total and long-chain n-3 polyunsaturated fatty acids (by 13.1% and 13.7%, respectively). A favourable decrease in the ratio of long-chain n-6 to n-3 polyunsaturated fatty acids (-9.1%) was also observed. CONCLUSIONS: After a short-term diet and exercise intervention in overweight/obese breast cancer survivors, we observed significant changes in dietary nutrients and fatty acid biomarkers, suggesting positive dietary changes that could be relevant for breast cancer prognosis.

Sildenafil does not Improve Exercise Capacity under Acute Hypoxia Exposure.

The increase in pulmonary arterial pressure (PAP) due to hypoxic pulmonary vasoconstriction (HPV) could be a limiting factor for physical performance during hypoxic exposure. Sildenafil has been shown to reduce PAP in situations of moderate or severe hypoxia, and consequently its role as an ergogenic aid and even a possible doping substance must be considered. We performed a double-blind crossover study to determine the effects of sildenafil on cardiovascular, respiratory and metabolic parameters in normoxia and during acute exposure to hypobaric hypoxia (4 000 m) at rest and during maximal and submaximal (60% VO2 max) exercise tests. One hour before testing started, sildenafil (100 mg) or a placebo was orally administered to 11 volunteers. In normoxic conditions, sildenafil did not affect performance. Similarly, no significant differences were found in cardiovascular and respiratory parameters in hypoxic conditions at rest or during exercise. The use of sildenafil to improve physical performance in non-acclimatized subjects is not supported by our data.

5-year mortality in cardiac surgery patients with low cardiac output syndrome treated with levosimendan: prognostic evaluation of nt-probnp and c-reactive protein.

AIM: To determine the clinical risk factors predictive of the 5--year mortality in patients with low cardiac output syndrome (LCOS) after cardiac surgery. In addition, to assess the influence of inflammation and myocardial dysfunction severity, as measured by C--reactive protein (CRP) and N--terminal pro--brain natriuretic peptide (NT--proBNP) concentrations, on outcome. METHODS: We studied 30 patients who underwent cardiac surgery and developed postoperative LCOS requiring inotropic support for longer than 48 hours after intensive care unit (ICU) admission. All patients received a 24--hour infusion of levosimendan after study enrolment. We measured the following at baseline, 24 h, 48 h and 7 days: clinical data, serum NT--proBNP and serum CRP levels. Patients were followed--up at 5 years for death by any cause. A risk--adjusted Cox proportional hazards regression model was used for statistical analysis. Hazard ratios and their 95% confidence intervals (CI) are presented. RESULTS: The 5--year mortality was 36.6% (n = 11). The predictors of 5--year mortality were the presence of dilated cardiomyopathy (HR = 36.909; 95% CI: 1.901-716.747; P = 0.017), a higher central venous pressure (CVP) at 48 hours (HR = 2.686; 95% CI: 1.383-5.214; P = 0.004), and lower CRP levels on day 7 (HR = 0.963; 95% CI: 0.933-0.994; P = 0.021). NT--proBNP levels showed a trend to higher initial levels in survivors without statistical significance, but were not associated with 5--year mortality. CONCLUSIONS: The presence of dilated cardiomyopathy, elevated CVP at 48 h and reduced CRP levels on day 7 predicted 5--year mortality in patients who developed postoperative LCOS after cardiac surgery. NT--proBNP levels in the first postoperative week were not predictors of long--term outcomes.

CD34+ circulating progenitor cells after different training programs.

Circulating progenitor cells (CPC) are bone marrow-derived cells that are mobilized into the circulation. While exercise is a powerful mediator of hematopoiesis, CPC levels increase, and reports of their activation after different types of exercise are contradictory. Moreover, few studies have compared the possible effects of different training programs on CPC concentrations. 43 physically active healthy male subjects (age 22±2.4 years) were assigned to 4 different training groups: aerobic, resistance, mixed and control. Except for the control group, all participants trained for 6 weeks. Peripheral blood samples were collected through an antecubital vein, and CPC CD34(+) was analyzed on different days: pre-training, post-training, and 3 weeks after finishing the training period. While no significant differences in CPC were observed either within or between the different training groups, there was a tendency towards higher values post-training and large intra- and intergroup dispersion. We detected an inverse linear relationship between pre-training values and % of CPC changes post-training (p<0.001). In the CPC values 3 weeks after training this inverse relationship was maintained, though to a lower extent (p<0.001). No changes in CPC CD34(+) were detected after 6 weeks of different training groups, or after 3 weeks of follow-up.

Predictors of long-term mortality in patients with cirrhosis undergoing cardiac surgery.

AIM: Little is known regarding the long-term outcome in cirrhotic patients undergoing cardiac surgery. The objective of this study was to identify preoperative and postoperative mortality risk factors and to determine the best predictors of long-term outcome. METHODS: Fifty-eight consecutive cirrhotic patients requiring cardiac surgery between January 2004 and January 2009 were prospectively studied at our institution. Seven patients (12%) died. A complete follow-up was performed in the whole survival group until November 2012 (mean 46±28 months). Variables usually measured on admission and during the first 24 h of the postoperative period were evaluated together with cardiac surgery scores (Parsonnet, EuroSCORE), liver scores (Child-Turcotte-Pugh, Model for End-Stage Liver Disease, United Kingdom End-Stage Liver Disease score), and ICU scores (Acute Physiology and Chronic Health Evaluation II and III, Simplified Acute Physiology Score II and III, Sequential Organ Failure Assessment). RESULTS: Twelve patients (23.5%) died during follow-up; six were Child class A and six class B. Comparing survivors vs. non-survivors using univariate analysis, variables associated with better long-term outcome were lower arterial lactate 24 h after admission (1.7±0.4 vs. 2.1±0.7 mmol·L(-1), P=0.03) and higher urine output in the first 24 h (2029±512 vs. 1575±627 mL, P=0.03). The receiver operating characteristic curve showed that the Simplified Acute Physiology Score III score had the best predictive value for long-term outcome (AUC: 77.4±0.76%; sensitivity: 83.3%; specificity: 64.9%, P=0.005). Multivariate analysis identified Simplified Acute Physiology Score III score (P=0.02) and urine output in the first 24 h (P=0.02) as independent factors associated with long-term outcome. Long-term survival was 82.4% for Child A, 47.6% for Child B and 33.3% for Child C (P=0.001). CONCLUSION: Long-term survival in cirrhotic patients requiring cardiac surgery is a more valuable prognostic measure than short-term survival. Urine output in the first 24 h may be a valuable predictor of long-term outcome in these patients. The Simplified Acute Physiology Score III is also useful.

Effect of a diet and physical activity intervention on body weight and nutritional patterns in overweight and obese breast cancer survivors.

Energy restriction from a low-calorie diet and increased energy expenditure induced by physical activity (PA) could promote weight loss/maintenance and be important determinants of breast cancer (BC) prognosis. The aim of this study was to assess participation and adherence of overweight and obese BC survivors to a lifestyle intervention and to demonstrate the capacity of this intervention to induce weight loss and nutritional changes. This single-arm pre-post study, which involved one-hourly weekly diet sessions delivered by a dietician and 75-min bi-weekly PA sessions of moderate-to-high intensity led by PA monitors, was offered to overweight and obese BC survivors shortly after treatment. Before and after the intervention, anthropometry, dietary information, quality of life (QoL) and cardiorespiratory fitness (CRF) were collected. A total of 112 BC survivors were invited to participate: 42 of them started the intervention and 37 completed it. Participants attended more than 90 % of the sessions offered and showed a significant weight loss of 5.6 ± 2.0 kg, as well as significant decreases in body mass index, fat mass and waist circumference. Significant decreases in total energy (-25 %), fat (-35 %), saturated fat (-37 %) and carbohydrate (-21 %) intakes were observed while QoL and CRF showed significant increases. This feasibility study demonstrated the success of a short-term diet and PA intervention to induce weight loss and promote healthful changes in BC survivors. Assessing the long-term effects of these changes, and in particular their possible impact of BC prognosis, and designing interventions reaching a wider number of BC survivors are still issues to be addressed.

[Nicotinamide adenine dinucleotide (NADH) in patients with chronic fatigue syndrome]. / Nicotinamida adenina dinucleótido (NADH) en pacientes con síndrome de fatiga crónica.

BACKGROUND: Nicotinamide adenine dinucleotide (NADH) may be depleted in chronic fatigue syndrome (SFC). The purpose of the study was to evaluate the efficacy of supplementation with NADH in these patients. MATERIAL AND METHODS: A double blind, placebo controlled, 3 month long clinical trial was conducted. The patients were randomized to oral NADH oral 20mg or placebo during the first two months. The intensity of the fatigue, functional performance, mood state, functional impact of the fatigue, quality of life, sleep quality, exercise capacity and functional reserve as well as the investigator's and patient's opinion on the efficacy of the intervention prior to and at 30, 60 and 90 days of the onset of the treatment were evaluated. A stress test was performed in the baseline visit and at 60 days (last day of the double blind treatment). RESULTS: A total of 86 patients, 77 of whom completed the study (mean age, 47 years, 72 women) were enrolled. No significant differences were found in most of the variable studied at the end of the study. Administration of NADH was associated to a decrease in anxiety condition of -1.0 points (p<0.05) and of -0.2 points (p=NS) in the placebo assigned group. Maximum heart rate after the stress test decreased a mean of -8.1l/min (p<0.05) in the NADH group and increased by +1.7l/min in the placebo group (p=0.73). No differences were found in the perception of efficacy with NADH and placebo, by the investigator and patients. CONCLUSIONS: Administration of oral NADH was associated to a decrease in anxiety and maximum heart rate, after a stress test in patients with CFS. On the contrary, this treatment did not modify other clinical variables and the global functional performance.

L-tryptophan supplementation can decrease fatigue perception during an aerobic exercise with supramaximal intercalated anaerobic bouts in young healthy men.

Physical exercise is often terminated not due to muscle fatigue but because of inadequate neural drive in the serotonergic system. Modifications in activity levels of the serotonergic system, induced by variations in the availability of L-tryptophan (a serotonin precursor) may alter neural drive. We examined the effect of L-tryptophan supplementation on physical performance by combining aerobic work with brief periods of supramaximal intensity that closely mimics the activity typical of team sports. Twenty healthy young sportsmen (mean age 21.2 +/- 0.7 years) performed a submaximal exercise on a cycle ergometer, with a workload corresponding to 50% of their respective VO(2) max for 10 min, followed by a maximal intensity exercise for 30 s. This sequence was repeated three times and, after the fourth series, each participant continued to exercise at the highest speed that he could sustain for 20 min. This protocol was performed twice: once with and finally without supplementation of L-tryptophan, in random order and double-blind. Peak power output, average anaerobic power output, and power output during the last 20 min of the trial were higher on the trials performed with L-tryptophan supplementation than on those performed with placebo. The distance covered during the last 20 min of the trial was 11,959 +/- 1,753 m on placebo and 12,526 +/- 1,617 m on L-tryptophan (p < .05). In conclusion, in some types of exercises, modification of the serotonergic system may improve the physical performance.

Is short-term amiodarone use post cardiac surgery a cause of acute respiratory failure?

AIM: It was believed that amiodarone-related adverse respiratory effects were found only when receiving amiodarone on a long-term basis, but several reports seem to contradict this hypothesis. The aim of this study was to evaluate, in an intensive care unit (ICU), the possibility of acute respiratory toxicity induced by short-term amiodarone administration following cardiac surgery. METHODS: We conducted a prospective clinical trial of 111 consecutive patients admitted to our ICU after cardiac surgery (basically, coronary artery bypass graft and/or valve surgery) and who received short-term prophylactic amiodarone treatment if they were considered at high risk of developing atrial fibrillation. We administered 900 mg/day intravenously for the first 2 days and 600 mg/day on the following days of the ICU stay. The oxygenation index (PaO2/FiO2 ratio) was evaluated at admission, and then 24 and 48 h postsurgery. RESULTS: One-hundred and two patients were included in the study (9 were excluded for bradycardia), and 25 received amiodarone treatment. The Parsonnet and APACHE II scores differed slightly between the treated and nontreated groups. There were no significant differences between the treated and nontreated groups with respect to left atrial pressure, the number of packed red cells transfused or the oxygenation index at admission and 24 and 48 h postsurgery. CONCLUSION: The short-term administration of amiodarone under the conditions of the present study does not seem to affect respiratory function.

Influence of the recycled material percentage on the rheological behaviour of HDPE for injection moulding process.

The amount of polymer material wasted during thermoplastic injection moulding is very high. It comes from both the feed system of the part, and parts necessary to set up the mould, as well as the scrap generated along the process due to quality problems. The residues are managed through polymer recycling that allows reuse of the materials in the manufacturing injection process. Recycling mills convert the parts into small pieces that are used as feed material for injection, by mixing the recycled feedstock in different percentages with raw material. This mixture of both raw and recycled material modifies material properties according to the percentage of recycled material introduced. Some of the properties affected by this modification are those related to rheologic behaviour, which strongly conditions the future injection moulding process. This paper analyzes the rheologic behaviour of material with different percentages of recycled material by means of a capillary rheometer, and evaluates the influence of the corresponding viscosity curves obtained on the injection moulding process, where small variations of parameters related to rheological behaviour, such as pressure or clamping force, can be critical to the viability and cost of the parts manufactured by injection moulding.

Selective prophylaxis of atrial fibrillation with amiodarone after cardiac surgery.

AIM: Atrial fibrillation (AF) is common after cardiac surgery, but prophylaxis for patients especially prone to developing this arrhythmia has not been studied to date. We investigated amiodarone as prophylaxis for AF in selected patients after open-heart surgery. METHODS: In the first stage we studied a group of 204 consecutive cardiac surgery patients and devised a formula from some of the known risk factors of AF for each sex to serve as a predictor model. In this first group we were able to quantify the probability of developing this arrhythmia. In the second stage we applied this formula to a group of 231 consecutive cardiac surgery patients and then selectively treated the high-risk patients for AF: 25 men (16.1%) and 29 women (53.7%). In the first 24 h of treatment with amiodarone, 22 patients (10 men and 12 women) were excluded from the study due to sinus bradycardia. Therapy consisted of amiodarone 900 mg intravenously every 24 h for the first 2 postoperative days, followed by 600 mg intravenously every 24 h until discharge from the Intensive Care Unit. RESULTS: Expected AF in males fell from 34.4% (52/151) in the observation group to 11% (17/155) in the treated group, and in females from 50.9% in the observation group (27/53) to 9.3% (5/54) in the treated group (P<0.001). CONCLUSIONS: Patient-selective prophylaxis of AF with amiodarone can be a highly effective measure.

The effect of supplementation with n-3 fatty acids on the physical performance in subjects with spinal cord injury.

A global physical evaluation was performed in 21 males with spinal cord injury (SCI), at the beginning and at three and six months of omega-3 fatty acid (FA) supplementation. A significant increase in the proportion of eicosapentaenoic acid and docosahexanoic acid in plasma was observed in response to the supplementation (p<0.05). After six months of FA supplementation, strength endurance time increased from 127.7+/-19.0 s to 215.2+/-45.6 s in the right arm, and from 139+/-27.6 s to 237.7+/-48.7 s, in the left arm. The time to perform 20 repetitions of 70% maximum workload showed a reduction of 41% between the first and the third test. The time taken to cover a 90 meter long track, with a 6% slope, was reduced from 66.9+/-8.0 s to 59.3+/-6.7 s, at the end of the study (p<0.05). In conclusion, omega-3 FA supplementation could contribute to improve the functional capabilities in SCI subjects.

Continual supplementation with n-3 fatty acids does not modify plasma lipid profile in spinal cord injury patients.

STUDY DESIGN: A prospective study during a diet modification. OBJECTIVE: To observe the evolution of the plasma lipid profile in a group of spinal cord injury (SCI) patients given a supplement of a mixture of docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA). SETTING: Department of Physiological Sciences II, Medical School of the University of Barcelona and Guttmann Institut of Badalona, Barcelona, Spain. METHODS: A total of 19 adult males with SCI, 17 with paraplegia and two with tetraplegia, were given a daily supplement of 1.5 g of DHA and 0.75 g of EPA for 6 months. Determination of plasma values of DHA, EPA, total cholesterol, HDL-c, LDL-c, VLDL-c, triglycerides, and glucose was performed before supplementation and at 3 and 6 months of supplementation. RESULTS: A statistically significant increase in the plasma concentration of EPA (F=30.556, P<0.05) and DHA (F=106.6, P<0.05) was observed after 3 and 6 months of supplementation. However, there were no observable differences in the plasma concentration of total-cholesterol, HDL-c, LDL-c, VLDL-c, and triglycerides during the study. CONCLUSION: DHA-EPA supplementation for 6 months does not modify the glycemic and lipid plasmatic levels in SCI patients. Despite its absence of effect on the serum lipid profile, n-3 fatty acids may induce beneficial cardiovascular effects in this population.

Creatine supplementation and performance in 6 consecutive 60 meter sprints.

Creatine is an ergogenic aid used in individual and team sports. The aim of this study is to analyze the effect of monohydrate creatine supplementation on physical performance during 6 consecutive maximal speed 60 meter races, and the changes induced in some characteristic biochemical and ventilatory parameters. The study was carried out on nineteen healthy and physically active male volunteers, and randomly distributed into two groups: Group C received a supplement of creatine monohydrate (20 g/day for 5 days) and group P received placebo. Tests were performed before and after supplementation. No significant changes were observed in weight or body water measured by bioimpedance or the sum of 7 skinfold or performance during the 60 meter races. Group C showed a statistically significant increase in plasma creatinine from 69.8 +/- 12.4 to 89.3 +/- 12.4 micromol x L(-1) (p<0.05). In group C in the second control day (after creatine supplementation), expiratory volume V(E), O2 uptake and CO2 production were lower after 2 minutes of active recovery period. These results indicate that creatine monohydrate supplementation does not appear to improve the performance in 6 consecutive 60 meter repeated races but may modify ventilatory dynamics during the recovery after maximal effort.

Physiological adaptations to exercise in people with spinal cord injury.

The number of patients that suffer some type of spinal cord lesion in recent years are high and have increased because of factors such as traffic accidents. Although their life expectancy has increased, cardiovascular illnesses is one of the main causes of morbidity and mortality. Since the degree of physical fitness is an important factor regarding the risk of cardiovascular disease, the objective of the present study was to examine the global adaptation (cardiorespiratory, metabolic and thermoregulatory response) of the organism to exercise and the application of this data to the habitual practice of physical activity to improve state of health. A group of 42 patients with spinal injury, 85% of whom were paraplegic and the remaining 15% tetraplegic performed 42 exercise tests on a cycloergometer. Body temperature (tympanum, surface of the deltoids and surface of the back), metabolic parameters (plasma uric acid, glycemia, plasma lactate), cardiocirculatory adaptation (heart rate, blood pressure arm, blood pressure leg) and ventilatory adaptation (VO2, VCO2, fr Vt, VE) were monitored. Blood pressure in the arm, blood concentrations of lactate and ventilatory parameters showed an evolution statistically dependent on the work to which the subject was submitted. Heart rate showed a statistically significant correlation with the ventilatory parameters and work load. The proportional response of the cardioventilatory parameters to the increase in the work load allowed us to evaluate the repercussion of a given exercise and thus avoid exercise of an excessive intensity that could produce cardiocirculatory changes that might entail an added risk. Heart rate presents an excellent correlation, shown in this work, with the oxygen consumption and could therefore be used to quantify the cardiorespiratory and metabolic repercussion of the exercise carried out. Furthermore, this quantification may allow for the adaptation of exercise intensity to the patient thus improving the results obtained from the practice of exercise that has been proven so necessary in these patients.

Long-term evolution of blood lipid profiles and glycemic levels in patients after spinal cord injury.

OBJECTIVE: To analyze the lipid and glycemic profiles in relation to age, time elapsed post injury and the level of injury in a group of patients with SCI. SUBJECTS: 2135 subjects with SCI were recruited during the annual routine health check-up carried out at the Institut Guttmann of Badalona, in Spain. The patients were classified according to the level of SCI and their age. METHODS: Serum lipid profiles and glycemic (glucose) levels were determined. Data was collected between 1996 and 2001, all biochemical analysis being performed by the same laboratory. RESULTS: Serum cholesterol levels show a statistically significant correlation with patient's age(P<0.001) and with time elapsed after injury (P<0.05). Differences can be observed between the values obtained from the different injury level groups (F=22.14; P<0.001). LDL-c shows a statistically significant difference between the four different age groups (F=3.51, P<0.05). There is an increase in plasma triglycerides related to the increase in age of the patients without observable differences between the injury level groups. The concentration of serum glucose increases with age (P<0.001) and also with the time elapsed after injury (P<0.05). CONCLUSION: There is a direct relationship between various biochemical parameters (total cholesterol, LDL-c and glucose) and the age of the patients, but not with the severity or time of evolution of the spinal cord injury.

Normoxic ventilatory response in lowlander and Sherpa elite climbers.

The differences in ventilatory response to exercise of some highland ethnic communities is a controversial issue. We have evaluated the differences in ventilatory response to exercise at sea level between two groups of elite climbers, four Himalayan Sherpas (S) and four Caucasian lowlanders (C), after descent from extreme altitude. All of them performed a progressive-intensity exercise test on a treadmill under normoxic conditions. Pulmonary gas exchange was obtained until exhaustion by means of an automatic gas-analyzer system. Significant differences in expired ventilation and carbon dioxide production were found between the two groups, the VE x VO2(-1) being lower in the S at rest (41.9 +/- 5) in comparison with C (48.7 +/- 9) (P < 0.05), higher at medium loads of the test (S = 28.2 +/- 4 vs. C = 25.7 +/- 2; P < 0.05) and reaching similar values at higher loads (S = 34.5 + 2 vs. C = 35.6 +/- 4; NS). We conclude that the special ventilatory response observed in these highlanders could explain their adaptation to altitude, allowing higher oxygen blood saturation at medium working loads and reducing the risk of neurological injury caused by a high ventilatory response when exercising at high intensity effort under extreme altitude environment.

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.