[Alpine medicine--a stay at middle altitude].
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Altitude Sickness↗
Biomedical subjects
Günther Schwaberger
Publications and source records attributed to Günther Schwaberger.
[Aspects and necessity of moderate-altitude research].
Alpinism in all its variations is a leading factor in tourism. Within a few decades, alpine sports, even at high altitudes, have become available to a wide range of people. Now, more people than ever before are hiking, trekking, climbing and skiing at moderate and high altitudes. Annually, 40 million people spend time in the Alps and 100 million visit high altitudes worldwide. However, alpine excursions may entail health problems and many aspects of impaired adaptation to altitude remain unstudied. High-altitude research has mainly been associated with expeditions, with moderate altitudes receiving far less attention, though most tourism takes place at that level. The overwhelming numbers of alpine tourists mean that there is urgent need for high- and moderate-altitude medical research, which would also be within the realm of political responsibility in mountainous countries. Research in mountain medicine and dissemination of relevant findings can show how to improve and conserve performance in healthy individuals and could point the way toward new, safe approaches in the rehabilitation of patients with chronic diseases. It is imperative that mountain medicine continues to develop on a scientific basis.
Academies and Institutes↗
[Performance testing in mountaineering].
Laboratory ergometry to exhaustion allows cardiopulmonal risk assessment for the prevention of health problems related to mountaineering. Moreover, exercise testing evaluates functional status, so permitting individualized training programs and evaluation of training effects. Additionally, mountaineering-specific performance diagnosis allows individual as well as group-specific determination of exercise performance related to field conditions. Laboratory tests are standardized, easy to perform and cost effective. Treadmill ergometry with constant walking speed and increasing inclination is suggested to be predictive for mountaineering performance. On the other hand, the validity for the specific conditions for mountaineering is questionable. Standardized laboratory exercise tests combined with sport-specific exercise tests provide rough information on the ability to sustain real-situation strain. To compare individual exercise performance, published data tables obtained from field tests may be used. It must, however, be mentioned that high-altitude-adaptation is independent of exercise performance evaluated separately.
Acclimatization↗
Beta1-adrenoceptor mediated origin of the heart rate performance curve deflection.
PURPOSE: The deflection of the HR performance curve (HRPC) has been described as an objective marker of submaximal exercise performance. HR response to incremental cycle ergometer exercise is shown to be neither linear nor uniform and a physiological explanation of the deflection phenomenon is lacking. We hypothesized that differences in the beta1-adrenoceptor site are the source of these differences. The aim of the study was to investigate the influence of the highly selective beta1-adrenoceptor (beta1-AR) antagonist bisoprolol (Bi) on the HRPC in young healthy male subjects with different HR response patterns. METHODS: Sixteen subjects were treated in randomized order with Bi or a placebo (Pl) in two separate trials. HR response during incremental cycle ergometer exercise was compared between the two trials. Blood lactate concentration (La) and ventilatory variables were measured throughout both tests. RESULTS: Bi changed the direction of the HRPC more in subjects with a regular, s-shaped response pattern under placebo than those with a nonregular or linear pattern. The influence of Bi on the HR at the second lactate turn point was significantly related (R = 0.78; P < 0.001) to the pattern of the HRPC in Pl conditions. CONCLUSION: We suggest that differences between the subjects with regular s-shaped versus nonregular HRPC may be due to differences at the beta1-AR site. The origin of the HRPC deflection is mediated in part by the beta1-AR sensitivity.
Adrenergic beta-Antagonists↗
Effect of beta(1)-selective adrenergic blockade on maximal blood lactate steady state in healthy men.
The aim of this study was to compare the effect of taking bisoprolol (B), a highly beta(1)-selective adrenoceptor antagonist to that of a placebo (P) on maximal lactate steady state (MLSS), which reflects the transition from oxidative to partially anaerobic metabolism. Ten healthy male subjects [mean (SD) age 23 (3) years, height 181 (6) cm, body mass 76 (6) kg] randomly received oral P or B (5 mg x day(-1)) for 2 weeks using a double-blind crossover design. In the 2nd week, the subjects performed an incremental cycle ergometer test until exhaustion to determine the second blood lactate turn point (LTP(2)). At regular intervals of 24-48 h, the subjects performed 2-3 steady-state tests to determine the MLSS. During the incremental exercise, heart rate (HR) was significantly lower at rest (15 beats x min(-1)), at LTP(2) (23 beats x min(-1)) and at maximal power output (19 beats x min(-1)) when taking B compared to P. Oxygen pulse was significantly higher taking B and no significant differences were observed for any of the respiratory gas exchange measurements (RGEM) (oxygen consumption, carbon dioxide production, minute ventilation, respiratory exchange ratio), exercise intensity or blood lactate concentration (LA) at baseline, at LTP(2) and at maximal power output. During exercise at constant intensity, significant differences between B and P were found for HR [148 (12) compared to 176 (11) beats x min(-1)] and oxygen pulse [21.8 (1.9) compared to 19.2 (1.6) ml] at MLSS. No difference was found for exercise intensity [216 (18) compared to 218 (18) W], for RGEM, LA [5.3 (1.1) compared to 4.8 (1.5) mmol x l(-1)] and ratings of perceived exertion [18.1 (1.6) compared to 17.4 (1.7)] for B and P at MLSS. In both, the power output at LTP(2) was slightly higher than power output at MLSS (within an intensity step). Commonly measured cardiorespiratory and subjective variables determined during treatment with 5 mg bisoprolol can be used for testing cardiorespiratory fitness and for prescription of training intensity.
Adrenergic beta-Antagonists↗
Prolonged endurance challenge at moderate altitude: effect on serum eosinophil cationic protein, eosinophil dynamics, and lung function.
BACKGROUND: Eosinophils contain granule proteins such as eosinophil cationic protein (ECP) that have proinflammatory effects on airways. ECP may be released on activation of eosinophils into the plasma and is widely used as a marker of bronchial hyperreactivity and allergic inflammation. Environmental factors as well as intense physical exertion may influence eosinophil-related bronchial hyperreactivity. STUDY OBJECTIVES: To investigate the effect of endurance exercise at moderate altitude on levels of circulating eosinophils, serum ECP, serum osmolality (sOS), and dynamic pulmonary function parameters in healthy mountaineers. SETTING: Alpine field study performed in the Alps of Upper Styria in Austria. Type of exercise: Ascent of a mountain at maximal speed. PARTICIPANTS: Thirty healthy male volunteers from a troop of military mountaineers. RESULTS: Mean ECP concentration increased by 66% at the summit checkpoint (H2) and remained at 63% above baseline (base checkpoint [H0]) after descent (H4), while the blood eosinophil count decreased concomitantly from 250/microL at H0 (preexercise) to 118/microL (53%) at H2 and to 22/microL (81%) at H4. The total serum ECP concentration adjusted to sOS correlated negatively with blood eosinophil count (r = - 0.37; p < 0.0001) and PaO(2) (r = - 0.34; p < 0.001), but positively with the peak expiratory flow (PEF) [r = 0.45; p < 0.0001]. Although sOS correlated with serum ECP at H2 (r = 0.47; p = 0.02) and at 12 h after the start of the experiment (H12) [r = 0.57; p = 0.003], the relationship between total ECP and sOS (r = 0.19; p = 0.034) was less pronounced. FEV(1) in percentage of FVC (%FEV(1)/FVC) [the Tiffenau test], forced expiratory flow rate at 25% of vital capacity, and PEF were significantly higher at H2 than at H0 and H4. %FEV(1)/FVC decreased to 88% (p < 0.01) and 83% (p < 0.001) predicted at H12 and 24 h after start of the experiment, respectively. CONCLUSION: Results provide strong evidence for nonspecific activation of blood eosinophils during prolonged intense aerobic exercise at moderate altitude, modifying both eosinophil dynamics and regulation of ECP release in healthy subjects.
Adult↗