Sudden Cardiac Death Risk in Downhill Skiers and Mountain Hikers and Specific Prevention Strategies

Sudden cardiac death (SCD) still represents an unanticipated and catastrophic event eliciting from cardiac causes. SCD is the leading cause of non-traumatic deaths during downhill skiing and mountain hiking, related to the fact that these sports are very popular among elderly people. Annually, more than 40 million downhill skiers and mountain hikers/climbers visit mountainous regions of the Alps, including an increasing number of individuals with pre-existing chronic diseases. Data sets from two previously published case-control studies have been used to draw comparisons between the SCD risk of skiers and hikers. Data of interest included demographic variables, cardiovascular risk factors, medical history, physical activity, and additional symptoms and circumstances of sudden death for cases. To establish a potential connection between the SCD risk and sport-specific physical strain, data on cardiorespiratory responses to downhill skiing and mountain hiking, assessed in middle-aged men and women, have been included. It was demonstrated that previous myocardial infarction (MI) (odds ratio; 95% CI: 92.8; 22.8–379.1; p < 0.001) and systemic hypertension (9.0; 4.0–20.6; p < 0.001) were predominant risk factors for SCD in skiers, but previous MI (10.9; 3.8–30.9; p < 0.001) and metabolic disorders like hypercholesterolemia (3.4; 2.2–5.2; p < 0.001) and diabetes (7.4; 1.6–34.3; p < 0.001) in hikers. More weekly high-intensity exercise was protective in skiers (0.17; 0.04–0.74; p = 0.02), while larger amounts of mountain sports activities per year were protective in hikers (0.23; 0.1–0.4; <0.001). In conclusion, previous MI history represents the most important risk factor for SCD in recreational skiers and hikers as well, and adaptation to high-intensity exercise is especially important to prevent SCD in skiers. Moreover, the presented differences in risk factor patterns for SCDs and discussed requirements for physical fitness in skiers and hikers will help physicians to provide specifically targeted advice

Effects of Pre-acclimatization Applying the ‘‘Climb High and Sleep Low’’ Maxim: An Example of Rapid but Safe Ascent to Extreme Altitude

Pre-acclimatization at a convenient high-altitude location may represent an appropriate method before climbing a more hostile target mountain. The aim of the present field report was to demonstrate the effectiveness of such pre-acclimatizing applying the ‘‘climb high sleep low’’ maxim for a subsequent rapid ascent to almost 7000 m. After some pre-acclimatization in the Alps the authors flew to Chile for further pre-acclimatization in the Aymara village of Putre (3650 m). From there they undertook sojourns up to altitudes of 5700 m within 3 days. Subsequently they went back to Arica (sea level) and climbed Ojos del Salado (6893 m) within 5 days without any health problems. Measurements of heart rate and arterial oxygen saturation and of cerebral oxygenation by near infrared spectroscopy at rest and during exercise indicated adequate acclimatization status. This field report demonstrates highly effective pre-acclimatization by the ‘‘climb high and sleep low’’ strategy supporting anecdotal reports. The up and down strategy may likely have induced hypoxia (pre)conditioning and subsequently allowed rapid ascent to extreme altitudes without any complications. The duration of the carry-over effect after pre-acclimatization has to be evaluated and proposed physiological mechanisms have to be proved by controlled studies in larger samples

AEROBIC POWER IN CHILD, CADET AND SENIOR JUDO ATHLETES

The aim of the present study was to compare performance and physiological responses during arm and leg aerobic power tests of combat duration in male child, cadet and senior judo athletes. Power output and physiological parameters, i.e., peak oxygen uptake ( ·VO2peak), peak ventilation, peak heart rate, lactate, and rate of perceived exertion, of 7 child (under 15 years: age class U15, 12.7 ± 1.1 yrs), 10 cadet (U17, 14.9 ± 0.7 yrs) and 8 senior ( 20, 29.3 ± 9.2 yrs) male judo athletes were assessed during incremental tests of combat duration on an arm crank and a cycle ergometer. Children as well as cadets demonstrated higher upper body relative VO2peak than seniors (37.3 ± 4.9, 39.2 ± 5.0 and 31.0 ± 2.1 ml∙kg-1∙min-1, respectively); moreover, upper and lower body relative VO2peak decreased with increasing age (r = -0.575, p < 0.003 and r = -0.580, p < 0.002, respectively). Children showed lower blood lactate concentrations after cranking as well as after cycling when compared to seniors (7.8 ± 2.4 vs. 11.4 ± 2.1 mmol∙l-1 and 7.9 ± 3.0 vs. 12.0 ± 1.9 mmol���l-1, respectively); furthermore, blood lactate values after cranking increased with age (r = 0.473, p < 0.017). These differences should be considered in planning the training for judo athletes of different age classes

The Use of Pulse Oximetry in the Assessment of Acclimatization to High Altitude

Background: Finger pulse oximeters are widely used to monitor physiological responses to high-altitude exposure, the progress of acclimatization, and/or the potential development of high-altitude related diseases. Although there is increasing evidence for its invaluable support at high altitude, some controversy remains, largely due to differences in individual preconditions, evaluation purposes, measurement methods, the use of different devices, and the lacking ability to interpret data correctly. Therefore, this review is aimed at providing information on the functioning of pulse oximeters, appropriate measurement methods and published time courses of pulse oximetry data (peripheral oxygen saturation, (SpO2) and heart rate (HR), recorded at rest and submaximal exercise during exposure to various altitudes. Results: The presented findings from the literature review confirm rather large variations of pulse oximetry measures (SpO2 and HR) during acute exposure and acclimatization to high altitude, related to the varying conditions between studies mentioned above. It turned out that particularly SpO2 levels decrease with acute altitude/hypoxia exposure and partly recover during acclimatization, with an opposite trend of HR. Moreover, the development of acute mountain sickness (AMS) was consistently associated with lower SpO2 values compared to individuals free from AMS. Conclusions: The use of finger pulse oximetry at high altitude is considered as a valuable tool in the evaluation of individual acclimatization to high altitude but also to monitor AMS progression and treatment efficacy

Preparation for Endurance Competitions at Altitude: Physiological, Psychological, Dietary and Coaching Aspects. A Narrative Review

It was the Summer Olympic Games 1968 held in Mexico City (2,300 m) that required scientists and coaches to cope with the expected decline of performance in endurance athletes and to establish optimal preparation programs for competing at altitude. From that period until now many different recommendations for altitude acclimatization in advance of an altitude competition were proposed, ranging from several hours to several weeks. Those recommendations are mostly based on the separate consideration of the physiology of acclimatization, psychological issues, performance changes, logistical or individual aspects, but there is no review considering all these aspects in their entirety. Therefore, the present work primarily focusses on the period of altitude sojourn prior to the competition at altitude based on physiological and psychological aspects complemented by nutritional and sports practical considerations