Background: Many papers showed that long-lasting exposure to hypobaric hypoxia changed the metabolic cost of work and substrate contribution, elevating exercise energy expenditure and carbohydrates utilization. Only few of them have shown how long this adaptive changes are maintained. The aim of the study was to assess the impact of prolonged sojourn at high altitude on the physiological cost of sub-maximal work performed at the sea level.Material/Methods: Eight members of two high altitude expeditions (Lenin Peak 7,134 m a.s.l. and Somoni Peak 7,495m a.s.l.), 7 males and 1 female, mean age 26 (±4.1) years, volunteered for this study. Aerobic performance was measured by a direct method (breath-by-breath) using an expiratory gas analyser (Oxycon Pro, Jaeger) with an incremental exercise test till exhaustion. The sea level examinations were performed 7 days before the expedition (BEx) and 7 days after (AEx) the last day at over 2,500m a.s.l. Participants spent 32 (±3) days over 2,500m a.s.l. at the mean altitude of 4,712m a.s.l. (±499m).Results: Prolonged sojourn at high altitude has changed the ventilatory parameters of sub-maximal work measured at the sea level. The sojourn resulted in an increase in the ventilatory volume (tidal volume, minute ventilation and breath frequency) during the sub-maximal work performed with the same workload. However, the respiratory exchange ratio remained at a high level compared to the baseline.Conclusions: We suggest that the adaptive changes introduced during the sojourn remain at the sea level and cause increased carbohydrate metabolism.
Introduction: The Borg Scale for perceived exertion is well established in science and sport to keep an appropriate level of workload or to rate physical strain. Although it is also often used at moderate and high altitude, it was never validated for hypoxic conditions. Since pulse rate and minute breathing volume at rest are increased at altitude it may be expected that the rating of the same workload is higher at altitude compared to sea level.Material and methods: 16 mountaineers were included in a prospective randomized design trial. Standardized workload (ergometry) and rating of the perceived exertion (RPE) were performed at sea level, at 3,000 m, and at 4,560 m. For validation of the scale Maloney-Rastogi-test and Bland-Altmann-Plots were used to compare the Borg ratings at each intensity level at the three altitudes; p < 0.05 was defined as significant.Results: In Bland-Altmann-Plots more than 95% of all Borg ratings were within the interval of 1.96 x standard deviation. There was no significant deviation of the ratings at moderate or high altitude. The correlation between RPE and workload or oxygen uptake was weak.Conclusion: The Borg Scale for perceived exertion gives valid results at moderate and high altitude – at least up to about 5,000 m. Therefore it may be used at altitude without any modification. The weak correlation of RPE and workload or oxygen uptake indicates that there should be other factors indicating strain to the body. What is really measured by Borg’s Scale should be investigated by a specific study.
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Exposure of alpine skiing athletes, while training, at altitude hypoxia and low ambient temperature can modify the response of the immune system and increase reactive oxygen and nitrogen species (RONS) generation. The aim of this study was to evaluate the impact of six day training model "live low - train high" on selected indicators of immune and antioxidant-prooxidant balance of alpine skiing competitors. The study was performed in 7 men, alpine skiers, who underwent 6-day training at Kaunertal glacier (3160 m). Before departure to glacier training, and after returning to sea level participants underwent series of tests. Somatic characteristics, anaerobic exercise capacity, blood morphological parameters and concentrations of interleukin 6 (IL-6), C-reactive protein (hsCRP), thyroid stimulating hormone (TSH), thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), total iron (Fe) and total iron binding capacity (TIBC) were assessed. High altitude training has led to a significant increase in anaerobic capacity (p<0.05) and serum concentrations of IL-6 and hsCRP (p<0.05). A negative correlation among the difference in iron (ΔFe) concentration between two study terms and the change of hsCRP levels was also found (p<0.05). Alpine training conditions led to a slight increase in immunological indices concentration in studied skiers. However, it did not cause any significant change in prooxidant-antioxidant balance, which could be related to earlier anaerobic training adaptation.
Visual loss in the wilderness setting is potentially fatal. Firstly it may be a warning sign of a serious systemic problem and secondly the patient may lose their functional independence and ability to respond to objective danger. The issues discussed in this paper fall broadly into two categories, those that are unique to the high altitude setting and those that could happen anywhere but require treatment to protect vision then standard ophthalmological care is unavailable. The aims are to provide practical knowledge on how to manage simple eye problems and also how to recognize the warning signs when evacuation may be required. In keeping with all wilderness medicine, preparation and prevention are essential to avoid eye problems in the mountains. This paper is intended for physicians, interested non-medical people and expedition operators as a practical guide to the treatment and prevention of eye problems on expeditions.
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