Search results for "Altitude"
showing 10 items of 184 documents
Performance of Kenyan athletes in mountain versus flat marathon running - An example in Switzerland
2013
Harm, C., Knechtle, B., Rust, A.C., Rosemann, T., Lepers, R. & Onywera, V. (2013). Performance of Kenyan athletes in mountain versus flat marathon running - An example in Switzerland. J. Hum. Sport Exerc., 8(4), pp.881-893. The purpose of this study was to compare running performance of Kenyans in a flat city marathon and a mountain marathon in Switzerland. Running times of top three overall Kenyan runners were compared with running times of top three overall runners of other nations in a mountain and a flat marathon held in Switzerland between 2003 and 2011. In the mountain marathon top three male Kenyans achieved with 199±23min the 11th fastest running time behind athletes from Italy (177…
Age and sex interactions in mountain ultramarathon running - the Swiss Alpine Marathon.
2012
Evelyn Eichenberger,1 Beat Knechtle,1,2 Christoph Alexander Rüst,1 Thomas Rosemann,1 Romuald Lepers31Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland; 2Gesundheitszentrum St Gallen, St Gallen, Switzerland; 3INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, FranceBackground: The aims of the study were to examine the (a) participation, (b) difference in running times between the sexes, and (c) age-related decline in the running times of ultramarathoner women and men competing in the Swiss Alpine Marathon from 1998 to 2011.Methods: The ultramarathoners competing in the Swiss Alpine Marathon were analyzed in ter…
Climatic gradients along the windward slopes of Mount Kenya and their implication for crop risks. Part 1: climate variability
2012
In tropical mountains, the way topographical gradients translate in terms of intra-seasonal and interannual climate variability (especially rainfall and evapotranspiration) is relatively unknown, yet it is an important issue for agriculture and food security. The eastern slopes of Mount Kenya, in East Africa, with their wide range of agro-ecological conditions, are appropriate for the study of these aspects. Daily (monthly) rainfall data from 11 (24) stations at different elevations and exposures are collected for the period 1961-2006. For the elevation belts suitable for farming and agro-pastoral activities, mostly below 2000 m, it is found that not all rainfall characteristics co-vary wit…
Effects of rainfall events on the evapotranspiration retrieved by an energy balance model
2009
An alternative way to map the actual evapotranspiration (ET) spatial distribution at daily scale is the application of residual surface energy balance models to satellite images that are characterised by high temporal frequency and moderate spatial resolution, like those acquired by the MODIS sensors on board of TERRA and AQUA platforms. Within this research the well-known SEBAL model has been applied on an area located in the southern part of Sicily (Imera Meridionale catchment) using four images acquired between the 27th of March and the 11th of April 2007. The catchment extends for about 2000 km2 and includes both mountains and hill areas: the first are located in the northern part (the …
Plasma leptin and vascular endothelial growth factor (VEGF) in normal subjects at high altitude (5050 m)
2013
Context: High altitude (HA) is a model of severe hypoxia exposure in humans. We hypothesized that nocturnal hypoxemia or acute maximal exercise at HA might affect plasma leptin and VEGF levels. Objectives: Plasma leptin, VEGF and other metabolic variables were studied after nocturnal pulse oximetry and after maximal exercise in healthy lowlanders on the 3rd-4th day of stay in Lobuche (5050 m, HA) and after return to sea level (SL). Results: Leptin was similar at SL or HA in both pre- and post-exercise conditions. Pre-exercise VEGF at HA was lower, and cortisol was higher, than at SL, suggesting that nocturnal intermittent hypoxia associated with periodic breathing at HA might affect these v…
''Sex-related Trends In Participation and Performance In the 'swiss Bike Masters' From 1994-2012''
2013
Gloor, Roman Urs | Knechtle, Beat | Knechtle, Patrizia | Ruest, Christoph Alexander | Haupt, Samuel | Rosemann, Thomas | Lepers, Romuald; International audience; ''General participation in contests such as ultra-marathons and ultra-triathlons has increased considerably over the past 30 years, especially among women. This study investigated performance trends in the Swiss Bike Masters, one of the first and most prestigious mountain bike, ultra-endurance races in its class, with comparisons of participation and performance trends to similar races. The development of performance in the Swiss Bike Masters held between 1994 and 2012 was investigated by analysing the number of finishers, their ag…
Testing Individual Risk of Acute Mountain Sickness at Greater Altitudes
2009
The assessment of an individual's degree of acclimatization to altitude is difficult. This is particularly applicable to military operations that have to be performed at altitude. This study describes a new and simple test that allows for the determination of an individual's risk for high-altitude illness at higher altitudes. The prediction is based on the lowest oxygen saturation (SaO2) found during an uphill run at high altitude (11,060 ft [3,371 m]), combined with the time needed to complete the run. The test results were compared against the severity of high-altitude symptomatology on the summit of Mont Blanc (15,762 ft [4,808 m]). The main outcome was the significant correlation betwee…
Safety and Ergogenic Properties of Combined Aminophylline and Ambrisentan in Hypoxia.
2017
We hypothesized that concomitant pharmacological inhibition of the endothelin and adenosine pathway is safe and improves exercise performance in hypoxic humans, via a mechanism that does not involve augmentation of blood oxygenation. To test this hypothesis, we established safety and drug interactions for aminophylline (500 mg) plus ambrisentan (5 mg) in normoxic volunteers. Subsequently, a placebo‐controlled study was employed to test the combination in healthy resting and exercising volunteers at simulated altitude (4,267 m). No serious adverse events occurred. Drug interaction was minimal or absent. Aminophylline alleviated hypoxia‐induced headaches. Aminophylline, ambrisentan, and their…
A population-based coprological study of human fascioliasis in a hyperendemic area of the Bolivian Altiplano
1997
The community of Chijipata Alta, at an altitude of 3850 m, near the southern coast of Lake Titicaca in the Northern Altiplano of Bolivia, was surveyed for human fascioliasis. The global prevalence (66.7 %) and intensity (eggs per gram of faeces - epg: range: 24-4440; arithmetic mean: IooI; geometric mean: 390) proved to be the highest known in the world by means of coprological techniques. These results suggest the existence of highly hyperendemic subzones among the large human fascioliasis-endemic zone of the Bolivian Northern Altiplano. Despite the decrease in prevalence and intensity from children (75.0%, 24-4440 epg) to adults (41.7%, 144-864 epg), our findings show that in an hyperende…
Soil-transmitted helminth infections at very high altitude in Bolivia
2001
A cross-sectional study of soil-transmitted helminthiases in the Northern Bolivian Altiplano was carried out over the 6-year period 1992-97. Prevalences, intensities and associations were analysed from coprological results obtained in 31 surveys (28 in schools and 3 in individuals of all age-groups) performed in 24 Aymara communities located between the city of La Paz and Lake Titicaca, at an altitude of 3800-4200 m. Ascaris lumbricoides and Trichuris trichiura were detected, with local prevalences in the range 1.2-28.0% and 0.0-24.0%, respectively. Significant differences in prevalence rates of trichuriasis were detected, with highest prevalences in male schoolchildren and in subjects aged…