Time filter

Source Type

Sankt Gallen, Switzerland

Knechtle B.,Facharzt FMH fur Allgemeinmedizin | Knechtle B.,University of Zurich | Knechtle P.,Facharzt FMH fur Allgemeinmedizin | Kohler G.,University of Basel
Research in Sports Medicine | Year: 2011

We evaluated the change in body mass including fat mass and skeletal muscle mass in one ultracyclist whilst cycling 1,000 km in 48 hours at a constant intensity of ∼48% VO2max, corresponding to a heart rate frequency of ∼105 ± 5 bpm. A 1 kg fat mass decrease resulted, with the largest decrease occurring between the 12th and the 24th hour. No steady state in metabolism was observed and no regular decrease of subcutaneous adipose tissue resulted. This result is backed up by the nuclear magnetic resonance (NMR) urine analysis. Body water increase with simultaneous dehydration is possibly due to endocrine-induced renal water retention, in order to maintain metabolism processes that are required for energy supply and blood flow during very prolonged exercise. Both applied methods, the anthropometric and the bioelectrical impedance analysis, analyse fluid accumulation-especially in the skinfolds of the lower extremities-apparently incorrectly as an increase in body mass and not as an increase in fluids. Copyright © Taylor & Francis Group, LLC. Source

Knechtle B.,Facharzt FMH fur Allgemeinmedizin | Knechtle B.,University of Zurich | Knechtle P.,Facharzt FMH fur Allgemeinmedizin | Lepers R.,University of Burgundy
Scandinavian Journal of Medicine and Science in Sports | Year: 2011

We examined the changes in participation and performance trends in ultra-triathlons, from the Double Iron (7.6km swimming, 360km cycling, 84.4km running) to the Deca Iron (38km swimming, 1800km cycling, 422km running), between 1985 (first year of a Double Iron) and 2009 (25 years). The mean finish rate for all distances and races was 75.8%. Women accounted for ∼8-10% of the ultra-triathlons starters. For Double and Triple Iron, the number of finishers per year increased, from 17 to 98 and from 7 to 41, respectively. In the Deca Iron, the finishers per race have remained <20 since the first event was held, up to 2009. Concerning World best performances, the men were ∼19% faster than the women in both the Double and Triple Iron, and ∼30% faster in a Deca Iron. With the increasing length of ultra-triathlons, the best women became relatively slower compared with the best men. Further investigations are required to understand why this gender difference in total performance time increased with the distance in ultra-triathlons. © 2010 John Wiley & Sons A/S. Source

Knechtle B.,Facharzt FMH fur Allgemeinmedizin | Knechtle B.,University of Zurich | Rust C.A.,University of Zurich | Rosemann T.,University of Zurich | Lepers R.,University of Burgundy
Age | Year: 2012

The aims of this study were (1) to investigate the participation and performance trends at the '100 km Lauf Biel' in Switzerland from 1998 to 2010, and (2) to compare the age-related changes in 100-km running performance between males and females. For both sexes, the percent of finishers significantly (P<0.01) decreased for the 18-29 and the 30-39-year age groups, while it significantly (P<0.01) increased for the 40-49 and the 50-59-year age groups over the studied period. From 1998 to 2010, the mean age of the top ten finishers increased by 0.4 years per annum for both females (P=0.02) and males (P=0.003). The running time for the top ten finishers remained stable for females, while it significantly (P=0.001) increased by 2.4 min per annum for males. There was a significant (P<0.001) age effect on running times for both sexes. The best 100-km running times was observed for the age comprised between 30 and 49 years for males, and between 30 and 54 years for females, respectively. The age-related decline in running performance was similar until 60-64 years between males and females, but was greater for females compared to males after 65 years. Future studies should investigate the lifespan from 65 to 75 years to better understand the performance difference between male and female master ultra-marathoners. © The Author(s) 2011. Source

Haupt S.,University of Zurich | Knechtle B.,University of Zurich | Knechtle P.,Facharzt FMH fur Allgemeinmedizin | Rust C.A.,University of Zurich | And 2 more authors.
Research in Sports Medicine | Year: 2013

The age-related changes in ultraendurance performance have been previously examined for running and triathlon but not mountain biking. The aims of this study were (i) to describe the performance trends and (ii) to analyze the age-related performance decline in ultraendurance mountain biking in a 120-km ultraendurance mountain bike race the "Swiss Bike Masters" from 1995 to 2009 in 9,325 male athletes. The mean (±SD) race time decreased from 590 ± 80 min to 529 ± 88 min for overall finishers and from 415 ± 8 min to 359 ± 16 min for the top 10 finishers, respectively. The mean (±SD) age of all finishers significantly (P < 0.001) increased from 31.6 ± 6.5 years to 37.9 ± 8.9 years, while the age of the top 10 remained stable at 30.0 ± 1.6 years. The race time of mountain bikers aged between 25 and 34 years was significantly (P < 0.01) faster compared with the race time of older age groups. The age-related decline in performance in endurance mountain bikers in the "Swiss Bike Masters" appears to start earlier compared with other ultraendurance sports. © 2013 Copyright Taylor and Francis Group, LLC. Source

Etter F.,University of Zurich | Knechtle B.,University of Zurich | Bukowski A.,Facharzt FMH fur Allgemeinmedizin | Rust C.A.,University of Zurich | And 2 more authors.
Journal of Sports Sciences | Year: 2013

This study investigated the participation and performance trends as well as the age and gender interaction at the Olympic distance 'Zürich Triathlon' (1.5 km swim, 40 km cycle and 10 km run) from 2000 to 2010 in 7,939 total finishers (1,666 females and 6,273 males). Female triathletes aged from 40 to 54 years significantly (P < 0.05) increased their participation while the participation of younger females and males remained stable. Males of 50-54 years of age and females of 45-49 years of age improved their total race time. For elite top five overall triathletes, mean gender differences in swimming, cycling, running and overall race time were 15.2 ± 4.6%, 13.4 ± 2.3%, 17.1 ± 2.5%, and 14.8 ± 1.8%, respectively. For both elite and age group athletes, the gender difference in cycling time was significantly (P <0.001) lower than for swimming and running. The gender difference in overall Olympic distance triathlon performance increased after the age of 35 years, which appeared earlier compared to long distance triathlon as suggested by previous studies. Future investigations should compare gender difference in performance for different endurance events across age to confirm a possible effect of exercise duration on gender difference with advancing age. © 2013 Copyright Taylor and Francis Group, LLC. Source

Discover hidden collaborations