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Introduction
Education
January 2008 - July 2011
October 2000 - September 2003
October 1998 - September 2000
Publications
Publications (48)
Purpose
Laboratory tests are commonly performed by cross‐country (XC) skiers due to the challenges of obtaining reliable performance indicators on snow. However, only a few studies have reported reliability data for ski‐specific test protocols. Therefore, this study examined the test–retest reliability of ski‐specific aerobic, sprint, and neuromusc...
Introduction: When exercising in the cold, optimizing thermoregulation is essential to maintain performance. However, no study has investigated thermal parameters with wearable-based measurements in a field setting among elite Nordic skiers. Therefore, this study aimed to assess the thermal response and sensation measured at different body parts du...
Recently, a new automated carbon monoxide (CO) rebreathing method (aCO) to estimate haemoglobin mass (Hbmass) was introduced. The aCO method uses the same CO dilution principle as the widely used optimised CO rebreathing method (oCO). The two methods differ in terms of CO administration, body position, and rebreathing time. Whereas with aCO, CO is...
Cross-country (XC) ski races involve a variety of formats, two different techniques and tracks with highly variable topography and environmental conditions. In addition, XC skiing is a major component of both Nordic combined and biathlon competitions. Research in this area, both in the laboratory and field, encounters certain difficulties that may...
We recently measured the development of hemoglobin mass (Hbmass) in 10 Swiss national team endurance athletes between ages 16–19. Level of Hbmass at age 16 was an important predictor for Hbmass and endurance performance at age 19. The aim was to determine how many of these young athletes were still members of Swiss national teams (NT) at age 25, ho...
During early parenthood, walking and/or running while pushing a stroller is a common form of endurance exercise among both recreationally active individuals and athletes. Here, we investigate how pushing a stroller influences the energetic cost, gross efficiency (GE), and kinematic behavior of well-trained men and women while walking or running on...
Purpose:
It is unknown, whether endurance training stimulates hemoglobin mass (Hbmass) and V[Combining Dot Above]O2max increases during late adolescence. Therefore, this study assessed the influence of endurance training on Hbmass, blood volume parameters, and V[Combining Dot Above]O2max in endurance athletes and control subjects from age 16 to 19...
The rim width of cross-country mountain bike wheel sets has increased in recent years, but the effect of this increase on performance remains unknown. The aim of this study was to analyse the influence of rim width on rolling resistance and off-road speed. We compared 3 tubeless wheel sets: 25 mm inner width as baseline, 30 mm width with the same t...
Performance and maximal oxygen uptake (VO2max) in endurance sports is mainly limited by the oxygen supply to active muscle. Since total amount of hemoglobin (Hbmass) determines in large part the oxygen transport capacity of the blood, Hbmass is a main limiting factor for endurance performance. The importance of a high Hbmass in endurance athletes i...
Theoretical background: The next two major competitions in athletics will be held in Doha, Qatar (World Championships 2019) and in Tokyo, Japan (Olympic Games 2020). On both occasions, extreme environmental conditions are expected: A wet bulb globe temperature (WBGT) of ~28°C in Doha and of ~30°C in Tokyo (Murata et al., 2016), indicating "high" an...
New Findings
What is the central question of this study?
It has been assumed that athletes embarking on an ‘live high–train low’ (LHTL) camp with already high initial haemoglobin mass (Hb mass ) have a limited ability to increase their Hb mass further post‐intervention. Therefore, the relationship between initial Hb mass and post‐intervention incre...
Purpose:
To compare individual hemoglobin mass (Hbmass) changes following a live high-train low (LHTL) altitude training camp under either normobaric hypoxia (NH) or hypobaric hypoxia (HH) conditions in endurance athletes.
Methods:
In a crossover design with a one-year washout, 15 male triathletes randomly performed two 18-d LHTL training camps...
The aim of this study was to compare the accuracy among a high number of current mobile cycling power meters used by elite and recreational cyclists against a first principle-based mathematical model of treadmill cycling. 54 power meters from 9 manufacturers used by 32 cyclists were calibrated. While the cyclist coasted downhill on a motorised trea...
The main aim of the present study was to quantify the magnitude of differences introduced when estimating a given blood volume compartment (e.g. plasma volume) through the direct determination of another compartment (e.g. red cell volume) by multiplication of venous haematocrit and/or haemoglobin concentration. However, since whole body haematocrit...
Although a low rolling resistance is advantageous in mountain bike cross-country racing, no studies have used the virtual elevation method to compare tyres from different manufacturers as used in international competitions so far. The aims of this study were to assess the reliability of this method, to compare the off-road rolling resistance betwee...
Background
The aims of the present study were to investigate the impact of three whole blood donations on endurance capacity and hematological parameters and to determine the duration to fully recover initial endurance capacity and hematological parameters after each donation.
Methods
Twenty-four moderately trained subjects were randomly divided i...
The purpose of this study was to analyse the effect of bike type - the 26-inch-wheel bike (26" bike) and the 29-inch-wheel bike (29" bike) - on performance in elite mountain bikers. Ten Swiss National Team athletes (seven males, three females) completed six trials with individual start on a simulated cross-country course with 35 min of active recov...
Purpose:
We investigated association of hematological variables with specific fitness performance in elite team-sport players.
Methods:
Hemoglobin mass (Hbmass) was measured in 25 elite field hockey players using the optimized (2 min) CO-rebreathing method. Hemoglobin concentration ([Hb]), hematocrit and mean corpuscular hemoglobin concentration...
Purpose We investigated association of hematological variables with specific fitness performance in elite team-sport players. Methods Hemoglobin mass (Hb mass) was measured in 25 elite field hockey players using the optimized (2 min) CO-rebreathing method. Hemoglobin concentration ([Hb]), hematocrit and mean corpuscular hemoglobin concentration (MC...
Duplicate haemoglobin mass (Hbmass) measurements are recommended before and after altitude training sojourns to identify individual adaptations in athletes with a high level of certainty. Duplicate measurements reduce typical error (TE) and disclose measurement outliers, but are usually made on separate days, which is not a practical protocol for r...
To investigate physical performance and hematological changes in 32 elite male team-sport players after 14 days of 'live high-train low' (LHTL) in normobaric hypoxia (≥14 h.day at 2800-3000 m) combined with repeated-sprint training (6 sessions of 4 sets of 5 x 5-s sprints with 25 s of passive recovery) either in normobaric hypoxia at 3000 m (LHTL+R...
Specific crosscountry mountain bike (MTB) laboratory tests are used to monitor training and performance of elite athletes. To better follow up long-term performance development we designed a new MTB specific treadmill-based cycling time trial. The purpose of this study was to investigate the relationship between different physiological parameters f...
INTRODUCTION: In elite endurance athletes, hemoglobin mass (Hbmass) is reported to be very stable over years, but can temporary increase with altitude training (Schmidt & Prommer, 2008). Such Hbmass changes are small in relation to the usual measurement error of the carbon monoxide (CO) rebreathing method. Double or triplicate measurements can enha...
Text: Introduction: A specific period of combined training overload (OLP) with a subsequent period with reduced training load (tapering) (TP) as preparation for a competition is widely used in endurance sport to reach an enhanced competition performance. It has been suggested that taper-associated changes of red cell volume (RCV) and blood volume (...
Measurements of haemoglobin mass (Hb(mass)) with the carbon monoxide (CO) rebreathing method provide valuable information in the field of sports medicine, and have markedly increased during the last decade. However, several different approaches (as a combination of the rebreathing procedure and subsequent calculations) for measuring Hb(mass) are us...
It is unclear if hemoglobin mass (Hbmass) and red cell volume (RCV) increase in endurance athletes with several years of endurance training from adolescence to adulthood. The aim of this study, therefore, was to determine with a controlled cross-sectional approach whether endurance athletes at the ages of 16, 21, and 28 yr are characterized by diff...
Introduction In elite endurance sport, it is important that athletes train in specific training zones. Especially young athletes have to learn to correctly appraise the individual training intensities. Often, it is not possible to test young endurance athletes under laboratory settings and field tests can be an appropriate method to determine indiv...
Introduction Crosscountry (XC) ski-specific testing is used to support elite athletes regarding their training control as well as to predict performance of competitive ski season (Alsobrook & Heil, 2009, Staib et al., 2000). The purpose of this study was to investigate the relationship between the results of two different laboratory preseason rolle...