Gunnar Treff

Gunnar Treff
Paracelsus Medical University Salzburg · Institute of Sports Medicine

PD Dr. biol. hum.

About

65
Publications
12,346
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446
Citations
Citations since 2016
45 Research Items
406 Citations
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
Additional affiliations
November 2021 - November 2021
Paracelsus Medical University Salzburg
Position
  • PostDoc Position

Publications

Publications (65)
Article
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Purpose: Elite rowers have large body dimensions, a high metabolic capacity, and they realize high training loads. These factors suggest a high total energy requirement (TER), due to high exercise energy expenditure (EEE) and additional energetic needs. We aimed to study EEE and intensity related substrate utilization (SU) of elite rowers during ro...
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Many endurance athletes aim to increase endurance performance at or near sea-level by hypoxic training, which can be realized in natural or artificial altitude via three main concepts: living and training in hypoxia, living in hypoxia and training in normoxia, or living in normoxia and training in hypoxia. The scientific evidence for these concepts...
Article
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https://www.germanjournalsportsmedicine.com/archiv/archive-2022/issue-2/variability-of-mechanical-power-output-in-elite-rowers-during-ergometer-testing/
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Introduction The Concept 2 (C2) rowing ergometer is used worldwide for home-based training, official competitions, and performance assessment in sports and science. Previous studies reported a disparate underestimation of mechanical power output positively related to an unclearly defined stroke variability. The aim of this study was to quantify the...
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Background: Metabolic stress is high during training and competition of Olympic rowers, but there is a lack of biomedical markers allowing to quantify training load on the molecular level. We aimed to identify such markers applying a complex approach involving inflammatory and immunologic variables. Methods: Eleven international elite male rowers (...
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Background Asthma and/or airway hyper-responsiveness (AHR) are common in elite endurance athletes with a high prevalence rate of beta-2 adrenoreceptor (beta-2) agonists use. Nevertheless, there are data on dose-dependent ergogenic effects of beta-2 agonists suggesting increased muscle strength, endurance and neuromuscular performance. Therefore, mo...
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The aim of this study was to investigate differences in skeletal muscle gene expression of highly trained endurance and strength athletes in comparison to untrained individuals at rest and in response to either an acute bout of endurance or strength exercise. Endurance (ET, n = 8, ⩒O2max 67 ± 9 mL/kg/min) and strength athletes (ST, n = 8, 5.8 ± 3.0...
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Decreased oxygen saturation (SO2) at high altitude is associated with potentially life-threatening diseases, e.g., high-altitude pulmonary edema. Wearable devices that allow continuous monitoring of peripheral oxygen saturation (SpO2), such as the Garmin Fēnix® 5X Plus (GAR), might provide early detection to prevent hypoxia-induced diseases. We the...
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Training studies in elite athletes traditionally focus on the relationship between scheduled training (TRAIN) and performance. Here, we added activities outside of scheduled training i.e., off-training (OFF) contributing to total training (TOTAL) to evaluate the contribution of OFF on performance. Eight elite rowers recorded OFF and TRAIN during wa...
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Olympic rowing in its current form is a high-intensity boat race covering a distance of 2000 m with fastest race times ranging ~5.5-7.5 min, depending on boat class, sex, and environmental factors. To realize such race times, rowers need strength and endurance, which is physiologically evident in an oxidative Adaption of the skeletal muscles, a hig...
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We wanted to demonstrate the relationship between blood volume, cardiac size, cardiac output and maximum oxygen uptake (VO 2max) and to quantify blood volume shifts during exercise and their impact on oxygen transport. Twenty-four healthy, non-smoking, heterogeneously trained male participants (27 ± 4.6 years) performed incremental cycle ergometer...
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Purpose Previously we demonstrated the feasibility of a six-week-long combination of high-intensity interval endurance and strength training (HIT/HIRT) for women with nonmetastatic breast cancer leading to improvements in psychological well-being and performance. Now we report results of a 24-month follow-up. Methods Previous intervention (IG, n =...
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Allogenic stem cell transplantation (aSCT) is the only potentially curative treatment for high-risk hematological diseases. Despite advancements in supportive measures, aSCT outcome is still affected by considerable transplant-related mortality. We implemented a new sarcopenia assessment prior to aSCT to evaluate its predictive capability for all-c...
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The interest in trekking and mountaineering is increasing, and growing numbers of individuals are travelling to high altitude. Following ascent to high altitude, individuals are at risk of developing one of the three forms of acute high-altitude illness: acute mountain sickness (AMS), high-altitude cerebral edema (HACE), and high-altitude pulmonary...
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Purpose To evaluate the intra-unit (RELINTRA) and inter-unit reliability (RELINTER) of two structurally identical units of the metabolic analyser K5 (COSMED, Rome, Italy) that allows to utilize either breath-by-breath (BBB) or dynamic mixing chamber (DMC) technology. Methods Identical flow- and gas-signals were transmitted to both K5s that always...
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Background At high altitude the brain is exposed to hypoxic stress, which may result in neurological conditions with acute mountain sickness (AMS) being the most common one. We hypothesized that rapid ascent to high altitude alters neuro‐axonal integrity that can be detected by increased concentration of serum neurofilament light (sNfL) in the bloo...
Article
Wind braked rowing ergometers are used worldwide for training and testing of rowers, but data on validity and reliability of the calculated mechanical power output are scarce. Studies published so far are based on data generated by human rowers, inevitably adding biological variability without any option to clamp particular variables like stroke st...
Chapter
Rowing is an Olympic sport with very old long tradition. Besides competitions, it is an ideal life-time strength endurance type of sport, which can be practiced into an advanced age. In training competitive rowers, metabolic strain is extremely high, making recovery and nutrition a major issue, but even in high performance rowing the amount and rat...
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The liver-derived hormone hepcidin plays a key role in iron metabolism by mediating the degradation of the iron export protein ferroportin 1 (FPN1). Circulating levels of hepcidin and the iron storage protein ferritin are elevated during the recovery period after acute endurance exercise, which can be interpreted as an acute phase reaction to inten...
Article
Purpose: Automated metabolic analyzers are frequently utilized to measure maximal oxygen consumption (V˙O2max). However, in portable devices, the results may be influenced by the analyzer's technological approach, being either breath-by-breath (BBB) or dynamic micro mixing chamber mode (DMC). The portable metabolic analyzer K5 (COSMED, Rome, Italy...
Article
Introduction: Acute mountain sickness (AMS) may develop in non-acclimatized individuals after exposure to altitudes ≥2500m. Anecdotal reports suggest that endurance trained (ET) athletes with a high maximal oxygen uptake (VO2max) may be at increased risk for AMS. Possible underlying mechanisms include a training-induced increase in resting parasym...
Article
Purpose: The portable metabolic analyzer COSMED K5 (Rome, Italy) allows to switch between breath-by-breath (BBB) and dynamic mixing chamber (DMC) mode. This study aimed to evaluate the reliability and validity of the K5 in BBB and DMC at low, moderate, and high metabolic rates. Methods: Two K5 simultaneously operated in BBB or DMC, while (i) a m...
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The training intensity distribution (TID) of endurance athletes has retrieved substantial scientific interest since it reflects a vital component of training prescription: (i) the intensity of exercise and its distribution over time are essential components for adaptation to endurance training and (ii) the training volume (at least for most enduran...
Article
The purpose of this study was to investigate echocardiographic changes in left ventricular (LV) diastolic filling and left atrial (LA) strain mechanics following prolonged exercise. Ten male triathletes completed a 60-min swim, 180-min bike exercise, and a 60-min all-out run in a laboratory environment. Special attention was paid to prevent dehydra...
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Abstract The left (LA) and right (RA) atria undergo adaptive remodeling in response to hemodynamic stress not only induced by endurance exercise but also as part of several cardiovascular diseases thereby confounding differential diagnosis. Echocardiographic assessment of the atria with novel speckle tracking (STE)-derived variables broadens the di...
Article
Introduction: Successful rowers are heavier and taller than their opponents, but the effect of these variables on long-term career attainment in juniors has not been examined. We therefore analysed this in a large sample of elite German junior rowers. Methods: Former German Junior National Team rowers (N = 910; 399 females) were grouped accordin...
Article
There is a growing interest in exploring irisin response to acute exercise; however, the associations of acute exercise-induced irisin release with training status and exercise mode are not fully understood. This study was primarily designed to evaluate these associations. Sixteen healthy adults (8 trained versus 8 untrained) underwent a bout of cy...
Article
Purpose: Ramp tests are continuously increasing exercise tests used for determination of maximal oxygen uptake (⩒O2max), which is identifiable by a plateau in ⩒O2despite increasing mechanical power output (LOAD). On wind-braked rowing ergometers (RowErg) it is hardly feasible to ensure a continuous increase in LOAD until test termination, because...
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Background Blood oxygen saturation (SpO2) is frequently measured to determine acclimatization status in high-altitude travellers. However, little is known about nocturnal time course of SpO2 (SpO2N), but alterations in SpO2N might be practically relevant as well. To this end, we describe the time-course of SpO2N in mountaineers at high altitude....
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The aim of this pilot study was to analyze the off-training physical activity (PA) profile in national elite German U23 rowers during 31 days of their preparation period. The hours spent in each PA category (i.e., sedentary: <1.5 metabolic equivalents (MET); light physical activity: 1.5–3 MET; moderate physical activity: 3–6 MET and vigorous intens...
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Polarized (POL) training intensity distribution (TID) emphasizes high-volume low-intensity exercise in zone (Z)1 (< first lactate threshold) with a greater proportion of high-intensity Z3 (> second lactate threshold) compared to Z2 (between first and second lactate threshold). In highly trained rowers there is a lack of prospective controlled evide...
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Introduction: There is a large variety of body fat (BF) measurements, which differ in validity and reliability. The aim of this study was to measure subcutaneous adipose tissue (SAT) using ultrasound (US) in highly trained junior rowers in a field setting, establish fat patterning profiles, and compare the profiles between male and female athletes...
Article
This study examined sleep-wake habits and subjective jet-lag ratings of 55 German junior rowers (n = 30 male, 17.8 ± 0.5 years) before and during the World Rowing Junior Championships 2015 in Rio de Janeiro, Brazil. Athletes answered sleep logs every morning, and Liverpool John Moore's University Jet-Lag Questionnaires each evening and morning. Fol...
Article
The ingestion of exogenous carbohydrates (CHO) during prolonged endurance exercise, such as long-distance triathlon, is considered beneficial with regards to performance. However, only little is known whether this performance benefit differs among different forms of CHO administration. To this end, the purpose of our study was to determine the impa...
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Purpose The aim of this study was to investigate the incidence of hyponatremia during 28 days of high volume rowing training. Methods 30 members of the German junior rowing team (21 males, 9 females) were studied during a training camp of four weeks duration. Serum sodium ([Na + ]) and osmolality were assessed at baseline before entering the traini...
Article
To investigate the incidence of hyponatremia and its relationship to plasma copeptin, a surrogate marker for arginine vasopressin (AVP) during 28 days of high volume rowing training. Thirty rowers of the German junior national team (21 male) were studied during a training camp. Serum sodium ([Na(+)]), osmolality, and copeptin were measured before t...
Article
Assessing athletes’ hydration is relevant in regard to health and performance. The review focuses on valid markers of hydration status that are inexpensive and feasible in field test settings. Urine specific gravity is a valid marker of hydration status in most cases, easily and exactly measured with a refractometer. Changes of body mass accurately...
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Gastrointestinal (GI) blood loss is a possible reason for anemia in athletes. To quantify the impact on endurance performance, we present data of a world-class rower who developed anemia due to GI blood loss but maintained his training volume. Eight months after recording four normal hematological values over 6 months, an anemic state was detected....
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To elucidate cell free DNA (cfDNA) clearance kinetics following an acute bout of high intensity exercise by measuring circulating DNase activity reduction (AR). Serum cfDNA concentration and DNase-AR were measured prior to and post (immediately post, 7 and 30 minutes post) an acute bout of rowing exercise until exhaustion. Serum cfDNA concentration...
Article
Elite rowers are highly endurance trained and present with a large lean body mass (LBM), which is closely related to total haemoglobin mass (tHbmass), a major determinant of blood O2-transport. This study aims to determine the magnitude of tHbmass in elite rowers and its relation to performance parameters that are common in rowing worldwide. 13 row...
Article
Zur in vivo-Validierung von Spiroergometrie-Geräten (SPERG) wird das SPERG üblicherweise mit der Douglas-Bag-Methode verglichen. Das zur Trennung von Inspirations- und Exspirationsluft vor dem Douglas-Bag notwendige Y-Ventil gibt es in Ausführungen mit Trennwand (YT) oder ohne (YO). Diese Y-Ventile erlauben neben der Originalposition (ORIG) auch di...
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The reliability of field tests is mainly dependent on high methodological standards. Quality of laboratory methods (lactate and gas exchange measurement) is of critical importance. During multi-stage tests, step duration and step increments should be standardized and uniform. Evaluation procedures (lactate or ventilatory threshold determination) an...
Article
Resistance training induces differenciated adaptions. Depending on the applied method, neural or anabolic adaptions may dominate. Neural adaptions already reveal in the early stage of a training program, since force improvements can be seen even without muscle hypertrophy. During this phase, upcoming adaptions on myofibrilliar protein level are ini...

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