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Human metabolism is highly variable. At one end of the spectrum, defects of enzymes, transporters, and metabolic regulation result in metabolic diseases such as diabetes mellitus or inborn errors of metabolism. At the other end of the spectrum, favorable genetics and years of training combine to result in physiologically extreme forms of metabolism in athletes. Here, we investigated how the highly glycolytic metabolism of sprinters, highly oxidative metabolism of endurance athletes, and highly anabolic metabolism of natural bodybuilders affect their serum metabolome at rest and after a bout of exercise to exhaustion. We used targeted mass spectrometry-based metabolomics to measure the serum concentrations of 151 metabolites and 43 metabolite ratios or sums in 15 competitive male athletes (6 endurance athletes, 5 sprinters, and 4 natural bodybuilders) and 4 untrained control subjects at fasted rest and 5 minutes after a maximum graded bicycle test to exhaustion. The analysis of all 194 metabolite concentrations, ratios and sums revealed that natural bodybuilders and endurance athletes had overall different metabolite profiles, whereas sprinters and untrained controls were more similar. Specifically, natural bodybuilders had 1.5 to 1.8-fold higher concentrations of specific phosphatidylcholines and lower levels of branched chain amino acids than all other subjects. Endurance athletes had 1.4-fold higher levels of a metabolite ratio showing the activity of carnitine-palmitoyl-transferase I and 1.4-fold lower levels of various alkyl-acyl-phosphatidylcholines. When we compared the effect of exercise between groups, endurance athletes showed 1.3-fold higher increases of hexose and of tetradecenoylcarnitine (C14:1). In summary, physiologically extreme metabolic capacities of endurance athletes and natural bodybuilders are associated with unique blood metabolite concentrations, ratios, and sums at rest and after exercise. Our results suggest that long-term specific training

Das Ziel dieser Studie war es, die Auswirkungen eines Ultramarathons auf die mediale Meniskusextrusion (MME) in gesunden Athleten zu untersuchen. Generell wird eine MME von mehr als 3 mm als pathologisch angesehen und ist ein indirektes Zeichen für einen Funktionsverlust des Meniskus. Untersucht wurde die MME mittels Ultraschall im Stehen und Liegen während eines siebentägigen Etappenlaufes in den Alpen. Dabei zeigte sich eine reversible MME von mehr als 3 mm in gesunden, symptomfreien Knien. Dies zeigt, dass der Meniskus eine enorme elastische Kapazität hat und sich kurzfristig an höhere Belastungen anpassen kann. Daher sollte der aktuelle Begriff der Meniskusextrusion nicht ausschließlich als Zeichen einer Pathologie im MRT bewertet werden., The aim oft the present study was to evaluate the influence of mountain ultramarathon running on the medial meniscus extrusion (MME) in healthy athletes. MME of more than 3 mm is seen as pathological and as an indirect sign for loss of function oft the meniscus. MME was determined in supine and standing position via ultrasound imaging during a seven day stage run in the alps. The meniscus showed a reversible MME of more than 3 mm in healthy knees. This suggests that the meniscus has viscoelastic capacities showing shortterm adaptions to high loads. Therefore the term of MME should not only be considered as a pathological sign in MRI imaging.

Background Advanced footwear technology improves average running economy compared with racing flats in sub-elite athletes. However, not all athletes benefit as performance changes vary from a 10% drawback to a 14% improvement. The main beneficiaries from such technologies, world-class athletes, have only been analyzed using race times. Objective The aim of this study was to measure running economy on a laboratory treadmill in advanced footwear technology compared to a traditional racing flat in world-class Kenyan (mean half-marathon time: 59:30 min:s) versus European amateur runners. Methods Seven world-class Kenyan and seven amateur European male runners completed a maximal oxygen uptake assessment and submaximal steady-state running economy trials in three different models of advanced footwear technology and a racing flat. To confirm our results and better understand the overall effect of new technology in running shoes, we conducted a systematic search and meta-analysis. Results Laboratory results revealed large variability in both world-class Kenyan road runners, which ranged from a 11.3% drawback to a 11.4% benefit, and amateur Europeans, which ranged from a 9.7% benefit to a 1.1% drawback in running economy of advanced footwear technology compared to a flat. The post-hoc meta-analysis revealed an overall significant medium benefit of advanced footwear technology on running economy compared with traditional flats. Conclusions Variability of advanced footwear technology performance appears in both world-class and amateur runners, suggesting further testing should examine such variability to ensure validity of results and explain the cause as a more personalized approach to shoe selection might be necessary for optimal benefit.

Background: Patients with critical illness can lose more than 15% of muscle mass in one week, and this can have long-term detrimental effects. However, there is currently no synthesis of the data of intensive care unit (ICU) muscle wasting studies, so the true mean rate of muscle loss across all studies is unknown. The aim of this project was therefore to systematically synthetise data on the rate of muscle loss and to identify the methods used to measure muscle size and to synthetise data on the prevalence of ICU-acquired weakness in critically ill patients. Methods: We conducted a systematic literature search of MEDLINE, PubMed, AMED, BNI, CINAHL, and EMCARE until January 2022 (International Prospective Register of Systematic Reviews [PROSPERO] registration: CRD420222989540. We included studies with at least 20 adult critically ill patients where the investigators measured a muscle mass-related variable at two time points during the ICU stay. We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and assessed the study quality using the Newcastle-Ottawa Scale. Results: Fifty-two studies that included 3251 patients fulfilled the selection criteria. These studies investigated the rate of muscle wasting in 1773 (55%) patients and assessed ICU-acquired muscle weakness in 1478 (45%) patients. The methods used to assess muscle mass were ultrasound in 85% (n = 28/33) of the studies and computed tomography in the rest 15% (n = 5/33). During the first week of critical illness, patients lost every day -1.75% (95% CI -2.05, -1.45) of their rectus femoris thickness or -2.10% (95% CI -3.17, -1.02) of rectus femoris cross-sectional area. The overall prevalence of ICU-acquired weakness was 48% (95% CI 39%, 56%). Conclusion: On average, critically ill patients lose nearly 2% of skeletal muscle per day during the first week of ICU admission.

91 Skirennläufer (9-14a) wurden prospektiv beobachtet, um die Inzidenz von Verletzungen und Erkrankungen zu registrieren. Die traumatischen Verletzungen zeigten eine Inzidenz von 1,1/1000 Trainingsstunden, die Überlastungsverletzungen 0,3/1000 Trainingsstunden. Trainingsvolumen und Intensität stellten keinen signifikanten Risikofaktor für Verletzungen dar. Die Trainingsintensität stellte einen Risikofaktor für gehäufte Erkrankungen in der gleichen Woche dar, das Trainingsvolumen zeigte sich als Risikofaktor für Erkrankungen in der Folgewoche., 91 elite youth ski racers (9-14a) were prospectively recorded to monitor injuries and illnesses. Injuries represented an incidence of 1.1/1000 hours of training, overuse injuries 0.3/1000 hours of training. Weekly training volume and training intensity did not represent a significant risk factor for traumatic and overuse injuries. Training intensity was a significant risk factor for illnesses in the same week, whereas training volume represents a risk factor for illnesses in the following week.

Exercise improves the insulin sensitivity of glucose uptake in skeletal muscle. Due to that, exercise has become a cornerstone treatment for type 2 diabetes mellitus (T2DM). The mechanisms by which exercise improves skeletal muscle insulin sensitivity are, however, incompletely understood. We conducted a systematic review to identify all genes whose gain or loss of function alters skeletal muscle glucose uptake. We subsequently cross-referenced these genes with recently generated data sets on exercise-induced gene expression and signaling. Our search revealed 176 muscle glucose-uptake genes, meaning that their genetic manipulation altered glucose uptake in skeletal muscle. Notably, exercise regulates the expression or phosphorylation of more than 50% of the glucose-uptake genes or their protein products. This included many genes that previously have not been associated with exercise-induced insulin sensitivity. Interestingly, endurance and resistance exercise triggered some common but mostly unique changes in expression and phosphorylation of glucose-uptake genes or their protein products. Collectively, our work provides a resource of potentially new molecular effectors that play a role in the incompletely understood regulation of muscle insulin sensitivity by exercise.

Das Ziel dieser Studie war es, die Auswirkungen eines Ultramarathons auf die mediale Meniskusextrusion (MME) in gesunden Athleten zu untersuchen. Generell wird eine MME von mehr als 3 mm als pathologisch angesehen und ist ein indirektes Zeichen für einen Funktionsverlust des Meniskus. Untersucht wurde die MME mittels Ultraschall im Stehen und Liegen während eines siebentägigen Etappenlaufes in den Alpen. Dabei zeigte sich eine reversible MME von mehr als 3 mm in gesunden, symptomfreien Knien. Dies zeigt, dass der Meniskus eine enorme elastische Kapazität hat und sich kurzfristig an höhere Belastungen anpassen kann. Daher sollte der aktuelle Begriff der Meniskusextrusion nicht ausschließlich als Zeichen einer Pathologie im MRT bewertet werden., The aim oft the present study was to evaluate the influence of mountain ultramarathon running on the medial meniscus extrusion (MME) in healthy athletes. MME of more than 3 mm is seen as pathological and as an indirect sign for loss of function oft the meniscus. MME was determined in supine and standing position via ultrasound imaging during a seven day stage run in the alps. The meniscus showed a reversible MME of more than 3 mm in healthy knees. This suggests that the meniscus has viscoelastic capacities showing shortterm adaptions to high loads. Therefore the term of MME should not only be considered as a pathological sign in MRI imaging.

Diese Dissertation zeigt die Entwicklung und Validierung tragbarer Systeme zur nicht-invasiven Ermittlung wichtiger Vitalparameter für Sport und Gesundheit, um Sportler vor gesundheitsschädlichen Situationen zu schützen. Die Körperkerntemperatur und der Wasserhaushalt spielen in warmen Bedingungen eine übergeordnete, hitzebestimmte und leistungsbestimmende Rolle. In der Arbeit werden Zusammenhänge zwischen invasiven und nicht-invasiven Messungen dieser Parameter untersucht, anschließend ein Prototyp aufgebaut und validiert. Zusätzlich werden Faktoren der Mensch-Maschine-Umwelt Interaktion betrachtet und Ansätze für die Anwendbarkeit von Wearables in Sport und Gesundheit geliefert., This dissertation shows the development and validation of wearable systems for non-invasive assessment of important vital parameters in sports and health care to protect the athlete from harmful events. Body core temperature and hydration are heat relevant and performance determinating parameters, which play a superior role in hot environements. This work analyzes relationships between invasive and non-invasive measurments of these variables. Based on the results a prototype was designed, build up and validated. Additionally, important factors of human-machine-environment-interaction are considered and provide attempts for applications of wearables in sports and health care.

In 1924, Otto Warburg asked “How does the metabolism of a growing tissue differ from that of a non-growing tissue?” Currently, we know that proliferating healthy and cancer cells reprogramme their metabolism. This typically includes increased glucose uptake, glycolytic flux and lactate synthesis. A key function of this reprogramming is to channel glycolytic intermediates and other metabolites into anabolic reactions such as nucleotide-RNA/DNA synthesis, amino acid-protein synthesis and the synthesis of, for example, acetyl and methyl groups for epigenetic modification. In this review, we discuss evidence that a hypertrophying muscle similarly takes up more glucose and reprogrammes its metabolism to channel energy metabolites into anabolic pathways. We specifically discuss the functions of the cancer-associated enzymes phosphoglycerate dehydrogenase and pyruvate kinase muscle 2 in skeletal muscle. In addition, we ask whether increased glucose uptake by a hypertrophying muscle explains why muscularity is often negatively associated with type 2 diabetes mellitus and obesity.

Resistance training promotes metabolic health and stimulates muscle hypertrophy, but the precise routes by which resistance exercise (RE) conveys these health benefits are largely unknown. Aim: To investigate how acute RE affects human skeletal muscle metabolism. Methods: We collected vastus lateralis biopsies from six healthy male untrained volunteers at rest, before the first of 13 RE training sessions, and 45 min after the first and last bouts of RE. Biopsies were analysed using untargeted mass spectrometry-based metabolomics. Results: We measured 617 metabolites covering a broad range of metabolic pathways. In the untrained state RE altered 33 metabolites, including increased 3-methylhistidine and N-lactoylvaline, suggesting increased protein breakdown, as well as metabolites linked to ATP (xanthosine) and NAD (N1-methyl-2-pyridone-5-carboxamide) metabolism; the bile acid chenodeoxycholate also increased in response to RE in muscle opposing previous findings in blood. Resistance training led to muscle hypertrophy, with slow type I and fast/intermediate type II muscle fibre diameter increasing by 10.7% and 10.4%, respectively. Comparison of post-exercise metabolite levels between trained and untrained state revealed alterations of 46 metabolites, including decreased N-acetylated ketogenic amino acids and increased beta-citrylglutamate which might support growth. Only five of the metabolites that changed after acute exercise in the untrained state were altered after chronic training, indicating that training induces multiple metabolic changes not directly related to the acute exercise response. Conclusion: The human skeletal muscle metabolome is sensitive towards acute RE in the trained and untrained states and reflects a broad range of adaptive processes in response to repeated stimulation.

Low- and moderate-intensity exercise is safe and feasible during childhood cancer treatment. The feasibility of a bout of high-intensity interval training (HIIT) in this population has not been analyzed to date. Pediatric cancer patients aged between 6 and 18 years were selected based on clinical conditions to perform ten sets of 15 s HIIT (>90% of estimated maximal heart rate (HRmax)) and 1 min active recovery on a bicycle ergometer within the first three chemotherapy courses. We assessed safety and feasibility criteria and the following parameters: perceived exertion rate, heart rate, and lactate and adrenaline concentrations. Out of 212 eligible patients, 11 patients aged 13.9 ± 3.6 years (n = 7 ♂) with lymphoma, leukemia, rhabdomyosarcoma, nephroblastoma, and synovial sarcoma completed the bout of HIIT without serious adverse events. During exercise, patients reached a BORG value maxima of 16 ± 1.2, and their heart rates rose from 78 ± 17 beats per minute (bpm) at rest to 178 ± 12 bpm after exercise (90 ± 6% estimated HRmax). The power-to-weight ratio was 2 ± 0.5 W/kg (watt per kilogram). Blood lactate concentrations increased from 1.09 ± 0.50 mmol/L (millimole per liter) at rest to 5.05 ± 1.88 mmol/L post-exercise. Our preliminary data suggest that HIIT is applicable only in a small number of childhood cancer patients. Individually adapted exercise protocols for patients with multiple impairments are needed.

Background: Face masks are an effective, non-pharmacological strategy to reduce the transmission of Severe Acute Respiratory Syndrome Coronavirus-2 and other pathogens. However, it is a challenge to keep masks sealed during exercise, as ventilation can increase from 5 to 10 L/min at rest to up to 200 L/min so that masks may be blown away from the face. To reduce leakage e.g. during exercise, a face mask was developed that is taped onto the face. The aim of this study was to investigate during a graded exercise test the effect of a taped filter mask on the perception of breathlessness, heart rate, blood lactate concentration, and oxygen saturation when compared to a surgical mask and no mask. Methods: Eight healthy trained participants (4 females), aged 24.5 ± 3.3 years performed graded exercise test until volitional exhaustion under three conditions: (1) No mask/control, (2) surgical mask or (3) taped filter mask. During these tests, we measured perception of breathlessness, heart rate, blood lactate concentration and peripheral oxygen saturation and analysed the resultant data with one or two-way repeated measures ANOVAs. We also used a questionnaire to evaluate mask comfort and analysed the data with paired t-tests. Results: When compared to wearing no mask, maximal workload was significantly reduced with a taped filter face mask by 12 ± 6% (p < 0.001) and with a surgical mask by 3 ± 6% (p > 0.05). Moreover, subjects perceive the sensation of "severe breathlessness" at a 12 ± 9% lower workload (p = 0.012) with a taped face mask, and 7 ± 13% lower workload with a surgical mask (p > 0.05) when compared to wearing no mask. Oxygen saturation at 65% of the maximal workload is 1.5% lower (p = 0.018) with a taped mask than no mask. Heart rate and blood lactate concentration are not significantly different in-between no mask, surgical mask and taped mask at any workload. When compared to wearing a surgical mask, wearing a taped filter face mask has a significantly better

The Hippo signal transduction network regulates transcription through Yap/Taz-Tead1-4 in many tissues including skeletal muscle. Whilst transgenic mice have been generated for many Hippo genes, the resultant skeletal muscle phenotypes were not always characterized. Here, we aimed to phenotype the hindlimb muscles of Hippo gene-mutated Lats1−/−, Mst2−/−, Vgll3−/−, and Vgll4+/− mice. This analysis revealed that Lats1−/− mice have 11% more slow type I fibers than age and sex-matched wild-type controls. Moreover, the mRNA expression of slow Myh7 increased by 50%, and the concentration of type I myosin heavy chain is 80% higher in Lats1−/− mice than in age and sex-matched wild-type controls. Second, to find out whether exercise-related stimuli affect Lats1, we stimulated C2C12 myotubes with the hypertrophy agent clenbuterol or the energy stress agent AICAR. We found that both stimulated Lats1 expression by 1.2 and 1.3 fold respectively. Third, we re-analyzed published datasets and found that Lats1 mRNA in muscle is 63% higher in muscular dystrophy, increases by 17–77% after cardiotoxin-induced muscle injury, by 41–71% in muscles during overload-induced hypertrophy, and by 19–21% after endurance exercise when compared to respective controls. To conclude, Lats1 contributes to the regulation of muscle fiber type proportions, and its expression is regulated by physiological and pathological situations in skeletal muscle.

Diese Dissertation zeigt die Entwicklung und Validierung tragbarer Systeme zur nicht-invasiven Ermittlung wichtiger Vitalparameter für Sport und Gesundheit, um Sportler vor gesundheitsschädlichen Situationen zu schützen. Die Körperkerntemperatur und der Wasserhaushalt spielen in warmen Bedingungen eine übergeordnete, hitzebestimmte und leistungsbestimmende Rolle. In der Arbeit werden Zusammenhänge zwischen invasiven und nicht-invasiven Messungen dieser Parameter untersucht, anschließend ein Prototyp aufgebaut und validiert. Zusätzlich werden Faktoren der Mensch-Maschine-Umwelt Interaktion betrachtet und Ansätze für die Anwendbarkeit von Wearables in Sport und Gesundheit geliefert., This dissertation shows the development and validation of wearable systems for non-invasive assessment of important vital parameters in sports and health care to protect the athlete from harmful events. Body core temperature and hydration are heat relevant and performance determinating parameters, which play a superior role in hot environements. This work analyzes relationships between invasive and non-invasive measurments of these variables. Based on the results a prototype was designed, build up and validated. Additionally, important factors of human-machine-environment-interaction are considered and provide attempts for applications of wearables in sports and health care.