Silvia Achtzehn

• Dr. rer. nat.
• Deutsche Sporthochschule Köln

Current research in brain stimulation suggests transcutaneous auricular vagus nerve stimulation (taVNS) as a promising tool to modulate cognitive functions in healthy populations, such as attention, memory, and executive functions. Empirical evidence in single task contexts, suggests that taVNS promotes holistic task processing, which strengthens t...

Performing two tasks at the same time (dual-tasking) leads to performance decrements. This performance decline has been attributed to between task interference due to simultaneously occurring stimulus response translation processes. In the context of parallel processing, prioritizing of Task 1 has been found to reduce dual-task interference. This i...

Background and Objectives: Angiogenesis describes the outgrowth of new capillaries from already existing ones. Different biomarkers regulate this process. Physical exercise and hypoxia are key stimuli for the activation of different angiogenic molecules, such as the vascular endothelial growth factor (VEGF). matrix metalloproteases (MMPs)-2 and -9...

Background and Objectives: During intense training periods, there is a high need to monitor the external and especially the internal training load in order to fine-tune the training process and to avoid overreaching or overtraining. However, data on stress reactions, especially of biomarkers, to high training loads in children and youth are rare. T...

The aim of this study was to investigate inter-day and -week as well as intra- and inter-individual variation of selected biomarkers in high-performance youth soccer players to assist practitioners interpreting player’s internal load to counteract underperformance and unwanted health risks. Eleven male youth soccer players were tested multiple time...

Biomarkers of cartilage metabolism are sensitive to changes in the biological and mechanical environment and can indicate early changes in cartilage homeostasis. The purpose of this study was to determine if a daily locomotion replacement program can serve as a countermeasure for changes in cartilage biomarker serum concentration caused by immobili...

BACKGROUND: The aim of this study was to identify the acute hormonal responses of salivary testosterone (T) and cortisol (C) concentrations during and after two different resistance exercises involving the lower and the upper body, respectively. METHODS: For this reason, 13 healthy recreationally trained male athletes performed an identical streng...

PURPOSE: This study examined the acute effects of a single session of Whole-body Cryotherapy (WBC) following severe intermittent running exercise on biomarkers of inflammation, muscle damage and stress. METHODS: Endurance-trained males (n = 11) were tested twice using a within-participant, balanced cross-over design that consisted of 5 × 5 min of...

Athletes schedule their training and recovery in periods, often utilizing a pre-defined strategy. To avoid underperformance and/or compromised health, the external load during training should take into account the individual’s physiological and perceptual responses. No single variable provides an adequate basis for planning, but continuous monitori...

For many years, POCT devices have been employed alongside central laboratory methods to analyze biomarkers in high-performance and elite sports. However, there has been a paucity of publications to date on studies in high-performance and elite athletes where POCT is explicitly mentioned as measuring methodology. For this reason, the present chapter...

The objective of the study was to test the hypothesis that serum levels of cartilage oligomeric matrix protein (COMP) would decrease and serum levels of tumor-necrosis factor alpha (TNF-α) and selected matrix metalloproteinases (MMPs) would increase in response to bed rest (BR) and that these changes are unaffected by the intake of potassium bicarb...

Zusammenfassung In der Sportmedizin und -wissenschaft sowie im Hochleistungssport werden Untersuchungen sowohl unter standardisierten Bedingungen im Labor als auch im Feld durchgeführt. Es kommen dabei die unterschiedlichsten medizinischen Messmethoden zum Einsatz. Fast immer werden sie von Blutanalysen begleitet, wobei sowohl hochkomplexe Laborver...

Im Leistungs- und Spitzensport werden seit vielen Jahren zur Optimierung von Training sowie zur Beurteilung von Belastungs- und Erholungsprozessen, und damit zur Vermeidung von Überlastungsreaktionen von Athleten, neben komplexen Laborverfahren auch Messgeräte zur Analyse von Biomarkern eingesetzt, die zu den POCT-Mess systemen gezählt werden [56]....

PurposeThe aim of the present study was to compare the effects of high-intensity interval training (HIIT) vs high-volume training (HVT) on salivary stress markers [cortisol (sC), testosterone (sT), alpha-amylase (sAA)], metabolic and cardiorespiratory response in young athletes. Methods Twelve young male cyclists (14 ± 1 years; 57.9 ± 9.4 mL min−1...

There is a debate on the optimal way of monitoring training loads in elite endurance athletes especially during altitude training camps. In this case report, including nine members of the German national middle distance running team, we describe a practical approach to monitor the psychobiological stress markers during 21 days of altitude training...

To examine the effects of aqua-cycling (AC) vs. passive-recovery (P) on performance, markers of muscle damage, delayed onset of muscle soreness (DOMS), and the persons perceived physical state (PEPS) after 300 counter movement jumps (CMJ).20 male participants completed 300 CMJ. Afterwards, they were randomly assigned to either the P-group or the AC...

Objectives: The aim was to determine metabolic and hormonal responses to strength training with or without superimposed electromyostimulation (EMS) at the beginning and the end of a 6 week training period. Methods: 20 strength trained subjects were randomly assigned to two groups. The first group (S) performed 4 sets of back squats with a consta...

Objectives: The purpose of the present study was to evaluate the effects of superimposed electromyostimulation (E) during cycling on myokines and markers of muscle damage, as E might be a useful tool to induce a high local stimulus to skeletal muscle during endurance training without performing high external workloads. Methods: 13 subjects parti...

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PURPOSE: The purpose of the present study was to evaluate the effects of superimposed electromyostimulation (E) during cycling on the acute hormonal and metabolic response, as E might be a useful tool to intensify endurance training without performing high external workloads. METHODS: Thirteen subjects participated in three experimental trials each...

Endothelial microparticles (EMP) are complex vesicular structures shed from activated or apoptotic endothelial cells. As endurance exercise affects the endothelium, the objective of the study was to examine levels of EMP and angiogenic growth factors following different endurance exercise protocols. 12 subjects performed 3 different endurance exerc...

The aim of the present study was to compare the effects of active (A) vs. passive (P) recovery during high-intensity interval training on the acute hormonal and metabolic response. Twelve triathletes/cyclists performed four 4 min intervals on a cycle ergometer, either with A- or P-recovery between each bout. Testosterone, hGH, cortisol, VEGF, HGF a...

This study explored the role of trait emotional intelligence (EI) in emotion regulation and performance under pressure. Twenty-eight tennis players performed two series of 35 serves, separated by a pressure manipulation. Reaction to pressure was assessed using both subjective (self-report emotion question-naire) and objective (cortisol secretion, t...

The aim was to compare the acute hormonal response to a single HIT session at the beginning and end of a HIT shock microcycle. 13 male junior triathletes (15.8±1.8 yrs.) performed 16 HIT sessions within a 2 week period. Venous blood samples were collected before and after the first and last HIT session. Significant increases in cortisol (first sess...

The exercise-induced metabolic stress can be influenced by the mode of recovery and is associated with acute hormonal responses. Therefore, it is hypothesized that active recovery between high intensity intervals reduces the metabolic stimulus and therefore the hormonal response compared to passive recovery. 12 male cyclist/triathletes performed fo...

Previous intervention studies suggest that leptin, insulin, insulin-like growth factor 1 (IGF-1), and triiodthyronine (T3) are sensitive markers of inadequate energy intake in relation to exercise expenditures. Because of limitations in metabolic hormone measurements, self-reported energy availability (EA) based on food and activity records may pre...

In the last years, mainly 2 high-intensity-training (HIT) protocols became common: First, a Wingate-based "all-out" protocol and second, a 4×4 min protocol. However, no direct comparison between these protocols exists, and also a comparison with high-volume-training (HVT) is missing. Therefore, the aim of the present study was to compare these 3 en...

Book of Abstracts, p127.

The purpose of the present study was to compare the acute hormonal response of angiogenic regulators to a short-term hypoxic exposure at different altitudes with and without exercise. 7 subjects participated in 5 experimental trials. 2 times subjects stayed in a sedentary position for 90 min at 2 000 m or 4 000 m, respectively. The same was carried...

We test the hypothesis that breathing oxygen-enriched air (F(I)O(2) = 100%) maintains exercise performance and reduces fatigue during intervals of maximal-intensity cycling. Ten well-trained male cyclists (age 25 ± 3 years; peak oxygen uptake 64.8 ± 6.2 ml · kg(-1) · min(-1); mean ± s) were exposed to either hyperoxic or normoxic air during the 6-m...

This study aimed to quantify the intensity profile of elite downhill mountain bike races during competitions. Seventeen male downhill racers (22 ± 5 y; 185.1 ± 5.3 cm; 68.0 ± 3.9 kg; VO2peak: 59.4 ± 4.1 mL·min·kg-1) participated in the International German Downhill Championships in 2010. The racers' peak oxygen uptake and heart rate (HR) at 2 and 4...

The goal of the study was to evaluate and to quantify the effects of local electromyostimulation (EMS) during cycling on the cardiorespiratory system, muscle metabolism, and perceived exertion compared with cycling with no EMS. Ten healthy men (age: 24.6 ± 3.2 years, V[Combining Dot Above]O2max: 54.1 ± 6.0 ml·min·kg) performed 3 incremental cycle e...

Lactate (La) and H(+)-ions are unequally distributed in the blood between plasma and red blood cells (RBCs). To our knowledge there is no data concerning the effects of an oral ingestion of bicarbonate (HCO(3) (-)) on repeated high intensity sprint exercise and La and H(+) distribution between plasma and RBCs. Since an oral ingestion of HCO(3) (-)...

Iron depletion seems to occur more frequently among athletes than in the general population and may affect performance capacity. Only little information is available about the prevalence of iron status abnormalities in young elite athletes and whether iron depletion is associated with gender, sport, age or nutrition- and exercise-related factors in...

To examine the correlation of peak oxygen uptake (VO2 peak), velocity at lactate threshold (V(LT)), and running economy (RE) in a group of Special Force Squad members. VO2 peak, V(LT), and RE of 120 male elite special force police squad members (VO2 peak, 57.4 +/- 4.3 mL minute(-1) kg(-1); age, 28.9 +/- 5.2 years; body mass index, 24.2 +/- 1.6 kg m...

Studies in humans use blood lactate to determine the degree of the exercise intensity, suggesting that exercise with elevated blood lactate concentrations results in increased BDNF plasma concentrations. However, it is not clear if lactate per se or rather other mechanisms are responsible for changes in blood BDNF concentrations. The lactate clamp...

The purpose of the present study was to compare the acute hormonal response to a short-term high-intensity training (HIT) versus a high-volume endurance training (HVT) and to investigate the effects of acid-base status on cytokines involved in angiogenesis (VEGF and bFGF). Eleven subjects participated in three experimental trials. Two times subject...

The purpose of the present study was to examine the acute hormonal response of a short term high-intensity training (HIT) versus a high volume endurance training (HVT) and to determine the contribution of the metabolic acidosis as a stimulus for possibly different reactions of circulating hGH, IGF-1, IGFBP-3 and cortisol. Eleven subjects participat...

Previous studies have indicated that aerobic pathways contribute to 13-27% of the energy consumed during short-term (10-20 s) sprinting exercise. Accordingly, the present investigation was designed to test the hypothesis that prior breathing of oxygen-enriched air (F(in)O(2) = 60%) would enhance power output and reduce fatigue during subsequent spr...

Training volume in swimming is usually very high compared to the relatively short competition time. Recent studies assessing high intensity training show similar physiological effects compared to high volume training. Studies comparing these effects in children are yet to be investigated. The aim of the study was to compare the effects of high inte...

Three textiles with increasing compressive surface were compared with non-compressive conventional clothing on physiological and perceptual variables during sub-maximal and maximal running. Fifteen well-trained endurance athletes (mean+/-s: age 27.1+/-4.8 years, VO(2max) 63.7+/-4.9 ml x min(-1) x kg(-1)) performed four sub-maximal (approximately 70...

Exercise induced proteinuria is a common phenomenon in high performance sports. Based on the appearance of so called "effort urines" in routine doping analysis the purpose of this study was to investigate the influence of exercise induced proteinuria on IEF profiles and SDS-PAGE relative mobility values (rMVs) of endogenous human erythropoietin (EP...

The goals of the study were: Establishment of reference values of reticulocytes [% RET] in young athletes (age 16.7 ± 3.5 yrs) and the comparison of data from three different laboratory machines Sysmex R500, Sysmex XT-2000i (both Sysmex, Norderstedt) and ADVIA 120 (Bayer HealthCare, Fernwald). Further goals were to analyze the device dependent infl...

The goals of the study were: Establishment of reference values of reticulocytes [% RET] in young athletes; (age 16.7±3.5 yrs) and the comparison of data from three different laboratory machines Sysmex R500, Sysmex XT-2000i; (both Sysmex, Norderstedt) and ADVIA 120; (Bayer HealthCare, Fernwald). Further goals were to analyze the device dependent inf...

This study aimed to investigate the biological response to hypoxia as a stimulus, as well as exercise- and vibration-induced shear stress, which is known to induce angiogenesis. Twelve male cyclists (27.8 +/- 5.4 yr) participated in this study. Each subject completed four cycle training sessions under normal conditions (NC) without vibration, NC wi...