Sensitivity of serum concentration of cartilage biomarkers to 21-days of bed rest

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 bicarbonate or whey protein. Seven and nine healthy male subjects participated in two 21-day 6° head down tilt crossover BR-studies with nutrition interventions. Serum samples were taken before, during, and after BR and biomarker concentrations were measured using commercial enzyme-linked immunosorbent assays. MMP-3 during BR was significantly lower than at baseline (reduction greater 20%; p < 0.001). MMP-3 increased significantly from 14 to 21 days of BR (+7%; p = 0.049). COMP during BR was significantly lower than at baseline (reduction greater 20%; p < 0.001). MMP-3 and COMP returned to baseline within 1 day after BR. MMP-9 on day 3 of BR was significantly lower than at baseline (-31%; p < 0.033) and on days 3, 5, and 14 of BR significantly lower than at the end of and after BR (reduction greater 35%; p < 0.030). The nutritional countermeasures did not affect these results. The observed changes in cartilage biomarkers may be caused by altered cartilage metabolism in response to the lack of mechanical stimulus during BR and inflammatory biomarkers may play a role in changes in biomarker levels.; Immobilization independently from injury can cause altered cartilage biomarker concentration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res

Nonautomated Pre-Performance Routine in Tennis : An Intervention Study

The effect of a nonautomated pre-performance routine (PPR) on performance in a high-pressure situation was investigated. Twenty-nine tennis players served in a low- and high-pressure condition in a pre- and posttest design. The intervention group learned a nonautomated PPR for 4 weeks. Increases in subjective but not objective (i.e., cortisol) levels of stress were detected in the high-pressure conditions. The intervention group showed a significant decrease in performance in the high-pressure condition in the pretest (p =.005) but not posttest (p =.161). Using a nonautomated PPR may benefit athletes who experience a drop in performance in high-pressure situations. Copyright © Association for Applied Sport Psychology

Intra-Individual and Seasonal Variation of Selected Biomarkers for Internal Load Monitoring in U-19 Soccer Players

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 times during two 3-week periods at midpoint (3-wkmid) and at the end (3-wkend) of the first half of a German under-19 1. Bundesliga season. The levels of creatine kinase (CK), urea, and C-reactive protein (CRP) were measured during 3-wkmid and 3-wkend each Monday, Wednesday, and Friday. In 3-wkmid the CK median was 14% higher (241 vs. 212 U/L) compared to 3-wkend (P = 0.26, ES = 0.16). Overall, the medians of CK, urea (P = 0.59, ES = 0.08), and CRP (P = 0.56, ES = 0.10) during 3-wkmid did not differ to the values of 3-wkend. Daily coefficient of variations (CVs) ranged from 22 to 71% (CK), 17 to 37% (urea), and 9 to 164% (CRP). Individual medians ranged from 101 to 350 U/L (CK), 23 to 50 mg/dL (urea), and 0.6 to 1.1 mg/L (CRP). High intra-individual variability was demonstrated by large intra-individual CVs (medians: CK 50%, urea 18%, and CRP 45%). Our data show (i) large inter-day and inter-week variability of all biomarkers, depending on the external load and (ii) considerable inter- and intra-individual parameter variations. Creatine kinase concentrations could sensitively reflect soccer-specific loads during the season

Locomotion replacement exercise cannot counteract cartilage biomarker response to 5 days of immobilization in healthy adults

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 immobilization. Ten healthy male subjects (mean ± 1 standard deviation, age: 29.4±5.9 years; body mass: 77.7±4.1 kg) participated in the cross-over 5 days bed rest study with three interventions: control (CON), standing (STA) and locomotion replacement training (LRT). Serum samples were taken before, during, and after bed rest. Biomarker concentrations were measured using commercial enzyme-linked immunosorbent assays. Cartilage oligomeric matrix protein (COMP) levels after 24hrs of bed rest decreased independently of the intervention (-16.8 to -9.8%) and continued to decreased until 72hrs of bed rest (minimum, -23.2 to -20.6%). LRT and STA did not affect COMP during bed rests (p=0.056) but there was a strong tendency for a slower decrease with LRT (-9.4%) and STA (-11.7%) compared to CON (-16.8%). MMP-3 levels decreased within the first 24hrs of bed rest (CON: -22.3%; STA: -14.7%; LRT: -17%) without intervention effect. Both COMP and MMP-3 levels recovered to baseline levels during the 6 days recovery period. MMP-1, MMP-9 and TNF-alpha levels were not affected by immobilization or intervention. COMP and MMP-3 are mechanosensitive cartilage biomarkers affected by immobilization, and simple interventions such as standing upright or LRT during bed rest cannot prevent these changes. Clinical significance: Simple locomotion interventions cannot prevent cartilage biomarker change during bed rest

Integrated framework of load monitoring by a combination of smartphone applications, wearables and point-of-care testing provides feedback that allows individual responsive adjustments to activities of daily living

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 monitoring of a combination of several indicators of internal and external load during training, recovery and off-training as well may allow individual responsive adjustments of a training program in an effective manner. From a practical perspective, including that of coaches, monitoring of potential changes in health and performance should ideally be valid, reliable and sensitive, as well as time-efficient, easily applicable, non-fatiguing and as non-invasive as possible. Accordingly, smartphone applications, wearable sensors and point-of-care testing appear to offer a suitable monitoring framework allowing responsive adjustments to exercise prescription. Here, we outline 24-h monitoring of selected parameters by these technologies that (i) allows responsive adjustments of exercise programs, (ii) enhances performance and/or (iii) reduces the risk for overuse, injury and/or illness

The role of trait emotional intelligence in emotion regulation and performance under pressure

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 questionnaire) and objective (cortisol secretion, tennis serve success) measures. The pressure manipulation was successful with observed increases in anxiety and decreases in self-confidence and tennis serve performance. Trait EI was found to predict cortisol secretion over state emotion measures. Performance under pressure was predicted by self-confidence and cortisol secretion, but not by trait EI. These findings provide some preliminary evidence that trait EI and cortisol secretion are important in athlete responses to pressure situations

Acute Exhaustive Exercise under Normoxic and Normobaric Hypoxic Conditions Differentially Regulates Angiogenic Biomarkers in Humans

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 or the extracellular matrix cleavage fragment endostatin. The present study aimed to investigate influences of short-term, intensive cycling exercise under both normoxic and normobaric hypoxic conditions on the mentioned parameters. Materials and Methods: Twelve male subjects (age: 23.3 ± 2.0 years) participated in the study. All subjects conducted four intensive cycling tests until individual exhaustion in a randomized order under the following conditions: normoxia, 2000 m, 3000 m and 4000 m above sea level. Blood samples were taken before (pre) and 10 min, 30 min, 60 min and 240 min post exercise and were analyzed by ELISA. Results: VEGF showed a significantly reduced concentration compared to the pre-value solely under 4000 m at 10 min post exercise. MMP-2 showed significantly reduced concentrations at 240 min post exercise under 4000 m. MMP-9 increased at 240 min post exercise under both 2000 m and 4000 m conditions. Endostatin was significantly increased at 10 min post exercise independently of the applied stimulus. Conclusions: The presented data show that intensive short-term exercise bouts facilitate the bioavailability of angiogenic, ECM (extracellular matrix)-related biomarkers. This finding is interesting for both health- and performance-related research as it demonstrates the positive effects of intensive short exercise interventions

Effects of active vs. passive recovery during Wingate-based training on the acute hormonal, metabolic and psychological response

Objective: 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. Design: 12 male cyclist/triathletes performed four 30 s all-out intervals, either with active (A) or passive (P) recovery between each bout. Human growth hormone (hGH), testosterone and cortisol, vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and macrophage migration inhibitory factor (MIF) were determined pre, 0', 30', 60' and 180' after both interventions. Metabolic stimuli and perturbations were characterized by lactate, blood gas (pH, BE, HCO3-, PO2, PCO2), and spirometric analysis. Results: Both interventions caused a transient increase in circulating levels of cortisol, testosterone, testosterone/cortisol-ratio, hGH, VEGF and HGF. Transient differences between A- and P-recovery were found only for testosterone and HGF directly after exercise, despite significant differences in metabolic disturbances (lactate, add base status). Conclusion: Based on the data of testosterone, hGH and the testosterone/cortisol-ratio, as well as on the data of VEGF and HGF it appears that this kind of exercise protocol may promote anabolic processes and may lead to pro-angiogenic conditions independent of the mode of recovery. However transient differences between A- and P-recovery were shown for testosterone and HGF. In contrast, cortisol and hGH, which are known to be sensitive for metabolic perturbations (e.g. pH) showed no differences. Therefore, it is proposed that if a certain threshold for metabolic perturbations is exceeded, a hormonal response is induced, which does not differ between A- and P-recovery. (C) 2013 Elsevier Ltd. All rights reserved

Training Load Measures and Biomarker Responses during a 7-Day Training Camp in Young Cyclists—A Pilot Study

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. Therefore, in this study, we aimed to investigate the training load of youth athletes during a training camp using a multilevel approach. Materials and Methods: Six trained youth male cyclists performed a 7-day preseason training camp. To investigate the internal training load, every morning, minimally invasive “point-of-care testing” (POCT) devices were used to analyze the following biomarkers: creatine kinase (CK), blood urea nitrogen (BUN), albumin (Alb), bilirubin (Bil), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total protein (TP). Additionally, data of training load measures (HR: heart rate, RPE: rating of perceived exertion, sRPE: session-RPE, TRIMP: training impulse, intensity (RPE:HR), and load (sRPE:TRIMP) ratios), self-perception (person’s perceived physical state, questionnaires on muscle soreness, and sleep quality), and measures of the autonomic nervous system (resting heart rate, heart rate variability) were collected. Two days before and after the training camp, subjects performed performance tests (Graded Exercise Test, Wingate Anaerobic Test, Counter Movement Jump). Results: Primarily, the biomarkers CK, BUN, and Alb, as well as the self-perception showed moderate to large load-dependent reactions during the 7-day training camp. The biomarkers returned to baseline values two days after the last training session. Power output at lactate threshold showed a small increase, and no changes were found for other performance parameters. Conclusions: The study suggests that a multilevel approach is suitable to quantify the internal training load and that different parameters can be used to control the training process. The biomarkers CK, BUN, and Alb are suitable for objectively quantifying the internal training load. The self-perception provides additional subjective information about the internal training load