Effects of Carbohydrate and Protein Administration by Food Items on Strength Response after Training in Stable COPD

Background: Chronic obstructive pulmonary disease (COPD) is one of the world’s most common diseases and reasons for death. Systemic consequences, especially reduced muscle strength, muscle mass and muscle function, are common and contribute to worsening prognosis and increasing morbidity and mortality. There is strong evidence that physical activity and strength training are effective in prolonging life and lead to better quality of life. Numerous studies have shown that ingestion of protein and carbohydrates after strength training can increase regeneration of strength in young athletes. Recently, we demonstrated that the same effect can be achieved with these macronutrients administered in a meal. Until now, it is not clear if patients with COPD, integrated in regular physical training, respond similarly. Methods: Prescribed strength training, consisting of two sets circular training with machines for big muscle groups was supplemented with a meal rich in protein and carbohydrates. Changes in maximum strength after 24 h were investigated to find out about the impact of this meal on physical capacity. A pilot study was conducted with pragmatic cross-over design. Results: With nutritive intervention, strength in both knee extensor and chest press were significantly higher than in control training. Conclusion: The study showed beneficial effects for the intake of protein and carbohydrates in changes in maximum strength. For now, the underlying mechanism remains unclear. Clinical relevance needs further research. The study design and study protocol can be used for further studies with only small adaptions

Validity of stable isotope data in doping control: perspectives and proposals

?13C and d13C values of endogenous urinary steroids represent physiological random variables. Measurement uncertainty and biological scatter likewise contribute to the variances. The statistical distributions of negative controls are well investigated, but there is little knowledge about the corresponding distributions of steroid-users. For these reasons valid discrimination of steroid users from non-users by 13C/12C analysis of endogenous steroids requires elaborate statistical treatment. Corresponding Bayesian approaches are presented following an introduction to the rationale. The use of mixture models appears appropriate. The distribution of routine data has been deconvolved and characterized accordingly. The mixture components, which presumably represent steroid users and non-users, exhibit considerable overlap. The validity of a given result depends on both the analytical uncertainty and the prior probability of doping offenses. Low analytical uncertainties but high prior probabilities facilitate valid detection of doping offenses. Two recommendations can be deduced. First, before starting an 13C/12C analysis, any initial suspicion should be well-substantiated. This precludes use of permissive criteria derived from the steroid profile. Secondly, knowledge of relevant 13C/12C distributions is required. This must cover representative numbers of authentic steroid users. Finally, it is desirable that the conditional probability for steroid administration rather than the measurement uncertainty is calculated and reported. This quantity possesses superior validity and it is largely independent of laboratory bias. The findings suggest and facilitate flexible handling of decision limits. Proposals for the evaluation of stable isotope data are presented. Copyright (c) 2012 John Wiley & Sons, Ltd

Physiological and metabolic responses as function of the mechanical load in resistance exercise

The present study aimed to investigate the relationship between the mechanical load during resistance exercise and the elicited physiological responses. Ten resistance-trained healthy male subjects performed 1 set of resistance exercise each at 55%, 70%, and 85% of 1 repetition maximum for as many repetitions as possible and in 4 training modes: 4-1-4-1 (4 s concentric, 1 s isometric, 4 s eccentric, and 1 s isometric successive actions), 2-1-2-1, 1-1-1-1, and explosive (maximum velocity concentric). Mean concentric power and total concentric work were determined. Oxygen uptake ((V) over dotO(2)) was measured during exercise and for 30 min post exercise. Total volume of consumed oxygen (O-2 consumed) and excess post-exercise oxygen consumption (EPOC) were calculated. Maximum blood lactate concentration (LAmax) was also determined. (V) over dotO(2) exhibited a linear dependency on mean concentric power. Mean concentric power did not have a detectable effect on EPOC and LAmax. An augmentation of total concentric work resulted in significant linear increase of O-2 consumed and EPOC. Total concentric work caused a significant increase in LAmax. In general, a higher mechanical load induced a larger physiological response. An increase in mean concentric power elicited higher aerobic energy turnover rates. However, a higher extent of total concentric work augments total energy cost covered by oxidative and (or) glycolytic pathways

Prediction of human dietary δ\u3csup\u3e15\u3c/sup\u3eN intake from standardized food records: Validity and precision of single meal and 24-h diet data

Natural stable isotope ratios (δ15N) of humans can be used for nutritional analyses and dietary reconstruction of modern and historic individuals and populations. Information about an individual’s metabolic state can be obtained by comparison of tissue and dietary δ15N. Different methods have been used to estimate dietary δ15N in the past; however, the validity of such predictions has not been compared to experimental values. For a total of 56 meals and 21 samples of 24-h diets, predicted and experimental δ15N values were compared. The δ15N values were predicted from self-recorded food intake and compared with experimental δ15N values. Predicted and experimental δ15N values were in good agreement for meals and preparations (r = 0.89, p \u3c .001) as well as for the 24-h diets (r = 0.76, p \u3c .001). Dietary δ15N was mainly determined by the amount of fish, whereas the contribution of meat to dietary δ15N values was less pronounced. Prediction of human dietary δ15N values using standardized food records and representative δ15N data sets yields reliable data for dietary δ15N intake. A differentiated analysis of the primary protein sources is necessary when relating the proportion of animal- derived protein in the diet by δ15N analysis

Hormonal response after masturbation in young healthy men – a randomized controlled cross-over pilot study

Background!#!Hormones like testosterone play a crucial role in performance enhancement and muscle growth. Therefore, various attempts to increase testosterone release and testosterone concentration have been made, especially in the context of resistance training. Among practitioners, sexual activity (coitus and masturbation) a few hours before training is often discussed to result in increases of testosterone concentration and thus promote muscle growth. However, there is no evidence to support this assumption and the kinetics of the testosterone and cortisol response after sexual activity have not been adequately investigated. Therefore, the aim of this pilot-study was to examine the kinetics of hormone concentrations of total testosterone, free testosterone and cortisol and their ratios after masturbation. In a three-arm single blinded cross-over study, the effects of masturbation with visual stimulus were compared to a visual stimulus without masturbation and the natural kinetics in healthy young men.!##!Results!#!The results showed a significant between-condition difference in free testosterone concentrations. Masturbation (p < 0.01) and a visual stimulus (p < 0.05) may seem to counteract the circadian drop of free testosterone concentrations over the day. However, no statistical change was observed in the ratios between total testosterone, free testosterone and cortisol.!##!Conclusions!#!It can be assumed that masturbation may have a potential effect on free testosterone concentrations but not on hormonal ratios. However, additional studies with larger sample sizes are needed to validate these findings

Case Study: Atypical delta C-13 values of urinary norandrosterone

Isotope ratio mass spectrometry (IRMS) has been established in doping control analysis to identify the endogenous or exogenous origin of a variety of steroidal analytes including the 19-norsteroid metabolite norandrosterone (NorA). NorA can be found naturally in human urine in trace amounts due to endogenous demethylation or in situ microbial degradation. The administration of nortestosterone (nandrolone) or different prohormones results in the excretion of urinary NorA. Usually, this can be detected by IRMS due to differing delta C-13 values of synthetic 19-norsteroids compared to endogenous reference compounds. The consumption of uncastrated pig edible parts like offal or even meat may also lead to a urinary excretion of NorA. In order to determine the delta C-13 values of such a scenario, urine samples collected after consumption of a wild-boar-testicle meal were analyzed. IRMS revealed highly enriched delta C-13 values for urinary NorA, which could be related to the completely corn-based nutrition of the animal. Isotopic analysis of the boar's bristles demonstrated a dietary change from C-3-based forage, probably in winter and spring, to a C-4-based diet in the last weeks to months prior to death. These results supported the interpretation of an atypical test result of a Central European athlete's doping control sample with delta C-13 values for NorA of -18 parts per thousand, most probably caused by the consumption of a wild boar ragout. As stated before, athletes should be fully aware of the risk that consumption of wild boar may result in atypical or even adverse analytical findings in sports drug testing

Effects of estradiol, estrogen receptor subtype-selective agonists and genistein on glucose metabolism in leptin resistant female Zucker diabetic fatty (ZDF) rats

The leptin resistant Zucker diabetic fatty (ZDF) rats are hyperphagic and become obese, but whereas the males develop type 2 diabetes mellitus (T2DM), the females remain euglycaemic. As estrogen deficiency is known to increase the risk of developing T2DM, we evaluated the role of ER subtypes alpha and beta in the development of glucose tolerance in leptin resistant ovariectomized (OVX) ZDF rats. At least six rats per group were treated with either vehicle (OVX), 17 beta-estradiol (E2), ER subtype-selective agonists (Alpha and Beta), or genistein (Gen) for 17 weeks. At the end of the treatment period a glucose tolerance assay was performed and the metabolic flux of C-13-glucose for the E2 group was investigated. OVX ZDF rats treated with E2, Alpha, Beta, and Gen tolerated the glucose significantly better than untreated controls. E2 treatment increased absorbance/flux of C-13-glucose to metabolic relevant tissues such liver, adipose tissue, gastrocnemius, and soleus muscle. Moreover, whereas Alpha treatment markedly increased mRNA expression of GLUT4 in gastrocnemius muscle, Beta treatment resulted in the largest fiber sizes of the soleus muscle. Treatment with Gen increased both the mRNA expression of GLUT 4 and the fiber sizes in the skeletal muscle. In addition, E2 and Alpha treatment decreased food intake and body weight gain. In summary, estrogen-improved glucose absorption is mediated via different molecular mechanisms: while activation of ER alpha seems to stimulate muscular GLUT4 functionality, activation of ER beta results in a hypertrophy of muscle fibers. In addition, selective activation of ER alpha decreased food intake and body weight gain. Our data further indicate that ER subtype-selective agonists and genistein improve systemic glucose tolerance also in the absence of a functional leptin signaling pathway. (C) 2015 Elsevier Ltd. All rights reserved

Prediction of human dietary N-15 intake from standardised food records: validity and precision of single meal and 24-h diet data

Natural stable isotope ratios (N-15) of humans can be used for nutritional analyses and dietary reconstruction of modern and historic individuals and populations. Information about an individual's metabolic state can be obtained by comparison of tissue and dietary N-15. Different methods have been used to estimate dietary N-15 in the past; however, the validity of such predictions has not been compared to experimental values. For a total of 56 meals and 21 samples of 24-h diets, predicted and experimental N-15 values were compared. The N-15 values were predicted from self-recorded food intake and compared with experimental N-15 values. Predicted and experimental N-15 values were in good agreement for meals and preparations (r=0.89, p<.001) as well as for the 24-h diets (r=0.76, p<.001). Dietary N-15 was mainly determined by the amount of fish, whereas the contribution of meat to dietary N-15 values was less pronounced. Prediction of human dietary N-15 values using standardised food records and representative N-15 data sets yields reliable data for dietary N-15 intake. A differentiated analysis of the primary protein sources is necessary when relating the proportion of animal-derived protein in the diet by N-15 analysis