Exhaustive Exercise Test Research Articles

Blunted cerebral hemodynamic responses to incremental exercise in patients with end-stage renal disease.

The aims of this study were to compare cerebral hemodynamics and maximal oxygen uptake (VO2peak) in patients with end-stage renal disease (ESRD) vs. age-matched healthy controls during maximal exercise. Twelve patients with ESRD and twelve healthy adults (CTR group) performed exhaustive incremental exercise test. Throughout the exercise test, near-infrared spectroscopy allowed the investigation of changes in oxyhemoglobin (∆O2Hb), deoxyhemoglobin (∆HHb), and total hemoglobin (∆THb) in the prefrontal cortex. Compared to CTR, VO2peak was significantly lower in ESRD group (P < 0.05). Increase in ∆THb (i.e., cerebral blood volume) was significantly blunted in ESRD (P < 0.05). ESRD patients also had impaired changes in cerebral ∆HHb and ∆O2Hb during high intensity of exercise (P < 0.05). Finally, no significant correlation was observed between VO2peak and changes in cerebral hemodynamics parameters in both groups (All P > 0.05). Maximal exercise highlights subtle disorders of both hemodynamics and neuronal oxygenation in the prefrontal cortex in patients with ESRD. This may contribute to both impaired cognitive function and reduced exercise tolerance throughout the progression of the disease.

Exercise-induced cardiac troponin release in athletes with versus without coronary atherosclerosis.

The magnitude of exercise-induced cardiac troponin (cTn) elevations is dependent on cardiovascular health status, and previous studies have shown that occult coronary atherosclerosis is highly prevalent among amateur athletes. We tested the hypothesis that middle-aged and older athletes with coronary atherosclerosis demonstrate greater cTn elevations following a controlled endurance exercise test compared with healthy peers. We included 59 male athletes from the Measuring Athletes' Risk of Cardiovascular events 2 (MARC-2) study and stratified them as controls [coronary artery calcium score (CACS) = 0, n = 20], high CACS [≥300 Agatston units or ≥75th Multi-Ethnic Study of Atherosclerosis (MESA) percentile, n = 20] or significant stenosis (≥50% in any coronary artery, n = 19). Participants performed a cycling test with incremental workload until volitional exhaustion. Serial high-sensitivity cTn (hs-cTn) T and I concentrations were measured (baseline, after 30-min warm-up, and 0, 30, 60, 120, and 180 min postexercise). There were 58 participants (61 [58-69] yr) who completed the exercise test (76 ± 14 min) with a peak heart rate of 97.7 [94.8-101.8]% of their estimated maximum. Exercise duration and workload did not differ across groups. High-sensitivity cardiac troponin T (Hs-cTnT) and high-sensitivity cardiac troponin I (hs-cTnI) concentrations significantly increased (1.55 [1.33-2.14]-fold and 2.76 [1.89-3.86]-fold, respectively) over time, but patterns of cTn changes and the incidence of concentrations >99th percentile did not differ across groups. Serial sampling of hs-cTnT and hs-cTnI concentrations during and following an exhaustive endurance exercise test did not reveal differences in exercise-induced cTn release between athletes with versus without coronary atherosclerosis. These findings suggest that a high CACS or a >50% stenosis in any coronary artery does not aggravate exercise-induced cTn release in middle-aged and older athletes.NEW & NOTEWORTHY Exercise-induced cardiac troponin (cTn) release is considered to be dependent on cardiovascular health status. We tested whether athletes with coronary atherosclerosis demonstrate greater exercise-induced cTn release compared with healthy peers. Athletes with coronary atherosclerosis did not differ in cTn release following exercise compared with healthy peers. Our findings suggest that a high CACS or a >50% stenosis in any coronary artery does not aggravate exercise-induced cTn release in middle-aged and older athletes.

Novel herbal beverage ameliorates exercise-induced fatigue in mice by modulating oxidative stress and reshaping the gut microbiota

With the demands of enhancing exercise performance, dietary supplements are widely used in the health management of athletes and who engaged in strenuous exercise. Based on the list of edible and medicinal materials approved by China's National Health Commission, we composed an herbal beverage formula named SRB, initially identified its chemical composition, and clarified its preventive effect on exercise-induced fatigue (EIF). SRB supplementation for four weeks significantly enhanced exercise performance in mice, as reflected by exhaustive swimming test and treadmill exercise test. In mice that underwent one single exhaustive exercise, SRB supplementation markedly reduced metabolite accumulation, increased glycogen contents in the liver and muscle, promoted anti-oxidative enzyme activities, decreased hepatic malondialdehyde (MDA) level, and protected quadriceps femoris morphology, respectively. Anti-oxidative stress effect of SRB may be relevant with increased gene expressions of nuclear factor-erythroid 2-related factor 2 (Nrf2) and antioxidant response element (ARE)-dependent gene. Moreover, SRB treatment altered gut bacterial community structure, e.g., increased the relative abundance of short-chain fatty acids (SCFAs)-producing bacteria and decreased the relative abundance of sulfate-reducing bacteria. Altogether, we identified SRB as an effective anti-EIF dietary supplement with prebiotic effects in C57BL/6 mice.

Skeletal muscle and heart failure – What is the relationship between central versus peripheral affections?

Background and aimHeart failure is considered as a systemic disease as beside the heart, skeletal muscle is affected. Methods and resultsIn this retrospective case-control study 64 men and 15 women with heart failure as well as an individually pairwise matched sample by sex, age and body mass index of healthy individuals from the COmPLETE cohort study performed an exhaustive cardiopulmonary exercise test, strength tests and anthropometric measurements. V̇O2peak was 28.6% lower in male and 24.6% lower in female patients with heart failure as compared to healthy controls. Strength parameters are significantly higher for counter movement jump in male subjects. In females, significant differences were detected for mid-thigh pull in healthy versus patients with heart failure. Skeletal muscle mass of patients was in male as well as female 3.7% lower than in controls. Furthermore, the function of skeletal muscle seems impaired as the ability to accelerate is significantly lower in affected male with a heart pathology. ConclusionIt seems that severe affections (approx. 25 to 30%) on cardiocirculatory level are associated with moderate to low affections on functional and structural capacity on skeletal muscle level. Further, as in the male cohort with a heart pathology acceleration meaning ‘fast’ contracting is impaired, it is suggested, that the central limitations respectively the low perfusion of skeletal muscle over years yield to adaptions on muscle cell level ingoing with a decreased ability of fast contracting. It is therefore suggested, that the central circulatory limitations in patients with heart failure, respectively the low perfusion of skeletal muscle over years, promote maladaptation's in the periphery.

A hydraulic model outperforms work-balance models for predicting recovery kinetics from intermittent exercise

Data Science advances in sports commonly involve “big data”, i.e., large sport-related data sets. However, such big data sets are not always available, necessitating specialized models that apply to relatively few observations. One important area of sport-science research that features small data sets is the study of recovery from exercise. In this area, models are typically fitted to data collected from exhaustive exercise test protocols, which athletes can perform only a few times. Recent findings highlight that established recovery models such as the so-called work-balance models are too simple to adequately fit observed trends in the data. Therefore, we investigated a hydraulic model that requires the same few data points as work-balance models to be applied, but promises to predict recovery dynamics more accurately. To compare the hydraulic model to established work-balance models, we retrospectively applied them to data compiled from published studies. In total, one hydraulic model and three work-balance models were compared on data extracted from five studies. The hydraulic model outperformed established work-balance models on all defined metrics, even those that penalize models featuring higher numbers of parameters. These results incentivize further investigation of the hydraulic model as a new alternative to established performance models of energy recovery.

Effect of Beta-Alanine Supplementation on Exercise-Induced Cell Damage and Lactate Accumulation in Female Basketball Players: A Randomized, Double-Blind Study.

Beta-alanine (BA) is a supplement that has received attention for its buffering potential among athletes. The aim of this study was to investigate the effects of BA supplementation on exercise performance and exercise-induced cell damage in female basketball players. Twenty-two female basketball players participated in a randomized, double-blind study. They ingested 6.4 g·day-1 of BA or an isocaloric placebo (dextrose) over 4 weeks. Exercise performance including aerobic (Bruce test), anaerobic (Wingate test), intermittent (Yo-Yo test) and basketball performance (countermovement jump and free throw shots) was measured before and following the intervention. Exercise measures were performed at the lab and free throw shots were undertaken on a wooden indoor basketball court. Blood samples were also collected before and after the exhaustive exercise to assess lactate concentration, creatine kinase (CK), lactate dehydrogenase (LDH) and malondialdehyde (MDA) activity. The exhaustive exercise test induced an increase in lactate concentration and MDA, CK and LDH activity (all p < 0.05). BA supplementation significantly reduced the lactate response to exhaustive exercise (p = 0.001); however, it had no significant effect on exercise-induced MDA, CK and LDH activity (all p > 0.05). Furthermore, exercise performance measures improved from pre- to post-test regardless of supplement/placebo ingestion (all p < 0.05). BA consumption over 4 weeks significantly reduced lactate accumulation following exhaustive exercise, but had no ergogenic effect in female basketball players. Usual dosing of BA does not seem to exhibit protective effect against oxidative damage.

Influence of extreme factors on the ratio of cardiointervals in the structure of the cardiocycle

BACKGROUND: The proportion of the golden section, discovered by Pythagoras, is of great importance in the organization of wildlife. Since the golden proportion is one of the criteria for self-organization in living nature, it is natural to assume that this criterion can also be manifested in the work of the heart. The organization of the cardiac cycle is the result of a long evolution of a living organism in the direction of optimizing the structure and functions, ensuring life with minimal energy consumption. However, in clinical medicine and physiological research, until recently, this approach has hardly been used, and there are only a few reports in the literature on the effectiveness of this method.&#x0D; AIM: To study the sensitivity of indicators of the symmetry analysis of the cardiocycle in accordance with the methodology of the golden section to physical exertion, hypoxic and temperature effects for an integral assessment of the functional state of the heart. For the geometric analysis of the ECG, the ratios of the main parameters were used to assess their compliance with the criteria of the golden section.&#x0D; MATERIALS AND METHODS: Geometric analysis of ECG interval intervals according to the principles of the golden section in healthy individuals exposed to debilitating physical activity, hypoxia, combined hyperthermia or low temperatures. In the course of the work, the results of a study of 252 male volunteers aged 2035 years were analyzed, of which 46 people underwent an exhaustive exercise test, 113 a hypoxic test, 34 a combined hyperthermia tolerance test, and 69 a moderate cooling tolerance test.&#x0D; RESULTS: the use of a geometric analysis of cardiocycles at rest, during exercise, as well as moderate exposure to typical adverse environmental factors (hypoxia, high or low temperatures) showed the fundamental possibility of assessing the dynamics of the functional state in young practically healthy individuals. The indicators characterizing the activity of the processes of regulation of myocardial work at the extracardiac and intracardiac levels were more dynamic. The indicator of symmetry analysis, which characterizes the level of myocardial homeostasis, energy processes and contractility, to a greater extent reflects unfavorable prognostic characteristics in terms of failure of myocardial adaptation. It has been established that for practically healthy individuals (in the normal state of activity, without external influences), the 1st class of the functional state occurs in 83% of cases, hemodynamic stress is noted in 16% of the subjects, hemodynamic inadequacy in 1%.&#x0D; CONCLUSIONS: The deviations from the ideal proportion of the golden section identified as a result of adverse external influences remained within acceptable fluctuations, which indicated a fairly perfect functioning of the heart and the cardiovascular system as a whole in the surveyed contingent of young, practically healthy individuals. Proposed by N.V. Dmitrieva (1989) the classification of functional states, based on the assessment of the degree of deviation of the calculated coefficients from the optimal value corresponding to the golden section, is not optimal for healthy young men, which include athletes without signs of sports heart and other myocardial pathology. It does not take into account the sign of the deviation, as a result, for the state of rest, with the predominance of bradycardia, typical for athletes, there is an overdiagnosis of tense hemodynamics. At the same time, the work of the heart during short-term intense physical exertion, which naturally causes pronounced sympathicotonia, can be unreasonably characterized as a premorbid or pathological condition.

Prenatal Exercise and Cardiovascular Health (PEACH) Study: impact of pregnancy and exercise on rating of perceived exertion during non-weight-bearing exercise.

The purpose of this study was to determine if rating of perceived exertion (RPE) during non-weight-bearing exercise is influenced by gestational age and exercise training. We conducted a randomized controlled trial to examine the influence of gestational age and exercise training (three to fourtimes per week for 25-40 minutes at 50%-70% of heart rate reserve) on RPE during an exhaustive cycling exercise test. We observed no influence of gestational age, or exercise training status on RPE responses to non-weight-bearing exercise during pregnancy. Trial registration number: NCT02948439. Novelty: Gestational age and/or exercise training does not influence rate of perceived exertion during non-weight-bearing exercise.

Tryptophan recovery index as a new biomarker for fitness.

The maximal oxygen uptake (VO2max) and maximal power output (Pmax) are commonly used parameters to evaluate the endurance fitness status. A connection between exercise and the kynurenine pathway (KP), which describes the metabolism of unused tryptophan, has already been reported. However, a potential association of the KP with endurance fitness levels remains unknown. In this study, adolescent competitive athletes performed an exhaustive incremental exercise test. Blood samples were taken before, directly after, and 30 minutes after the end of exercise. Tryptophan (Trp), kynurenine (Kyn) and kynurenic acid (KA) serum levels were determined by high-performance liquid chromatography (HPLC). Forty-four male and 27 female athletes (median age: 16 years) were recruited. During exhaustive exercise tests, Trp initially declined and then increased 30 minutes after discontinuing exercise. Similar findings were observed for Kyn, whereas KA levels behaved inversely. After incremental exhaustive exercise the relative increase of Trp concentrations, termed the tryptophan-recovery-index (TRI), showed a highly significant positive correlation with VO2max and Pmax (r=0.468 and 0.491, p-values <0.001). There was a significant gender-difference with higher levels of all metabolites at all measured time points in male participants. In the present study, a highly significant correlation was found between the TRI and the maximal oxygen uptake in well-trained athletes. The implementation of TRI can therefore be suggested as a biomarker for physical fitness.

Anti-fatigue Effects of Santé Premium Silver Perch Essence on Exhaustive Swimming Exercise Performance in Rats.

Aim: Fish soup is a traditional Chinese food usually offered as a healthy supplement to elders, pregnant women and persons who just had surgery. Silver perch (Santé premium silver perch essence, SPSPE) extract contains various quality proteins, collagen, minerals, trace elements, and branch chain amino acids (BCAA) that could help individuals recover from exhaustion and control body weight. However, there are very limited studies exploring the effects of fish extracts on exercise performance and fatigue, and relevant physiological mechanisms. Therefore, the purpose of this study was to investigate the effects of chronic SPSPE administration on exhaustive exercise performance.Method: Male Wistar rats weighing around 250 g were divided into 4 groups: Control, 1X SPSPE (6.2 ml/kg), 2X SPSPE (12.4 ml/kg) and 5X SPSPE (31.0 ml/kg). Rats were administrated SPSPE by oral gavage feeding every day for 33 days. Their body weight were measured every week. Before and after the exhaustive swimming test, the blood was collected for circulating lactate, glucose, ammonia, hormones, and myoglobin analysis. Rats were sacrificed after performing an exhaustive swimming exercise test. The liver tissues were collected for glycogen content and H&E staining.Results: After the administration of 1X and 5X SPSPE, swimming fatigue was significantly delayed (p = 0.024). There was no difference in the hormone plasma level between the control and SPSPE groups. The induction of plasma corticosterone and TBARS by exhaustive swimming exercise could be decreased by SPSPE administration. The increased plasma myoglobin concentration from exhaustive swimming exercise was weakened by SPSPE supplementation. The higher glycogen sparing contained in liver tissue was observed in SPSPE-treated groups (p < 0.05).Conclusion: SPSPE could efficiently delay swimming fatigue through sparing of liver glycogen and attenuation of plasma TBARS, myoglobin induction by exhaustive exercise. Our findings provide a scientific-based fundamental information and better understanding for developing a fish extract-based anti-fatigue supplement.

Home-based and personalized endurance training program for patients with mild to moderate hemophilia A: What can be expected?

Some studies suggest that an acute exercise bout can improve the hemostatic process in patients with hemophilia A (HA). No interventional studies have been carried out to assess the influence of endurance training on this effect. We aimed (1) to determine the acceptability of a 6-week personalized endurance training program that HA patients could implement in their daily life and (2) to determine the impact of this endurance training program on endurance capacity and various factors supporting the hemostatic process. Seventeen subjects with mild to moderate HA aged 18 to 45 years were engaged in a home-based and personalized endurance training program (eighteen training sessions, three sessions per week). For each subject, endurance capacity was assessed at inclusion during an exhaustive exercise test coupled with gas exchanges. From this endurance assessment, a personalized interval endurance training plan was drafted and standardized to provide moderate [at the first ventilatory threshold (VT)] to high (at the second VT) metabolic intensity training. At inclusion, the hemostatic process was assessed at rest and after the exhaustive exercise bout. These same tests were repeated after the endurance training program. All 17 patients completed the endurance training program. There were no bleeding-related incidents. Endurance power was increased after the training program (maximal aerobic power: +14%, +0% to +32% for median, minimum and maximum values respectively, P = 0.003; first ventilatory threshold power: +22%, 0% to +100%, P = 0.0006; second ventilatory threshold power: +25%, 0% to +53%, P = 0.0004). In patients with mild HA, endurance training slightly increased FVIII levels when assessed after the maximal exercise bout. Our results support the promotion of a personalized, standardized and home-based exercise prescription for hemophilia patients to improve their cardiorespiratory fitness without negatively influencing the coagulation process. Des études ont suggéré que la réalisation d’un exercice musculaire aigu peut améliorer l’efficacité du processus d’hémostase chez des patients porteurs d’une hémophilie A. Aucune étude interventionnelle n’a jamais été réalisée pour vérifier l’influence d’un entraînement régulier en endurance sur cet effet aigu. Notre étude de type interventionnelle, monocentrique, exploratoire et menée auprès d’un échantillon de patients hémophiles A avait pour objectifs (1) d’évaluer l’acceptabilité de la mise en place au domicile d’un programme d’entraînement en endurance prescrit et personnalisé et (2) de caractériser l’effet de cet entraînement sur les ressources fonctionnelles en endurance et sur le processus hémostatique. Un effectif de 17 patients hémophiles A de sévérité mineure à modérée et âgés de 18 à 45 ans a été recruté. Les ressources fonctionnelles en endurance ont été évaluées à l’inclusion par un test d’exercice musculaire sur bicyclette ergométrique couplé à la mesure des échanges gazeux respiratoires. Cette évaluation a permis de prescrire à chaque patient un programme d’entraînement personnalisé sur bicyclette ergométrique à domicile, à raison de 3 séances par semaine pendant 6 semaines, en créneaux, aux intensités des seuils ventilatoires et codifié via les contrôles de la fréquence cardiaque et de la puissance développée. Un accompagnement téléphonique par un éducateur médico-sportif était proposé au moins une fois par semaine. À l’inclusion, le processus d’hémostase était quantifié au repos et dans les suites immédiates du test d’exercice maximal. À l’issue du programme d’entraînement en endurance, toutes les mesures ont été contrôlées. Les 17 patients ont pu réaliser le programme d’entraînement prescrit. Aucun événement hémorragique n’a été signalé durant la période d’entraînement. À l’issue du programme d’entraînement et en comparaison avec les valeurs mesurées à l’inclusion, la puissance maximale aérobie a augmenté (+14 %, +0 % et +32 % pour respectivement la médiane, le minimum et le maximum ; p = 0,003) de même que les puissances mesurées aux seuils ventilatoires (1 er seuil ventilatoire : +22 %, 0 % et +100 %, p = 0,0006 ; 2 e seuil ventilatoire : +25 %, 0 % et +53 %, p = 0,004). À l’issue du programme d’entraînement, le processus d’hémostase n’a été dégradé chez aucun des patients. Dans le sous-groupe des patients porteurs d’une forme mineure de la maladie, l’entraînement en endurance a légèrement majoré la réponse sécrétoire en facteur VIII induite par la réalisation du test d’exercice d’intensité maximale. Notre étude a permis de vérifier que l’application d’une prescription d’entraînement en endurance à des patients porteurs d’une hémophilie A de sévérité mineure à modérée peut être envisagée au domicile des patients. Cette pratique induit une amélioration de la ressource fonctionnelle en endurance des patients hémophiles A sans modifier le processus d’hémostase.

Tomato powder is more effective than lycopene to alleviate exercise-induced lipid peroxidation in well-trained male athletes: randomized, double-blinded cross-over study

BackgroundConsumption of nutritional supplements to optimize recovery is gaining popularity among athletes. Tomatoes contain micronutrients and various bioactive components with antioxidant properties. Many of the health benefits of tomatoes have been attributed to lycopene encouraging athletes to consume pure lycopene supplements. The aim of this study was to compare the effect of tomato powder and lycopene supplement on lipid peroxidation induced by exhaustive exercise in well-trained male athletes.MethodsEleven well-trained male athletes participated in a randomized, double-blinded, crossover study. Each subject underwent three exhaustive exercise tests after 1-week supplementation of tomato powder (each serving contained 30 mg lycopene, 5.38 mg beta-carotene, 22.32 mg phytoene, 9.84 mg phytofluene), manufactured lycopene supplement (30 mg lycopene), or placebo. Three blood samples (baseline, post-ingestion and post-exercise) were collected to assess total anti-oxidant capacity (TAC) and variables of lipid peroxidation including malondialdehyde (MDA) and 8-isoprostane. Data were analyzed using repeated-measures of ANOVA at P < 0.05.ResultsTomato powder enhanced total antioxidant capacity (12% increase, P = 0.04). Exhaustive exercise, regardless of supplement/ placebo, elevated MDA and 8-isoprostane levels (P < 0.001). The elevation of 8–isoprostane following exhaustive exercise was lower in the tomato powder treatment compared to the placebo (9% versus 24%, p = 0.01). Furthermore, following exhaustive exercise MDA elevated to a lower extent in tomatoe powder treatment compared to the placebo (20% versus 51%, p = 0.009). However, such differences were not indicated between lycopene and placebo treatments (p > 0.05).ConclusionBeneficial effects of tomato powder on antioxidant capacity and exercise-induced lipid peroxidation may be brought about by a synergistic interaction of lycopene with other bioactive nutrients rather than single lycopene.

THE VALUE OF TREADMILL EXERCISE TEST PARAMETERS TO PREDICT THE MARATHON PERFORMANCE OF YOUNG AND MIDDLE-AGED RECREATIONAL ATHLETES IN CHINA

Objectives: This study will evaluate the results of parameters measured during a treadmill exercise test to predict marathon performances. Methods: We studied 171 Chinese recreational athletes who participated in marathons or half-marathons (42.2[Formula: see text]k or 21.1[Formula: see text]k, respectively) between October 2016 and December 2017. The participants completed a survey that included questions about demographics and training, and they underwent a treadmill exercise test according to the Bruce protocol. The number of years in training, mean weekly hours of training, mean weekly training volume, and performance time in subsequent marathon events were recorded and analyzed in this study. Results: The total exercise times achieved on the treadmill test were significantly longer for men compared to women ([Formula: see text]). The performance times in the half-marathons were significantly shorter for men compared to women ([Formula: see text]). Training volume was the only independent predictor of total exercise time on the treadmill and performance time in marathons and half-marathons (all [Formula: see text]). The value of the total exercise time on the treadmill to predict performance times in half-marathons ([Formula: see text]) was superior to full marathons ([Formula: see text]) and significantly better in study subjects aged 30–39 years ([Formula: see text], [Formula: see text]) and 40–49 years ([Formula: see text], [Formula: see text]) compared to study subjects aged 20–29 years and 50–59 years. The percentage of decrease in the maximal heart rate (MHR) at the end of one minute of recovery time was negatively correlated with performance times in marathons. Conclusions: The total exercise time achieved during an exhaustive treadmill exercise test and percentage of decrease in the MHR at the end of one minute of recovery time are accessible parameters that can help athletes manage their expectations and adjust their training plans. A large study that includes additional countries is needed to confirm the value of treadmill exercise test results for predicting marathon performance.

Effect of deep sea water on the exercise-induced fatigue of rats

This study is to investigate the effect of deep sea water (DSW) on the exercise-induced fatigue of rats. The exhaustive exercise test on the treadmill and the measurement of biochemical values related to fatigue were conducted after the two-week feeding to male Wistar rats with different hardnesses DSW (DRO, D100, D600) in different dosages (6, 12, 30 mL/kg·d). It was found that the exhausting time and the ratio of lactic acid elimination to lactic acid increment from the experiment groups were significantly better than those from the control group. The BUN level of rats fed with D100 in a dosage of 30 mL/kg·d and D600 in three dosages distinctly was lower than that of the control group. The liver glycogen content in the group that the rats fed with D100 in dosages of 6 and 30 mL/kg·d and D600 in a dosage of 30 mL/kg·d showed significant difference compared with control group. However, the weight gain, kidney-body weight ratio, spleen-body weight ratio, and total plasma protein level in the rats of experimental groups showed no significant difference from those of control group. It suggested that endurance, adaptation for exercising load and accelerating elimination in fatigue of rats were improved when fed with higher hardness and dosage of DSW.

Effects Of Carbohydrate-Electrolyte Solution Supplementation On Fluid Retention And Aerobic Capacity After Exhaustive Exercise

Rehydration, or restoration of fluid spaces, is important when exhaustive endurance exercise (EEE) has compromised hydration status. Previous studies only investigated the effects of carbohydrate-electrolyte solution (CE) supplementation to facilitate replacement after exercise induced dehydration. CE supplementation for 1 hour before and 1 hour after EEE may play an important role in fluid retention and enhancing aerobic capacity. PURPOSE: To examine the effects of CE supplementation on fluid retention and aerobic capacity after EEE. METHODS: In a double-blind, crossover and counterbalanced designed study, nineteen health male participants were asked to intake ORS-SH@, an oral rehydration solution, (150 mL four times within an hour) or placebo (water) for 1 hour before and 1 hour after EEE. All participants completed graded exercise test to exhaustion on treadmill for determination of maximal oxygen consumption (VO2max) before supplementation, and then completed the exhaustive endurance exercise test at the intensity of 70% VO2max for 60 min. Then, the exercise intensity increased at 90% VO2max until exhaustion after supplementation. The average heart rate, maximal heart rate, running time to exhaustion and peak oxygen uptake were recorded during the exercise period. The body weight was recorded 15-min, 30-min, 45-min and 60-min of after EEE to calculate the dehydration rate and beverage hydration index (BHI). RESULTS: The dehydration rates in participants with ORS-SH@ treatment at 15-min, 30-min and 45-min of after EEE were significantly lower than with placebo treatment (-1.77±0.50% vs. -2.06±0.66%; -1.69±0.54% vs. -1.95±0.66%; -1.48±0.51% vs. -1.76±0.65%, respectively, p < .05). In addition, the BHI in participants with ORS-SH@ treatment at 15-min, 30-min and 45-min of after EEE (1.19±0.36, 1.22±0.43 and 1.27±0.54) were significantly higher than with placebo treatment (p < .05). However, there were no significant differences in other variables between treatments. CONCLUSIONS: ORS-SH@ supplementation can effectively enhance fluid retention after EEE. However, ORS-SH@ supplementation had no benefits on aerobic capacity. Supported by Panion & BF Biotech Inc. (Grant No: A-107-077)

Total Dietary Antioxidant Intake Including Polyphenol Content: Is it Capable to Fight against Increased Oxidants within the Body of Ultra-Endurance Athletes?

The role of dietary antioxidants on exhaustive exercise-induced oxidative stress has been well investigated. However, the contribution of total dietary antioxidant capacity on exogenous antioxidant defense and exercise performance has commonly been disregarded. The aims of the present investigation were to examine (i) the effects of dietary total antioxidant intake on body antioxidant mechanisms, and (ii) an exhaustive exercise-induced oxidative damage in ultra-endurance athletes. The study included 24 ultra-marathon runners and long-distance triathletes (12 male and 12 female) who underwent an acute exhaustive exercise test (a cycle ergometer (45 min at 65% VO2max) immediately followed by a treadmill test (75% VO2max to exhaustion). Oxidative stress-related biomarkers (8-isoprostaglandin F2alpha (8-iso PGF2a), total oxidant status (TOS, total antioxidant status (TAS)) in plasma were collected before and after exercise. Oxidative stress index was calculated to assess the aspect of redox balance. Blood lactate concentrations and heart rate were measured at the 3rd and 6th min after exercise. Dietary antioxidant intake was calculated using the ferric reducing ability of plasma (FRAP) assay. Dietary total antioxidant intake of the subjects was negatively correlated with pre-exercise TOS concentrations (rs = −0.641 in male, and rs = −0.741 in females) and post- vs. pre- (∆) 8-iso PGF2a levels (rs = −0.702 in male; p = 0.016, and rs = −0.682 in females; p = 0.024), and positively correlated with ∆ TAS concentrations (rs = 0.893 in males; p = 0.001, and rs = 0.769 in females; p = 0.002) and post- exercise lactate concentrations (rs = 0.795 for males; p = 0.006, and rs = 0.642 for females; p = 0.024). A positive meaningful (p = 0.013) interaction was observed between time at exhaustion and dietary antioxidant intake (rs = 0.692) in males, but not in females. In conclusion, the determination of total dietary antioxidant intake in ultra-endurance athletes may be crucial for gaining a better perspective on body antioxidant defense against exhaustive exercise-induced oxidative stress. However, the effects of dietary antioxidant on exercise performance and recovery rate needs further investigation.

Effects of Escherichia coli strain Nissle 1917 on exercise-induced disruption of gastrointestinal integrity

PurposeThe aim of the current study was to investigate the effects of the probiotic Escherichia coli strain Nissle 1917 (EcN) on the exercise-induced disruption of gastrointestinal (GI) integrity and the associated release of damage and inflammatory markers.MethodsAfter a pre-performance test, 19 untrained subjects (aged 18–35 years) passed two identical exhaustive treadmill exercise tests in an intensity corresponding to 60–80% VO2max in a test–retest design. The exercise tests were separated by a time period of 4 weeks. During this period, all subjects ingested 5 ml of an EcN suspension daily. Serum samples were taken before, immediately following and 3 h after both exercise tests. They were analyzed for indicators of GI integrity (zonulin; claudin-3; LPS), various damage and redox markers (I-FABP, GOT; GPT; TBARS) and inflammatory parameters (hsCRP; leucocytes). GI complaints were evaluated by a questionnaire.ResultsThe intake of EcN resulted in a significantly lower increase in I-FABP and TBARS after exercise (p < 0.05). In contrast, no effect of EcN supplementation was found for hsCRP and leucocyte numbers. Similarly, no differences were found for levels of zonulin and claudin-3. Exercise-associated GI complaints were not affected by the probiotic supplement.ConclusionThe probiotic EcN reduced the exercise-associated increase in oxidative stress. This antioxidative mechanism probably leads to a reduction of GI epithelial damage after exhaustive exercise. The lack of EcN effects on other markers of GI permeability and systemic inflammation is most likely due to an inadequate exercise load, with rather small and insignificant exercise effects on these parameters.

Changes of Total and Tumor Specific Cell Free Dna During an Exhaustive Cycling Exercise Test

PURPOSE: Circulating, cell free DNA (cfDNA) is known to directly accumulate in a load-dependent fashion in various aerobic and anaerobic exercise sessions within minutes. Furthermore, increases of cfDNA at baseline have been reported for different patient groups with cancer to depend on malignancy and tumor progression. Typically, such analysis did not differentiate between cfDNA and circulating tumor derived levels of DNA (ctDNA). Here we investigated for the first time, whether exercise to voluntary exhaustion induces increases in cfDNA and ctDNA in patients with advanced stage cancer. METHODS: In a pilot study, individuals with solid tumors of diverse entities and an age matched control group (n = 5) were subjected to a step-wise incremental cycling spiroergometry until exhaustion. Blood samples were taken before, directly after, and 90 minutes after the end of the test. Total cfDNA was quantified directly from the blood plasma using a qPCR targeting repetitive Line-1 elements and ctDNA was measured following silica-based total DNA purification and enrichment from plasma and subsequent specific quantification using a nested qPCR assay targeting the seven most frequent oncogenic KRAS sequences in comparison to wild-type sequence. Additionally, DNase activity reduction was measured with a commercial ELISA kit. RESULTS: We quantified total cfDNA in all blood samples and detected and quantified ctDNA concentrations in all three samples of one cancer patient with metastatic colon cancer. Total cfDNA concentrations increased 1.7-fold (95% CI 1.28-2.22-fold; p<0.01) in all tumor patients during exercise, but to a significantly lesser extent (p=0.003) than in the healthy control group (3.7-fold; CI 2.23-6.15-fold, p<0.01). The decrease of cfDNA concentrations during the recovery period was significantly lower in tumor patients than in the healthy control (1.8-fold vs 5.5-fold decrease, p=0.001), independent of the DNase activity. Tumor DNA increased only slightly, causing a relative decrease in the ctDNA during exercise. CONCLUSIONS: cfDNA kinetics seem to be less dynamic in tumor patients, especially the depletion of cfDNA from the plasma seems to be impaired. This effect does not seem to be a result of circulating DNA originating from the Tumor.

Reliability and Validity of Tethered Swimming Lactate Minimum Test and Their Relationship With Performance in Young Swimmers

To test the reliability and validity of tethered swimming lactate minimum test in young swimmers. Lactate minimum test was performed twice to test the reliability (experiment 1; n = 13). In addition, the validity was investigated through lactate minimum test relationships with tethered swimming lactate threshold and peak force obtained during graded exercise test (experiment 2; n = 11). Finally, the correlations with mean speeds observed during 200-m (s200m) and 30-minute continuous efforts (s30min) were also analyzed (experiment 3; n = 15). In all experiments, the lactate minimum test began with 3-minute all-out effort to induce lactatemia, followed by an exhaustive graded exercise test. The lactate minimum intensity and mean force during the entire 3-minute all-out effort (MF) showed high reliability (coefficient of variation < 8.9% and intraclass correlation coefficient > .93). The lactate minimum intensity was not different compared with lactate threshold (P = .22), presenting high correlations (r = .92) and agreement (95% limits of agreement = ±7.9N). The mean force during the entire 3-minute all-out effort was similar to peak force obtained during graded exercise test (P = .41), presenting significant correlations (r = .88) and high indices of agreement (95% limits of agreement = ±11.3N). In addition, lactate minimum test parameters correlated both with mean speeds observed during 200-m (r > .74) and 30-minute continuous efforts (r > .70). Thus, tethered swimming lactate minimum test can be used for training recommendations and to monitor aerobic adaptations in young swimmers.

Aberrant peak lactate response in MS.

The peak blood lactate response to an exhaustive exercise test in a number of chronic conditions has been shown to differ from that seen in healthy, untrained individuals. However, this has not been investigated for patients with multiple sclerosis (MS). The main objective was to determine and compare the peak blood lactate response to exercise and the maximal workload between two groups of MS patients with different illness severity. Twenty-five patients with a relapsing-remitting disease course (Group RR) and 41 patients with a secondary- or primary chronic progressive disease course (group CP) performed an exhaustive incremental bicycle ergometry. Peak blood lactate, maximal workload, peak oxygen consumption and maximal heart rate were measured. The peak blood lactate levels and maximal workload differed significantly between the groups (group CP < group RR; p < 0.001). Furthermore spiroergometric peak performance markers in both groups were significantly lower than predicted for healthy age and sex matched untrained groups. A reduced peak blood lactate response to exercise is a novel finding for MS patients. This calls into doubt if the lactate performance tests and lactate thresholds used for healthy individuals can be transferred to MS patients.