Exercise-related hemoconcentration and hemodilution in hydrated and dehydrated athletes: An observational study of the Hungarian canoeists

Hemoconcentration during exercise is a well-known phenomenon, however, the extent to which dehydration is involved is unclear. In our study, the effect of dehydration on exercise-induced hemoconcentration was examined in 12 elite Hungarian kayak-canoe athletes. The changes of blood markers were examined during acute maximal workload in hydrated and dehydrated states. Dehydration was achieved by exercise, during a 120-minute extensive-aerobic preload. Our research is one of the first studies in which the changes in blood components were examined with a higher time resolution and a wider range of the measured parameters. Hydration status had no effect on the dynamics of hemoconcentration during both the hydrated (HS) and dehydrated (DHS) load, although lower maximal power output were measured after the 120-minute preload [HS Hemoglobin(Hgb) Max median 17.4 (q1 17.03; q3 17.9) g/dl vs. DHS Hgb Max median 16.9 (q1 16.43; q3 17.6) g/dl (n.s); HS Hematocrit(Hct) Max 53.50 (q1 52.28; q3 54.8) % vs. DHS Hct Max 51.90 (q1 50.35; q3 53.93) % (n.s)]. Thirty minutes after the maximal loading, complete hemodilution was confirmed in both exercises. Dehydration had no effect on hemoconcentration or hemodilution in the recovery period [HS Hgb R30’ 15.7 (q1 15.15; q3 16.05) g/dl (n.s.) vs. DHS Hgb R30’ 15.75 (q1 15.48; q3 16.13) g/dl (n.s.), HS Hct R30’ 48.15 (q1 46.5; q3 49.2) % vs. DHS Hct R30’ 48.25 (q1 47.48; q3 49.45) % (n.s.)], however, plasma osmolality did not follow a corresponding decrease in hemoglobin and hematocrit in the dehydrated group. Based on our data, metabolic products (glucose, lactate, sodium, potassium, chloride, bicarbonate ion, blood urea nitrogen) induced osmolality may not play a major role in the regulation of hemoconcentration and post-exercise hemodilution. From our results, we can conclude that hemoconcentration depends mainly on the intensity of the exercise

Increased Short-Term Variability of the QT Interval in Professional Soccer Players: Possible Implications for Arrhythmia Prediction

BACKGROUND: Sudden cardiac death in competitive athletes is rare but it is significantly more frequent than in the normal population. The exact cause is seldom established and is mostly attributed to ventricular fibrillation. Myocardial hypertrophy and slow heart rate, both characteristic changes in top athletes in response to physical conditioning, could be associated with increased propensity for ventricular arrhythmias. We investigated conventional ECG parameters and temporal short-term beat-to-beat variability of repolarization (STV(QT)), a presumptive novel parameter for arrhythmia prediction, in professional soccer players. METHODS: Five-minute 12-lead electrocardiograms were recorded from professional soccer players (n = 76, all males, age 22.0±0.61 years) and age-matched healthy volunteers who do not participate in competitive sports (n = 76, all males, age 22.0±0.54 years). The ECGs were digitized and evaluated off-line. The temporal instability of beat-to-beat heart rate and repolarization were characterized by the calculation of short-term variability of the RR and QT intervals. RESULTS: Heart rate was significantly lower in professional soccer players at rest (61±1.2 vs. 72±1.5/min in controls). The QT interval was prolonged in players at rest (419±3.1 vs. 390±3.6 in controls, p<0.001). QTc was significantly longer in players compared to controls calculated with Fridericia and Hodges correction formulas. Importantly, STV(QT) was significantly higher in players both at rest and immediately after the game compared to controls (4.8±0.14 and 4.3±0.14 vs. 3.5±0.10 ms, both p<0.001, respectively). CONCLUSIONS: STV(QT) is significantly higher in professional soccer players compared to age-matched controls, however, further studies are needed to relate this finding to increased arrhythmia propensity in this population

Relationship between the heart rate and E/A ratio in athletic and non-athletic males in different ages

Introduction: One of the most important effects of regular physical training is the adaptation of the cardiovascular system. The basic importance of the “athlete’s heart” is manifested in two fields, one is the public health, the second is the competitive sport. The aim of the present study is to clarify whether the higher E/A quotient of athletes is a favorable change in the intrinsic relaxation properties of the left ventricle. Question: The higher E/A quotient of physically active persons can be explained by the training bradycardia, or it can be supposed as an independent effect of regular physical exercise? Methods: Peak early (E) and atrial blood flow velocities (A) were assessed by Doppler echocardiography at rest in males (N=1237) the E` and A` were assessed by Tissue Doppler Imaging (TDI), (N=144) all the data were collected in Hungary, from 1993–2011. Relationship between E/A and resting heart rate (HR), was determined by linear regression analysis. Pearson correlation coefficients were used to express the connection between heart rate and the transmitral E/A and TDI determined E’/A’ quotients in 19-35 yr old males. Student t-test was used to establish the differences between transmitral and TDI determined velocities and indices in athletes and non-athletes. Results: The E/A decreased with age, the rate of decrease was slower in the physically trained subjects, except in children. In children, adolescent-young and young adult subjects E/A against HR equations of the athletic and non-athletic groups were similar, differences between the means were only due to the differences of the HR. In the 31–44 yr old males, the intercepts of the athletes’ regression lines were higher. The oldest (>44 yr) active subjects showed a significant regression while sedentary males did not. According to the results of TDI it seems that the disturbing effect of the heart rate is really stronger in case of the E/A while there was no significant correlation in the E’/A’ values. However, significant differences were seen both in E/A values and in TDI measurements of the medial part of the mitral valve (med. E’/A’) between athletes and non-athletes. Conclusions: The HR-independent beneficial effect of regular physical training on the diastolic function manifests itself at the older ages. According to our results, the long-term physical training (mainly endurance type) can diminish the age-associated impairment of diastolic function but the impact of resting HR should always be taken into consideration when assessing intergroup differences in the E/A ratio, especially when studying the effect of exercise training upon cardiac function

The effect of organic beetroot and black currant supplementation on adolescent female handball players performance : pilot study

Athletes are under tremendous external mental pressure to improve their performance, which is materially leading to an increasing frequency of consumption of dietary supplements in elite sports, both in the adult and youth age groups. Adequate physical development of athletes, minimizing their health risks, and maintaining a clean playfulness in sports play are prerequisites for the safe performance optimization of junior athletes. In our study, 14-17 years old, first-class classified adolescent and youth female handball players (n=12) with at least two years of sports training history were included. In the preparatory phase of the study, we measured their body composition (Inbody 720), handgrip strength and the participants performed a maxima type bicycle-ergometer load. The study was followed by a 10-day supplementation period with beet (n=8) and currant concentrate (n=4), after which the intervention effects were moni - tored by measuring their performance under the ergonomic load of the bicycle, measuring body composition and handgrip strength. Formulations used in a double blind, placebocontrolled study were tested in an accredited la - boratory for total polyphenol, nitrate and flavonoid content. The results before and after the intervention were compared with a one-sample t-test, the signific - ance level was p < 0.05. After 10 days of dietary supplementation, we found no difference in the relative muscle mass, rela - tive fat mass, right handgrip strength of the partici - pants in any of the groups studied. There was a significant increase in left handgrip strength in the currant concentrate group. There was no significant improvement in performance physiological param - eters either. The low number of items and short-term supplementation have not been shown to be effective in improving the performance of female athletes

Hormonal Neuroendocrine and Vasoconstrictor Peptide Responses of Ball Game and Cyclic Sport Elite Athletes by Treadmill Test.

ObjectiveOur objective was to evaluate complex hormonal response in ball game and cyclic sport elite athletes through an incremental treadmill test, since, so far, variables in experimental procedures have often hampered comparisons of data.MethodsWe determined anthropometric data, heart rate, maximal oxygen uptake, workload, plasma levels of lactate, adrenaline, noradrenaline, dopamine, cortisol, angiontensinogen and endothelin in control (n = 6), soccer (n = 8), handball (n = 12), kayaking (n = 9) and triathlon (n = 9) groups based on a Bruce protocol through a maximal exercise type of spiroergometric test.ResultsWe obtained significant increases for adrenaline, 2.9- and 3.9-fold by comparing the normalized means for soccer players and kayakers and soccer players and triathletes after/before test, respectively. For noradrenaline, we observed an even stronger, three-time significant difference between each type of ball game and cyclic sport activity.ConclusionsExercise related adrenaline and noradrenaline changes were more pronounced than dopamine plasma level changes and revealed an opportunity to differentiate cyclic and ball game activities and control group upon these parameters. Normalization of concentration ratios of the monitored compounds by the corresponding maximal oxygen uptake reflected better the differences in the response level of adrenaline, noradrenaline, dopamine and cortisol