Andrzej Klusiewicz

Pre-exercise serum cortisol concentration and responses to laboratory exercise

Relationships between the postexercise values of blood lactate concentration, pH, oxygen uptake, heart rate, power output on the one hand, and the pre- and postexercise blood cortisol concentrations on the other, were studied in 74 male and 40 female athletes (wrestlers and senior and junior rowers), performing graded exercise of increasing intensity. The senior rowers, junior rowers and wrestlers had different exercise protocols. The senior rowers of both sexes had significantly higher rest concentrations of serum cortisol than the junior athletes. A significant correlation between postexercise lactate concentrations and pre-exercise cortisol concentrations was found in all the male groups (“common”r = 0.515,P < 0.001), but not in the female ones (r = 0.162) . It was concluded that the pre-exercise cortisol concentrations might condition anaerobic-glycolytic metabolism in physical exercise.

Endurance training selectively increases HDL-bound sphingosine-1-phosphate in the plasma

Sphingosine‐1‐phosphate (S1P) is a bioactive lysosphingolipid that is found in relatively high concentration in human plasma. Erythrocytes, endothelial cells, and activated platelets are the main sources of circulating S1P. The majority of plasma S1P is transported bound to high‐density lipoprotein (HDL) and albumin. In recent years, HDL‐bound S1P attracted much attention due to its cardioprotective and anti‐atherogenic properties. We have previously found that endurance‐trained athletes are characterized by higher plasma S1P concentration compared to untrained individuals. This finding prompted us to examine the effect of endurance training on S1P metabolism in blood. Thirteen healthy, untrained, male subjects completed an 8‐week training program on a rowing ergometer. Three days before the first, and 3 days after the last training session, blood samples were drawn from an antecubital vein. We found that total plasma S1P concentration was increased after the training. Further analysis of different plasma fractions showed that the training selectively elevated HDL‐bound S1P. This effect was associated with activation of sphingosine kinase in erythrocytes and platelets and enhanced S1P release from red blood cells. We postulate that increase in HDL‐bound S1P level is one of the mechanisms underlying beneficial effects of regular physical activity on cardiovascular diseases.

Reference Values of Maximal Oxygen Uptake for Polish Rowers

Abstract The aim of this study was to characterize changes in maximal oxygen uptake over several years and to elaborate current reference values of this index based on determinations carried out in large and representative groups of top Polish rowers. For this study 81 female and 159 male rowers from the sub-junior to senior categories were recruited from the Polish National Team and its direct backup. All the subjects performed an incremental exercise test on a rowing ergometer. During the test maximal oxygen uptake was measured with the BxB method. The calculated reference values for elite Polish junior and U23 rowers allowed to evaluate the athletes’ fitness level against the respective reference group and may aid the coach in controlling the training process. Mean values of VO2max achieved by members of the top Polish rowing crews who over the last five years competed in the Olympic Games or World Championships were also presented. The results of the research on the “trainability” of the maximal oxygen uptake may lead to a conclusion that the growth rate of the index is larger in case of high-level athletes and that the index (in absolute values) increases significantly between the age of 19-22 years (U23 category).

Characteristics of the Respiratory Muscle Strength of Women and Men at Different Training Levels

Abstract Introduction. The objective of the study was to determine the maximal inspiratory mouth pressure (PImax) of highly trained male and female athletes competing in endurance sports and of non-training students of both sexes. Analysis was conducted of the dependence of PImax levels on somatic indices and training experience. The reproducibility of the method for measuring PImax index was determined. Material and methods. The study examined a total of 234 training and non-training individuals (78 women and 156 men). The test subjects were measured for PImax, as well as inspiratory time, active time, passive time and diaphragm relaxation time. A group of 59 women and men (training and non-training) were tested a second time within 5-7 days of the first test to determine the reproducibility of the PImax measurements. Results and conclusion. The measurements were found to be highly reproducible (between the first and second tests no statistically significant differences were found, all spirometric indices included in the study were shown to demonstrate a significant correlation, and total error for all of the analyzed indexes was between 11.1 and 24.3%). Reference ranges for PImax were determined for women and men at different training levels. PImax was shown to have a positive dependence on somatic indices characterizing male and female body mass.

Effects of Endurance Training on Functional Status of the Respiratory Muscles in Healthy Men

Abstract Introduction. The aim of the study was to assess the influence of an 8-week endurance training program on the functional status of the respiratory muscles and breathing efficiency. Material and methods. Thirteen healthy, untrained, male students of Physical Education volunteered to participate in the study. Before and after the subjects completed the training program, they were subjected to anthropometric and spirometric measurements, and performed an incremental stress test. The spirometric measurements included maximal inspiratory pressure (PImax), active time, passive time, and diaphragm relaxation time. Measuring PImax is a simple method of evaluating the strength of the inspiratory muscles. The 8-week training program was performed on a rowing ergometer 3 times per week, using aerobic workloads. Results. The study did not confirm a significant improvement in the measured spirometric parameters following the training program. However, we observed a trend of increase in PImax values by 12 ± 21% of borderline after the training program and a significant correlation (p < 0.05) between the changes in PImax and those in VO2 max. Following the training there was also a significant reduction in the amount of body fat by 1.4 kg and an improvement of work capacity. The response of the respiratory system to exercise was also enhanced, as breathing efficiency improved (tidal volume increased in maximal exercise, while lung ventilation, the ventilatory equivalent for oxygen, and breathing frequency decreased in submaximal exercise). Conclusions. The findings of the study suggest that traditional endurance training which is implemented over a 8 weeks is not a sufficiently strong stimulus to cause a significant increase in the strength of the inspiratory muscles.

Ocena zmian o charakterze wczesnej repolaryzacji w grupie młodych sportowców wyczynowych trenujących wioślarstwo. Prevalence and determinants of the early repolarisation pattern in a group of young high endurance rowers.

BACKGROUND The prevalence and significance of the early repolarisation (ER) pattern in the general population has raised a number of questions. Even less data are available on athletes. AIM To determine the prevalence and determinants of ER in a group of young high endurance athletes. METHODS We studied 117 rowers (46% women, mean age 17.5 ± 1.5 years, mean training duration 4.3 ± 1.8 years). On 12-lead electrocardiogram (ECG), we evaluated inferolateral leads for the presence of the ER pattern, defined as at least 0.1 mV elevation of the QRS-ST junction (J point) from the baseline in at least two leads. All subjects underwent detailed echocardiographic study, cardiopulmonary exercise test with evaluation of VO₂max (mean 57.1 ± 8.4 mL/kg/min), and evaluation of complete blood count and biometric parameters (fat tissue, body mass index, body surface area). RESULTS We identified 35 subjects with ER in the inferior and/or lateral leads. The phenomenon was more frequent in males (n = 25, 21.36% of the overall study population) than in females (n = 10, 8.54%, p = 0.01). The training duration in both groups (with or without ER) was similar (4.4 ± 1.5 vs. 4.3 ± 1.8 years, p > 0.05). Athletes with the ER pattern had significantly higher VO₂max (58.8 ± 7.8 vs. 55.3 ± 8.2 mL/kg/min, p = 0.03), lower resting heart rate (58.7 ± 11.3 vs. 65.4 ± 11.9 bpm, p < 0.01), higher haemoglobin level (15.2 ± 0.8 vs. 14.6 ± 1.2 g/dL, p < 0.01), higher red blood cell count (5.31 ± 0.3 vs. 4.98 ± 0.4 million/μL, p = 0.04), and lower fat tissue mass (12.1 ± 4.4 vs. 14.9 ± 6.0 kg, p < 0.01). Compared with the others, the ER group was characterised by a higher left atrial area index (12.2 ± 1.3 vs. 11.5 ± 1.6 cm²/m², p = 0.01), right atrial area index (9.9 ± 1.3 vs. 9.0 ± 1.4 cm²/m², p < 0.01), and right ventricular basal diameter index (2.0 ± 0.2 vs. 1.9 ± 0.2 cm/m², p = 0.04). We found no significant differences in any other cardiac size and function parameters. CONCLUSIONS ER pattern in the inferior and/or lateral leads is a frequent finding in the population of young high endurance rowers. The presence of ER pattern is associated with gender and a number of parameters reflecting the general level of fitness and may be considered an electrophysiological sign of the athletes heart. The significance of these alterations should be evaluated in prospective follow-up studies.

Ocena zmian o charakterze wczesnej repolaryzacji w grupie młodych sportowców wyczynowych trenujących wioślarstwo

BACKGROUND The prevalence and significance of the early repolarisation (ER) pattern in the general population has raised a number of questions. Even less data are available on athletes. AIM To determine the prevalence and determinants of ER in a group of young high endurance athletes. METHODS We studied 117 rowers (46% women, mean age 17.5 ± 1.5 years, mean training duration 4.3 ± 1.8 years). On 12-lead electrocardiogram (ECG), we evaluated inferolateral leads for the presence of the ER pattern, defined as at least 0.1 mV elevation of the QRS-ST junction (J point) from the baseline in at least two leads. All subjects underwent detailed echocardiographic study, cardiopulmonary exercise test with evaluation of VO₂max (mean 57.1 ± 8.4 mL/kg/min), and evaluation of complete blood count and biometric parameters (fat tissue, body mass index, body surface area). RESULTS We identified 35 subjects with ER in the inferior and/or lateral leads. The phenomenon was more frequent in males (n = 25, 21.36% of the overall study population) than in females (n = 10, 8.54%, p = 0.01). The training duration in both groups (with or without ER) was similar (4.4 ± 1.5 vs. 4.3 ± 1.8 years, p > 0.05). Athletes with the ER pattern had significantly higher VO₂max (58.8 ± 7.8 vs. 55.3 ± 8.2 mL/kg/min, p = 0.03), lower resting heart rate (58.7 ± 11.3 vs. 65.4 ± 11.9 bpm, p < 0.01), higher haemoglobin level (15.2 ± 0.8 vs. 14.6 ± 1.2 g/dL, p < 0.01), higher red blood cell count (5.31 ± 0.3 vs. 4.98 ± 0.4 million/μL, p = 0.04), and lower fat tissue mass (12.1 ± 4.4 vs. 14.9 ± 6.0 kg, p < 0.01). Compared with the others, the ER group was characterised by a higher left atrial area index (12.2 ± 1.3 vs. 11.5 ± 1.6 cm²/m², p = 0.01), right atrial area index (9.9 ± 1.3 vs. 9.0 ± 1.4 cm²/m², p < 0.01), and right ventricular basal diameter index (2.0 ± 0.2 vs. 1.9 ± 0.2 cm/m², p = 0.04). We found no significant differences in any other cardiac size and function parameters. CONCLUSIONS ER pattern in the inferior and/or lateral leads is a frequent finding in the population of young high endurance rowers. The presence of ER pattern is associated with gender and a number of parameters reflecting the general level of fitness and may be considered an electrophysiological sign of the athletes heart. The significance of these alterations should be evaluated in prospective follow-up studies.

Indirect Methods of Assessing Maximal Oxygen Uptake in Rowers: Practical Implications for Evaluating Physical Fitness in a Training Cycle

Abstract The aim of the study was to evaluate the usefulness of indirect methods of assessment of VO2max for estimation of physical capacity of trained male and female rowers during a training cycle. A group of 8 female and 14 male rowers performed the maximal intensity test simulating the regatta distance (a 2 km test) and a submaximal incremental exercise test on a rowing ergometer. The suitability of the indirect methods of predicting VO2max during the training cycle was evaluated by performing the tests twice: in females at an interval of five months and in males at an interval of seven months. To indirectly estimate VO2max, regression formulas obtained for the linear relationship between the examined effort indices were utilized based on 1) mean power obtained in the 2 km test, and 2) submaximal exercises after the estimation of PWC170. Although the suitability of the two indirect methods of assessment of VO2max was statisticaly confirmed, their usefulness for estimation of changes in physical fitness of trained rowers during the training cycle was rather low. Such an opinion stems from the fact that the total error of these methods (range between 4.2-7.7% in female and 5.1-7.4% in male rowers) was higher than the real differences in VO2max values determined in direct measurements (between the first and the second examination maximal oxygen uptake rose by 3.0% in female rowers and decreased by 4.3% in male rowers).