NO ASSOCIATION BETWEEN tHbmass AND POLYMORPHISMS IN THE HBB GENE IN ENDURANCE ATHLETES.

The aim of this study was to examine the association between tHbmass and HBB gene polymorphisms in athletes of endurance disciplines. Eighty-two well-trained athletes (female n=36, male n=46), aged 19.3 ± 2.7 years, representing cross country skiing (n=37) and middle- and long-distance running (n=45), participated in the study. Genotyping for 2 polymorphisms in the HBB gene (- 551C/T and intron 2, +16 C/G) was performed using restriction fragment length polymorphism analysis. Total haemoglobin mass (tHbmass) was determined by the optimized carbon monoxide rebreathing method. Blood morphology, indices of iron status (ferritin, transferrin receptor and total iron binding capacity) and C reactive protein were also determined. No differences were found in the HBB genotype and allele frequencies between male and female athletes. Regardless of the polymorphisms, no relationships were found between HBB genotypes as well as alleles and relative values of tHbmass, expressed per body mass (g · kg(-1) BM), both in female and male athletes. Our results demonstrated that -551 C/T and intron 2, +16 C/G polymorphisms of the HBB gene have no association with total haemoglobin mass in endurance athletes. It cannot be ruled out that several polymorphisms, each with a small but significant contribution, may be responsible for the amount of haemoglobin.

Comparison of physiological reactions and physiological strain in healthy men under heat stress in dry and steam heat saunas.

The aim of the paper was to follow up major physiological reactions, provoked by heat stress during dry and wet sauna baths. A physical strain index and subjective estimation of heat comfort of subjects who had not taken sauna baths before was also evaluated. Ten healthy males aged 25-28 underwent a dry sauna bath and then after a one-month break they underwent a steam sauna bath. Each time, they entered the sauna chamber 3 times for 15 minutes with five-minute breaks. During breaks they cooled their bodies with a cold shower and then rested in a sitting position. Before and after the baths, body mass and blood pressure were measured. Rectal temperature and heart rate were monitored during the baths. The physiological strain index (PSI) and cumulative heat strain index (CHSI) were calculated. Subjects assessed heat comfort by Bedford's scale. Greater body mass losses were observed after the dry sauna bath compared to the wet sauna (-0.72 vs. -0.36 kg respectively). However, larger increases in rectal temperature and heart rate were observed during the wet sauna bath (38.8% and 21.2% respectively). Both types of sauna baths caused elevation of systolic blood pressure, but changes were greater after the dry one. Diastolic pressure was reduced similarly. Subjective feelings of heat comfort as well as PSI (4.83 ± 0.29 vs. 5.7 ± 0.28) and CHSI (76.3 ± 18.4 vs. 144.6 ± 21.7) were greater during the wet sauna bath. It can be concluded that due to high humidity and reduction of thermoregulation mechanisms, the wet sauna is more stressful for the organism than the dry sauna, where the temperature is higher with low humidity. Both observed indexes (PSI and CHSI) could be appropriate for objective assessment of heat strain during passive heating of the organism.

Modulatory effect of N-acetylcysteine on pro-antioxidant status and haematological response in healthy men.

The aim of this study was to follow up whether the modification of pro-antioxidant status by 8-day oral application of N-acetylcysteine (NAC) in healthy men affects the haematological response, whether there is a direct relationship between antioxidant defences and erythropoietin (EPO) secretion and whether NAC intake enhances exercise performance. Fifteen healthy men were randomly assigned to one of two groups: control or NAC (1,200 mg d(-1) for 8 days prior to and 600 mg on the day of exercise trial). To measure the ergogenic effectiveness of NAC, subjects performed incremental cycle exercise until exhaustion. NAC administration significantly influenced the resting and post-exercise level of glutathione (+31%) as well as the resting activity of glutathione enzymes (glutathione reductase, -22%; glutathione peroxidase, -18%). The oxidative damage markers, i.e., protein carbonylation and lipid peroxidation products (thiobarbituric acid reactive substance) were reduced by NAC by more than 30%. NAC noticeably affected the plasma level of EPO (+26%), haemoglobin (+9%), haematocrit (+9%) and erythrocytes (-6%) at rest and after exercise. The mean corpuscular volume and the mean corpuscular haemoglobin increased by more than 12%. Plasma total thiols increased by 17% and directly correlated with EPO level (r = 0.528, P < 0.05). NAC treatment, contrary to expectations, did not significantly affect exercise performance. Our study has shown that 8-day NAC intake at a daily dose of 1,200 mg favours a pro-antioxidant status and affects haematological indices but does not enhance exercise performance.

Activity of selected enzymes in erythrocytes and level of plasma antioxidants in response to single whole-body cryostimulation in humans.

The influence of extremely low temperatures on the human body and physiological reactions is not fully understood. The aim of this research was to estimate the influence of a single exposure to cryogenic temperature (-130 degrees C), without subsequent kinesiotherapy, on the activity of the most crucial antioxidant enzymes in erythrocytes: superoxide dismutase (SOD), catalase (CAT), glutathione reductase (R-GSSG), glutathione peroxidase (GPx) and glutathione transferase (T-GSH). In the plasma, the concentrations of glutathione, uric acid, albumins and extra-erythrocyte haemoglobin as components of the non-enzymatic antioxidant system were evaluated. The subjects were 10 healthy young men. Blood was sampled in the morning on the day of cryostimulation, 30 min after cryostimulation and the next morning. The enzymatic response of the antioxidant defence to the influence of the extremely low temperature resulted in an immediate, significant, increase in GPx and R-GSSG activities, but a decrease in CAT and T-GSH activities. We observed an increase in the concentrations of all the examined non-enzymatic antioxidants, especially extra-erythrocyte haemoglobin and uric acid, which had both increased further the day after cryostimulation. The results indicate that a single stimulation with cryogenic temperatures results in oxidative stress in a healthy body, but that the level of stress is not very high. It seems that in this case the most significant role in the antioxidant mechanisms is played by peroxidase.

The comparison of antioxidant and hematological properties of N-acetylcysteine and alpha-lipoic acid in physically active males.

The aim of this study was to follow up whether the modification of pro-antioxidant status by oral thiol administration such as N-acetylcysteine and alpha-lipoic acid affects the hematological response. Twenty-eight healthy men participated in two independent experiments. Subjects were randomly assigned to one of four groups: controls (C(NAC) and C(ALA)), N-acetylcysteine (NAC) and alpha-lipoic acid (ALA). 1200 mg of N-acetylcysteine, 600 mg of alpha-lipoic acid or placebo were administered for 8 days in two doses. NAC or ALA administration significantly elevated plasma total antioxidant status (TAS) and reduced protein carbonylation (PC) and lipid peroxidation (TBARS) by more than 30 %. The reduced glutathione (GSH) and hematological parameters changed only in response to NAC administration. NAC significantly elevated the level of GSH (+33%), EPO (+26%), Hb (+9%) and Hct (+9%) compared with C(NAC). The mean corpuscular volume (MCV) and the mean corpuscular hemoglobin (MCH) also increased by more than 12% after NAC. The numerous negative or positive correlations between the measures of TAS, PC, TBARS and hematological parameters were found, which suggest the NAC-induced interaction between pro-antioxidant and hematological values. Our study has shown that both N-acetylcysteine and alpha-lipoic acid intake reveal an antioxidant action, but only N-acetylcysteine improves the haematological response.

The effect of repeated whole-body cryostimulation on the HSP-70 and lipid metabolisms in healthy subjects.

The aim of this study was to evaluate the effects of exposure to 30 daily whole body cryostimulation (WBC) on lipid metabolic parameters and serum HSP-70 concentration. The study involved 45 volunteers, homogeneous in terms of diet and daily physical activity. Blood samples were collected before and after the 10(th), the 20(th), and the 30(th) session and one month after the intervention. Total cholesterol, HDL, TG concentrations and Apolipoprotein A-I, ApoB and HSP-70 protein levels were determined in serum. Additionally, the LI (Lipid Index) and the LDL level were calculated. During exposure, positive changes in the lipid profile that included a decrease in the TCh, initiated after the 20th WBC session with a simultaneous decrease in TG and LDL levels, and an increase in the HDL concentration were observed. These changes were accompanied by a downward trend in the ApoB concentration and a decrease in the ApoB:ApoA-I ratio after 30 sessions. The nature of these changes persisted for a month after the exposure. The obtained results indicate metabolic benefits that result from prolonged exposure to cryogenic temperatures, confirming the postulate of using WBC in the regulation of lipid metabolism and the prevention of cardiovascular diseases.

Effect of sex and menstrual cycle in women on starting speed, anaerobic endurance and muscle power.

The aim of our study was to compare the indicators of starting speed, anaerobic endurance and power in women as well as men, and to investigate whether the values of these indicators differ in women during the follicular and luteal phases of the menstrual cycle. The studied group included 16 men and 16 women. The subjects performed the 20-second maximal cycling sprint test. The men performed the test twice at 14-day intervals. The women undertook the test 4 times: twice during the middle of follicular phase and twice in the middle of luteal phase in separate menstrual cycles. Hormonal changes during the menstrual cycle do not influence anaerobic performance, starting speed or anaerobic endurance in women. Anaerobic performance in men is higher than in women with similar aerobic performance expressed as VO2max/LBM (lean body mass). A lower power decrease with time was noted for women than men, with a similar time of maintaining power in both groups. This is evidence of women's better anaerobic endurance compared to men. At the same time, the men had significantly better starting speed rates than women.

Changes in oxidative stress and acid-base balance in men and women following maximal-intensity physical exercise.

Oxidative stress may be caused by an increased rate of ATP resynthesis during physical exercise. The aim of this study was to compare changes in the prooxidant-antioxidant state of blood plasma between men and women after maximal-intensity exercise, and to assess the relationship between these changes and the value of the maximal oxygen uptake (VO(2max)) as well as between these changes and the value of post-exercise disruptions in acid-base balance. Study participants comprised 10 women (20.7 ± 0.5 years) and 10 men (22.3 ± 0.5 years) who were physically active but did not engage in competitive sports training. VO(2max) was determined via treadmill incremental test (VO(2max) relative to body mass: 44.48 ± 1.21 ml/kg/min and 59.16 ± 1.55 ml/kg/min for women and men, respectively). The level of acid-base balance indicators (ABB), lactate concentration (La⁻), the level of total oxidative status (TOS), the level of total antioxidative capacity (TAC), and uric acid (UA) concentration were measured before and after the test. An oxidative stress indicator (OSI) was also calculated. Men showed a significant post-exercise increase in the level of TOS and OSI, while women showed a significant post-exercise increase in the level of TAC. Post-exercise changes in UA concentration were insignificant. Post-exercise changes in TOC in men depended on the absolute values of VO(2max), on VO(2max)/LBM, and on post-exercise changes in La⁻ concentration.

Effect of creatine malate supplementation on physical performance, body composition and selected hormone levels in spinters and long-distance runners.

PURPOSE: The aim of the study was to determine whether creatine malate (CML) supplementation results in similar ergogenic effect in sprinters and long-distance runners. The other goal was to compare changes in body composition, physical performance and hormone levels after six-week training in athletes, divided into subgroups supplemented with creatine malate or taking placebo. RESULTS: Six-week supplementation combined with physical training induced different effects in athletes. Significantly higher increases in relative and absolute peak power and total work (p < 0.05) were found in sprinters compared to other groups. Except for growth hormone, post-exercise venous blood serum hormone levels exhibited no statistically significant differences in athletes. After CML loading period, a significant increase in growth hormone was found in the group of sprinters. CONCLUSIONS: A significant ergogenic effect was found in sprinters, which was reflected by the increase in anaerobic exercise indices and morphological indices and elevated growth hormone level, after graded exercise testing. The significant increase in the distance covered during graded test was only observed in supplemented long-distance runners, whereas no significant changes in maximal oxygen uptake, relative peak power and relative total work were noticed. This could be caused by later anaerobic threshold appearance in exercise test to exhaustion.

Erythrocytic system under the influence of physical exercise and training.

It is obvious that physical performance, endurance capacity and resistance to fatigue in humans are dependent upon many different factors. One factor, the oxygen carrying capacity of blood, seems to be of particular importance. This factor is mainly determined by haemoglobin concentration, number of circulating erythrocytes and the efficiency of their functions. A single bout of physical effort and, even more, repeated exercise may change the morphological indices of blood and influence the erythropoietic processes in the bone marrow. That is why there is so great an interest now attached to the effects of physical exercise on the erythrocytic system. Although in recent years many papers have been published on the subjects their findings pertaining to the effects of single bouts of exercise and systematic training on the erythrocytic system are often contradictory. The haematological parameters in some top-class athletes, particularly those performing in endurance disciplines are lowered at rest. Anaemia has been described in sportsmen, even among the members of Olympic teams. This type of anaemia has been called 'sports anaemia', 'athletes' anaemia' or 'postexercise anaemia' in order to emphasise its character. Among many possible causes which may bring about the development of sports anaemia the most commonly recognised are: postexercise plasma expansion, intensified haemolysis during physical efforts, iron deficiency, losses of erythrocytes by the way of bleeding into the digestive and urinary systems and also some disturbances in erythropoiesis. However, there is evidence of the intensification of erythropoiesis by many factors occurring during physical exercise.

Exercise thermoregulation in Thai and Polish male subjects.

The aim of this study was to compare the efficiency of exercise thermoregulatory functions in Thai and Polish groups. Twelve Thai and 14 Polish healthy male students were included. An exercise test on a bicycle ergometer at 53% of the maximal work load was performed at ambient air temperature of 30 degrees C and relative humidity of 70%. The test was terminated when rectal temperature (Tre) rose by 1.2 degrees C. Duration of this exercise considered as an index of the efficiency of exercise thermoregulatory functions. The duration of test exercise was evidently longer in Thais (44.8 min) than in Polish students (34.1 min). The rate of increase in the internal body temperature was lower in Thais (0.029 degrees C x min-1) than in Poles (0.037 degrees C x min-1) but exercise dehydration as well as the rate of body weight loss were significantly higher in Thais than in Poles. It can be concluded that the exercise thermoregulatory mechanisms are more efficient in Thais. Polish young athletes were poorly adapted to exercise in warm and humid environment and thus they require more exercise training in climatic chamber prior to competitions held in countries with warm and humid climate.

[The effect of aging on the activity of the autonomic nervous system in long distance runners]. / Wplyw starzenia sie na aktywnosc autonomicznego ukladu nerwowego u biegaczy dlugodystansowych.

The aim of the study was to evaluate the effect of endurance physical training on the autonomic function in runners. The study was performed on 20 long distance runners, divided into two groups. The first group of runners contained 12 young men of age of 20-24 years (age 21.75 +/- 1.4 years: mean S.D.--standard deviation). Into the second group 9 experienced runners, who practice long distance running for over 40 years, were qualified. The mean age of those runners was 52.9 +/- 7.2 years. Moreover two control groups, matched for age and gender were recruited. One of them was made up of 12 healthy volunteers (age 21.6 +/- 1.23 years), the second contained 9 men (age 52.9 +/- 7.2 years). In this study, the measurement of the cardiac autonomic nervous system, using the HRV computer assisted programme (Proster, Poland), was performed. The characteristics of the HRV (heart rate variability) were estimated. We have observed, that the RR intervals in runners were longer than in healthy volunteers (1033.5 +/- 185.4 ms vs. 888.1 +/- 115.3 ms. p < 0.01). We have observed a tendency towards increasing of the RR intervals with the increase of age, of the tested person, as well. A reverse tendency, a shortening of the RR intervals with ageing, was observed in the control groups. The standard deviation of the RR intervals in runners was higher than in the control group (p < 0.05). In the young runners we noticed the prevalence of parasympathetic activity, expressed by the HF (high frequency) spectra (875.7 ms2 vs. 816.7 ms2) in comparison with the healthy individuals. In the old runners the prevalence of sympathetic activity, expressed by LF (low frequency) spectra (1088.75 ms2 vs. 220.1 ms2, p < 0.05) and parasympathetic activity (920.38 ms2 vs. 294.25 ms2) in comparison with the control group, was observed. It was expressed by the increase of the LF/HF ratio (0.75 vs. 2.1). The results of our study indicate, that the autonomic, particularly sympathetic, activity in sportsmen is not affected by ageing up to the sixth decade of life.

Comparison of physiological and acid-base balance response during uphill, level and downhill running performed at constant velocity.

The purpose of this study was to compare the physiological and the acid-base balance response to running at various slope angles. Ten healthy men 22.3 ± 1.56 years old participated in the study. The study consisted of completing the graded test until exhaustion and three 45-minute runs. For the first 30 minutes, runs were performed with an intensity of approximately 50% VO2max, while in the final 15 minutes the slope angle of treadmill was adjusted (0°; +4.5°; -4.5°), and a fixed velocity of running was maintained. During concentric exercise, a significant increase in the levels of physiological indicators was reported; during eccentric exercise, a significant decrease in the level of the analyzed indicators was observed. Level running did not cause significant changes in the indicators of acid-base balance. The indicators of acid-base balance changed significantly in the case of concentric muscle work (in comparison to level running) and after the eccentric work, significant and beneficial changes were observed in most of the biochemical indicators. The downhill run can be used for a partial regeneration of the body during exercise, because during this kind of effort an improvement of running economy was observed, and this type of effort did not impair the acid-base balance of body.

Assessment of the antioxidant effectiveness of alpha-lipoic acid in healthy men exposed to muscle-damaging exercise.

The aim of this study was to compare the indices of glutathione antioxidant system and oxidative damage level in resistance trained and untrained subjects and to assess the antioxidant action of alpha-lipoic acid in trained men exposed to muscle-damaging exercise. Thirteen trained and twenty untrained men (NT) participated in the comparative study. Then trained men were randomly assigned to T(CON) group (control) or T(ALA) group (alpha-lipoic acid, 600 mg . day(-1), for 8 days) and performed isometric/isokinetic effort of quadriceps muscles. The study has shown the significantly higher erythrocyte levels of glutathione (GSH), glutathione reductase (GR) and glutathione peroxidase (GPx) in T(CON) than NT but no differences in plasma lipid peroxidation (TBARS) and protein carbonylation (PC). However, total thiol (TT) concentration was two-fold lower in T(CON) than NT group. alpha-Lipoic acid variously influenced the post-exercise levels of GSH (+40%), GR (-24%) and GPx (+29%), but markedly reduced by over 30% the resting and post-exercise TBARS and PC in T(ALA) compared with T(CON). TT concentration significantly increased in T(ALA) but it did not reach the high level which was found in untrained group. It is concluded that alpha-lipoic acid supplementation diminishes oxidative damage. It does not abolish differences in glutathione antioxidant system between untrained and trained subjects but modulates a pro-antioxidant response to the muscle-damaging exercise.

Do changes in bone marrow pressure contribute to the egress of cell from bone marrow?

Pressure was measured in the femoral medullary cavity of rabbits whose femoral muscles were subjected to electrostimulation. After electrostimulation the pressure in the medullary cavity increased fivefold. In groups of experimental animals the number of reticulocytes leaving the bone marrow and the number of reticulocytes in the peripheral blood were determined and it was observed that electrostimulation was followed by a severalfold rise in the amount of reticulocytes in both the bone marrow and the peripheral blood. The authors found that a great role in the egress of reticulocytes from the bone marrow into the circulation is played by regulation of the pressure in medullary cavity effected by changes in blood flow through the bone marrow.

Post-exercise anaemia as a result of exercise overloading of the organism.

The aim of the present study was to determine the relation between the exercise load used in training and the changes in the basic parameters of the erythrocytic system. The experiments were carried out on 33 Wistar rats (females and males). The animals were forced to run at a velocity of 1.47 km/h inside an electrically-driven rotating drum. The experiments were performed for 35 days. In the 1st - (females) and 2nd - (males) group the exercise period was prolonged by 1 min per day on successive days, and by 2 min per day in the 3rd - (females) and 4th - (males) group. Prior to and after the training period the haemoglobin concentration, haematocrit, erythrocyte and reticulocyte counts were determined in the venous blood. Reticulocytes were divided into four age groups and the percentage each particular age group was calculated. All the trained groups manifested a decrease in haemoglobin concentration, hematocrit values and erythrocyte count and a concomitant elevation of the reticulocyte count with a shift towards youngest forms was found. Rats of the 3rd and 4th groups developed post-exercise anaemia.

The effect of intrarenal nickel subsulfide injections upon the activity of selected erythrocyte and bone marrow enzymes in rats.

The experiments were carried out on Wistar rats. The animals were divided into five groups: Group 1: control group; Group 2: the animals received a single intrarenal dose of nickel subsulfide (Ni3S2) in saline; Group 3: the animals receiving a single intrarenal dose of saline; Group 4: the animals receiving a single intrarenal dose of Ag2S in saline; Group 5: the animals receiving a single intrarenal dose of activated charcoal in saline. Prior to the procedure peripheral blood indices were determined. The experiments included animals manifesting polycythemia. Samples of blood and bone marrow were collected and the activities of AchE, GR and G6PD were determined. An increase in the activity of the three studied enzymes was detected in Groups no. 2 and 5.