The effect of exposure to cold on dexterity and temperature of the skin and hands

Objectives. This study aimed to determine the impact of low temperature (-1 °C, +5 °C) on manual dexterity and hand skin temperature after 1 h of exposure when using two types of protective gloves. Methods. Ten male participants wore double gloves or single gloves, when spending 1 h in a climatic chamber at -1, +5 or +20 °C. Before and after the cold exposure, measurements of mean weighted body skin temperature, hand skin temperature, the Purdue Pegboard Test and hand grip strength were performed. Results. There were statistically significant differences in the values of mean weighted body skin temperature and left and right hand skin temperature between the study variants. Conclusion. No effect of cold exposure (-1 °C, +5 °C) on manual dexterity was observed, but there was an effect of -1 °C temperature change on weighted mean skin temperature and hand skin temperature during 1 h of exposure. The decrease in both right and left hand skin temperature after cold exposure was the largest for -1 °C while using single gloves, and differed significantly from the other variants.

Fluid intake at work in foresters working in different thermal conditions

The primary aim of this study was to assess the impact of fluid intake on hydration status indices in men at work. The secondary aim was to determine the type of fluids drunk at work in different thermal conditions. Fifty-nine male foresters were examined before and after one working day during summer, autumn, and winter. Before and after work, urine and blood samples were obtained from foresters. Immediately after a shift, participants completed a questionnaire regarding fluid intake during one working day. The amount of fluid consumed affects the hydration urine indices. Urine specific gravity and urine osmolality significantly decreased with increasing fluid intake (r = - 0.385 and r = - 0.405, respectively). Moreover, an impact of season on the type of fluids consumed by workers was observed. Tea was significantly more often chosen by workers to drink in winter (68%) than in summer (32%) (p = 0.026). The consumption of any non-alcoholic fluids contributes to the daily total water intake, but it is necessary to create individualized fluid replacement plans. Workers should know how much and what types of drinks to consume at work.

The Influence of Fatigue on the Characteristics of Physiological Tremor and Hoffmann Reflex in Young Men

The aim of the study was to determine the relationship between changes in physiological tremor after exercise and changes in the traction properties of the stretch reflex indirectly assessed using the Hoffmann reflex test. The research involved 19 young men practicing canoe sprint (age 16.4 ± 0.7 years, body mass 74.4 ± 6.7 kg, body height 182.1 ± 4.3 cm, training experience 4.8 ± 1.6 years). During resting tests, Hoffmann reflex measurements were performed from the soleus muscle, physiological tremor of the lower limb, and the blood lactate concentration was determined. Then, a graded test was carried out on the kayak/canoe ergometer. Immediately after the exercise and in the 10th and 25th minute following the exercise, Hoffmann's reflex of the soleus muscle was measured. The physiological tremor was measured at 5, 15 and 30 min after exercise. Blood lactate concentrations were determined immediately after physiological tremor. Both the parameters of Hoffmann's reflex and physiological tremor changed significantly after exercise. There were no significant interrelationships between Hoffmann reflex measurements and physiological tremor in resting and post-exercise conditions. No significant correlation was detected between changes in physiological tremor and changes in Hoffmann reflex parameters. It is to be assumed that there is no connection between a stretch reflex and a physiological tremor.

Lifestyle and environmental factors may induce airway and systemic inflammation in firefighters

Health status depends on multiple genetic and non-genetic factors. Nonheritable factors (such as lifestyle and environmental factors) have stronger impact on immune responses than genetic factors. Firefighters work is associated with exposure to air pollution and heat stress, as well as: extreme physical effort, mental stress, or a changed circadian rhythm, among others. All these factors can contribute to both, short-term and long-term impairment of the physical and mental health of firefighters. Increased levels of some inflammatory markers, such as pro-inflammatory cytokines or C-reactive protein (CRP) have been observed in firefighters, which can lead to local, acute inflammation that promotes a systemic inflammatory response. It is worth emphasizing that inflammation is one of the main hallmarks of cancer and also plays a key role in the development of cardiovascular and respiratory diseases. This article presents possible causes of the development of an inflammatory reaction in firefighters, with particular emphasis on airway inflammation caused by smoke exposure.

HIF-1α and NFIA-AS2 Polymorphisms as Potential Determinants of Total Hemoglobin Mass in Endurance Athletes

ABSTRACT

Malczewska-Lenczowska, J, Orysiak, J, Majorczyk, E, Sitkowski, D, Starczewski, M, and Żmijewski, P. HIF-1α and NFIA-AS2 polymorphisms as potential determinants of total hemoglobin mass in endurance athletes. J Strength Cond Res 36(6): 1596-1604, 2022-The aims of this study were to examine (1) the genotype distribution of rs11549465:C>T of the HIF-1α gene and rs1572312:C>A of the NFIA-AS2 gene; (2) the association between the genes and hematological status in endurance-oriented athletes; and (3) the association between the NFIA-AS2 gene and aerobic capacity in cyclists. Two hundred thirty-eight well-trained athletes (female n = 90, male n = 148) participated in the study. Total hemoglobin mass (tHbmass), blood morphology, intravascular volumes, i.e., erythrocyte volume (EV), blood volume (BV) and plasma volume (PV), and aerobic capacity indices, e.g., peak oxygen uptake (V̇o2peak), and power at anaerobic threshold (PAT) were determined. In both studied genes, the CC genotype was predominant. In the HIF-1α gene, there were no differences in genotype and allele distribution among athletes from different disciplines and between sexes. The distribution of genotypes and alleles of the NFIA-AS2 gene differed significantly in male athletes; the frequency of A allele carriers (CA + AA) was significantly higher in cyclists than in rowers and middle- and long-distance runners. The athletes with CC genotype of NF1A-AS2 had significantly higher relative values of: tHbmass (total female athletes, cyclists), PV, BV (cyclists), and EV (total male athletes, cyclists) and PAT (cyclists) than A allele carriers (CA + AA genotypes). In conclusion, our study indicates that NFIA-AS2 rs1572312:C>A polymorphism was associated with hematological status in endurance athletes, as well as aerobic capacity indices in male cyclists. It suggests that this polymorphism may be a determinant of quantity of hemoglobin and intrtavascular volumes, which in turn can have an impact on aerobic performance.

Hydration Status in Men Working in Different Thermal Environments: A Pilot Study

The aim of this study was to determine the effects of different seasons of the year and the time of day (before work vs. after work) on hydration status in men. The study involved sixty foresters who spent most of the work outdoors. During three seasons of the year (summer, autumn, and winter), indices of hydration status (body mass (BM) and percentage change of BM, total body water (TBW) and percentage change of TBW, serum osmolality (Sosm) and percentage change of Sosm, urine osmolality, urine-specific gravity (USG), urine color, and thirst) were determined before work on the first day (time point 1 used as baseline), immediately after work on the first day (time point 2), and before work on the following day (time point 3). USG decreased at time point 2 compared to time point 1 (p < 0.001) and time point 3 (p = 0.03). At time point 2 (p = 0.002) in winter and time point 3 in autumn (p = 0.049), serum osmolality was higher than in summer. In conclusion, the differences in hydration status depended on the time of day and season. A large percentage of foresters come to work inadequately hydrated, especially in colder seasons compared to summer.

Vitamin D Awareness and Intake in Collegiate Athletes

ABSTRACT

Leitch, BA, Wilson, PB, Ufholz, KE, Roemmich, JN, Orysiak, J, Walch, TJ, Short, SE, and Fitzgerald, JS. Vitamin D awareness and intake in collegiate athletes. J Strength Cond Res 35(10): 2742-2748, 2021-Poor vitamin D status is a risk factor for negative health and performance outcomes in athletes, but little is known about how athletes' awareness and beliefs about vitamin D affect their consumption of vitamin D. This observational study investigated awareness of vitamin D for health and performance among collegiate athletes and evaluated the association of vitamin D awareness with its dietary intake. Fifty-two female and 29 male Division I collegiate athletes completed an online vitamin D awareness and dietary intake questionnaire between November 1, 2015, and January 30, 2016. Median intake of vitamin D was 330 International Units (IU), which is below the recommended daily allowance (RDA) of 600 IU, but was greater in male athletes (693 IU) than female athletes (263 IU, p < 0.01). The RDA for vitamin D was met by 62% of men and 30% of women. Athletes responded that vitamin D "probably" or "definitely" will play a role in their health (88.9%) and athletic performance (71.6%). However, only 23.4 and 28.4% of athletes reported concern for their vitamin D levels or believed that they were at risk for deficiency, respectively. Results showed small-to-moderate, positive correlations (r = 0.28-0.495, p < 0.05) between aspects of vitamin D awareness and vitamin D intake, particularly with supplemental forms of vitamin D. Given the lack of awareness concerning risk of vitamin D deficiency, and the links between aspects of vitamin D awareness and vitamin D intake, nutritional education programs designed to increase vitamin D awareness in athletes may be an effective strategy to reduce deficiency.

Vitamin D and upper respiratory tract infections in young active males exposed to cold environments

INTRODUCTION AND OBJECTIVE

Performing indoor and outdoor work in cold environments may result in various adverse effects on human health and may lead to increased risk of respiratory infection. The aim of this study was to determine the relation of vitamin D status to secretory immunoglobulin A concentration, leucocyte counts, cytokine concentrations and incidence of upper respiratory tract infection (URTI) episodes in young active men during an autumn-winter period.

MATERIAL AND METHODS

The effect of work in a cold microclimate was studied among 23 young active male ice hockey players during a 19-week study period. Blood and saliva samples were collected 7 times during the study period. Incidence of URTI was evaluated using WURSS 21. White blood cell, neutrophil, lymphocyte, monocyte, eosinophil and basophil counts, concentrations of 25(OH)D, C-reactive protein, cortisol, IL-1ra, IL-10, IL-1β and immunoglobulins A, M and G, were determined in the blood. Secretory immunoglobulin A, A1 and A2 and cortisol were analysed in saliva. Spearman's correlations were used to evaluate relationships between initial or final 25(OH)D concentration and URTI incidence, as well as the immune and endocrine markers. Differences in URTI episodes, immune and endocrine parameters between sufficient ( ≥20 ng·ml ^-1) and deficient (<20 ng ·ml ^-1) vitamin D status groups were compared with the Mann-Whitney test.

RESULTS

There were no statistically significant correlations between mucosal and blood markers or URTI incidence and initial and final 25(OH)D concentrations. Immune, endocrine and URTI variables did not differ between deficient and sufficient vitamin D status groups.

CONCLUSIONS

25(OH)D concentration has no impact on mucosal and systemic immunity, nor on URTI episodes.

Utility of Novel Hypochromia and Microcythemia Markers in Classifying Hematological and Iron Status in Male Athletes

In athletes, no reliable indices exist for an unambiguous evaluation of hematological and iron status. Therefore, the utility of some new red blood cell (RBC) parameters was explored in 931 elite male athletes aged 13–35 years. To diagnose iron status, the values of ferritin and soluble transferrin receptor (sTfR), total iron binding capacity (TIBC), and basic blood morphology were determined in blood. The new hematological markers included among others: mean cellular hemoglobin content in reticulocytes (CHr), percentage of erythrocytes (HYPOm) and reticulocytes (HYPOr) with decreased cellular hemoglobin concentration, percentage of erythrocytes (LowCHm) and reticulocytes (LowCHr) with decreased cellular hemoglobin content, mean volume of reticulocytes (MCVr), and percentage of erythrocytes with decreased volume (MICROm). Despite adverse changes in reticulocyte hypochromia indices (CHr, LowCHr, HYPOr; p < 0.001) in the iron depletion state, the area under the receiver operating characteristic curve (AUC-ROC) values calculated for them were relatively low (0.539–0.722). In iron-deficient erythropoiesis (IDE), unfavorable changes additionally concern microcythemia indices in both reticulocytes and erythrocytes (MCVr, MCV, MICROm, and red cell volume distribution width—RDW), with especially high values of AUC-ROC (0.947–0.970) for LowCHm, LowCHr, and CHr. Dilutional sports anemia was observed in 6.1% of athletes. In this subgroup, only hemoglobin concentration (Hb), hematocrit (Hct), and RBC (all dependent on blood volume) were significantly lower than in the normal group. In conclusion, the diagnostic utility of the new hematology indices was not satisfactory for the detection of an iron depletion state in athletes. However, these new indices present high accuracy in the detection of IDE and sports anemia conditions.

Upper Respiratory Tract Infection and Mucosal Immunity in Young Ice Hockey Players During the Pretournament Training Period

Orysiak, J, Witek, K, Malczewska-Lenczowska, J, Zembron-Lacny, A, Pokrywka, A, and Sitkowski, D. Upper respiratory tract infection and mucosal immunity in young ice hockey players during the pretournament training period. J Strength Cond Res 33(11): 3129-3135, 2019-The aim of this study was to determine the effects of 17 days of training during preparation for the Ice Hockey Under 18 World Championship of the Polish ice hockey national team on the mucosal immune function and monitor upper respiratory tract infection (URTI) incidence before, during, and after the competition. Twelve male ice hockey players (age, 17.7 ± 0.5 years) were recruited for this study. The first saliva and blood collection took place at the beginning of the training camp (without training at the training camp), the second one was collected on the 9th day of the training camp immediately after the intensification of training, and the third collection was performed on the 13th day of training (4 days before leaving for the World Championship) in the tapering phase. To assess the mucosal immune function, concentrations of secretory immunoglobulin A (sIgA), sIgA1, and sIgA2 were analyzed in saliva. Cortisol concentration and creatine kinase activity were determined in blood, as indicators of stress and muscle damage, respectively. The Wisconsin Upper Respiratory Symptom Survey-21 questionnaire was used to assess URTI symptoms. A significant increase in the sIgA1 and sIgA2 concentrations was observed in the third collection compared with the second time point (114.45 ± 33.00 vs. 77.49 ± 27.29 and 88.97 ± 25.33 vs. 71.65 ± 32.44 U, respectively). There were no statistically significant correlations between the URTI incidence and saliva variables. In conclusion, the tapering period positively affects the mucosal immune function, especially sIgA1 and sIgA2 concentrations, with no significant change in the frequency of URTI in young ice hockey players.

Three DNA Polymorphisms Previously Identified as Markers for Handgrip Strength Are Associated With Strength in Weightlifters and Muscle Fiber Hypertrophy

Grishina, EE, Zmijewski, P, Semenova, EA, Cięszczyk, P, Humińska-Lisowska, K, Michałowska-Sawczyn, M, Maculewicz, E, Crewther, B, Orysiak, J, Kostryukova, ES, Kulemin, NA, Borisov, OV, Khabibova, SA, Larin, AK, Pavlenko, AV, Lyubaeva, EV, Popov, DV, Lysenko, EA, Vepkhvadze, TF, Lednev, EM, Bondareva, EA, Erskine, RM, Generozov, EV, and Ahmetov, II. Three DNA polymorphisms previously identified as markers for handgrip strength are associated with strength in weightlifters and muscle fiber hypertrophy. J Strength Cond Res 33(10): 2602-2607, 2019-Muscle strength is a highly heritable trait. So far, 196 single nucleotide polymorphisms (SNPs) associated with handgrip strength have been identified in 3 genome-wide association studies. The aim of our study was to validate the association of 35 SNPs with strength of elite Russian weightlifters and replicate the study in Polish weightlifters. Genotyping was performed using micro-array analysis or real-time polymerase chain reaction. We found that the rs12055409 G-allele near the MLN gene (p = 0.004), the rs4626333 G-allele near the ZNF608 gene (p = 0.0338), and the rs2273555 A-allele in the GBF1 gene (p = 0.0099) were associated with greater competition results (total lifts in snatch and clean and jerk adjusted for sex and weight) in 53 elite Russian weightlifters. In the replication study of 76 sub-elite Polish weightlifters, rs4626333 GG homozygotes demonstrated greater competition results (p = 0.0155) and relative muscle mass (p = 0.046), adjusted for sex, weight, and age, compared with carriers of the A-allele. In the following studies, we tested the hypotheses that these SNPs would be associated with skeletal muscle hypertrophy and handgrip strength. We found that the number of strength-associated alleles was positively associated with fast-twitch muscle fiber cross-sectional area in the independent cohort of 20 male power athletes (p = 0.021) and with handgrip strength in 87 physically active individuals (p = 0.015). In conclusion, by replicating previous findings in 4 independent studies, we demonstrate that the rs12055409 G-, rs4626333 G-, and rs2273555 A-alleles are associated with higher levels of strength, muscle mass, and muscle fiber size.

Vitamin D status and its relation to exercise performance and iron status in young ice hockey players

Objectives

The aim was to examine the association between serum vitamin D concentration and isometric strength of various muscle groups, vertical jump performance, and repeated sprint ability in young ice hockey players. The secondary aim was to determine the association between vitamin D deficiency and indices of iron status.

Methods

Fifty male ice hockey players (17.2±0.9 years) participated in this cross-sectional study. Exercise performance was evaluated using isometric strength measures of upper and lower extremities, vertical jump performance and repeated sprint ability (RSA). Blood samples were collected for the determination of serum 25-hydroxyvitamin D (25(OH)D) and multiple indicies of iron status.

Results

The mean serum 25(OH)D concentration was 30.4 ng·ml^-1 and ranged from 12.5 to 91.4 ng·ml^-1. Eleven participants (22%) had vitamin D deficiency and 20 athletes (40%) had vitamin D insufficiency. Serum 25(OH)D concentration was not positively correlated with isometric muscle strength, vertical jump performance, or RSA after adjusting for age, training experience, fat mass, fat free mass and height. Serum 25(OH)D concentration was not associated with indices of iron status.

Conclusion

Vitamin D insufficiency is highly prevalent in ice hockey players, but 25(OH)D concentration but it is not associated with exercise performance or indices of iron status.

The utility of salivary testosterone and cortisol concentration measures for assessing the stress responses of junior athletes during a sporting competition

BACKGROUND

This study examined the utility of salivary testosterone (T) and cortisol (C) concentration measures for assessing the acute stress responses of junior athletes during a sporting competition.

METHODS

Paired capillary blood and saliva samples were taken from 71 junior athletes (45 males, 26 females) before and after a simulated Olympic weightlifting competition. The concentration measures of salivary T and C were referenced against blood total T (TT) and C (TC) concentrations. All hormones were tested by immunoassay.

RESULTS

The competition promoted an increase in the blood TT concentrations of the male (10.1%±18.7%) and female (12.9%±19.9%) athletes (P<.05), with TC also rising in females (37.5%±69%) and tending to increase in males (23.2%±56.1%). No significant changes in salivary T or C were identified. Locally-weighted regression revealed that salivary T was strongly related to blood TT in males (r² =.84), but not females (r² =-.15), whereas salivary C was moderately related to blood TC in both sexes (r² =.43, r² =.48), respectively.

CONCLUSIONS

A short, high-intensity competition promoted a predictable stress-induced rise in blood TT and TC concentrations. We observed no hormonal stress responses in saliva under the current format, which could be explained by individual variability and blood-saliva differences in hormone kinetics. Still, the salivary T and C measures did show a moderate to strong ability to track individual blood TT (males only) and TC (both sexes) concentrations in a young athletic cohort across a broad physiological range. Recommendations for researchers and practitioners are presented.

Individual and Combined Influence of ACE and ACTN3 Genes on Muscle Phenotypes in Polish Athletes

Orysiak, J, Mazur-Różycka, J, Busko, K, Gajewski, J, Szczepanska, B, and Malczewska-Lenczowska, J. Individual and combined influence of ACE and ACTN3 genes on muscle phenotypes in polish athletes. J Strength Cond Res 32(10): 2776-2782, 2018-The aim of this study was to examine the association between angiotensin-converting enzyme (ACE) and α-actinin-3 (ACTN3) genes, independently or in combination, and muscle strength and power in male and female athletes. The study involved 398 young male (n = 266) and female (n = 132) athletes representing various sport disciplines (ice hockey, canoeing, swimming, and volleyball). All were Caucasians. The following measurements were taken: height of jump and mechanical power in countermovement jump (CMJ) and spike jump (SPJ), and muscle strength of 10 muscle groups (flexors and extensors of the elbow, shoulder, hip, knee, and trunk). The insertion-deletion (I/D) polymorphism of ACE and the R577X polymorphism of ACTN3 were typed using polymerase chain reaction (PCR) and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), respectively. The genotype distribution of the ACE and ACTN3 genes did not differ significantly between groups of athletes for either sex. There was no association between ACE and ACTN3 genotypes (alone or in combination) and sum of muscle strength, height of jump or mechanical power in both jump tests (CMJ and SPJ) for male and female athletes. These findings do not support an influential role of the ACE and ACTN3 genes in determining power/strength performance of elite athletes.

Total Hemoglobin Mass, Aerobic Capacity, and HBB Gene in Polish Road Cyclists

Malczewska-Lenczowska, J, Orysiak, J, Majorczyk, E, Zdanowicz, R, Szczepańska, B, Starczewski, M, Kaczmarski, J, Dybek, T, Pokrywka, A, Ahmetov, II, and Sitkowski, D. Total hemoglobin mass, aerobic capacity, and the HBB gene in polish road cyclists. J Strength Cond Res 30(12): 3512-3519, 2016-The relationship between genes, amount of hemoglobin, and physical performance are still not clearly defined. The aim of this study was to examine the association between-551C/T and intron 2, +16 C/G polymorphisms in the beta hemoglobin (HBB) gene and total hemoglobin mass (tHbmass) and aerobic capacity in endurance athletes. Total hemoglobin mass and aerobic capacity indices, i.e.,V[Combining Dot Above]O2max, oxygen uptake at anaerobic threshold (V[Combining Dot Above]O2AT), maximal power output (Pmax), and power at anaerobic threshold (PAT) were determined in 89 young road cyclists, female (n = 39) and male (n = 50), who were genotyped for 2 polymorphisms in the HBB gene. The relative values of aerobic capacity indices differed significantly among intron 2, +16 C/G polymorphisms of the HBB gene only in female cyclists; athletes with GG genotype had significantly higher values of V[Combining Dot Above]O2max (p = 0.003), V[Combining Dot Above]O2AT (p = 0.007), PAT (p = 0.015), and Pmax (p = 0.004) than C carriers. No relationships were found between the C-carrier model (CC + CG vs. GG in the case of intron 2, +16 C/G and CC + CT vs. TT for -551 C/T polymorphisms of the HBB gene) and relative values of tHbmass. Our results demonstrated that the HBB gene could be related to aerobic capacity, but it seems that it does not result from an increase in the amount of hemoglobin in the blood.

Mucosal immunity and upper respiratory tract infections during a 24-week competitive season in young ice hockey players

The aim of this study was to examine upper respiratory tract infections (URTI) and their associations with resting saliva and blood immune and endocrine parameters in ice hockey players. Twenty-seven participants (age 16.5 ± 0.5 years) completed the 24-week study period. The counts/concentrations of immune and endocrine markers were compared between healthy-prone athletes (≤2 episodes of URTI during the study period) and illness-prone athletes (≥3 episodes of URTI) and between the URTI state (when athletes had infections) and the healthy state (the time without URTI). There were no differences in concentration/counts of saliva and blood immune and endocrine parameters between the illness-prone and illness-free athletes. Athletes had significantly lower sIgA, sIgA1 and sIgA2 concentrations (sIgA: 119.88 ± 66.88, 144.10 ± 75.0 µg/ml; sIgA1: 90.2 ± 40.64, 108.44 ± 29.8 U; sIgA2: 67.58 ± 30.1, 80.3 ± 25.61 U, respectively) and significantly higher WBC, neutrophil, monocyte and eosinophil count values and IL-1ra concentration at the time when they had symptoms of URTI than in the period without symptoms of infections. There were no differences in salivary cortisol concentration between the period of URTI symptoms and the period without URTI symptoms. In conclusion, we observed lower concentrations of salivary immunoglobulins and higher levels of blood immune parameters during URTI in athletes, which may confirm the suppression of mucosal immunity and initiation responses to pathogenic infections by innate immunity.

Expression of SCGB1C1 gene as a potential marker of susceptibility to upper respiratory tract infections in elite athletes - a pilot study

High levels of exercise in athletes result in temporary immunosuppression, which could increase the susceptibility to upper respiratory tract infections. Understanding of immunological mechanisms responsible for this phenomenon could enable optimization of training schemes for elite athletes and avoidance of infection-related episodes of absence during sports championships. The aim of this study was to detect genes that may be responsible for modulation of individual susceptibility to infections. The blood and saliva samples were collected from 10 healthy, medically examined kayakers (4 females and 6 males) aged 24.7 ± 2.3 years. All samples were taken in the morning, after overnight fasting, in a seated position. The ELISA method was used to determine the levels of secretory immunoglobulin A (sIgA) and interleukin 5 (IL-5). Whole genome expression in blood was assessed using microarrays. The study did not reveal any significant correlation between genome expression and sIgA concentration. However, low expression of a gene involved in protection against the common cold – secretoglobin 1C1 (SCGB1C1) – was detected in athletes with high IL-5 concentrations (corrected p = 0.00065; fold change = 3.17). Our results suggest that blood expression of the SCGB1C1 gene might be a marker of susceptibility to upper respiratory tract infections in athletes.

Effect of BDKRB2 Gene -9/+9 Polymorphism on Training Improvements in Competitive Swimmers

The aim of the study was to investigate the possible association between the BDKRB2 gene and training-induced improvements in swimming performance in well-trained swimmers. One hundred Polish swimmers (52 men and 48 women, aged 18.1 ± 1.9 years), who competed in national and international competitions at middle- (200 m) and long-distance events (≥400 m), were included in the study. Athletes' genotype and allele distributions were analyzed in comparison to 230 unrelated sedentary subjects, who served as controls, with the χ test. All samples were genotyped for the BDKRB2 -9/+9 polymorphism by polymerase chain reaction. The effects of genotype on swimming performance improvements were analyzed with two-way (3 × 2; genotype × time) analysis of variance with metric age as a covariate. The training period of 1.9 ± 0.4 years had a significant (p < 0.01) effect on swimming performance, both in female and male athletes. Both in female and male athletes, the BDKRB2 gene -9/+9 polymorphism had no significant effect on swimming performance. An interaction effect of BDKRB2 gene -9/+9 polymorphism × time was found for swimming performance only in male athletes. Post hoc analyses showed that swimmers with the +9/+9 BDKRB2 genotype had a greater improvement in swimming performance than swimmers with the -9/+9 polymorphism (p ≤ 0.05). No interaction effects for gender × BDKRB2 gene -9/+9 polymorphism were found for either swimming performance or improvement in swimming performance. These results suggest that the response to long-term exercise training could be modulated by the BDKRB2 gene -9/+9 polymorphism in male athletes. In well-trained swimmers, BDKRB2 gene variation was not found to be an independent determinant of swimming performance.

The influence of hypoxic physical activity on cfDNA as a new marker of vascular inflammation

The phenomenon of circulating cell-free DNA (cfDNA) is important for many biomedical disciplines including the field of exercise biochemistry and physiology. It is likely that cfDNA is released into the plasma by apoptosis of endothelial cells and circulating endothelial progenitor cells (EPCs), and/or by NETosis of immune cells induced by strenuous exercise. Increases of cfDNA are described to be a potential hallmark for the overtraining syndrome, and might be related to aseptic vascular inflammation in athletes. Yet, the relevance of systemic inflammation and cfDNA with endothelial dysfunction in athletes still remains unclear. In this review article, we provide a current overview of exercise-induced cfDNA release to the circulation with special emphasis on its relationship with apoptosis and NETosis and the effect of hypoxic physical activity on vascular inflammation in athletes.

Overrepresentation of the ACTN3 XX genotype in elite canoe and kayak paddlers

The aim of the study was to examine the association between the ACTN3 R577X polymorphism in canoe sprint athletes (canoe and kayak paddlers) and their results at 200- or 1000-m distance. Eighty-six European white male athletes divided into 2 groups-successful, who were outstanding at national championships, and nonsuccessful in these competitions-and 354 nonathletic controls were included in this study. The R577X polymorphism of ACTN3 was typed using PCR-RFLP. ACTN3 genotype distribution among all tested athletes and controls was in Hardy-Weinberg equilibrium. The odds ratio (OR) for successful 1000-m athletes harboring the XX genotype compared with sedentary controls was 2.95 (95% confidence interval [CI]: 1.37-6.35), but the OR for nonsuccessful 200-m athletes having the XX genotype compared with controls was 2.64 (95% CI: 1.30-5.36). These results suggest that factors associated with the ACTN3 XX genotype in canoe and kayak paddlers might provide some competitive advantage in performance at 1000 m, but it seems to limit at 200 m. Further studies aimed at development of training strategies based on genetic factors are needed.

Relationship Between ACTN3 R577X Polymorphism and Physical Abilities in Polish Athletes

The purpose of this study was to examine the association between α-actinin 3 (ACTN3) R577X polymorphism and physical abilities of male athletes performing various sports (volleyball, ice hockey, canoeing, swimming). One hundred eighty-five subjects were recruited for the study. The following measurements were taken: height of jump and power output in countermovement jump and spike jump (SPJ) and muscle strength of 10 muscle groups. The R577X polymorphism of ACTN3 was typed using polymerase chain reaction restriction fragment length polymorphism. The results showed that RR genotype carriers develop greater power output in SPJ than RX and XX individuals (44.6 ± 11.1, 42.6 ± 11.0, and 38.4 ± 7.9 W·kg(-1) for RR, RX, and XX genotypes, respectively) and height of jump in SPJ (0.537 ± 0.075, 0.523 ± 0.072, and 0.498 ± 0.053 m for RR, RX, and XX genotypes, respectively). Muscle strength did not differ between genotype groups. This suggests that the ACTN3 gene has a greater impact on determining dynamic movements than influencing static muscle strength.

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.

The association between ace gene variation and aerobic capacity in winter endurance disciplines

The aim of the study was to examine the possible relationship between I/D polymorphism of ACE gene and selected indices of aerobic capacity among male and female athletes practising winter endurance sports. Sixty-six well-trained athletes (female n = 26, male n = 40), aged 18.4 ± 2.8 years, representing winter endurance sports (cross-country skiing, n = 48; biathlon, n = 8; Nordic combined, n = 10) participated in the study. Genotyping for ACE I/D polymorphism was performed using polymerase chain reaction. Maximal oxygen consumption (VO2max), maximal running velocity (Vmax) and running velocity at anaerobic threshold (VAT4) were determined in an incremental test to volitional exhaustion on a motorized treadmill. The ACE genotype had no significant effect on absolute VO2max, relative VO2max (divided by body mass or fat free body mass), VAT4 or Vmax. No interaction effect of gender x ACE genotype was found for each of the examined aerobic capacity indices. ACE gene variation was not found to be a determinant of aerobic capacity in either female or male Polish, well-trained endurance athletes participating in winter sports.

Total haemoglobin mass, blood volume and morphological indices among athletes from different sport disciplines

INTRODUCTION

Haemoglobin is a key determinant of maximal oxygen uptake. This study's objective was to assess total haemoglobin mass (tHb-mass), as well as blood volume and morphological indices in athletes training different sports disciplines.

MATERIAL AND METHODS

This study was conducted on 176 endurance and non-endurance athletes (males and females). tHb-mass, blood volume (BV), plasma volume (PV), and red cell volume (RCV) were determined by optimized carbon monoxide rebreathing method. Haemoglobin concentration (Hb), haematocrit (Hct), red blood count (RBC) were also determined.

RESULTS

In endurance sports, gender regardless, no significant differences in relative mean values of tHb-mass (12.8-13.1 g/kg - males; 10.4-10.6 g/kg - females), BV (90.8-94.0 ml/kg - males; 82.7-86.9 ml/kg - females), RCV (36.6-38.0 ml/kg - males; 31.1-31.5 ml/kg - females) or of PV in males (54.2-56.4 ml/kg) were observed. The above indices' relative values, gender regardless, were significantly lower in judo (11.2 ±0.7 g/kg, 81.8 ±5.9 ml/kg, 48.6 ±4.5 ml/kg and 33.1 ±2.0 ml/kg - males; 9.3 ±0.7 g/kg, 74.3 ±5.6 ml/kg, 46.4 ±4.0 ml/kg and 27.9 ±2.1 ml/kg - females) compared to endurance sports (p < 0.001). No substantial differences were observed in morphological blood indices in males, whereas this differentiation was found between certain sports in female athletes.

CONCLUSIONS

The lack of differences in tHb-mass, BV, PV and RCV in endurance sports and presence of this differentiation between various sports shows that the types of training might affect levels of mentioned indices. Measurements of tHb-mass and BV parameters prove Hb, Hct and RBC to have limited value for haematological status evaluations.