Changes in red blood cell parameters during incremental exercise in highly trained athletes of different sport specializations.

Background: During physical exercise, the level of hematological parameters change depending on the intensity and duration of exercise and the individual's physical fitness. Research results, based on samples taken before and after exercise, suggest that hematological parameters increase during incremental exercise. However, there is no data confirming this beyond any doubt. This study examined how red blood cell (RBC) parameters change during the same standard physical exertion in athletes representing different physiological training profiles determined by sport discipline. Methods: The study included 39 highly trained male members of national teams: 13 futsal players, 12 sprinters, and 14 triathletes. We used multiple blood sampling to determine RBC, hemoglobin (Hb), hematocrit value (Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red blood cell distribution width (RDW) before, during (every 3 min), and after (5, 10, 15, 20, and 30 min) an incremental treadmill exercise test until exhaustion. Results: There were no significant exercise-induced differences in RBC parameters between athletic groups. No significant changes were recorded in RBC parameters during the low-intensity phase of exercise. RBC, Hb, and Hct increased significantly during incremental physical exercise, and rapidly returned to resting values upon test termination. Conclusions: The general pattern of exercise-induced changes in RBC parameters is universal regardless of the athlete's physiological profile. The changes in RBC parameters are proportional to the intensity of exercise during the progressive test. The increase in hemoglobin concentration associated with the intensity of exercise is most likely an adaptation to the greater demand of tissues, mainly skeletal muscles, for oxygen.

Sports Participation Promotes Beneficial Adaptations in the Erythrocyte Guanylate Nucleotide Pool in Male Athletes Aged 20-90 Years.

Introduction: The guanine nucleotide pool (GTP, guanosine-5'-triphosphate; GDP, guanosine-5'-diphosphate, and GMP, guanosine-5'-monophosphate) is an essential energy donor in various biological processes (eg protein synthesis and gluconeogenesis) and secures several vital regulatory functions in the human body. The study aimed to predict the trends of age-related changes in erythrocyte guanine nucleotides and examine whether competitive sport and related physical training promote beneficial adaptations in erythrocyte guanylate concentrations. Methods: The study included 86 elite endurance runners (EN) aged 20-81 years, 58 sprint-trained athletes (SP) aged 21-90 years, and 62 untrained individuals (CO) aged 20-68 years. Results: The concentration of erythrocyte GTP and total guanine nucleotides (TGN) were highest in the SP group, lower in the EN group, and lowest in the CO group. Both athletic groups had higher guanylate energy charge (GEC) values than the CO group (p = 0.012). Concentrations of GTP, TGN, and GEC value significantly decreased, while GDP and GMP concentrations progressively increased with age. Conclusion: Such a profile of change suggests a deterioration of the GTP-related regulatory function in older individuals. Our study explicitly shows that lifelong sports participation, especially of sprint-oriented nature, allows for maintaining a higher erythrocyte guanylate pool concentration, supporting cells' energy metabolism, regulatory and transcription properties, and thus more efficient overall body functioning.

Life-long sports engagement enhances adult erythrocyte adenylate energetics.

Regular physical activity reduces age-related metabolic and functional decline. The energy stored in adenine nucleotides (ATP, ADP, and AMP) is essential to enable multiple vital functions of erythrocytes and body tissues. Our study aimed to predict the rate of age-related changes in erythrocyte adenylate energetics in athletes and untrained controls. The erythrocyte concentration of adenylates was measured in 68 elite endurance runners (EN, 20-81 years), 58 elite sprinters (SP, 21-90 years), and 62 untrained individuals (CO, 20-68 years). Resting concentrations of ATP, total adenine nucleotide pool, and ADP/AMP ratio were lowest in the CO group and highest in the SP group. The concentration of erythrocyte ADP and AMP was lowest in the EN group and highest in the CO group. In all studied groups, we found a significant increase in the concentration of most erythrocyte adenylate metabolites with age. For ADP and AMP, the trend was also significant but decreasing. Our study strongly suggests that lifelong sports and physical activity participation supports erythrocyte energetics preservation. Although the direction and the predicted rates of change are similar regardless of the training status, the concentrations of particular metabolites are more advantageous in highly trained athletes than in less active controls. Of the two analyzed types of physical training, sprint-oriented training seems to be more efficient in enhancing erythrocyte metabolism throughout adulthood and old age than endurance training.

Assessment of Nutrition Status in Amateur Windsurfers during Regattas in the Competitive Period-A Field Study.

Windsurfing is a demanding activity that requires a high level of physical fitness as well as appropriate training and nutritional strategies. Therefore, the aim of this study was to assess the dietary intake of amateur windsurfers and consider possible dietary mistakes. This field study was conducted among 10 Polish male amateur windsurfers (aged 22 ± 2 years, mean training experience of 9.5 ± 4 years). Dietary intake was assessed using a standardized 3-day food record. The total energy expenditure of each participant was estimated using a mobile fitness application. The daily energy supply in assessed portions of the windsurfers' food was lower than the estimated demand during the competition. The contribution of macronutrients to the total energy intake adhered to those guidelines, but not with the ones recommended for athletes practicing extreme sports. Daily fluid consumption was insufficient. In the windsurfers' diet, we noticed low consumption of vitamin D and calcium, while cholesterol, sodium, potassium, and phosphorus intake was too high. Nutritional practices of amateur windsurfers during the competitive period do not comply with current sports nutrition guidelines. The results suggest that windsurfers are in need of nutritional education and dietary counseling in order to meet macronutrient intake targets.

Combined Analysis of Blood Ammonia and Lactate Levels as a Practical Tool to Assess the Metabolic Response to Training Sessions in Male and Female Sprinters.

ABSTRACT: Kantanista, A, Kusy, K, Pospieszna, B, Korman, P, Wielinski, D, and Zielinski, J. Combined analysis of blood ammonia and lactate levels as a practical tool to assess the metabolic response to training sessions in male and female sprinters. J Strength Cond Res 35(9): 2591-2598, 2021-Previous research has mainly focused on blood ammonia and lactate concentration changes in response to exercise in laboratory settings. The aim of this study was to present a combined analysis of blood ammonia and lactate levels obtained during various training sessions performed under real training conditions. Differences between the sexes were also analyzed. The study subjects included 9 male and 8 female sprinters competing at the international level. The two-way analyses of variance, with repeated measures (time × sex), for lactate and blood ammonia concentrations during strength, speed (only lactate), speed with baton exchange, and speed endurance training sessions were significant. Blood ammonia and lactate levels obtained during repeated sprints were higher in male than female athletes. Peak lactate concentrations obtained from different training sessions were different in the female (F(3, 18) = 49.82, p ≤ 0.001, η2 = 0.893) and male (F(3, 21) = 312.26, p ≤ 0.001, η2 = 0.978) athletes; post hoc analyses of the men and women showed differences in maximum lactate concentration between training sessions, except in the speed and strength sessions. Peak ammonia concentrations obtained in the different training sessions were also different in the female (F(3, 18) = 121.06, p ≤ 0.001, η2 = 0.953) and male (F(3, 21) = 196.04, p ≤ 0.001, η2 = 0.965) athletes; in both the men and women, significant differences in maximum blood ammonia concentrations were found between the training sessions, except for the speed and speed with baton exchange training sessions. The results of this study indicate that the combined analysis of lactate and blood ammonia concentration provides the coach with valuable additional information about the level of adenosine triphosphate breakdown, the energy system contribution involved in muscle energy coverage during very short, repeated maximal sprints, and, most importantly, allows the coach to check whether preworkout goals were actually met.

Vitamin D and Indices of Bone and Carbohydrate Metabolism in Postmenopausal Women Subjected to a 12-Week Aerobic Training Program-The Pilot Study.

The purpose of this study was to assess the effect of Nordic walking training on the indices of bone and carbohydrate metabolism in relation to 25(OH)D levels in postmenopausal women that were subjected to the outdoor systematic physical activity. The study was performed in 10 postmenopausal women, who participated in a 12-week Nordic walking exercise program, taking place during spring months (March to June). Anthropometric and biochemical parameters were measured before and after the training program. Serum concentrations of 25-hydroksycholekalciferol (25(OH)D), parathyroid hormone (PTH), insulin, glucose, osteocalcin (OC), C-terminal telopeptide of type I collagen (CTX), and calcium were determined. After the Nordic walking exercise program, a significant increase in the serum levels of 25(OH)D and CTX and a decrease in body mass, body mass index (BMI), fat mass, and PTH concentrations were observed. The findings of the present study suggest that 25(OH)D, as important metabolic regulator, plays a role in the modification of bone markers' responses after the outdoor training program, independent of the physical activity effects.

The Effect of Training on Erythrocyte Energy Status and Plasma Purine Metabolites in Athletes.

This study aimed to assess the changes in red blood cell (RBC) energy status and plasma purine metabolites concentration over a one-year training cycle in endurance-trained (EN; n = 11, 20‒26 years), and sprint-trained (SP; n = 11, 20-30 years) competitive athletes in comparison to recreationally-trained individuals (RE; n = 11, 20‒26 years). Somatic, physiological, and biochemical variables were measured in four training phases differing in exercise load profile: transition, general, specific, and competition. Significantly highest values of RBC adenylate energy charge (AEC; p ≤ 0.001), ATP-to-ADP and ADP-to-AMP ratios (p ≤ 0.05), and plasma levels of adenosine (Ado; p ≤ 0.05) were noted in the competition phase in the EN and SP, but not in the RE group. Significantly lowest plasma levels of adenosine diphosphate (ADP; p ≤ 0.05), adenosine monophosphate (AMP; p ≤ 0.001), inosine (Ino; p ≤ 0.001), and hypoxanthine (Hx; p ≤ 0.001) accompanied by higher erythrocyte hypoxanthine-guanine phosphoribosyltransferase (HGPRT) activity (p ≤ 0.001), were observed in the competition phase in both athletic groups. No significant alterations were found in the erythrocyte concentration of guanine nucleotides in any group. In conclusion, periodized training of competitive athletes' results in a favorable adaptation of RBC metabolism. The observed changes cover improved RBC energy status (increased AEC and ATP/ADP ratio) and reduced purine loss with more efficient erythrocyte purine pool recovery (increased HGPRT activity and plasma levels of Ado; decreased Hx and Ino concentration).

Skeletal Muscle Cell Damage Indicators in Volleyball Players after the Competitive Phase of the Annual Training Cycle.

The aim of the study was to evaluate the impact of the competitive phase on physiological and metabolic indices and selected markers of skeletal muscle damage in male volleyball players. The study group consisted of 24 young male volleyball players. During the study, participants underwent two series of measurements, before and after the competitive phase of the annual training cycle. In both study terms, players performed an incremental treadmill running test to determine their ventilatory threshold and maximal oxygen uptake. Venous and capillary blood samples were taken for biochemical analysis. There was no significant difference in the physical fitness level, values of biochemical variables and the level of antioxidant status in the surveyed athletes between the two study terms. Significant changes within skeletal muscle damage markers were observed between the beginning and the end of the competitive period: an increase in the concentration of cellular DNA damage products (8-hydroxy-2'-deoxyguanosine; p < 0.0001) and a decrease in muscle activity of creatine kinase (p<0.05). In spite of the increment in cell damage markers, the unaffected level of physiological and biochemical markers may indicate that the experienced cell destruction did not negatively affect the level of physical fitness. When designing the annual training plan, coaches and athletes need to take into consideration that temporary physiological states - oxidative stress and inflammation - may be required to attain training adaptation.

Chemical and nutritional characteristics of high-fibre rye milling fractions.

BACKGROUND: Many studies have demonstrated the potential health benefits of consuming more high-fibre cereal-based food products. Therefore, there is a need to discover new ways to improve the overall nutritional balance of refined cereal products and focus on increasing their dietary fibre content, at the expense of readily digestible carbohydrates. METHODS: Lab-scale milling and sieving of whole rye grain was used to obtain two fractions rich in dietary fibre. The fractions were analysed and compared, in terms of microstructure, chemical com- position and nutritional quality. RESULTS: The two fractions significantly obtained differed in their particle size and contents of minerals, available saccharides, and nutritional fractions of starch and dietary fibre and its major components. The total dietary fibre concentrations in the coarse and fine fractions were 50.0 and 36.0 g/100 g, respectively, i.e. three and 2.2 times higher than that of wholegrain rye flour. Both fractions also differed in their relative proportions of major fibre components. In the fine fraction, the levels of soluble fibre, as well as soluble arabinoxylans and fructans, were significantly higher than those in the coarse fraction. CONCLUSIONS: It was shown that the application of a simple dry-fractionation method to wholemeal rye flour allows the preparation of two rye products which can serve as concentrated sources of dietary fibre low in available saccharides.

The effects of Nordic Walking training on selected upper-body muscle groups in female-office workers: A randomized trial.

BACKGROUND: Regular Nordic Walking training could improve fitness and reduce tenderness in selected muscle groups in office workers. OBJECTIVE: An assessment of the effects of a 12-week Nordic Walking training program on the perceived pain threshold (PPT) and the flexibility of selected upper-body muscle groups in postmenopausal female office workers. METHODS: 39 office workers were selected at random for the treatment group (NWg, n = 20) and the control group (Cg, n = 19). The persons from the NW group completed a 12-week Nordic Walking training program (3 times a week/1 hour). PPTs measurements in selected muscles and functional tests evaluating upper-body flexibility (Back Scratch - BS) were carried out twice in every participant of the study: before and after the training program. RESULTS: A significant increase in PPT (kg/cm2) was observed in the following muscles in the NW group only: upper trapezius (from 1,32 kg/cm2 to 1,99 kg/cm2), mid trapezius (from 2,92 kg/cm2 to 3,30 kg/cm2), latissimus dorsi (from 1,66 kg/cm2 to 2,21 kg/cm2) and infraspinatus (from 1,63 kg/cm2 to 2,93 kg/cm2). Moreover, a significant improvement in the BS test was noted in the NW group compared with the control group (from -1,16±5,7 cm to 2,18±5,1 cm in the NW group vs from -2,52±6,1 to -2,92±6,2 in the control group). CONCLUSIONS: A 12-week Nordic Walking training routine improves shoulder mobility and reduces tenderness in the following muscles: trapezius pars descendens and middle trapezius, infraspinatus and latissimus dorsi, in female office workers.

Influence of 12-week Nordic Walking training on biomarkers of endothelial function in healthy postmenopausal women.

BACKGROUND: The aim of this study was to evaluate the effects of a 12-week Nordic Walking (NW) intervention on nitric oxide synthase activity (eNOS), levels of antibodies against oxidatively modified low-density lipoproteins (oLAb), plasma antioxidant capacity (TAC), thiobarbituric acid reactive substance (TBARS) concentration, carbohydrate and lipid metabolism, and atherosclerosis risk factors (AIP) in postmenopausal women. METHODS: A sample of 39 women, divided into two comparable groups: training (N.=20) and control (N.=19), took part in the study. Participants in the training group performed a 12-week supervised NW training: 60-minute sessions of exercise, repeated three times per week. The biochemical and anthropometric data were obtained before and after the intervention. During the first and the last training sessions, the individual walking distance in trained group was measured. RESULTS: After the intervention, significant differences in covered distance, body mass, BMI, fat mass, insulin level (P<0.01), systolic blood pressure and TBARS concentration (P<0.05) were found in trained women. CONCLUSIONS: Applied training was able to improve functional capacity and body composition in healthy postmenopausal women. It appears to be no direct link between a significant decrease in the level of systolic blood pressure, the level of eNOS activity, TAC, oLAb and plasma TBARS concentration in trained women. It seems probable that NW training would be more effective for postmenopausal women with more severely impaired endothelial function.

Assessment of respiratory function in girls with scoliosis after thoracoplasty.

BACKGROUND: The aim of the study was to assess pulmonary function in patients after spinal fusion combined with thoracoplasty in comparison with subjects in whom thoracoplasty was not performed, but who underwent intensive rehabilitation. MATERIAL NA DMETHODS: The study population consisted of two groups of adolescent girls about two years after surgical correction of scoliosis by Cotrel-Dubousset method. The subjects in the first group (thoracoplasty group) underwent spinal fusion in combination with thoracoplasty, which consisted in subperiosteal resection of deformed segments of six ribs on top of the rib hump. Patients in the second group (rehabilitation group) had no thoracoplasty, but participated in a 4-week rehabilitation programme based on endurance training. Pulmonary function was assessed in all subjects with resting spirometry. Additionally, maximal oxygen uptake was determined using an indirect method. RESULTS: Spirometric parameters at rest were significantly higher in subjects participating in the rehabilitation program compared to the thoracoplasty patients. VO2max values were similar in both groups, indicating relatively good exercise capacity. CONCLUSIONS: Comprehensive motor rehabilitation based on endurance training has a favorable influence on pulmonary function in patients after surgical correction of scoliosis. A rehabilitation program should be included in the management of patients after spinal fusion combined with thoracoplasty.

Response of oxidative stress markers and antioxidant parameters to an 8-week aerobic physical activity program in healthy, postmenopausal women.

The aim of the study was to assess the influence of an 8-week aerobic physical activity program on oxidative stress markers, antioxidant parameters, and selected metabolic parameters in healthy, postmenopausal women. The study was carried out in a group of 41 healthy women (mean age 65 years) participating in an 8-week cycle ergometer physical workout of moderate intensity. Before and after completing the training program, the following parameters were assessed: total antioxidant status (TAS) and concentrations of thiobarbituric acid reactive substances (TBARS) in plasma, serum levels of antibodies against oxidatively modified low-density lipoproteins (LDL) (oLAB), serum concentrations of glucose, high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), insulin, and reduced glutathione (GSH) concentrations in red blood cells (RBC). Atherogenic index of plasma (AIP) and insulin resistance index (HOMA(IR)) were calculated. The 8-week aerobic physical activity program resulted in significant decrease (p<0.01) in serum glucose and LDL-cholesterol (LDL-C) levels, plasma TBARS concentrations (p<0.05), and in significant decrease of HOMA(IR) (p<0.01). TAS of plasma and GSH concentrations in RBC increased significantly (p<0.01) over the study period. The results show that an 8-week aerobic training enhanced insulin sensitivity, and improved the balance between oxidants and antioxidants in healthy, postmenopausal women.