Exercise-induced changes in lower limbs skin temperature against plasma ATP among individuals with various type and level of physical activity.

The objective of the study was to examine the lower limbs skin temperature (TSK) changes in response to exhaustive whole-body exercise in trained individuals in reference to changes in plasma adenosine triphosphate (ATP). Eighteen trained participants from distinct sport type ‒ endurance (25.2 ± 4.9 yr) and speed-power (25.8 ± 3.1 yr), and 9 controls (24,9 ± 4,3 yr) ‒ were examined. Lower limbs TSK and plasma ATP measures were applied in parallel in response to incremental treadmill test and during 30-min recovery period. Plasma ATP kinetics were inversely associated to changes in TSK. The first significant decrease in TSK (76-89% of V˙ O2MAX) occurred shortly before a significant plasma ATP increase (86-97% of V˙ O2MAX). During recovery, TSK increased, reaching pre-exercise values (before exercise vs. after 30-min recovery: 31.6 ± 0.4 °C vs. 32.0 ± 0.8 °C, p = 0.855 in endurance; 32.4 ± 0.5 °C vs. 32.9 ± 0.5 °C, p = 0.061 in speed-power; 31.9 ± 0.7 °C vs. 32.4 ± 0.8 °C, p = 0.222 in controls). Plasma ATP concentration did not returned to pre-exercise values in well trained participants (before exercise vs. after 30-min recovery: 699 ± 57 nmol l-1 vs. 854 ± 31 nmol l-1, p < 0.001, η2 = 0.961 and 812 ± 35 nmol l-1 vs. 975 ± 55 nmol l-1, p < 0.001, η2 = 0.974 in endurance and speed-power, respectively), unlike in controls (651 ± 40 nmol l-1 vs. 687 ± 61 nmol·l-1, p = 0.58, η2 = 0.918). The magnitude of TSK and plasma ATP response differed between the groups (p < 0.001, η2 = 0.410 for TSK; p < 0.001, η2 = 0.833 for plasma ATP). We conclude that lower limbs TSK change indirectly corresponds to the reverse course of plasma ATP during incremental exercise and the magnitude of the response depends on the level of physical activity and the associated to it long-term metabolic adaptation.

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.

Effects of 12-Week Combined Strength and Endurance Circuit Training Program on Insulin Sensitivity and Retinol-Binding Protein 4 in Women with Insulin-Resistance and Overweight or Mild Obesity: A Randomized Controlled Trial.

Background: Circuit training is an exercise mode, that may include both endurance and resistance components. There are premises that a combination of these two modalities brings additional benefits, particularly in improving insulin sensitivity. The retinol-binding protein 4 (RBP4) may inhibit signaling from insulin metabolic pathways in skeletal muscles, thus developing insulin resistance. This study aimed to evaluate whether moderate intensity circuit training combining strength and endurance exercise induces changes in tissue insulin sensitivity, carbohydrate and lipid metabolism, and serum RBP4 levels in insulin-resistant women. Methods: In this clinical controlled trial women diagnosed with insulin-resistance were randomly divided into two groups. The training group (T) performed circuit training combining strength (50%-80%1RM) and endurance (50%-75%HRR) exercise on five weight and two cardio machines, for 33 minutes, three times per week, for 3 months. Women from the control non-training group (NT) did not change their previous physical activity. At the beginning of the study and after the intervention period, a one-repetition maximum, body mass, and composition, resting heart rate (HR), blood pressure, glucose, insulin, blood lipids, thyroid-stimulating hormone (TSH), insulin-like growth factor-1 (IGF-1), RBP4, and insulin resistance (HOMA-IR) were measured. The results of 27 patients were analyzed using a two-way repeated measures ANOVA. Results: Significant differences in the pattern of change over time between the groups for resting HR (p < 0.010) and total lean mass (p < 0.039) were found. No differences in HOMA-IR, and RBP4 were observed post-study compared to pre-study in the T group. A significant correlation between RBP4 and TSH concentration was found. Conclusion: Twelve-week circuit training combining strength and endurance exercise has minor effects on HOMA-IR, glucose and lipid metabolism, IGF-1, TSH, and RBP4. Although moderate-intensity circuit training is considered safe, its effectiveness in patients with overweight and mild obesity may be insufficient to reduce insulin resistance. Trial Registration: ClinicalTrials.gov: NCT04528693, registered August 23, 2020.

Response of skin temperature, blood ammonia and lactate during incremental exercise until exhaustion in elite athletes.

The study aimed to evaluate the lower limb skin temperature (Tsk) and blood concentrations of lactate (LA) and ammonia (NH3) during exercise and recovery. Eleven elite sprint athletes (25 ± 3.4 yrs) and 11 elite endurance athletes (24.45 ± 5.4 yrs) performed an incremental running test until exhaustion. Body composition was estimated using the DXA method. Thermograms of the anterior and posterior surfaces of the lower limbs were recorded at rest, before each test stage (every 3 min, starting from 10 km h-1 and increasing by 2 km h-1), and in the 5th, 10th, 15th, 20th, and 30th minute of recovery. Endurance athletes had a higher maximum oxygen uptake than sprint athletes (5.0 ± 0.7 vs 4.3 ± 0.4 l·kg-1, p = 0.018), lower percentage of lean content (79 ± 2 vs 83 ± 2%, p < 0.001), and a higher percentage of fat content in the lower limbs (17 ± 2 vs 12 ± 2%, p < 0.001). In both groups, a significant decrease in Tsk was observed compared to resting value (endurance athletes-31.5 ± 0.6 °C; sprint athletes-32.3 ± 0.6 °C), during exercise (p < 0.001) and rewarming during recovery (p < 0.001). However, endurance athletes had a lower Tsk than sprint athletes at the exhaustion point (30.0 ± 1.1 vs 31.6 ± 0.8 °C, p < 0.05) and the pattern of change in Tsk differed between groups (p < 0.001). Tsk in the endurance athletes group decreased throughout the exercise protocol and returned more rapidly to initial values during recovery, while Tsk in the sprint group stabilised between moderate intensity and exhaustion, recovering more slowly after exercise. Both LA (endurance athletes-max 10.2 ± 1.5; sprint athletes-max 10.1 ± 1.4 mmol⋅L-1, p < 0.001) and NH3 (endurance athletes-max 75.6 ± 11.5; sprint athletes-max 76.7 ± 9.0 mmol⋅L-1, p < 0.001) increased during exercise and decreased during recovery (p < 0.001). During exercise, lower levels and slower increases in LA were observed during exercise in the endurance athletes' group (p < 0.05). A negative correlation was revealed between Tsk and fat percentage (r = -0.43 to -0.71, p < 0.05). Tsk was positively correlated with LA during recovery (r = 0.43 to 0.48, p < 0.05), and negatively during recovery (r = -0.45 to -0.54, p < 0.05). Differences between groups in maximum aerobic capacity, the pattern of change in Tsk, and the correlation between Tsk and LA suggest that individuals who decrease less Tsk during exercise and higher Tsk during recovery are those with better aerobic capacity. In addition, athletes with less body fat dissipate heat from their tissues more efficiently.

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.

Subjective assessment and biochemical evaluation of traction therapy in women with chronic low back pain: does body mass index matter? A clinical study.

BACKGROUND: Apart from the positive effect of lumbar traction on structural changes within the spine in patients with low back pain, it is likely that therapeutic effects are correlated with pain biomarkers in the blood. Among them, systemic metabolic factors related to obesity may play an important role. This is the first study designed to examine the effectiveness of traction therapy in two experimental groups with considerably different BMI and to assess relationships between blood biomarkers and low back pain intensity. METHODS: In the prospective clinical trial, women suffering from chronic low back pain were allocated into the normal-weight or obesity groups. Patients in both groups underwent twenty sessions of lumbar traction therapy (30 min a day, continuous mode with a force level of 25-30% of body weight). Before and after therapy subjective assessments of pain (VAS and PPT) were performed, and serum concentrations of aggrecan chondroitin sulfate 846 epitope (CS-846), neuropeptide Y, leptin, adipsin and growth and differentiation factor 15 (GDF-15) were determined. The data were statistically evaluated for 28 women. RESULTS: After therapy, the maximal low back pain decreased in both groups, GDF-15 concentration was reduced in the normal-weight group and increased in the obesity group, and CS-846 concentration decreased in the obesity group. The sensation of PPT in the lumbar spine and mean concentrations of neuropeptide Y, leptin and adipsin did not change in both groups. However, the relationships of GDF-15, leptin, and adipsin concentrations with the perception of pain were revealed. CONCLUSION: Distinct differences between the normal-weight and obesity groups pointed on the role of excessive adipose tissue in aggravating the inflammatory processes and in the development of low back pain. Adipsin, CS-846 and GDF-15 aspire to be the low back pain biomarkers in women with obesity, but there is a need for further research to answer whether they might be considered reliable biomarkers for the prognosis and monitoring of chronic low back treatment. TRIAL REGISTRATION: NCT04507074, registered prospectively on July 6, 2020.

Male and female athletes matched for maximum oxygen uptake per skeletal muscle mass: equal but still different.

BACKGROUND: We matched highly trained competitive male and female athletes using maximal oxygen uptake (V̇O2max) per kg skeletal muscle mass (SMM) to show sex differences in factors limiting V̇O2max. METHODS: Thirteen highly trained male (28±3.0 yr) vs. 13 female (21.3±3.0 yr) endurance athletes and 10 male (23.9±3.8 yr) vs. 10 female sprinters (21.9±3.3 yr) performed an incremental running treadmill test until exhaustion. Main cardiorespiratory variables were measured using ergospirometry. SMM was determined using the dual X-ray absorptiometry method and a regression equation based on measured appendicular lean soft tissue. Basic hematological parameters were obtained from capillary blood samples taken before exercise. RESULTS: In both endurance and sprint groups, male athletes had significantly higher muscle mass (by 8-12%) and substantially lower total fat (by 55-58%). For almost all body composition indicators, the effect size of sex differences was very large (Cohens d>1.4). Male athletes obtained significantly higher values in cardiorespiratory variables (by 12-34%) and factors related to oxygen transport (9-13%). Cohens d of the revealed differences was large or very large in both groups (0.8-2.1 in sprinters and 0.8-2.3 in endurance athletes). CONCLUSIONS: Male and female competitive athletes having the same V̇̇O2max per kg SMM strongly differ in main factors limiting maximum oxygen uptake. These differences are more pronounced in endurance- than in sprint-trained athletes. The strongest differences are seen for body composition (fat, lean, and muscle mass) and central cardiac factors.

No dynamic changes in the expression of genes related to the epigenetic mechanism during acute exercise.

Physical exercise results in structural remodeling in tissues and modifies cellular metabolism. Changes in gene expression lie at the root of these adaptations. Epigenetic changes are one of the factors responsible for such exercise-related alterations. One-hour acute exercise will change DNMT1, HDAC1, and JHDM1D transcriptions in PBMC. This study examined changes in the expression of genes responsible for epigenetic modifications (HDAC1, DNMT1, and JHDM1D) during and after an incremental exercise test on a treadmill and a 30-min recovery. Blood samples from 9 highly trained triathletes were tested. Examination of the transcripts showed no significant changes. Correlations between transcript results and biochemical indices revealed a significant (p = 0.007) relationship between JHDM1D mRNA and the number of monocytes at peak exercise intensity (exhaustion), while there was no significant (p = 0.053) correlation at rest. There are no rapid changes in the mRNA levels of the genes studied in blood cells in competitive athletes during acute exercise and recovery. Due to the small group of subjects studied, more extensive research is needed to verify correlations between transcription and biochemical variables.

Planned Physical Workload in Young Tennis Players Induces Changes in Iron Indicator Levels but Does Not Cause Overreaching.

The current study aimed to examine the impact of the training load of two different training camps on the immunological response in tennis players, including their iron metabolism. Highly ranked Polish tennis players, between the ages of 12 and 14 years, participated in two training camps that were aimed at physical conditioning and at improving technical skills. At baseline and after each camp, blood samples were analyzed, and the fatigue was assessed. The levels of pro- and anti-inflammatory indicators, iron, and hepcidin were determined. The levels of the heat shock proteins, (Hsp) 27 and 70, were also measured. All the effects were evaluated using magnitude-based inference. Although the training camps had different objectives, the physiological responses of the participants were similar. The applied programs induced a significant drop in the iron and hepcidin levels (a small-to-very-large effect) and enhanced the anti-inflammatory response. The tumor necrosis factor α levels were elevated at the beginning of each camp but were decreased towards the end, despite the training intensity being medium/high. The changes were more pronounced in the female players compared to the male players. Altogether, the results suggest that low-grade inflammation in young tennis athletes may be attenuated in response to adequately designed training. To this end, the applied physical workload with a controlled diet and rest-controlled serum iron levels could be the marker of well-designed training.

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.

Temperature and creatine kinase changes during a 10d taper period in sprinters.

Objective.The aim of this prospective cohort study, performed during a 10 d training camp, was to analyze the effect of a series of successive speed-power training sessions on the concurrent circadian changes in resting leg skin temperature and blood creatine kinase (CK) levels and to determine the correlation between them.Approach. Seventeen elite sprinters, aged 22-31 years, were examined. Every morning and evening, capillary blood samples were drawn to assay CK levels. Lower limb skin temperature was measured simultaneously, and thermal images were taken using an infrared camera.Main results. From the first day of the training camp, the base temperature levels began to drop to obtain a significant reduction from the 6th day (male) and from the 8th day (female) to the end of the camp. Simultaneously, CK levels increased in the male group from 8th to the end of the camp, but it did not change significantly in females. Regarding the circadian rhythm, the CK levels always rose during the day and declined during the night. The temperature decreased during the day and increased during the night until the 6th day. After that, the temperature changed oppositely till the end of camp, i.e. it increased during the day and decreased during the night. This could suggest that the training microcycle should last about a week because after this time there may be a disturbance in the temperature circadian rhythm and a significant CK accumulationSignificance. Multi-day speed-power training induced a progressive reduction in resting skin temperature and an elevation in CK levels. It also altered the circadian rhythm of the body skin temperature, which may indicate that after about 6 d of regular exercise, physiological deregulation may occur.

The effect of multi-ingredient intra- versus extra-cellular buffering supplementation combined with branched-chain amino acids and creatine on exercise-induced ammonia blood concentration and aerobic capacity in taekwondo athletes.

BACKGROUND: This study aimed to investigate the effect of multi-ingredient intra- (BA) versus extra- (ALK) cellular buffering factor supplementation, combined with the customary intake of branched-chain amino acids (BCAA) and creatine malate (TCM), on body composition, exercise variables, and biochemical and hematological parameters in 9 elite taekwondo athletes. METHODS: Eight-week randomized double-blind crossover BA (5.0 g·day-1 of ß-alanine) versus ALK (0.07 g·kgFFM-1·day-1 of sodium bicarbonate) supplementation combined with BCAA (0.2 g·kgFFM-1·day-1) and TCM (0.05 g·kgFFM-1·day-1) during a standard 8-week taekwondo training period was implemented. In the course of the experiment, body composition (dual X-ray absorptiometry), aerobic capacity (ergospirometric measurements during an incremental treadmill test until exhaustion), and exercise blood biomarkers concentrations were measured. Data were analyzed using repeated measures within-between interaction analysis of variance with the inclusion of experimental supplementation order. RESULTS: The maximum post-exercise blood ammonia concentration decreased in both groups after supplementation (from 80.3 ± 10.6 to 72.4 ± 10.2 µmol∙L-1, p = 0.013 in BA; from 81.4 ± 8.7 to 74.2 ± 8.9 µmol∙L-1, p = 0.027 in ALK), indicating reduced exercise-related adenosine triphosphate degradation. However, no differences were found in body composition, aerobic capacity, blood lactate concentration, and hematological parameters after neither BA (combined with BCAA and TCM) nor ALK (combined with BCAA and TCM) supplementation. CONCLUSIONS: In highly trained taekwondo athletes, neither extra- nor intracellular buffering enhancement resulting from BA and ALK supplementation, combined with BCAA and TCM treatment, affects body mass and composition, maximum oxygen uptake, and hematological indices, even though certain advantageous metabolic adaptations can be observed.

Aging Athlete's Heart: An Echocardiographic Evaluation of Competitive Sprint- versus Endurance-Trained Master Athletes.

BACKGROUND: Sports training triggers exercise-induced cardiac remodeling (EICR). Sprint- and endurance-trained master athletes are exposed to different hemodynamic stimuli accompanied by aging. The aim of this study was to compare EICR types in light of the Morganroth hypothesis, frequency of abnormalities, and relationships between cardiac traits and age. METHODS: In this observational cross-sectional study, echocardiographic examinations were conducted in 143 sprint-trained (age range, 36-83 years) and 114 endurance-trained (age range, 38-85 years) competitive master athletes. Structural and functional characteristics were compared with population reference values, and EICR types were identified. Athletic groups were compared using t tests and χ2 tests. Relationships with age were assessed using linear regression. RESULTS: In the sprint group, 51.0% of athletes had normal cardiac geometry (nonhypertrophic heart), 4.2% had eccentric hypertrophy, 36.4% had concentric remodeling, and 8.4% had concentric hypertrophy. In their endurance-trained peers, these proportions were 22.8%, 16.7%, 36.8%, and 23.7%, respectively. Many athletes in both groups had structural abnormalities, as assessed using population norms (up to ~81% for septal thickness) but their resting cardiac function was normal. The relationships of structural and functional cardiac characteristics with age were mostly weak to moderate and did not differ between training modalities. CONCLUSIONS: Even though many endurance- and sprint-oriented master athletes exceed population norms for cardiac structure, they do not go beyond the "gray zone" and preserve normal cardiac function. Therefore, physiologic adaptations, rather than pathologic abnormalities, are expected in aging but still active athletes. Inconsistent with the Morganroth hypothesis, EICR is shifted toward normal geometry in sprinters and toward concentric remodeling and hypertrophy in endurance runners. A better understanding of the mechanisms behind cardiac remodeling during aging is needed to adequately predict EICR types in master athletes.

Exercise Response to Real Combat in Elite Taekwondo Athletes Before and After Competition Rule Changes.

ABSTRACT: Janowski, M, Zielinski, J, and Kusy, K. Exercise response to real combat in elite taekwondo athletes before and after competition rule changes. J Strength Cond Res 35(8): 2222-2229, 2021-We hypothesize that recent (2017) changes in competition rules significantly affected kinematic (mechanical activity) and physiological (cardiopulmonary indices and lactate concentration) profile of the taekwondo combat, which is currently becoming more demanding in terms of exercise intensity and fatigue. Twenty two male and female elite taekwondo athletes were followed up for over 2 years. In total, 258 real tournament combats were included in the analysis (133 in old rules and 125 in new rules). Kinematic and physiological characteristics were recorded using a biomonitor (BioHarness 3; Zephyr Technologies) worn by athletes during tournaments. Blood samples were drawn after each combat for lactate concentration. Our research showed that recent amendments of competition rules were linked to a noticeable shift toward higher kinematic output and, consequently, increased physiological response. Significant increments in kinematic variables (3-8%), heart rate (HR) (1.5-1.8%), energy expenditure (EE) (3-5%), overall physiological load (2-4%), and lactate concentration (∼15% immediately after exercise and ∼25% in recovery) suggest that new rules are more demanding, although the statistical effect size is only small or moderate. In conclusion, after competition rule changes, there has been a shift in taekwondo combat profile toward greater body movement dynamics, higher intensity, and greater postexercise fatigue. The values of key indices of exercise response (mechanical activity, HR, EE, and lactate concentration) during tournaments are near or exceeding the maximum attained during progressive exercise until exhaustion. Therefore, more focus is needed on taekwondo-specific high-intensity training and postcombat recovery to adapt athletes to increased competition requirements.

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.

Maximal Oxygen Uptake Adjusted for Skeletal Muscle Mass in Competitive Speed-Power and Endurance Male Athletes: Changes in a One-Year Training Cycle.

We compared the changes in maximum oxygen uptake (V·O2max) calculated per skeletal muscle mass (SMM) with conventional V·O2max measures in a 1-year training cycle. We hypothesized that the pattern of changes would differ between SMM-adjusted and absolute or weight-adjusted values, and the differences between groups of distinct training specialization and status will depend on the measure used. Twelve sprinters (24.7 ± 3.3 years), 10 endurance runners (25.3 ± 5.3 years), and 10 recreationally trained controls (29 ± 4.5 years) performed a treadmill test until exhaustion to determine V·O2max. Their SMM was estimated based on the dual X-ray absorptiometry method and a regression equation. The significance of differences was assessed using analysis of variance (p ≤ 0.05). The pattern of the longitudinal change was not different between V·O2max/SMM and standard measures. Also, the significance of differences between sprinters and endurance athletes remained similar regardless of the V·O2max measure. Sprinters and controls had similar absolute (~4.3 L·min-1) and total weight-adjusted (~52 vs. ~56 mL·min-1·kg) V·O2max, but they significantly differed in SMM-adjusted V·O2max (~110 vs. ~130 mL·min-1·kg SMM-1). In summary, SMM-adjusted V·O2max is not more useful than standard measures to track longitudinal changes in competitive athletes. However, it allows to better distinguish between groups or individuals differing in training status. The results of our study are limited to male athletes.

The Effect of Sports Rules Amendments on Exercise Intensity during Taekwondo-Specific Workouts.

We aimed to compare the change in exercise response to taekwondo-specific circuit workouts before and after competition rule amendments. A total of 240 workouts in 15 elite athletes were analyzed over two years. Physiological and kinematic data were gathered with the wireless Bioharness system along with capillary blood samples for lactate concentration. Progressive exercise tests until exhaustion were periodically performed to obtain reference data. The rule changes resulted in significant increases (mainly medium or large effects) in the physiological (2.9-14.4%) and kinematic (4.8-10.1%) response to taekwondo-specific workouts. The largest increases were for peak breathing rate (12.0%), energy expenditure (6.6%), blood lactate immediately after exercise (10.2%) and at the 30th min of recovery (14.4%), and peak kinematic activity (10.1%). Significant differences between taekwondo-specific workouts and tournament combats persisted after the shift from old to new rules, ranging from 2.4 to 38.5% for physiological and from 2.9 to 15.5% for kinematic variables. The largest workout-combat differences were revealed for post-exercise (15.9%) and recovery (38.5%) blood lactate, peak (-15.8%) and relative (-15.0%) breathing rate, and mechanical (13.5%) and physiological (14.2%) intensity. Our study suggests that the rule amendments significantly modify the exercise response to discipline-specific workouts and that taekwondo-specific training sessions do not fully recreate the tournament demands in terms of physiological and kinematic load.

Plasma Concentration of Irisin and Brain-Derived-Neurotrophic Factor and Their Association With the Level of Erythrocyte Adenine Nucleotides in Response to Long-Term Endurance Training at Rest and After a Single Bout of Exercise.

The study aimed to assess the effect of a single bout of incremental exercise on irisin and BDNF plasma concentrations as related to erythrocyte purine nucleotides concentration at rest and after exercise. Master endurance master athletes (training experience 38 ± 6 years) and a group of untrained participants completed a single bout of progressive incremental exercise test until exhaustion. The dual-energy x-ray absorptiometry and blood collection were performed. Blood was taken twice at rest and 10 min after exercise. Concentrations of ATP, ADP, and AMP were assessed in the erythrocytes. Hypoxanthine and uric acid were determined in plasma using the high-performance liquid chromatography. Plasma concentrations of irisin and BDNF were assessed through the immunoenzymatic method. The ATP level, ATP/ADP ratio and AEC value were significantly higher in the athletic group. A significantly higher concentration of BDNF was it also noted in the trained group that correlated with the erythrocyte energy status at rest. The single session of exercise induced a significant increase in ATP erythrocyte levels in both groups. Both exerkines significantly correlated at rest with red blood cell adenine nucleotides and degradation products (BDNF positively and irisin negatively). The blood concentration of BDNF and irisin, in response to exercise, was not significantly different between groups. Obtained data revealed a higher erythrocyte energy status and lower purine degradation products concentration in master athletes. Also resting plasma exerkines differed substantially between groups. In conclusion, long-term training resulted in exercise adaptation reflected by a higher erythrocyte energy status, lower purine degradation products concentration and modified concentration of exerkines (higher BDNF and lower irisin blood concentrations). Therefore, we consider the training-induced adaptations in master athletes to be beneficial and significant. The moderate level of physical activity in the untrained group, even if sufficient in terms of general health, did not cause any discernible changes.

Change in Lactate, Ammonia, and Hypoxanthine Concentrations in a 1-Year Training Cycle in Highly Trained Athletes: Applying Biomarkers as Tools to Assess Training Status.

Wlodarczyk, M, Kusy, K, Slominska, E, Krasinski, Z, and Zielinski, J. Change in lactate, ammonia, and hypoxanthine concentrations in a 1-year training cycle in highly trained athletes: applying biomarkers as tools to assess training status. J Strength Cond Res 34(2): 355-364, 2020-The aim was to determine changes in biomarker (LA, NH3, purine metabolites) blood concentration during graded exercise and recovery throughout an annual training cycle in highly trained athletes of different training profiles. The study included 12 sprinters (SP, 21-30 years), 11 triathletes (TR, 20-31 years), 12 futsal players (FU, 19-31 years), and 13 amateur runners (AM, 20-33 years). Purine metabolite (hypoxanthine, xanthine, uric acid), ammonia (NH3), and lactate (LA) concentrations were determined at rest, during an incremental treadmill exercise test (every 3 minutes), and during recovery (5, 10, 15, 20, and 30 minutes postexercise) in 4 phases of an annual training cycle. Purine metabolite concentration was determined from plasma, whereas LA and NH3 from whole blood. For LA during exercise and recovery, certain significant differences between training phases within groups were observed for FU, TR, and SP but not for AM. For NH3, the greatest differences between examination points were observed for SP and TR near maximal exercise and in the first few stages of recovery. For hypoxanthine (Hx), the largest amount of differences between examination points was observed for FU, TR, and FU throughout the entire exercise spectrum. Biomarker concentration dynamics change during an incremental exercise test and postexercise in an annual training cycle. Biomarker responses differ depending on training type and magnitude of training loads used in various phases of an annual training cycle. When assessing training status using an incremental exercise test throughout an annual training cycle, NH3 and Hx concentration changes are more sensitive compared with LA.

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).