Acid–Base Balance, Blood Gases Saturation, and Technical Tactical Skills in Kickboxing Bouts According to K1 Rules

Background: Acid–base balance (ABB) is a major component of homeostasis, which is determined by the efficient functioning of many organs, including the lungs, kidneys, and liver, and the proper water and electrolyte exchange between these components. The efforts made during competitions by combat sports athletes such as kickboxers require a very good anaerobic capacity, which, as research has shown, can be improved by administering sodium bicarbonate. Combat sports are also characterized by an open task structure, which means that cognitive and executive functions must be maintained at an appropriate level during a fight. The aim of our study was to analyze the changes in ABB in capillary blood, measuring levels of H+, pCO2, pO2, HCO3−, BE and total molar CO2 concentration (TCO2), which were recorded 3 and 20 min after a three-round kickboxing bout, and the level of technical and tactical skills presented during the fight. Methods: The study involved 14 kickboxers with the highest skill level (champion level). Statistical comparison of mentioned variables recorded prior to and after a bout was done with the use of Friedman’s ANOVA. Results: 3 min after a bout, H+ and pO2 were higher by 41% and 11.9%, respectively, while pCO2, HCO3−, BE and TO2 were lower by 14.5%, 39.4%, 45.4% and 34.4%, respectively. Furthermore, 20 min after the bout all variables tended to normalization and they did not differ significantly compared to the baseline values. Scores in activeness of the attack significantly correlated (r = 0.64) with pre–post changes in TCO2. Conclusions: The disturbances in ABB and changes in blood oxygen and carbon dioxide saturation observed immediately after a bout indicate that anaerobic metabolism plays a large part in kickboxing fights. Anaerobic training should be included in strength and conditioning programs for kickboxers to prepare the athletes for the physiological requirements of sports combat.

Different patterns of chronic hypoxia lead to hierarchical adaptative mechanisms in goldfish metabolism

Some hypoxia-tolerant species, such as goldfish, experience intermittent and severe hypoxia in their natural habitat causing them to develop multiple physiological adaptations. However, in fish, the metabolic impact of regular hypoxic exposure on swimming performance in normoxia is less well understood. Therefore, we experimentally tested whether chronic exposure to constant (30 days at 10% air saturation) or intermittent hypoxia (3hrs in normoxia and 21hrs in hypoxia, 5 days a week) would result in similar metabolic and swimming performance benefits after reoxygenation. Moreover, half of the normoxic and intermittent hypoxic fish were put on a 20-day normoxic training regime. After these treatments, metabolic rate (standard and maximum metabolic rates: SMR and MMR) and swimming performance (critical swimming speed [Ucrit] and cost of transport [COT]) were assessed. In addition, enzyme activities (citrate synthase CS, cytochrome c oxidase COX and lactate dehydrogenase LDH) and mitochondrial respiration were examined in red muscle fibres. We found that acclimation to constant hypoxia resulted in (1) metabolic suppression (-45% SMR, and -27% MMR), (2) increased anaerobic capacity (+117% LDH), (3) improved swimming performance (+80% Ucrit, -71% COT) and (4) no changes at the mitochondrial level. Conversely, the enhancement of swimming performance was reduced following acclimation to intermittent hypoxia (+45% Ucrit, -41% COT), with a 55% decrease in aerobic scope, despite a significant increase in oxidative metabolism (+201% COX, +49% CS). This study demonstrates that constant hypoxia leads to the greatest benefit in swimming performance and that mitochondrial metabolic adjustments only provide minor help in coping with hypoxia.

Protective and Recovery Effects of Resveratrol Supplementation on Exercise Performance and Muscle Damage following Acute Plyometric Exercise

Plyometric exercise (PE) is an effective training method to increase muscle mass and strength. However, excessive or inappropriate conditions might cause exercise-induced muscle damage (EIMD). Resveratrol (RES) is a natural polyphenol plant antitoxin, which improves exercise performance, and exhibits anti-oxidation, anti-inflammatory, and anti-cancer effects. Therefore, this study investigated the effect of RES supplementation on the recovery of muscle damage, inflammation, soreness, muscle power, and anaerobic performance following plyometric-exercise-induced muscle damage (PEIMD). The present study was a double-blind, placebo-controlled research trial. Thirty-six young, untrained males were enrolled into the placebo (n = 12), RES-500 (500 mg RES/day, n = 12), or RES-1000 (1000 mg RES/day, n = 12) group by a jumping height-counterbalanced grouping design. At baseline, to pre-PEIMD, supplements were pre-loaded 7 days before they conducted PEIMD, and the exercise performance, delayed-onset muscle soreness (DOMS) and muscle damage biomarkers were measured over the experimental period at baseline, pre-PEIMD, and post-PEIMD at 2, 24, 48, and 72 h. As a result, we found that, at 72 h post-EIMD, the force peak (FP) and rate of force development (RFD) of the counter movement jump (CMJ) in RES groups showed no significant difference compared to that at baseline but was significantly greater than the placebo group. In the Wingate anaerobic test (WAnT), supplementation in the RES group had a better recovery effect on the relative peak power (RPP), relative mean power (RMP) and fatigue index (FI) (p < 0.05), especially in the high-dose group. For the detection of muscle pain after PEIMD, the RES supplement group was significantly better than the placebo group (p < 0.05). In addition, for muscle damage indexes, such as creatine kinase (CK) and lactate dehydrogenase (LDH), after PEIMD, supplementation with RES could significantly reduce and accelerate recovery (p < 0.05). In addition, the blood biochemical indicators of blood count, liver function, and kidney function showed that RES will not cause adverse risks to the human body. Our results suggest that replenishing RES in advance could effectively reduce muscle pain, increase exercise performance, and decrease muscle damage indicators caused by PEIMD, and the recovery was faster. Therefore, plyometric exercises combined with suitable RES supplementation could be an effective candidate for controlling muscle damage, improving physical adaption, and recovering anaerobic capacity.

The Influence of an 8-Week Training Program with Small-Sided Games on the Anaerobic Capacity of Junior Football Players

"ABSTRACT. Introduction. The level of development of anaerobic capacity at footballers requires the achievement of sporting performance. Objective. The study analyses whether the anaerobic capacity is developed as a result of the participation of the athletes in a training program with small-sided football games. Methods. A group of 40 athletes aged 16-18 years old were grouped in two equal teams, named: experimental group (EG) and control group (CG). During the period of the study, which was between 5.01.2021 – 27.02. 2021, the two groups were exposed to different training programs: the EG in a smallsided football games training program and the CG in a classic way. The following technology was used: Hosand GT.a – to measure HR – and the WittyGateMicrogate2 system for timing of the stress sample. Subjects took the YYIRTL1 sample. SPSS program, variant 23 was used for statistical analysis of the data. Results. The results taken in the initial test (IT) between the two groups had no statistical significance in YYIRTL1 field sample was concerned, but there could be noticed significant differences in the final test (FT) for the parameter indicating the hold time in the anaerobic zone>81%HRmax (U = 67.50, N1 = 20, N2 = 20, twotailed p = .000336, d = 1.46). Conclusions. The study shows that the anaerobic capacity of subjects has developed through the implementation of an 8-week period program where small-sided football games have been used."

Correlation of maximal respiratory exchange ratio with anaerobic power and maximal oxygen uptake in anaerobic trained athletes

Background and Study Aim. The respiratory exchange ratio (RER) is the ratio of the amount of carbon dioxide produced (VCO2) to the amount of oxygen uptake (VO2) is important. It indirectly informs about the predominant metabolic pathway to provide the energy needed during exercise. The relationship of maximal RER with aerobic and anaerobic capacity in athletes remains unclear. The purpose of this study was to investigate the relationship between maximal RER and anaerobic power and maximal oxygen uptake (VO2max) in anaerobic trained athletes. Material and Methods. Thirteen male alpine skiers (age 18.1 ± 3.1 years) competing in national and international competitions participated in the study. Athletes first performed an incremental treadmill run test to determine their VO2max (ml/kg/min), maximal RER (VCO2 / VO2) and maximal running speed (km/h). After 48 hours, the athletes performed the Wingate anaerobic test to determine peak power, mean power, minimum power, and fatigue index. Pearson correlation coefficients were used to examine the relations between variables. Results. Maximal RER was positively correlated with peak power (r = 0.587, p < 0.035), mean power (r = 0.656, p < 0.015) and minimum power (r = 0.674, p < 0.012). Maximal RER did not significantly correlate with fatigue index (p > 0.05). Maximal RER was negatively correlated with the VO2max (r = – 0.705, p < 0.007) and maximal running speed (r = – 0.687, p < 0.01). Conclusions. Maximal RER may be useful for evaluating anaerobic capacity in anaerobic-trained athletes. Measuring the maximal RER values of athletes during incremental exercise may provide information about physiological adaptations in response to physical training.

The effect of menstrual cycle phase on multiple performance test parameters

Objective: To determine changes in flexibility, dynamic balance, agility, vertical jump, aerobic capacity, anaerobic capacity, and muscle strength performances in women in the early follicular and midluteal phases of the menstrual cycle. Material and Methods: The study included eumenorrheic women over 18 years of age. Ovulation was detected using LH urine kits. Physical activity levels were determined using the "International Physical Activity Questionnaire-Short Form". Flexibility was evaluated with the sit-and-reach test, dynamic balance with the Y balance test, agility with the hexagon agility test, anaerobic power with the vertical jump test, aerobic capacity with the 20-meter shuttle run test, anaerobic capacity with the Wingate test, and muscle strength with an isokinetic dynamometer. Results: Twenty women participated in the study. The average age was 22.4 ± 0.9 years, and the average level of physical activity was 1162.2 ± 189.1 MET-min/week. The average menstrual cycle was 30.3 ± 0.5 days. The ‘minimum power’ value in Wingate test was higher during the midluteal phase compared with the follicular phase (p=0.048). The remaining parameters were not statistically different for the two menstrual phases (p>0.05). Conclusion: We conclude that different phases of the menstrual cycle affect performance parameters minimally and do not cause a statistically significant difference. Nevertheless, instead of establishing these changes as ‘clinically non-significant’, each athlete should be evaluated on an individual basis to develop individual training programs by taking into account the phases of the menstrual cycle.