Changes In Blood Lactate Concentration Research Articles

Differences in lactate metabolism between middle- and long-distance runners

It is important for runners and coaches to figure out the characteristics of lactate metabolism in terms of planning the proper training. This study investigated the differences in lactate production and oxidation capacities between middle- and long-distance runners by using blood lactate concentration. We hypothesized that long-distance runners have greater capacity to oxidize lactate and middle-distance runners have greater capacity to produce lactate. In this study, 14 middle- and 14 long-distance male runners performed a multi-stage incremental test until exhaustion. Each running stage was 3-minute with 1-minute rest between stages. Blood lactate concentration was measured at rest and after each stage, and some metrics associated with runner’s capacity to oxidative lactate during moderate intensity exercise were calculated. The changes in blood lactate concentration measured after the final state of the test were modeled as a biexponential time function to evaluate lactate productive and oxidative capacities after high-intensity exercise. During moderate-intensity exercise, long-distance runners showed significant decrease in blood lactate concentrations during the first few stages of the test compared to rest, indicating greater oxidation of lactate than production of lactate during moderate intensity exercise (p<0.05), while middle distance runners showed slight increase in blood lactate concentrations even for the first several stages. Middle-distance runners showed significantly higher amount of lactate produced (p<0.05) and greater lactate oxidation during high-intensity exercise than those in long-distance runners (p<0.01), suggesting that both lactate production and oxidation of middle-distance runners were greater than those of long-distance runners during high-intensity exercise. These results suggest that characteristics of lactate metabolism in middle- and long-distance runners depend partly on exercise intensity. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Evaluation of Blood Lactate among Different Player Roles: A Pilot Study on Competitive Young Male Soccer Players.

Soccer match requires anaerobic and aerobic energetic metabolism. The aim of this pilot study was to investigate the changes in blood lactate concentration in young male soccer players in different playing roles at different time points after the soccer match. Following an initial screening of 134 young soccer athletes, 8 male athletes (average age of 15.5 ± 5 SD) were chosen for their characteristics similar to those of competitive athletes. Players were categorized as goalkeeper, central defender, central midfielder, and forward. Blood lactate concentrations were determined using a portable device at different times (10 min, 5 and 16 h) after the soccer match by a maximum effort test on a treadmill. The data were analyzed by one-way analysis of variance ANOVA, followed by Bonferroni's post-hoc test. The following results (mean ± SD) were obtained: VO2max (%) 60.33 ± 3.10; blood lactate (mM) end match (10 min) 2.17 ± 0.78, post-match-early (after 5 h) 2.2 ± 0.42, postmatch-late (16 h) 3.2 ± 0.84. ANOVA analysis indicated that the blood LA concentrations at end-match (10 min) and post-match-early (5 h) were statistically significative lower than those determined at post-match-late (16 h) (p < 0.05). These results suggest that aerobic mechanisms can also use LA as an energy source, contributing to the reduction of its blood concentration. This effect can be due to reduced maximal work during a soccer match and to the LA removal during exercise at reduced intensity. These data can provide indications for planning suitable training strategies for young male soccer players.

Analysis of Course of Changes in Blood Lactate Concentration in Response to Graded Exercise Test and Modified Wingate Test in Adolescent Road Cyclists.

The purpose of this study was to analyze the course of changes in the blood lactate (BL) concentration in response to the graded exercise test (GXT) and the modified Wingate test (MWT). This study involved 23 male highly trained road cyclists (age: 16.2 ± 1.1 years; experience: 5.0 ± 2.1 years; VO2max 59.0 ± 3.5 mL × kg-1 × min-1). The analysis of BL concentration was conducted using an enzymatic-amperometric electrochemical technique. Our study provided the following information: (i) peak BL concentration in response to GXT (12.86 ± 2.32 mmol × L-1) and MWT (12.85 ± 1.47 mmol × L-1) is expected around the third minute after the completion of the trial; (ii) 60 min is not a sufficient period for BL concentration to return to resting values after GXT; (iii) post-GXT BL removal during the 60 min period is unsteady (3-20 min: -2.6 ± -0.6% × min-1; 20-60 min: -1.6 ± -0.3% × min-1; p-value for comparison < 0.01), whereas post-MWT BL removal during the 12 min period appears to be constant (3-6 min: -2.4 ± -5.6% × min-1, 6-9 min: -2.6 ± -1.8 % × min-1; 9-12 min: -3.1 ± -2.1 % × min-1; p-value for all comparisons < 0.01). When aiming to obtain valuable data regarding the course of changes in BL concentration during the post-exertion period, it is essential to consider the number of measurements and the time points in sample collection for analysis.

Reliability of the 3-Component Model of Aerobic, Anaerobic Lactic, and Anaerobic Alactic Energy Distribution (PCr-LA-O2) for Energetic Profiling of Continuous and Intermittent Exercise.

To assess the test-retest reliability of the continuous (PCr-LA-O2) and intermittent (PCr-LA-O2int) version of the 3-component model of energy distribution in an applied setting. Sixteen male handball players (age 23 [3]y, height 185 [7]cm, weight 85 [14]kg) completed the 30-15 Intermittent Fitness Test (30-15IFT) twice. Performance was assessed by peak speed (speed of the last successfully completed stage of the 30-15IFT [VIFT], in kilometers per hour) and time to exhaustion (in seconds). Oxygen uptake (in milliliters per kilogram per minute) and blood lactate concentrations (in millimoles per liter) were obtained before, during, and until 15minutes after exercise. Total metabolic energy (in joules per kilogram), total metabolic power (in watts per kilogram), and energy shares (in joules per kilogram and percentage) of the aerobic (energy contribution of the aerobic system [WAERint]), anaerobic lactic, and anaerobic alactic (anaerobic alactic energy [WPCrint]) systems were calculated using both model versions, respectively. Test-retest reliability was very good for VIFT (limits of agreement [LoA]: -1.13 to 0.63km·h-1, coefficient of variation [CV%] 1.68), time to exhaustion (LoA: -101 to 38s, CV% 2.92), peak oxygen uptake (LoA: -2.68 to 4.04mL·min-1·kg-1, CV% 1.48), and peak heart rate (-6.9 to 7.7 beats·min-1, CV% 1.1), but moderate for change in blood lactate concentration (LoA: -3.84 to 4.07mmol·L-1, CV% 11.43). Reliability of the modeled total energy and its fractions were high for total metabolic energy (LoA: -1489 to 1177J·kg-1, CV% 2.88), total metabolic power (LoA: -2.0 to 1.9W·kg-1, CV% 3.58), contribution of aerobic (LoA: -1673 to 1283J·kg-1, CV% 3.62), WAERint (LoA: -1760 to 2160J·kg-1, CV% 6.04), and moderate for anaerobic alactic (LoA: -368 to 439J·kg-1, CV% 14.85), WPCrint (LoA: -1707 to 988J·kg-1, CV% 9.98), and energy share of anaerobic lactic concentration (LoA: -229 to 235J·kg-1, CV% 11.43). Considering the inherent fluctuations of the underlying energetics, the reliabilities of both versions of the 3-component model of energy distribution are acceptable for applied settings.

Maximal Fat Metabolism Explained by Lactate-Carbohydrate Model

(1) Background: Maximal fat oxidation (MFO), its associated exercise intensity (Fatmax) and the cross-over point (COP) are known indirect calorimetry-based diagnostics for whole-body metabolic health and exercise. However, large inter- and intra-individual variability in determining their corresponding intensity makes their use inconsistent, whether the intensity is based on power output or oxygen uptake. Blood lactate concentration (BLC) has often reflected a range in MFO and COP, which may offer another non-indirect calorimetry dimension based on the near equilibrium between lactate and pyruvate at the molecular level, which biochemically determines an interchange between lactate and relative rate of carbohydrate (relCHO) and relative rate of fat utilization (relFAO). This paper proposes a new testing approach describing relCHO as a function of BLC, with an individualized half-maximal activation constant of relCHO (kel), to explain and predict the variability in MFO, Fatmax and COP. (2) Methods: Following ethical approval, twenty-one healthy males participated in the incremental cardiorespiratory maximal test, and capillary BLC was measured. Indirect calorimetry relCHO and relFAO were calculated, and a constant kel that reflected 50% of CHO saturation level was estimated as a sigmoid function of BLC (mmol·L−1): relCHO = 100/(1 + kel/BLC2). (3) Results: 86% of relCHO variability was explained by BLC levels. The individualized kel estimations, which were 1.82 ± 0.95 (min/max 0.54/4.4) (mmol·L−1)2 independently explained 55% MFO and 44% of COP variabilities. Multiple regression analysis resulted in kel as the highest independent predictor of Fatmax (adjusted r-square = 22.3%, p &lt; 0.05), whilst classic intensity-based predictors (peak power, maximal oxygen uptake, fixed BLC at 4 mmol·L−1) were not significant predictors. (4) Conclusions: The BLC-relCHO model, with its predictor kel explains the inter- and intra-individual variability in MFO, its exercise intensity Fatmax and power outs at COP through dynamic changes in BLC, fat and carbohydrates regardless of the intensity at which exercise takes place. kel capability as a predictor of MFO, Fatmax and COP independently of their associated intensities provides a new diagnostic tool in physiological exercise testing for health and exercise performance.

What is the physiological impact of reducing the 2,000m Olympic distance in rowing to 1,500m and 1,000m for French young competitive rowers? Insights from the energy system contribution.

French rowing federation reduced the competition distance to 1,500 and 1,000 m in rowers under 16- (U16) and 14-year-old (U14) respectively, to prepare them progressively to the Olympic 2,000 m distance in under 18-year-old (U18). This study aimed to check the hypothesis that relative aerobic (%EAe) and anaerobic (%EAn) energy contributions would be comparable between the competition distances since the more oxidative profile of younger age categories could offset the greater anaerobic contribution induced by shorter rowing races. Thirty-one 12- to 17-year-old competitive rowers performed a race of 2,000, 1,500, or 1,000 m on a rowing ergometer according to their age category. %EAe and %EAn were estimated from oxygen consumption, changes in blood lactate concentration and their energy equivalents. %EAe was lower in U16 than U18 (84.7 vs. 87.0%, p < 0.01), and in U14 than U16 (80.6 vs. 84.7%, p < 0.001). %EAn was higher in U16 than U18 (15.3 vs. 13.0%, p < 0.01), and in U14 than U16 (19.4 vs. 15.3%, p < 0.01). The results did not confirm our initial hypothesis since %EAe and %EAn were significantly different between the race distances, and thus age categories. However, %EAn in U18, U16 and U14 were found to be in the range of values previously found in adult rowers over the 2,000 m Olympic distance (12–30%). Therefore, on a practical level, the strategy implemented by the French rowing federation to reduce the competition distance in the younger age categories could be relevant to progressively prepare them to the physiological requirements encountered over the Olympic distance.

Cold Water Immersion as a Method Supporting Post-Exercise Recovery

The aim of the study was to assess the effect of cold water immersion on changes in blood lactate concentration during post-exercise recovery in swimmers subjected to2-minute exercise test (front crawl swimming movements) using a VASA Swim Ergometer, with the maximum arm speed movements, as during the freestyle technique. The study covered 11 professional swimmers of the MKP Szczecin club, tested twice with a two-week interval. Each participant performed an exercise test twice, once with a passive recovery period, and the second time with cold water immersion after exercise, as a method potentially supporting the post-exercise recovery process. Each time before the test, immediately after and at 3, 6 and 9 minutes after exercise, the concentration of lactate in the capillary blood was measured. Statistical analysis of the obtained results showed that cold water immersion applied immediately after exercise resulted in a faster reduction of lactate concentration. The conducted research confirms that cold water immersion used in post-exercise recovery may be an effective method of restoring optimal physical fitness as part of the training process.

Differences in Physiological and Perceptual Responses to High Intensity Interval Exercise Between Arm and Leg Cycling.

This study compared changes in oxygen uptake (VO2), heart rate (HR), blood lactate concentration (BLa), affective valence, and rating of perceived exertion (RPE) between sessions of high intensity interval exercise (HIIE) performed on the arm (ACE) and leg cycle ergometer (LCE). Twenty three active and non-obese men and women (age and BMI=24.7±5.8year and 24.8±3.4kg/m2) initially underwent graded exercise testing to determine VO2max and peak power output (PPO) on both ergometers. Subsequently on two separate days, they performed 10 1min intervals of ACE or LCE at 75 %PPO separated by 1min of active recovery at 10 %PPO. Gas exchange data, HR, and perceptual responses were obtained continuously and blood samples were acquired pre- and post-exercise to assess the change in BLa. VO2max and PPO on the LCE were significantly higher (p<0.001) than ACE (37.2±6.3 vs. 26.3±6.6ml/kg/min and 259.0±48.0 vs. 120.0±48.1W). Mean VO2 (1.7±0.3 vs. 1.1±0.3L/min, d=2.3) and HR (149±14 vs. 131±17 b/min, d=2.1) were higher (p<0.001) in response to LCE vs. ACE as was BLa (7.6±2.6 vs. 5.3±2.5mM, d=2.3), yet there was no difference (p=0.12) in peak VO2 or HR. Leg cycling elicited higher relative HR compared to ACE (81±5 vs. 75±7 %HRmax, p=0.01), although, there was no difference in relative VO2 (63±6 vs. 60±8 %VO2max, p=0.09) between modes. Affective valence was lower during LCE vs. ACE (p=0.003), although no differences in enjoyment (p=0.68) or RPE (p=0.59) were demonstrated. Overall, HIIE performed on the cycle ergometer elicits higher relative heart rate and blood lactate concentration and a more aversive affective valence, making these modes not interchangeable in terms of the acute physiological and perceptual response to interval based exercise.

Acute Physiological Responses to Resistance Exercise With Continuous Versus Intermittent Blood Flow Restriction: A Randomized Controlled Trial.

The primary goal of this investigation was to examine the physiological responses of blood flow restriction (BFR) resistance exercise (RE) performed with continuous or intermittent BFR and to compare these results to those from conventional high- and low-load RE without BFR. Fourteen men randomly completed the following experimental trials: (1) low-load RE with continuous BFR (cBFR), (2) low-load RE with intermittent BFR (iBFR), (3) low-load RE without BFR (LI), and (4) conventional high-load RE without BFR (HI). For the cBFR, iBFR, and LI exercise trials, participants performed four sets of 30–15–15–15 repetitions of the bilateral leg press (LP) and knee extension (KE) exercises, at an intensity of 20% of their one-repetition maximum (1-RM), at a 1.5-s contraction speed, and with a 1-min rest period between sets. The only difference between the cBFR and iBFR protocols was that the pressure of the cuffs was released during the rest intervals between sets for the iBFR trial. For the HI trial, participants completed four sets of 10 repetitions of the same exercises, at 70% of 1-RM, with a 1-min rest period between sets, and at the same contraction speed. Muscle activity was assessed during each set using superficial electromyography, as well as changes in blood lactate concentration [La–] from baseline at 5 min post exercise and in muscle swelling and plasma volume (%ΔPV) at 5 and 15 min post exercise. There were no significant differences in muscle activity (p < 0.05) across the cBFR, iBFR, and LI protocols at any time point, whereas they were all significantly lower than HI. There were also no significant (p < 0.05) differences across the three low-load RE conditions for [La–],%ΔPV, or muscle swelling. HI elicited significantly (p < 0.05) greater responses than cBFR, iBFR, and LI for all the physiological markers measured. In conclusion, RE combined with cBFR or iBFR induce the same acute physiological responses. However, the largest physiological responses are observed with HI, probably because of the significantly greater exercise volumes. Therefore, releasing the pressure of the restrictive cuffs during the rest periods between sets will not hinder the acute physiological responses from BFR RE.

Ingestion of a moderate dose of alcohol enhances physical exercise-induced changes in blood lactate concentration.

The consumption of alcoholic beverages influences carbohydrate and lipid metabolism, although it is not yet clear whether metabolism during physical exercise at different intensities is also affected. This was the objective of the present study. Eight young and healthy volunteers performed a treadmill test to identify the running speed corresponding to a lactate concentration of 4 mM (S4mM). At least 48 h later, they were subjected to two experimental trials (non-alcohol or alcohol) in which they performed two 1-km running sessions at the following intensities: 1) S4mM; 2) 15% above S4mM. In both trials, blood lactate, triglycerides, and glucose concentrations were measured before and after exercise. The acute alcohol intake increased triglycerides, but not lactate concentration under resting conditions. Interestingly, alcohol intake enhanced the exercise-induced increase in lactate concentration at the two intensities: S4mM (non-alcohol: 4.2±0.3 mM vs alcohol: 4.8±0.9 mM; P=0.003) and 15% above S4mM trial (P=0.004). When volunteers ingested alcohol, triglycerides concentration remained increased after treadmill running (e.g., at S4mM - at rest; non-alcohol: 0.2±0.5 mM vs alcohol: 1.3±1.3 mM; P=0.048). In contrast, glucose concentration was not modified by either alcohol intake, exercise, or their combination. We concluded that an acute alcohol intake changed lactate and lipid metabolism without affecting blood glucose concentration. In addition, the increase in lactate concentration caused by alcohol was specifically observed when individuals exercised, whereas augmented triglycerides concentration was already observed before exercise and was sustained thereafter.

Changes in blood lactate and muscle activation in elite rock climbers during a 15-m speed climb.

The purpose of this study was to investigate the changes in blood lactate concentration (BL) and muscle activity patterns during a 15-m speed climbing competition that consisted of ten consecutive climbing actions on a standardized artificial wall in trained rock climbers. Twelve trained rock climbers participated in this study. Surface electromyography (sEMG) and video signals were synchronized and recorded during climbing. The blood lactate was also tested 3min after completing the climb. The average climbing time was 8.1 ± 2.1s for the 15-m speed climb across all subjects, accompanied by a BL of 7.6 ± 1.9mmol/L. The climbing speed and power firstly increased and then slightly decreased relative to peak value during the 15-m speed climbing. The results showed there was a positive correlation between the BL and the climbing time, r = 0.59, P = 0.043. The sEMG showed the flexor digitorum superficialis (FDS) electric activity was the highest, followed by the biceps brachii (BB) and latissimus dorsi. The instantaneous median frequency of sEMG of FDS and BB significantly decreased during the 15-m speed climbing. All the participants showed the higher sEMG RMS (%) in the terminal phase than that in the initial phase, especially with a greater increase in the left upper limbs. However, the lower limbs muscles presented no significant changes in the sEMG amplitude during climbing. The FDS and BB play an important role in completing the 15-m speed climbing. The median frequency of arm EMG decreased more than that of legs, suggesting more fatigue. The blood lactate concentration increases in the current study suggest that a certain amount of glycolysis supplies energy in completing 15-m speed rock climbing. Based on the current data, it is suggested that muscular endurance of FDS and BB muscles in upper limbs should be improved for our climbers in this study.

An examination of a modified Yo-Yo test to measure intermittent running performance in rugby players

This study examined how starting each shuttle in the prone position altered the internal, external and perceptual responses to the Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1). Using a randomized crossover design, 17 male rugby players completed the Yo-Yo IR1 and prone Yo-Yo IR1 on two separate occasions. External loads (via microtechnology), , heart rate (HR) and rating of perceived exertion (RPE) were measured at 160, 280 and 440 m (sub-maximal) and when the test was terminated (peak). The pre-to-post change in blood lactate concentration (Δ[La]b) was determined for both tests. All data were analysed using effect sizes (ES) and magnitude-based inferences. Between-trial differences (ES ± 90% CL) indicated that total distance was most likely lower (−1.87 ± 0.19), whereas other measures of peak external load were likely to very likely higher during the prone Yo-Yo IR1 (0.62–1.80). Sub-maximal RPE was likely to most likely higher (0.40–0.96) and peak RPE very likely higher (0.63 ± 0.41) in the prone Yo-Yo IR1. The change in [La]b was likely higher after the prone Yo-Yo IR1. Mean HR was possibly lower at 440 m (−0.25 ± 0.29) as was peak HR (−0.26 ± 0.25) in the prone Yo-Yo IR1. , and were likely to very likely higher at 280 and 440 m (ES = 0.36–1.22), while peak values were possibly to likely higher (ES = 0.23–0.37) in the prone Yo-Yo IR1. Adopting a prone position during the Yo-Yo IR1 increases the internal, external and perceptual responses, placing greater emphasis on metabolically demanding actions typical of rugby.

Oxygen saturation and lactate concentration gradient from the right atrium to the pulmonary artery in the immediate postoperative following cardiac surgery with extracorporeal circulation.

ObjectiveThis prospective study aimed to characterize the changes in blood lactate concentration and blood oxygen saturation in patients during the immediate postoperative period of cardiac surgery with extracorporeal circulation.MethodsBlood samples were collected from 35 patients in a rapid and random order from the arterial line and from the proximal and distal port of a pulmonary artery catheter.ResultsThe results showed no statistically significant differences between the blood oxygen saturation in the right atrium (72% ± 0.11%) and the blood oxygen saturation in the pulmonary artery (71% ± 0.08%). The blood lactate concentration in the right atrium was 1.7mmol/L ± 0.5mmol/L, and the blood lactate concentration in the pulmonary artery was 1.6mmol/L ± 0.5mmol/L (p < 0.0005).ConclusionThe difference between the blood lactate concentration in the right atrium and the blood lactate concentration in the pulmonary artery might be a consequence of the low blood lactate concentration in the blood from the coronary sinus, as it constitutes an important substrate for the myocardium during this period. The lack of differences between the blood oxygen saturation in the right atrium and the percentage of blood oxygen saturation in the pulmonary artery suggests a lower oxygen extraction by the myocardium given a lower oxygen consumption.

Inglês

The aim of the study was to verify the return curve of lactate to baseline levels after a session of the Tabata protocolwith a stationary bike roller. Therefore Ten male cyclists (30.95 ±6.46 years, 80.07 ±9.04 kg; 177.1 ±6.84 cm) were submitted toeight maximum intensity of 20s series, 10s active recovery there between. Venous blood collected the day before the test,pretest, posttest, after 1h, 12h, 24h, 48h, and 72h characterized the study design. There was a significant difference (p<0.05) inthe post-test collections and after 1h, returning to baseline levels in post collection 12h. The peak of the curve was the post-test.The Tabata protocol causes changes in blood lactate concentrations, and normalcy turns between 1h and 12h after exercise.

Exercise training with blood flow restriction has little effect on muscular strength and does not change IGF-1 in fit military warfighters

ObjectiveAerobic exercise with blood flow restriction (aBFR) has been proposed as an adjunctive modality in numerous populations, potentially via an enhanced growth factor response. However, the effects of aBFR on highly trained warfighters have yet to be examined. The purpose of this study was to determine if adjunctive aBFR as part of a regular physical training regimen would increase markers of aerobic fitness and muscle strength in elite warfighters. In addition, we sought to determine whether the changes in blood lactate concentration induced by aBFR would be associated with alterations in the insulin-like growth factor (IGF) axis. DesignActive-duty US Naval Special Warfare Operators (n=18, age=36.8±2.2years, weight=89.1±1.2kg, height=181.5±1.4cm) from Naval Amphibious Base Coronado were recruited to participate in 20days of adjunctive aBFR training. Peak oxygen consumption (VO2 peak), ventilatory threshold (VT), and 1-repetition max (1-RM) bench press and squat were assessed pre- and post-aBFR training. Blood lactate and plasma IGF-1 and IGF-binding protein-3 (IGFBP-3) were assessed pre-, 2min post-, and 30min post-aBFR on days 1, 9, and 20 of aBFR training. ResultsFollowing aBFR training there were no changes in VO2 peak or VT, but there was an increase in the 1-RM for the bench press and the squat (5.0 and 3.9%, respectively, P<0.05). Blood lactate concentration at the 2-min post-exercise time point was 4.5–7.2-fold higher than pre-exercise levels on all days (P<0.001). At the 30-min post-exercise time point, blood lactate was still 1.6–2.6-fold higher than pre-exercise levels (P<0.001), but had decreased by 49–56% from the 2-min post-exercise time point (P<0.001). Plasma IGF-1 concentrations did not change over the course of the study. On day 9, plasma IGFBP-3 concentration was 4–22% lower than on day 1 (P<0.01) and 22% lower on day 9 than on day 20 at the 30-min post-exercise time point (P<0.001). ConclusionsOur data suggest that aBFR training does not lead to practical strength adaptations or alterations in the IGF axis in a population of highly trained warfighters.

Acute Changes in Blood Lactate Concentration, Muscle Thickness, and Strength After Walking with Blood Flow Restriction in Older Adults

Acute Changes in Blood Lactate Concentration, Muscle Thickness, and Strength After Walking with Blood Flow Restriction in Older Adults

Changes in blood lactate concentrations during taekwondo combat simulation.

The aim of this study was to analyze blood lactate response before, during and after simulated taekwondo fight in young male athletes. The experiment was composed of simulated official taekwondo fight. During the experiment a total of 7 blood samples (25 μL) were collected that following: at rest, after 1st, 2nd, and 3rd rounds, and 3, 5, and 10 min after the end of combat. The results showed that blood lactate concentrations [Lac]B increased significantly after 1st, 2nd, and 3rd rounds of the combat compared to the rested values. The [Lac]B after 3rd round was higher when compared to 3, 5, and 10 min of recovery. After 10 min of passive recovery, the [Lac]B was significantly lesser than 3 and 5 min of recovery, and 2nd round. These data showed that taekwondo requires high activation of anaerobic lactic metabolism, and improves the ability to rapidly remove the lactate from blood.

Endurance skills of young team game players

Background: The aim of the present study was to assess physiological-biochemical reactions to incremental exercise loads and the levels and development of endurance skills in young male and female team game players. Material/Methods: The study sample comprised 370 soccer, handball, basketball and volleyball players (186 girls and 184 boys) from the Lower Silesian Regional Teams in Poland, aged 14.20 ±1.37 years (boys) and 13.90 ±1.15 years (girls). The exercise test consisted ofthe shuttle run Beep Test for estimation of aerobic fitness. The assessment of endurance skills was based on the length of the covered distance in the Beep Test as well as on measurements of the heart rate (physiological) and blood lactate concentration (metabolic). Results: Among the four studied groups of players a statistically significant improvement in endurance skills was noted in male volleyball players (p ≤ 0.05). Conclusions: Significantly higher levels of endurance skills in young male handball, basketball and volleyball players and in female volleyball players who remained on the regional teams for two consecutive years may be an indication of the players’ proper selection and training. Significant changes in blood lactate concentration in young players, revealed in both cross-sectional and continuous studies, were only noted in male volleyball players. Significant decreases in the heart rate in the cross-sectional study was found only in male handball and basketball players and in female basketball players, whereas in the continuous study only in male handball players. An assessment of young players’ physiological-biochemical reactions on the basis of exercise test results can effectively enhance the optimization of training loads.

Blood lactate concentrations in elite Polish 100 m sprinters

The main objective of this study was to show and analyse the changes in blood lactate concentrations in Polish elite sprinters. The study sample was comprised of 9 top male sprinters and 8 top female sprinters, all finalists from the Polish national championships. Blood lactate concentrations were evaluated with the use of a Lactate Scout measuring device. The measurements were taken pre-exercise and at 1, 5 and 10 minutes post-exercise. Before warm-up, the mean blood lactate concentration in male subjects was 1.40 ± 0.24 mmol/L and for female subjects 1.23 ± 0.24 mmol/L. During the first minute of recovery, the post-exercise lactate concentration rose to 9.38 ± 2.18 mmol/L in male sprinters and to 6.73 ± 2.48 mmol/L in female sprinters. Five minutes after the end of the 100 m sprint, the lactate level for females was 11.01 ± 2.14 mmol/L and for males 10.11 ± 0.99 mmol/L. Lactate concentrations at 10 minutes post-exercise reached 9.51 ± 1.23 mmol/L for male sprinters and 9.09 ± 1.46 mmol/L for female sprinters. The observed blood lactate concentration changes in Polish elite sprinters after a 100 m race provide new information regarding recovery dynamics which can be useful in designing sprint training.

Psychophysiological response and energy balance during a 14-h ultraendurance mountain running event.

Many studies have researched the psychophysiological response and energy balance of athletes in numerous ultraendurance probes, but none has investigated an ultraendurance mountain running event. The current study aims to analyze changes in blood lactate concentration, rating of perceived exertion, heart rate, heart rate variability, and energy balance after the performance of an ultraendurance mountain running event. The parameters in the 6 participants who finished the event were analyzed (age, 30.8 ± 3.1 years; height, 176.2 ± 8.6 cm; body mass, 69.2 ± 3.7 kg). The race covered 54 km, with 6441 m of altitude change, 3556 m downhill and 2885 m uphill. The athletes completed together the race in 14 h and 6 min. After the ultraendurance event, the athletes presented a negative energy balance of 4732 kcal, a blood lactate concentration of 2.8 ± 0.3 mmol/L, a heart rate mean/heart rate maximum ratio of 0.64, a heart rate mean of 111.4 ± 5.9 beats/min, a decrease in vagal modulation, and an increase in sympathetic modulation, and recorded 19.5 ± 1.5 points on the 6-20 rating of perceived exertion scale. The event was a stressful stimulus for the athletes despite the low intensity measured by blood lactate concentration and heart rate. The results obtained may be used by coaches as a reference parameter of heart rate, heart rate variability, rating of perceived exertion, and lactate concentration to develop specific training programs. In addition, the energy balance data obtained in this research may improve nutritional intake strategies.