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The study aimed to identify and quantify the metabolites profile and metabolic pathways in human muscle tissue engaged during exhaustive high‐intensity cycling exercise. Seven healthy physically active men performed a graded exercise test and an exhaustive supramaximal effort at 115% of maximal aerobic power with muscles biopsies performed in rest and immediately after exhaustion for quantifying of muscle metabolites changes by 1H‐NMR spectroscopy. The time until exhaustion (tlim) recorded was 224.7 ± 35.5 s whereas the muscle pH at exhaustion was 6.48 ± 0.05. A total of 54 metabolites were identified and quantified. The most enriched and impacted pathways included: beta oxidation of very long chain fatty acids, mitochondrial electron transport chain, alanine aspartate, and glutamate metabolism, citric acid cycle, arginine biosynthesis, propanoate metabolism, threonine and 2‐oxobutanoate degradation and pyruvate metabolism. In addition, the muscle concentrations in Post exercise, compared to Pre increased significantly (p < 0.0398) for fumarate (42.0%), succinate (101.2%), glucose (249.7%), lactate (122.8%), O‐acetylcarnitine (164.7%), glycerol (79.3%), AMP (288.2%), 2‐oxobutyrate (121.0%), and methanol (58.5%), whereas decreased significantly (p < 0.010) for creatine phosphate (−70.2%), ADP (−56.5%), carnitine (−33.5%), and glutamate (−42.3%). Only the succinate was significantly correlated with tlim (r = −0.76; p = 0.0497). Besides the classical expected contribution of glycolytic and phosphagen energetic pathways, it was demonstrated that the high‐intensity exercise is also associated with pathways indicatives of amino acid and fatty acid oxidation metabolisms, highlighting the inverse relation between changes in the intramuscular succinate levels and tlim. [ABSTRACT FROM AUTHOR]

Objective: To investigate the recovery of male water polo athletes applying full body photobiomodulation therapy (PBMT) regarding inflammation and muscle damage markers, testosterone and cortisol hormonal responses, heart rate variability (HRV), maximal voluntary contraction, and squat jump (SJ) after official water polo matches. Background: PBMT has been applied locally on specific muscle groups to induce faster recovery and improve the performance of athletes and nonathletes. However, many sports modalities require movement of the whole body, and a full body PBMT could be more adequate to irradiate large muscle areas homogeneously and faster. Methods: In a randomized, parallel, and double-blinded design, 13 athletes (whole team) aged 18 years attended the study and were allocated into two groups: PBMT (dose of 6.9 J/cm2, irradiance of 46.17mW/cm2, 5 min irradiation) and placebo treatment. The study was conducted during the 2019 Brazilian under 20 water polo championship. All athletes were assessed by blood samples and neuromuscular evaluation. Immediately after each match, all athletes received PBMT (effective or placebo). Results: No significant interactions (raw values and percentage related to baseline) were observed for testosterone and cortisol, tumor necrosis factor-alpha, interleukin-6, creatine kinase concentration, maximal isometric voluntary contraction, SJ test, and HRV. Only an isolated interaction (decrease) was found for lactate dehydrogenase (LDH) response after the first match (p = 0.004, post-hoc p = 0.038). Conclusions: The parameters of the full body PBMT of this study did not induce faster recovery of inflammatory, muscle damage (excepting LDH), testosterone, cortisol, HRV, and neuromuscular responses during repeated days of water polo matches. [ABSTRACT FROM AUTHOR]

β-Alanine supplementation is a popular nutritional ergogenic aid among the sports community. Due to its efficacy, already proven in the literature, to increase the intramuscular carnosine content (β-alanyl-L-histidine), whose main function is intramuscular buffering, β-alanine supplementation has become a nutritional strategy to improve performance, mainly in high-intensity efforts. However, although many studies present evidence of the efficacy of β-alanine supplementation in high-intensity efforts, discrepancies in outcomes are still present and the performance enhancing effects seem to be related to the specificities of each sport discipline, making it difficult for athletes/coaches to interpret the efficacy of β-alanine supplementation. Thus, this study carried out a review of the literature on this topic and summarized, analyzed, and critically discussed the findings with the objective of clarifying the current evidence found in the literature on different types of efforts and sport modalities. The present review revealed that inconsistencies are still found in aerobic parameters determined in incremental tests, except for physical working capacity at the neuromuscular fatigue threshold. Inconsistencies are also found for strength exercises and intermittent high-intensity efforts, whereas in supramaximal continuous mode intermittent exercise, the beneficial evidence is strong. In sports modalities, the evidence should be analyzed separately for each sporting modality. Thus, sports modalities that have strong evidence of the ergogenic effects of β-alanine supplementation are: cycling race of 4 km, rowing race of 2,000 m, swimming race of 100 and 200 m, combat modalities, and water polo. Finally, there is some evidence of slight additional effects on physical performance from cosupplementation with sodium bicarbonate. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the effects of regular participation in recreational table tennis training on bone health, body composition and lipid profile of elderly men. 20 regular recreational table tennis players (11.6 ± 3.6 years of experience) and 20 sedentary older adults (age, mass and sex matched of 65-75 years) participated in the study. Serum triglycerides, total cholesterol, HDL-cholesterol, and LDL-cholesterol concentrations were determined after 12 h fasting. Body composition was analyzed using dual-energy X-ray absorptiometry. Regular recreational table tennis participants displayed higher HDL-cholesterol (p = 0.03) and lower LDL-cholesterol (p = 0.04) and triglycerides (p = 0.002) compared to sedentary participants. In the regular recreational table tennis participants compared with sedentary participants, total (p = 0.001), sub-regional [lumbar spines (p = 0.001), arm (p = 0.006), leg (p < 0.008)] and site-specific [femoral neck (p = 0.007), trochanter (p = 0.03), and ward’s triangle (p = 0.001)] bone mineral densities were higher. Body fat percentage (p = 0.04) and total and sub-regional fat mass [arm (p = 0.004), leg (p = 0.02), and trunk (p = 0.04)] were lower. There was no significant difference in the total and sub-regional lean mass between groups (p > 0.05). This study offers preliminary evidence to suggest that recreational table tennis training, with the potential for permanent implementation, is associated with beneficial effects on body composition and lipid profile in older adult men. Further research regarding recreational table tennis to be used as a health-promoting activity for older adults is warranted. [ABSTRACT FROM AUTHOR]

The purpose of the study was to investigate the sensitivity of an alternative maximal accumulated oxygen deficit (MAODALT) method to discriminate the "anaerobic" capacity while comparing: least trained (LT) participants (n = 12), moderately trained (MT) participants (n = 12), endurance trained (ET) participants (n = 16), and rugby (RG) players (n = 11). Participants underwent a graded exercise test on a treadmill and a supramaximal effort for assessing MAODALT. MAODALT was calculated as the sum of oxygen equivalents from the phosphagen and glycolytic metabolic pathways. MAODALT was significantly higher (P < 0.05) in RG (64.4 ± 12.1 mL · kg-1) than in ET (56.8 ± 5.4 mL · kg-1; effect size [ES] = 0.77; +13.5%), MT (53.8 ± 5.3 mL · kg-1; ES = 1.08; +19.8%), and LT (49.9 ± 4.5 mL · kg-1; ES = 1.50; +36.4%). In addition, the magnitude-based inference analysis revealed that MAODALT was likely (LT vs. MT), very likely (MT vs. RG, and ET vs. RG) and most likely (LT vs. ET, and LT vs. RG) different between all groups, except for MT and ET, which presented an unclear difference. In conclusion, MAODALT was sensitive enough to distinguish the "anaerobic" capacity in individuals with different training status, especially for RG players compared with LT participants and MT participants. [ABSTRACT FROM AUTHOR]

This study compared 2 repeated-sprint ability (RSA) tests in basketball players. Both tests included 10 x 30-m sprints, with the difference that the previously validated test (RSA2COD) featured 2 changes of direction (COD) per sprint, whereas the experimental test (RSA5COD) featured 5 CODs per sprint. Test performances and metabolic demands were specifically assessed in 20 basketball players. First, RSA5COD test-retest reliability was investigated. Then, RSA2COD, RSA5COD sprint times, peak speeds, oxygen uptake (...O2) and posttest blood lactate concentration [La-] were measured. The RSA5COD results showed to be reliable. RSA2COD performance resulted better than the RSA5COD version (p < 0.01), with shorter sprint times and higher peak speeds. Over sprints, the tests did not differ from each other in terms of ...O2 (p > 0.05). Over whole bout, the RSA2COD was more demanding than the RSA5COD, considering overall metabolic power requirement (i.e., VO2-driven + [La-]-driven components). Given that RSA5COD (a) mimics real game-play as sprint distance and action change frequency/direction and (b) has the same metabolic expenditure per task completion as metabolic cost, RSA5COD is a valuable option for players and coaches for training basketball-specific agility and assessing bioenergetic demands. [ABSTRACT FROM AUTHOR]

The article discusses research investigating the relationship between aerobic and anaerobic parameters from three-minute all-out tethered swimming and 400-meter (m) maximal front crawl effort in 30 swimmers. Topics include maximal lactate steady state (MLSS) and measures of lactate minimum (LMI), three-minute final force, which is equivalent to critical force (CF3-MIN), and peak oxygen uptake (Vo2peak).

PURPOSE: To analysis the effect of cycling exercise at acute severe intensity domain on modulation of metabolomic profile in human muscle tissue, as well as to report the main metabolic pathways. METHODS: Seven healthy physically active men (21±2 yrs and VO2max of 43.6±4.6 mL·kg-1·min-1) were underwent to an effort until exhaustion at severe intensity domain. Vastus lateralis muscle biopsies were performed before (at rest) and immediately after the effort for quantifying the muscle metabolites changes using ¹H-NMR spectroscopy. RESULTS: The time until exhaustion (tlim) recorded was 224.7±35.5 s, whereas the energetic contribution corresponded to 71.2±2.8% oxidative, 20.0±3.0% glycolytic and 8.8±1.3% phosphagen. The muscle pH after cycling exhaustion was 6.48±0.05. A total of 54 metabolites were identified and quantified. The most impacted pathways (impact > 0.0) included: beta oxidation of very long chain fatty acids (0.049), mitochondrial electron transport chain (0.060), alanine aspartate and glutamate metabolism (0.200), citric acid cycle (0.118), arginine biosynthesis (0.117), propanoate metabolism (0.004), threonine and 2-oxobutanoate degradation (0.143) and pyruvate metabolism (0.084). The muscle metabolite concentrations Pre and Post exercise increased for fumarate (42%, p=.025), succinate (101%, p=.021), glucose (245%, p=.001), lactate (123%, p=.004), O-acetylcarnitine (165%, p=.011), glycerol (79%, p=.040), AMP (288%, p=.008), 2-oxobutyrate (121%, p<.001) and methanol (58%, p=.034). There were decreases for creatine phosphate (-70%, p=.008), ADP (-56%, p=.007), carnitine (-33%, p=.006) and glutamate (-42%, p=.009). However, only the succinate had a significantly correlation with tlim (r=-0.76, p=.0497). In addition, the muscle pH measured at exhaustion was significantly correlated with tlim (r=-0.83; p=.042), the post-exercise succinate concentration (r=0.93; p=.006). CONCLUSIONS: Besides the classical expected contribution of glycolytic and phosphagen energetic pathways, the high-intensity exercise was associated with pathways indicatives of amino acid and fatty acid oxidation metabolisms, highlighting the inverse correlation between intramuscular succinate levels and tlim. Supported by FAPESP Grant 2018/21126-6 [ABSTRACT FROM AUTHOR]

The article discusses research which was conducted to investigate the effect hyperlactemia and blood acidosis induction had on lactate minimum intensity in cyclists. Researchers evaluated 20 recreationally trained male athletes who were experienced cyclists and underwent three lactate minimum tests while performing on an electromagnetic cycle ergometer. They found that hyperlactemia induction modes effected lactate minimum power and physiological responses in the cyclists.

The article reports on research conducted to verify the physiological responses and the match characteristics of table tennis and to compare the responses in 2 different performance level athletes from official tournaments. Researchers evaluated 12 players with regional experience and eight with national and international experience. They found that table tennis matches present the aerobic system as a principal output energy with the phosphagenic system being the most important.

The article reports on research conducted to to investigate the reliability and validity of the running anaerobic sprint test (RAST) in anaerobic assessment and predicting short-distance performance. Researchers evaluated 40 members of the armed forces. They found that the test procedure is reliable and valid and can be used to measure running anaerobic power and predict short-distance performances.

The aim of this study was to validate critical frequency specific test (critf) for the estimation of the aerobic endurance in table tennis players. Methods: Eight male international-level table tennis players participated of this study. Specific tests were applied by using a mechanical ball thrower to control the intensity of the exercise. The critf was determined by applying three or four series of exercises to exhaustion (Tlim). The critf was evaluated by using lactate steady state test (90, 100, and 106 % of critf intensity). The other specific test was an incremental protocol used to determine the anaerobic threshold (AnTBI) and the onset of blood lactate accumulation (OBLA) using a ball thrower. Results: The critf (39.87 ± 3.31 balls·min-1) was not significantly different among AnTBI (48.11 ± 7.36 balls·min-1) and OBLA3.5 (49.36 ± 12.04 balls·min-1) frequencies and it was correlated with AnTBI parameter (r = 0.78). At frequencies of the 90 and 100% of critf a dynamic equilibrium was verified in lactate concentration between the eighth and twentieth minutes. However, this dynamic equilibrium was not found at 106% intensity. Conclusion: The data indicate that in table tennis the critf model can be used for measuring the aerobic endurance. [ABSTRACT FROM AUTHOR]

The article discusses a study which verifies the applicability of anaerobic work capacity (AWC) determined from the critical power model in elite table tennis players. It demonstrates tests including the critical frequency test used to determinate the anaerobic work capacity and wingate tests performed using leg and arm ergometers. It is concluded that the AWC determined by a modified critical power test was not a good index for measurement of anaerobic capacity in table tennis players.

This study investigated whether a heavy-intensity priming exercise precisely prescribed within the heavy-intensity domain would lead to a greater peak-power output (POpeak) and a longer maximal oxygen uptake (V̇ o 2max) plateau. Twelve recreationally active adults participated in this study. Two visits were required: 1) a step-ramp-step test [ramp-incremental (RI) control], and 2) an RI test preceded by a priming exercise within the heavy-intensity domain (RI primed). A piecewise equation was used to quantify the V̇ o 2 plateau duration (V̇ o 2plateau-time). The mean response time (MRT) was computed during the RI control condition. The delta (Δ) V̇ o 2 slope (S; mL·min−1·W−1) and V̇ o 2-Y intercept (Y; mL·min−1) within the moderate-intensity domain between conditions (RI primed minus RI control) were also assessed using a novel graphical analysis. V̇ o 2plateau-time (P = 0.001; d = 1.27) and POpeak (P = 0.003; d = 1.08) were all greater in the RI primed. MRT (P < 0.001; d = 2.45) was shorter in the RI primed compared with the RI control. A larger ΔV̇ o 2plateau-time was correlated with a larger ΔMRT between conditions (r = –0.79; P = 0.002). This study demonstrated that heavy-intensity priming exercise lengthened the V̇ o 2plateau-time and increased POpeak. The overall faster RI-V̇ o 2 responses seem to be responsible for the longer V̇ o 2plateau-time. Specifically, a shorter MRT, but not changes in RI-V̇ o 2-slopes, was associated with a longer V̇ o 2plateau-time following priming exercise. NEW & NOTEWORTHY: It remains unclear whether priming exercise extends the maximal oxygen uptake (V̇ o 2max) plateau and increases peak-power output (POpeak) during ramp-incremental (RI) tests. This study demonstrates that a priming exercise, precisely prescribed within the heavy-intensity domain, extends the plateau at V̇ o 2max and leads to a greater POpeak. Specifically, the extended V̇ o 2max plateau was associated with accelerated RI-V̇ o 2 responses. [ABSTRACT FROM AUTHOR]

Within the initial minutes of square-wave exercise transitions above the moderate-intensity domain, the reliance on the anaerobic energy sources may induce some levels of metabolic instability; however, no study has attempted to limit metabolic instability at exercise onset by manipulating the exercise transition phase to a target work rate (WR). Purpose: This study aimed to investigate whether a ramp-to-constant WR (rCWR) transition compared with a square-wave-to-constant WR (CWR) transition within the heavy-intensity domain can reduce metabolic instability and decrease the oxygen cost of exercise. Methods: Fourteen individuals performed (i) a ramp-incremental test to task failure, (ii) a 21-min CWR within the heavy-intensity domain, and (iii) an rCWR to the same WR. Oxygen uptake (...O2), lactate concentration ([La-]), and muscle oxygen saturation (SmO2) were measured. ...O2 and ...O2 gain (...O2-G) during the first 10-min steady-state ...O2 were analyzed. [La-] before, at, and after steady-state ...O2 and SmO2 during the entire 21-min steady-state exercise were also examined. Results: ...O2 and ...O2-G during rCWR (2.49 ± 0.58 L⋅min-1 and 10.7 ± 0.2 mL⋅min-1⋅W-1, respectively) were lower (P < 0.001) than CWR (2.57 ± 0.60 L⋅min-1 and 11.3 ± 0.2 mL⋅min-1⋅W-1, respectively). [La-] before and at steady-state ...O2 during the rCWR condition (1.94 ± 0.60 and 3.52 ± 1.19 mM, respectively) was lower than the CWR condition (3.05 ± 0.82 and 4.15 ± 1.25 mM, respectively) (P <0.001). [La-] dynamics after steady-state ...O2 were unstable for the rCWR (P = 0.011). SmO2 was unstable within the CWR condition from minutes 4 to 13 (P <0.05). Conclusions: The metabolic disruption caused by the initial minutes of square-wave exercise transitions is a primary contributor to metabolic instability, leading to an increased ...O2-G compared with the rCWR condition approach. The reduced early reliance on anaerobic energy sources during the rCWR condition may be responsible for the lower ...O2-G. [ABSTRACT FROM AUTHOR]

Purpose: The present study investigated the recovery of performance and neuromuscular fatigue after cycling repeated sprints. Methods: Ten participants performed two sessions of repeated sprints (one session: 10 × 10-s sprints, 30-s recovery) separated by 24 h (R24-S1 and R24-S2) and two sessions separated by 48 h (R48-S1 and R48-S2). The recovery condition (i.e., 24 or 48 h) was randomized and separated by 1 wk. All sessions were performed on a recumbent bike, allowing minimal delay between sprints termination and neuromuscular measurements. Neuromuscular function of knee extensors (neuromuscular assessment [NMA]) was assessed before sessions (presession), after the fifth sprint (midsession), and immediately after (postsession). Before sessions, baseline NMA was also carried out on an isometric chair. The NMA (bike and chair) was composed of maximal voluntary contraction (MVC) of knee extension and peripheral neuromuscular stimulation during the MVC and on relaxed muscle. Results: The sprints performance was not significantly different between sessions and did not presented significant interaction between recovery conditions. MVC was significantly lower at R24-S2 compared with R24-S1 (−6.5% ± 8.8%, P = 0.038) and R48-S2 (−5.6% ± 8.2%, P = 0.048), whereas resting potentiated high-frequency doublet (Db100) was lower at R24-S2 compared with R24-S1 (−10.4 ± 8.3, P = 0.01) (NMA on chair). There were significant reductions in MVC (>30%, P < 0.001) and Db100 (>38%, P < 0.001) from pre- to postsession in all sessions, without significant interactions between recovery conditions (NMA on bike). Conclusion: Cycling repeated sprints induce significant fatigue, particularly at the peripheral level, which is fully restored after 48 h, but not 24 h, of recovery. One versus two days of recovery does not affect neuromuscular fatigue appearance during cycling repeated-sprint sessions. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to verify the acute effects of photobiomodulation (PBM) using different doses of LED on peak running velocity (Vpeak) and physiological parameters. Materials and methods: The study had a randomized, crossover, double-blind, and placebo-controlled format, in which 15 physically active males were submitted, besides the control (CON), to four conditions performed 5 min before the maximal incremental treadmill tests for the determination of Vpeak: placebo (PLA) and three conditions of PBM application at different doses: PBM applied with 30 J per area (PBM1), PBM applied with 120 J per area (PBM2), and PBM applied with 180 J per area (PBM3). The LED was applied using an equipment with 56 diodes of red light (660 nm; 50 mW/cm² and 1.5 J/cm² each diode) and 48 diodes of infrared light (850 nm; 150 mW/cm² and 4.5 J/cm² each diode). The PBM was applied in two regions of the quadriceps muscle, two regions of the femoral biceps muscle, and one region of the gastrocnemius muscle in both legs. Results: There was no difference among the outcomes from PBM irradiations and PLA condition for the variables, Vpeak (CON = 13.4 - 1.6; PLA = 13.4 - 1.6; PBM1 = 13.5 - 1.7; PBM2 = 13.4 - 1.6; PBM3 = 13.4 - 1.7 km/h), similar to other variables associated with aerobic running performance analyzed during the maximal incremental treadmill tests for Vpeak determination: lactate peak, heart rate, and rating of perceived exertion. Conclusions: We concluded that the application of different doses of PBM using LEDs did not modify Vpeak and physiological and perceptual parameters. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of prior LED sessions on the responses of cardiorespiratory parameters during the running incremental step test. Twenty-six healthy, physically active, young men, aged between 20 and 30 years, took part in this study. Participants performed two incremental load tests after placebo (PLA) and light-emitting diode application (LED), and had their gas exchange, heart rate (HR), blood lactate, and rating of perceived exertion (RPE) monitored during all tests. The PLA and LED conditions were compared using the dependent Student t test with significance set at 5%. The T test showed higher maximum oxygen uptake (VO2max) (PLA = 47.2 ± 5.7; LED = 48.0 ± 5.4 ml kg-1 min-1, trivial effect size), peak velocity (Vpeak) (PLA = 13.4 ± 1.2; LED = 13.6 ± 1.2 km h-1, trivial effect size), and lower maximum HR (PLA = 195.3 ± 3.4; LED = 193.3 ± 3.9 b min-1, moderate effect size) for LED compared to PLA conditions. Furthermore, submaximal values of HR and RPE were lower, and submaximal VO2 values were higher when LED sessions prior to the incremental step test were applied. A positive response of the previous LED application in the blood lactate disappearance was also demonstrated, especially 13 and 15 min after the test. It is concluded that LED sessions prior to exercise modify cardiorespiratory response by affecting running tolerance during the incremental step test, metabolite clearance, and RPE. Therefore, LED could be used as a prior exercise strategy to modulate oxidative response acutely in targeted muscle and enhance exercise tolerance. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the outcomes from 2 weeks of training load intensification strategy in female water polo players diagnosed with functional overreaching (F-OR) with no F-OR players (acute fatigue) on the performance outcomes and hormonal, immunological, and cardiac autonomic nervous system responses. Twenty-two female water polo players were allocated into control and intensification group during 7 weeks. The swimming performance, biochemical parameters, heart rate variability, profile of mood states, and upper respiratory tract infection symptoms were assessed twice before and twice after 2 weeks of intensification period. F-OR showed a worsening in total time of the repeated sprint ability (RSA) test compared with the control group and the acute fatigue group after intensification (p = 0.035). Furthermore, after the tapering period, the F-OR group maintained worse total time of the RSA test than the acute fatigue group (p = 0.029). In addition, the acute fatigue group showed improvement in total time of the RSA test after intensification compared with the control group (p < 0.001). No significant interactions were found for the other parameters. Therefore, periods of intensification without the F-OR development can promote higher gains in the total time of the RSA test after intensification and tapering period. [ABSTRACT FROM AUTHOR]

Background: Photobiomodulation therapy (PBMT) is defined as non-thermal electromagnetic irradiation through laser or light-emitting diode sources. In recent decades, PBMT has attracted attention as a potential preconditioning method. The current meta-analysis was conducted to assess the effectiveness of PBMT in improving mode-specific exercise performance in healthy young adults. Methods: A computerized literature search was conducted, ending on 15 May 2022. The databases searched were PubMed, Cochrane Central Register of Controlled Trials, Embase, SPORTDiscus, and the Physiotherapy Evidence Database. Inclusion/exclusion criteria limited articles to crossover, double-blind, placebo-controlled studies investigating the PBMT effects as a preconditioning method. The included trials were synthesized according to exercise mode (single-joint, cycling, running, and swimming). All results were combined using the standardized mean differences (SMDs) method and the 95% confidence intervals (CIs) were described. Results: A total of 37 individual studies, employing 78 exercise performance measurements in 586 participants, were included in the analyses. In single-joint exercises, PBMT improved muscle endurance performance (SMD 0.27, 95% CI 0.12–0.41; p < 0.01) but not muscle strength performance (p = 0.92). In cycling, PBMT improved time to exhaustion performance (SMD 0.35, 95% CI 0.10–0.59; p < 0.01) but had no effect on all-out sprint performance (p = 0.96). Similarly, PBMT had no effect on time to exhaustion (p = 0.10), time-trial (p = 0.61), or repeated-sprint (p = 0.37) performance in running and no effect on time-trial performance in swimming (p = 0.81). Conclusion: PBMT improves muscle endurance performance in single-joint exercises and time to exhaustion performance in cycling but is not effective for muscle strength performance in single-joint exercises, running, or swimming performance metrics. [ABSTRACT FROM AUTHOR]

Background: Cold-water immersion (CWI) is one of the main recovery methods used in sports, and is commonly utilized as a means to expedite the recovery of performance during periods of exercise training. In recent decades, there have been indications that regular CWI use is potentially harmful to resistance training adaptations, and, conversely, potentially beneficial to endurance training adaptations. The current meta-analysis was conducted to assess the effects of the regular CWI use during exercise training on resistance (i.e., strength) and endurance (i.e., aerobic exercise) performance alterations. Methods: A computerized literature search was conducted, ending on November 25, 2019. The databases searched were MEDLINE, Cochrane Central Register of Controlled Trials, and SPORTDiscus. The selected studies investigated the effects of chronic CWI interventions associated with resistance and endurance training sessions on exercise performance improvements. The criteria for inclusion of studies were: (1) being a controlled investigation; (2) conducted with humans; (3) CWI performed at ≤ 15 °C; (4) being associated with a regular training program; and (5) having performed baseline and post-training assessments. Results: Eight articles were included before the review process. A harmful effect of CWI associated with resistance training was verified for one-repetition maximum, maximum isometric strength, and strength endurance performance (overall standardized mean difference [SMD] = − 0.60; Confidence interval of 95% [CI95%] = − 0.87, − 0.33; p < 0.0001), as well as for Ballistic efforts performance (overall SMD = − 0.61; CI95% = − 1.11, − 0.11; p = 0.02). On the other hand, selected studies verified no effect of CWI associated with endurance training on time-trial (mean power), maximal aerobic power in graded exercise test performance (overall SMD = − 0.07; CI95% = − 0.54, 0.53; p = 0.71), or time-trial performance (duration) (overall SMD = 0.00; CI95% = − 0.58, 0.58; p = 1.00). Conclusions: The regular use of CWI associated with exercise programs has a deleterious effect on resistance training adaptations but does not appear to affect aerobic exercise performance. Trial Registration: PROSPERO CRD42018098898. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effects of drop jumps (DJs) on supramaximal cycling performance, anaerobic capacity (AC), electromyography, and fatigue. Thirty-eight recreational cyclists participated into 3 independent studies. In study 1 (n = 14), neuromuscular fatigue was assessed with the twitch interpolation technique. In study 2 (n = 16), the AC and metabolic contributions were measured with the maximal accumulated oxygen deficit method and the sum of the glycolytic and phosphagen pathways. In study 3 (n = 8), postactivation potentiation (PAP) induced by repeated DJs was evaluated. The DJ protocol was effective for significantly improving cycling performance by +9.8 and +7.4% in studies 1 and 2, respectively (p ≤ 0.05). No differences were observed in electromyography between conditions (p = 0.70); however, the force evoked by a doublet at low (10 Hz) and high frequencies (100 Hz) declined for control (-16.4 and -23.9%) and DJ protocols (-18.6 and -26.9%) (p < 0.01). Force decline was greater in the DJ condition (p < 0.03). Anaerobic capacity and glycolytic pathway contributions were +7.7 and +9.1% higher after DJ protocol (p = 0.01). Peak force during maximal voluntary contraction (+5.6%) and doublet evoked force at 100 Hz (+5.0%) were higher after DJs. The DJ protocol induced PAP, improved supramaximal cycling performance, and increased AC despite higher peripheral fatigue. [ABSTRACT FROM AUTHOR]

The study aimed to (a) typify the cardiorespiratory, metabolic, and performance responses during a single sprint interval training (SIT) session, (b) investigate the interference of 2 subsequent sessions on cardiorespiratory, metabolic, and performance responses, and (c) verify the relationships of SIT total work performed with aerobic fitness indices. Thirty-six untrained men performed 2 SIT sessions (SIT1 and SIT2) separated by 24 hours of recovery. Each session was composed of 4 Wingate bouts interspersed by 4 minutes. Within SIT sessions, bout work, peak power, and mean power of each Wingate bout decreased significantly, while the fatigue index increased over time (p < 0.001). The SIT elicited lower acute responses of oxygen uptake and heart rate than maximal values (≈67 and ≈79%, respectively) (p < 0.05) as well as a short time spent at high cardiorespiratory demand. For SIT outcomes, no interactions were verified between Wingate bout performance, average heart rate, and average oxygen uptake. In addition, the oxygen uptake integral (SIT1:300.5 ± 38.6 ml·kg; SIT2:306.9 ± 41.1 ml·kg) and total work (SIT1:54.6 ± 10.4 kJ; SIT2:54.9 ± 10.6 kJ) did not differ between SIT sessions (p > 0.05). Furthermore, significant moderate to strong correlations were found between SIT1 and SIT2 total work and peak oxygen uptake (r = 0.48; r = 0.52, respectively), maximal aerobic power (r = 0.89; r = 0.89, respectively), and respiratory compensation point (r = 0.80; r = 0.78, respectively). In summary, an SIT session elicited a short time spent at high cardiorespiratory demand, while the SIT total work was significantly correlated with aerobic fitness indices. In addition, 2 consecutive SIT sessions interspaced by 24 hours did not affect performance outcomes, or cardiorespiratory and blood responses. [ABSTRACT FROM AUTHOR]

The purpose of the study was to describe the training load distribution of a young female water polo team in different cycles of the season and verify its subsequent effects on specific fitness measured by the repeated sprints ability (RSA) test, aerobic endurance measured by the lactate minimum test, incidence and severity of upper respiratory tract infection (URTI) symptoms, and muscle damage markers. The training load (i.e., rating of perceived exertion × session duration) of 20 young female water polo players (mean ± SD: age = 15.65± 1.× years; body mass=60.9×611.0 kg; height=1.62±0.1 m) was monitored, and the incidence and severity of URTI was assessed during part of the season. In addition, we assessed the lactate minimum speed (LMS), RSA, creatine kinase (CK), and lactate dehydrogenase (LDH) blood concentration during the season. The level of significance set was p < 0.05. The training loads were higher in the specific period (p<0.01), whereas a high incidence of URTI was observed in the general cycle. The LMS was greater in the general cycle (p < 0.05), whereas total time and best time in the RSA test were greater in the competitive cycle (p < 0.05). The CK and LDH concentrations were significantly lower during the competitive cycle (p < 0.01). The general cycle of a female water polo team is critical regarding URTI and muscle damage, even with smaller training loads than the specific period. [ABSTRACT FROM AUTHOR]

Due to the controversy about the sensitive of lactate minimum intensity (LMI) to training and the need to develop other tool for aerobic fitness evaluation, the purpose of this study was to analyze the sensitivity of glucose minimum intensity (GMI) and LMI to endurance training. Eight trained male cyclists (21.4 ± 1.9 years, 67.6 ± 7.5 kg and 1.72 ± 0.10 m) were evaluated twice, before and after 12 weeks of training. GMI and LMI were calculated, respectively, by the lowest blood glucose and lactate values attained during an incremental test performed after a hyperlactemia induction, and VO2max was determined during standard incremental effort. The training was prescribed in three different zones and controlled by heart rate (HR). The training distribution was equivalent to 59.7%, 25.0% and 15.3% below, at and above anaerobic threshold HR respectively. The anaerobic threshold evaluated by GMI and LMI improvement 9.89 ± 4.35% and 10.28 ± 9.89 respectively, after training, but the VO2max 2.52 ± 1.81%. No differences were found between GMI and LMI in pre (218.2 ± 22.1 vs 215.0 ± 18.6 W) and post (240.6 ± 22.9 vs 237.5 ± 18.8 W) training situations. LMI and GMI were sensitive to 12-week aerobic training in cyclist; thus, both protocols can be used to assess aerobic adaptation, athletes diagnostic and prescribe training. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of fatigue induced by a repeated sprint ability (RSA) test on the neuromuscular responses of soccer players with a recent history of lower limb injuries (CH) and a matched control group in good fitness condition (GH). Design: This was a case-control study. Participants: Nine CH and 9 GH. Independent Variable: Allocation to CH or GH. Main Outcome Measures: Each player was assessed for blood lactate concentration and jumping performance [squat jump (sJ) and countermovement jump (CMJ)] before/after RSA. Post-RSA rate of perceived exertion (RPE) was obtained. Receiver operating characteristic analysis was performed to calculate RSA sensitivity and specificity in distinguishing between CH and GH. intraclass correlation coefficient was used to assess reliability. Results: No baseline differences were found for any variable. ASJ before/after RSA was -14 ± 2% and -5 ± 2% in CH and GH, respectively (P < 0.05). ACMJ before/after RSA was -15 ± 2% and -7 ± 2% in CH and GH, respectively (P < 0.05). ASJ-based and ACMJ-based (before/after RSA) area under curve (AUC) resulted in 0.90 ± 0.07 and 0.86 ± 0.09, respectively, with both AUCs differentiating between CH and GH with 77.78% sensitivity and 88.89% specificity. Pooled AUC resulted in 0.88 ± 0.06. Intraclass correlation coefficient was high (0.85/0.97). Conclusions: Repeated sprint ability is a simple, low-cost field test potentially able to assist in clinical decision making for return to sport. [ABSTRACT FROM AUTHOR]

Aims The present study verified the responses of selected endoplasmic reticulum (ER) stress proteins (i.e., BiP, ATF-6, pIRE1, pPERK, and peIF2alpha) in mice skeletal muscles after three different running overtraining (OT) protocols with same external load (i.e., intensity vs. volume), but performed in downhill, uphill and without inclination. Materials and methods The rodents were randomly divided into control (CT; sedentary mice), overtrained by downhill running (OTR/down), overtrained by uphill running (OTR/up) and overtrained by running without inclination (OTR) groups. The incremental load test and exhaustive test were used as performance parameters. Forty hours after the exhaustive test performed at the end of the OT protocols (i.e., at the end of week 8) and after a 2-week total recovery period (i.e., at the end of week 10), the extensor digitorum longus (EDL) and soleus muscles were removed and used for immunoblotting. Key findings For both skeletal muscle types, the OTR/down protocol increased the pIRE-1, pPERK and peIF2alpha, which were not normalized after the total recovery period. At the end of week 8, the other two OT protocols up-regulated the BiP, pPERK and peIF2alpha levels only for the soleus muscle. These ER stress proteins were not normalized after the total recovery period for the OTR/up group. Significance The above findings suggest that the OTR/down protocol-induced skeletal muscle ER stress may be linked to a pathological condition in EDL and soleus muscles. [ABSTRACT FROM AUTHOR]

The article discusses research of the maximal lactate steady-state (MLSS) in soccer players using anaerobic threshold (AT) determined on the soccer-specific Hoff circuit (ATHoff) to predict exercise intensity. Topics include the importance of aerobic fitness to soccer player performance, aerobic capacity evaluation for performance optimization, and the reproducibility of AT determined on the Hoff circuit in the prediction of MLSS.

The purpose of this research was to examine how an 11-day taper after an 8.5-week experimental training cycle affected lactate levels during maximal exercise, mean force, and performance in training swimmers, independent of shaving, psychological changes, and postcompetition effects. Fourteen competition swimmers with shaved legs and torsos were recruited from the São Paulo Aquatic Federation. The training cycle consisted of a basic training period (endurance and quality phases) of 8.5 weeks, with 5,800 m·d-1 mean training volume and 6 d·wk-1 frequency; and a taper period (TP) of 1.5 weeks' duration that incorporated a 48% reduction in weekly volume without altering intensity. Attained swimming force (SF) and maximal performance over 200-m maximal swim (Pmax) before and after taper were measured. After taper, SF and Pmax improved 3.6 and 1.6%, respectively (p < 0.05). There were positive correlations (p < 0.05) between SF and Pmax before (r = 0.86) and after (r = 0.83) the taper phase. Peak lactate concentrations after SF were unaltered before (6.79 ± 1.2 mM) and after (7.15 ± 1.8 mM) TP. Results showed that TP improved mean swimming velocity, but not in the same proportion as force after taper, suggesting that there are other factors influencing performance in faster swimming. [ABSTRACT FROM AUTHOR]