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1.
Does Low-Level Laser Therapy Decrease Muscle-Damaging Mediators After Performance in Soccer Athletes Versus Sham Laser Treatment? A Critically Appraised Topic.
Bettleyon, J, Kaminski, TW
Journal of sport rehabilitation. 2020;(8):1210-1213
Abstract
Clinical Scenario: Low-level laser therapy (LLLT) is a controversial topic for its use in athletic recovery, mainly due to inconsistency in research regarding the application of LLLT. Articles on LLLT have assessed its effectiveness in untrained humans through pain scales, functional scales, and blood draws, and it has been found capable in nonathletic rehabilitative use. The controversy lies with LLLT in the recovering athlete. Not only do athletes need to perform at high levels, but each sport is unique in the metabolic demands placed on the athletes' bodies. This modality can alter chemical mediators of the inflammatory process, specifically blood lactate (BL) and creatine kinase (CK). During soccer contests, it is a common problem for athletes to have an average CK level of 800 U/L and BL of 8 mmol·L, increasing delayed-onset muscle soreness and fatigue. Micro-CK level elevation is associated with cellular membrane damage, localized hypoxia, and electrolyte imbalances, hindering the recovery process. Clinical Question: Does LLLT decrease muscle-damaging mediators effecting player fatigue and delayed-onset muscle soreness after performance in soccer athletes versus sham treatment? Summary of Key Findings: In 3 studies, preperformance, postperformance, or preperformance and postperformance LLLT was performed and evaluated BL (2 of 3) and CK (2 of 3). In each article, BL and CK showed a significant decrease (P < .05) when performed either preperformance or postperformance versus the control group. The greatest decrease in these mediators was noticed when postperformance laser therapy was performed. Clinical Bottom Line: LLLT at 10, 30, or 50 J performed at a minimum of 2 locations on the rectus femoris, vastus lateralis, and vastus medialis bilaterally for 10 seconds each is significant in decreasing blood serum levels of BL and CK when performed postexercise. Strength of Recommendations: All 3 articles obtained a Physiotherapy Evidence Database score of ≥8/10.
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2.
Effects of a Ketogenic Diet on Muscle Fatigue in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial.
Sjödin, A, Hellström, F, Sehlstedt, E, Svensson, M, Burén, J
Nutrients. 2020;(4)
Abstract
Ketogenic low-carbohydrate high-fat (LCHF) diets are increasingly popular in broad sections of the population. The main objective of this study was to evaluate the effects of a non-energy-restricted ketogenic LCHF diet on muscle fatigue in healthy, young, and normal-weight women. Twenty-four women were randomly allocated to a 4-week ketogenic LCHF diet followed by a 4-week control diet (a National Food Agency recommended diet), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and were included in the analyses. Treatment effects were evaluated using mixed models. The ketogenic LCHF diet had no effect on grip strength or time to fatigue, measured with handgrip test (day 24-26). However, cycling time to fatigue decreased with almost two minutes (-1.85 min 95% CI:[-2.30;-1.40]; p < 0.001) during incremental cycling (day 25-27), accommodated with higher ratings of perceived exertion using the Borg scale (p < 0.01). Participants' own diary notes revealed experiences of muscle fatigue during daily life activities, as well as during exercise. We conclude that in young and healthy women, a ketogenic LCHF diet has an unfavorable effect on muscle fatigue and might affect perceived exertion during daily life activities.
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3.
No Effect of New Zealand Blackcurrant Extract on Recovery of Muscle Damage Following Running a Half-Marathon.
Costello, R, Willems, MET, Myers, SD, Myers, F, Lewis, NA, Lee, BJ, Blacker, SD
International journal of sport nutrition and exercise metabolism. 2020;(4):287-294
Abstract
New Zealand blackcurrant (NZBC) contains anthocyanins, known to moderate blood flow and display anti-inflammatory properties that may improve recovery from exercise-induced muscle damage. The authors examined whether NZBC extract supplementation enhances recovery from exercise-induced muscle damage after a half-marathon race. Following a randomized, double-blind, independent groups design, 20 (eight women) recreational runners (age 30 ± 6 years, height 1.73 ± 0.74 m, body mass 68.5 ± 7.8 kg, half-marathon finishing time 1:56:33 ± 0:18:08 hr:min:s) ingested either two 300-mg/day capsules of NZBC extract (CurraNZ™) or a visually matched placebo, for 7 days prior to and 2 days following a half-marathon. Countermovement jump performance variables, urine interleukin-6, and perceived muscle soreness and fatigue were measured pre, post, and at 24 and 48 hr after the half-marathon and analyzed using a mixed linear model with statistical significance set a priori at p < .05. The countermovement jump performance variables were reduced immediately post-half-marathon (p < .05), with all returning to pre-half-marathon levels by 48 hr, except the concentric and eccentric peak force and eccentric duration, with no difference in response between groups (p > .05). Urine interleukin-6 increased 48-hr post-half-marathon in the NZBC group only (p < .01) and remained unchanged compared with pre-half-marathon levels in the placebo group (p > .05). Perceived muscle soreness and fatigue increased immediately post-half-marathon (p < .01) and returned to pre-half-marathon levels by 48 hr, with no difference between groups (p > .05). Supplementation with NZBC extract had no effect on the recovery of countermovement jump variables and perceptions of muscle soreness or fatigue following a half-marathon in recreational runners.
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4.
Comparative efficacy of active recovery and cold water immersion as post-match recovery interventions in elite youth soccer.
Pooley, S, Spendiff, O, Allen, M, Moir, HJ
Journal of sports sciences. 2020;(11-12):1423-1431
Abstract
The current study compared cold-water immersion (CWI) and active recovery (AR) to static stretching (SS) on muscle recovery post-competitive soccer matches in elite youth players (n = 15). In a controlled crossover design, participants played a total of nine competitive soccer games, comprising three 80 minute games for each intervention (SS, CWI and AR). Muscle oedema, creatine kinase (CK), countermovement jump performance (CMJA) and perceived muscle soreness (PMS) were assessed pre-, immediately post-, and 48 hours post-match and compared across time-intervals and between interventions. Following SS, all markers of muscle damage remained significantly elevated (P < 0.05) compared to baseline at 48 hours post-match. Following AR and CWI, CMJA returned to baseline at 48 hours post-match, whilst CK returned to baseline following CWI at 48 hours post-match only. Analysis between recovery interventions revealed a significant improvement in PMS (P < 0.05) at 48 hours post-match when comparing AR and CWI to SS, with no significant differences between AR and CWI observed (P > 0.05). Analysis of %change for CK and CMJA revealed significant improvements for AR and CWI compared to SS. The present study indicated both AR and CWI are beneficial recovery interventions for elite young soccer players following competitive soccer matches, of which were superior to SS.
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5.
Effects of mechanical bed massage on biochemical markers of exercise-induced back muscle fatigue in athletes: A randomized controlled trial.
Zhong, H, Eungpinichpong, W, Wang, X, Chatchawan, U, Wanpen, S, Buranruk, O, Wang, C
Journal of back and musculoskeletal rehabilitation. 2020;(5):793-800
Abstract
BACKGROUND Many previous studies have explored the effects of manual massage on back muscle fatigue, and most of the mechanical massage techniques imitate manual massage. However, it is unknown whether mechanical and manual massage have the same functions for exercise-induced back muscle fatigue. OBJECTIVE To investigate the effects of mechanical bed massage on the biochemical markers of exercise-induced back muscle fatigue in male collegiate athletes. METHODS Twenty-eight male collegiate athletes who met the experimental criteria were recruited in this randomized controlled trial, and randomly assigned to a mechanical bed massage group (experimental group) or resting group (control group). The subjects performed eight bouts of reverse sit-up in the prone position and received 20 minutes of the intervention. Creatine kinase, blood lactate, and serum cortisol levels were measured at baseline, after fatigue, after intervention, and after 24 hours. RESULTS The level of serum cortisol of the control group was significantly higher than that of the experimental group after the intervention (p< 0.05). The comparison of the two groups for blood lactate levels showed no significant differences at any of the measurement time-points (p> 0.05). There was no significant difference in creatine kinase levels immediately after the intervention (p> 0.05), but a significant difference in creatine kinase level was observed between the two groups 24 hours later (p< 0.05). CONCLUSIONS Significant differences were observed between mechanical bed massage and rest condition on serum cortisol and creatine kinase for exercise-induced muscle fatigue. Therefore, mechanical bed massage may reduce stress and muscle damage for the athlete after training or competition.
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6.
Caffeine increases peripheral fatigue in low- but not in high-performing cyclists.
Santos, PS, Felippe, LC, Ferreira, GA, Learsi, SK, Couto, PG, Bertuzzi, R, Pereira, G, Lima-Silva, AE
Applied physiology, nutrition, and metabolism = Physiologie appliquee, nutrition et metabolisme. 2020;(11):1208-1215
Abstract
The influence of cyclists' performance levels on caffeine-induced increases in neuromuscular fatigue after a 4-km cycling time trial (TT) was investigated. Nineteen cyclists performed a 4-km cycling TT 1 h after ingesting caffeine (5 mg·kg-1) or placebo (cellulose). Changes from baseline to after exercise in voluntary activation (VA) and potentiated 1 Hz force twitch (Qtw,pot) were used as markers of central and peripheral fatigue, respectively. Participants were classified as "high performing" (HP, n = 8) or "low performing" (LP, n = 8) in accordance with their performance in a placebo trial. Compared with placebo, caffeine increased the power, anaerobic mechanical power, and anaerobic work, reducing the time to complete the trial in both groups (p < 0.05). There was a group versus supplement and a group versus supplement versus trial interaction for Qtw,pot, in which the postexercise reduction was greater after caffeine compared with placebo in the LP group (Qtw,pot = -34% ± 17% vs. -21% ± 11%, p = 0.02) but not in the HP group (Qtw,pot = -22% ± 8% vs. -23% ± 10%, p = 0.64). There was no effect of caffeine on VA, but there was a group versus trial interaction with lower postexercise values in the LP group than in the HP group (p = 0.03). Caffeine-induced improvement in 4-km cycling TT performance seems to come at the expense of greater locomotor muscle fatigue in LP but not in HP cyclists. Novelty Caffeine improves exercise performance at the expense of a greater end-exercise peripheral fatigue in low-performing athletes. Caffeine-induced improvement in exercise performance does not affect end-exercise peripheral fatigue in high-performing athletes. High-performing athletes seem to have augmented tolerance to central fatigue during a high-intensity time trial.
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7.
Muscle fibre activation and fatigue with low-load blood flow restricted resistance exercise-An integrative physiology review.
Wernbom, M, Aagaard, P
Acta physiologica (Oxford, England). 2020;(1):e13302
Abstract
Blood flow-restricted resistance exercise (BFRRE) has been shown to induce increases in muscle size and strength, and continues to generate interest from both clinical and basic research points of view. The low loads employed, typically 20%-50% of the one repetition maximum, make BFRRE an attractive training modality for individuals who may not tolerate high musculoskeletal forces (eg, selected clinical patient groups such as frail old adults and patients recovering from sports injury) and/or for highly trained athletes who have reached a plateau in muscle mass and strength. It has been proposed that achieving a high degree of muscle fibre recruitment is important for inducing muscle hypertrophy with BFRRE, and the available evidence suggest that fatiguing low-load exercise during ischemic conditions can recruit both slow (type I) and fast (type II) muscle fibres. Nevertheless, closer scrutiny reveals that type II fibre activation in BFRRE has to date largely been inferred using indirect methods such as electromyography and magnetic resonance spectroscopy, while only rarely addressed using more direct methods such as measurements of glycogen stores and phosphocreatine levels in muscle fibres. Hence, considerable uncertainity exists about the specific pattern of muscle fibre activation during BFRRE. Therefore, the purpose of this narrative review was (1) to summarize the evidence on muscle fibre recruitment during BFRRE as revealed by various methods employed for determining muscle fibre usage during exercise, and (2) to discuss reported findings in light of the specific advantages and limitations associated with these methods.
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8.
Muscle Metabolism and Fatigue during Simulated Ice Hockey Match-Play in Elite Players.
Vigh-Larsen, JF, Ermidis, G, Rago, V, Randers, MB, Fransson, D, Nielsen, JL, Gliemann, L, Piil, JF, Morris, NB, DE Paoli, FV, et al
Medicine and science in sports and exercise. 2020;(10):2162-2171
Abstract
PURPOSE The present study investigated muscle metabolism and fatigue during simulated elite male ice hockey match-play. METHODS Thirty U20 male national team players completed an experimental game comprising three periods of 8 × 1-min shifts separated by 2-min recovery intervals. Two vastus lateralis biopsies were obtained either during the game (n = 7) or pregame and postgame (n = 6). Venous blood samples were drawn pregame and at the end of the first and last periods (n = 14). Activity pattern and physiological responses were continuously monitored using local positioning system and heart rate recordings. Further, repeated-sprint ability was tested pregame and after each period. RESULTS Total distance covered was 5980 ± 199 m with almost half the distance covered at high skating speeds (>17 km·h). Average and peak on-ice heart rate was 84% ± 2% and 97% ± 2% of maximum heart rate, respectively. Muscle lactate increased (P ≤ 0.05) more than fivefold and threefold, whereas muscle pH decreased (P ≤ 0.05) from 7.31 ± 0.04 pregame to 6.99 ± 0.07 and 7.13 ± 0.11 during the first and last periods, respectively. Muscle glycogen decreased by 53% postgame (P ≤ 0.05) with ~65% of fast- and slow-twitch fibers depleted of glycogen. Blood lactate increased sixfold (P ≤ 0.05), whereas plasma free fatty acid levels increased 1.5-fold and threefold (P ≤ 0.05) after the first and last periods. Repeated-sprint ability was impaired (~3%; P ≤ 0.05) postgame concomitant with a ~10% decrease in the number of accelerations and decelerations during the second and last periods (P ≤ 0.05). CONCLUSIONS Our findings demonstrate that a simulated ice hockey match-play scenario encompasses a high on-ice heart rate response and glycolytic loading resulting in a marked degradation of muscle glycogen, particularly in specific sub-groups of fibers. This may be of importance both for fatigue in the final stages of a game and for subsequent recovery.
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9.
Monitoring Muscle Fatigue Progression during Dynamic Exercise.
Rannou, F, Nybo, L, Andersen, JE, Nordsborg, NB
Medicine and science in sports and exercise. 2019;(7):1498-1505
Abstract
PURPOSE To develop and validate a novel model for assessment of peripheral fatigue progression during dynamic exercise. METHODS Seven males and four females (24 ± 3 yr) completed one-legged knee-extensor exercise at 40% of peak power output (PPO) for 12 min (40% PPO). Additionally, an exhaustive bout lasting approximately 6 min (84% ± 2% PPO; 59 ± 10 W) was contrasted to two bouts completed at ±5% of the target workload. Trials were completed in randomized order. Percutaneous electrical stimulation of m. vastus lateralis during the passive knee-flexion phase allowed quantification of maximal twitch force every 30 s in parallel with RPE. RESULTS Elicited twitch force remained unchanged during the 40% PPO trial. During the three exhaustive bouts, exercise differed in duration (561 ± 154 s, 366 ± 64 s, 245 ± 61 s; P < 0.001) and amplitude of elicited twitch force showed a curvilinear decline across time. Elicited twitch force at exhaustion was approximately 60% reduced and similar between the exhaustive trials (intraclass correlation coefficient, 0.76; 95% confidence interval, 0.48-0.92). The increase in RPE during exercise was strongly correlated to the gradually reduced evoked twitch force (repeated-measures correlation, 0.89; 95% confidence interval, 0.62-0.97). CONCLUSIONS The developed model permits quantification of muscle fatigue progression during continuous dynamic one-legged knee-extension and a biphasic fatigue pattern is demonstrated during intense exercise. The model is sensitive to small changes in intensity, and it provides a novel approach for studying muscular mechanisms and their temporal relation to fatigue progression in vivo.
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10.
Effect of β-alanine supplementation during high-intensity interval training on repeated sprint ability performance and neuromuscular fatigue.
Milioni, F, de Poli, RAB, Saunders, B, Gualano, B, da Rocha, AL, Sanchez Ramos da Silva, A, Muller, PTG, Zagatto, AM
Journal of applied physiology (Bethesda, Md. : 1985). 2019;(6):1599-1610
Abstract
The study investigated the influence of β-alanine supplementation during a high-intensity interval training (HIIT) program on repeated sprint ability (RSA) performance. This study was randomized, double-blinded, and placebo controlled. Eighteen men performed an incremental running test until exhaustion (TINC) at baseline and followed by 4-wk HIIT (10 × 1-min runs 90% maximal TINC velocity [1-min recovery]). Then, participants were randomized into two groups and performed a 6-wk HIIT associated with supplementation of 6.4 g/day of β-alanine (Gβ) or dextrose (placebo group; GP). Pre- and post-6-wk HIIT + supplementation, participants performed the following tests: 1) TINC; 2) supramaximal running test; and 3) 2 × 6 × 35-m sprints (RSA). Before and immediately after RSA, neuromuscular function was assessed by vertical jumps, maximal isometric voluntary contractions of knee extension, and neuromuscular electrical stimulations. Muscle biopsies were performed to determine muscle carnosine content, muscle buffering capacity in vitro (βmin vitro), and content of phosphofructokinase (PFK), monocarboxylate transporter 4 (MCT4), and hypoxia-inducible factor-1α (HIF-1α). Both groups showed a significant time effect for maximal oxygen uptake (Gβ: 6.2 ± 3.6% and GP: 6.5 ± 4.2%; P > 0.01); only Gβ showed a time effect for total (-3.0 ± 2.0%; P = 0.001) and best (-3.3 ± 3.0%; P = 0.03) RSA times. A group-by-time interaction was shown after HIIT + Supplementation for muscle carnosine (Gβ: 34.4 ± 2.3 mmol·kg-1·dm-1 and GP: 20.7 ± 3.0 mmol·kg-1·dm-1; P = 0.003) and neuromuscular voluntary activation after RSA (Gβ: 87.2 ± 3.3% and GP: 78.9 ± 12.4%; P = 0.02). No time effect or group-by-time interaction was shown for supramaximal running test performance, βm, and content of PFK, MCT4, and HIF-1α. In summary, β-alanine supplementation during HIIT increased muscle carnosine and attenuated neuromuscular fatigue, which may contribute to an enhancement of RSA performance.NEW & NOTEWORTHY β-Alanine supplementation during a high-intensity interval training program increased repeated sprint performance. The improvement of muscle carnosine content induced by β-alanine supplementation may have contributed to an attenuation of central fatigue during repeated sprint. Overall, β-alanine supplementation may be a useful dietary intervention to prevent fatigue.