Purpose: Molecular hydrogen has been shown to possess antioxidant, anti-inflammatory, ergogenic, and recovery-enhancing effects. This study aimed to assess the effect of molecular hydrogen administration on muscle performance, damage, and perception of soreness up to 24 h of recovery after two strenuous training sessions performed on the same day in elite fin swimmers. Methods: Eight females (mean ± SD; age 21.5 ± 5.0 years, maximal oxygen consumption 45.0 ± 2.5 mL.kg-1.min-1) and four males (age 18.9 ± 1.3 years, maximal oxygen consumption 52.2 ± 1.7 mL.kg-1.min-1) performed 12 × 50 m sprints in the morning session and a 400 m competitive performance in the afternoon session. Participants consumed hydrogen-rich water (HRW) or placebo 3 days before the sessions (1,260 mL/day) and 2,520 mL on the experimental day. Muscle performance (countermovement jump), muscle damage (creatine kinase), and muscle soreness (100 mm visual analogue scale) were measured during the experimental day and at 12 and 24 h after the afternoon session. Results: HRW compared to placebo reduced blood activity of creatine kinase (156 ± 63 vs. 190 ± 64 U.L-1, p = 0.043), muscle soreness perception (34 ± 12 vs. 42 ± 12 mm, p = 0.045), and improved countermovement jump height (30.7 ± 5.5 cm vs. 29.8 ± 5.8 cm, p = 0.014) at 12 h after the afternoon session. Conclusion: Four days of HRW supplementation is a promising hydration strategy for promoting muscle recovery after two strenuous training sessions performed on the same day in elite fin swimmers. Clinical Trial Registration: clinicaltrials.gov, identifier NCT05799911.

Despite the known beneficial effects of creatine in treating exercise-induced muscle damage (EIMD), its effectiveness remains unclear. This study investigates the recovery effect of creatine monohydrate (CrM) on EIMD. Twenty healthy men (21-36 years) were subjected to stratified, randomized, double-blind assignments. The creatine (CRE) and placebo (PLA) groups ingested creatine and crystalline cellulose, respectively, for 28 days. They subsequently performed dumbbell exercises while emphasizing eccentric contraction of the elbow flexors. The EIMD was evaluated before and after exercise. The range of motion was significantly higher in the CRE group than in the PLA group 24 h (h) post exercise. A similar difference was detected in maximum voluntary contraction at 0, 48, 96, and 168 h post exercise (p = 0.017-0.047). The upper arm circumference was significantly lower in the CRE group than in the PLA group at 48, 72, 96, and 168 h post exercise (p = 0.002-0.030). Similar variation was observed in the shear modulus of the biceps brachii muscle at 96 and 168 h post exercise (p = 0.003-0.021) and in muscle fatigue at 0 and 168 h post exercise (p = 0.012-0.032). These findings demonstrate CrM-mediated accelerated recovery from EIMD, suggesting that CrM is an effective supplement for EIMD recovery.

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently consumed by athletes to manage muscle soreness, expedite recovery, or improve performance. Despite the prevalence of NSAID use, their effects on muscle soreness and performance, particularly when administered prophylactically, remain unclear. This randomized, double-blind, counter-balanced, crossover study examined the effect of consuming a single dose of each of three NSAIDs (celecoxib, 200 mg; ibuprofen, 800 mg; flurbiprofen, 100 mg) or placebo 2 h before on muscle soreness and performance following an acute plyometric training session. Twelve healthy adults, aged 18-42 years, completed a standardized plyometric exercise session consisting of 10 sets of 10 repetitions at 40 % 1-repetition maximum (1RM) on a leg press device. During exercise, total work, rating of perceived exertion, and heart rate were measured. Maximum voluntary contraction force (MVC), vertical jump height, and muscle soreness were measured before exercise and 4-h and 24-h post-exercise. We found no significant differences in total work, heart rate, or rating of perceived exertion between treatments. Additionally, no significant differences in muscle soreness or vertical jump were observed between treatments. Ibuprofen and flurbiprofen did not prevent decrements in MVC, but celecoxib attenuated decreases in MVC 4-h post exercise (p < 0.05). This study suggests that athletes may not benefit from prophylactic ibuprofen or flurbiprofen treatment to prevent discomfort or performance decrements associated with exercise, but celecoxib may mitigate short-term performance decrements.

BACKGROUND: Blackcurrant is rich in anthocyanins that may protect against exercise-induced muscle damage (EIMD) and facilitate a faster recovery of muscle function. We examined the effects of New Zealand blackcurrant (NZBC) extract on indices of muscle damage and recovery following a bout of strenuous isokinetic resistance exercise.
METHODS: Using a double-blind, randomised, placebo controlled, parallel design, twenty-seven healthy participants received either a 3 g·day-1 NZBC extract (n = 14) or the placebo (PLA) (n = 13) for 8 days prior to and 4 days following 60 strenuous concentric and eccentric contractions of the biceps brachii muscle on an isokinetic dynamometer. Muscle soreness (using a visual analogue scale), maximal voluntary contraction (MVC), range of motion (ROM) and blood creatine kinase (CK) were assessed before (0 h) and after (24, 48, 72 and 96 h) exercise.
RESULTS: Consumption of NZBC extract resulted in faster recovery of baseline MVC (p = 0.04), attenuated muscle soreness at 24 h (NZBC: 21 ± 10 mm vs. PLA: 40 ± 23 mm, p = 0.02) and 48 h (NZBC: 22 ± 17 vs. PLA: 44 ± 26 mm, p = 0.03) and serum CK concentration at 96 h (NZBC: 635 ± 921 UL vs. PLA: 4021 ± 4319 UL, p = 0.04) following EIMD.
CONCLUSIONS: Consumption of NZBC extract prior to and following a bout of eccentric exercise attenuates muscle damage and improves functional recovery. These findings are of practical importance in recreationally active and potentially athletic populations, who may benefit from accelerated recovery following EIMD.

BACKGROUND: Soccer-specific speed-endurance training induces short-term neuromuscular fatigue and performance deterioration over a 72-h recovery period, associated with elevated markers of exercise-induced muscle damage. We compared the effects of whey vs. soy protein supplementation on field activity, performance, muscle damage and redox responses following speed-endurance training in soccer players.
METHODS: Ten well-trained, male soccer players completed three speed-endurance training trials, receiving whey protein (WP), soy protein (SP) or an isoenergetic placebo (PL; maltodextrin) according to a randomized, double-blind, crossover, repeated-measures design. A pre-loading period was applied in each trial during which protein supplementation was individually adjusted to reach a total protein intake of 1.5 g/kg/day, whereas in PL protein intake was adjusted at 0.8-1 g/kg/day. Following pre-loading, two speed-endurance training sessions (1 and 2) were performed 1 day apart, over a 3-day experimental period. During each session, field activity and heart rate were continuously monitored using global positioning system and heart rate monitors, respectively. Performance (isokinetic strength of knee extensors and flexors, maximal voluntary isometric contraction, speed, repeated sprint ability, countermovement jump), muscle damage (delayed-onset of muscle soreness, creatine kinase activity) and redox status (glutathione, total antioxidant capacity, protein carbonyls) were evaluated at baseline (pre), following pre-loading (post-load), and during recovery from speed-endurance training.
RESULTS: High-intensity and high-speed running decreased (P ≤ 0.05) during speed-endurance training in all trials, but WP and SP mitigated this response. Isokinetic strength, maximal voluntary isometric contraction, 30-m speed, repeated sprint ability and countermovement jump performance were similarly deteriorated during recovery following speed-endurance training in all trials (P ≤ 0.05). 10 m speed was impaired at 24 h only in PL. Delayed-onset of muscle soreness, creatine kinase, total antioxidant capacity and protein carbonyls increased and glutathione decreased equally among trials following speed-endurance training (P ≤ 0.05), with SP inducing a faster recovery of protein carbonyls only at 48 h (P ≤ 0.05) compared to WP and PL.
CONCLUSIONS: In conclusion, increasing daily protein intake to 1.5 g/kg through ingestion of either whey or soy protein supplements mitigates field performance deterioration during successive speed-endurance training sessions without affecting exercise-induced muscle damage and redox status markers.
BACKGROUND: Name of the registry: clinicaltrials.gov.
BACKGROUND: NCT03753321 . Date of registration: 12/10/2018.

The authors sought to determine whether consuming collagen peptides (CP) enhances musculoskeletal recovery of connective tissues following a damaging exercise bout. Resistance-trained males consumed 15 g/day of CP (n = 7) or placebo (n = 8), and after 7 days, maximal voluntary isometric contraction (MVIC), countermovement jump height, soreness, and collagen turnover were examined. Five sets of 20 drop jumps were performed and outcome measures were collected 24, 48, and 120 hr postexercise. Countermovement jump height was maintained in the CP group at 24 hr (PRE = 39.9 ± 8.8 cm vs. 24 hr = 37.9 ± 8.9 cm, p = .102), whereas the CP group experienced a significant decline at 24 hr (PRE = 40.4 ± 7.9 cm vs. 24 hr = 35.5 ± 6.4 cm, p = .001; d = 0.32). In both groups, muscle soreness was significantly higher than PRE at 24 hr (p = .001) and 48 hr (p = .018) but not at 120 hr (p > .05). MVIC in both legs showed a significant time effect (left: p = .007; right: p = .010) over the 5-day postexercise period. Neither collagen biomarker changed significantly at any time point. CP supplementation attenuated performance decline 24 hr following muscle damage. Acute consumption of CP may provide a performance benefit the day following a bout of damaging exercise in resistance-trained males.

BACKGROUND: Strenuous physical exercise may cause acute muscle soreness (AMS), which occurs directly after exercise, as well as delayed onset muscle soreness (DOMS), which occurs about 24 h after exercise. Studies of acupuncture\'s effect on DOMS have had contradictory results, whereas its effect on AMS has not been extensively studied. The main goal of this study was to evaluate acupuncture\'s effects on AMS and DOMS and on the prevention of DOMS.
METHODS: 45 volunteers were randomised into a verum acupuncture group, a sham acupuncture group and a control group. After exercise-induced muscle damage was elicited, muscle soreness and pressure pain threshold were assessed at different time points. The outcome assessments were performed before (T1) and 20 min after the first acupuncture treatment (T2); then, 24 h later, they were performed before (T3) and 20 min after the second acupuncture treatment (T4). In the verum and sham acupuncture groups, acupuncture was performed for 2 min, immediately after T1 and T3 assessments, whereas subjects in the control group simply rested for 2 min without treatment. Verum acupuncture was given at ST34, ST36 and LR3, whereas sham acupuncture was given at three nontraditional points.
RESULTS: We found that verum acupuncture can reduce the occurrence of AMS by one-half and DOMS by one-third. We also found specific and nonspecific acupuncture effects in AMS and DOMS.
CONCLUSIONS: The uneven induction of muscle damage identified by our study, as shown by heterogeneity in pressure pain threshold values, may have led to the contradictory results in published studies on DOMS.

BACKGROUND: Low level laser therapy (LLLT) is among novel methods for preventing and treating muscle damage and soreness induced by volitional exercise, but little is known about using LLLT before neuromuscular electrical stimulation. The aim of this first randomised, double blind, crossover trial addressing this issue was to evaluate effects of LLLT on muscle damage and oxidative stress, as well as recovery of muscle function after a single session of isometric neuromuscular electrical stimulation(NMES).
METHODS: Twenty four moderately active, healthy men aged 21-22 years received 45 electrically evoked tetanic, isometric contractions of the quadriceps femoris, preceded by LLLT or sham-LLLT. Maximal isometric voluntary muscle torques, perceived soreness, and blood samples were analysed from baseline to 96 h post intervention. We measured plasma markers of muscle damage (the activity of creatine kinase), and inflammation (C-reactive protein), and evaluated redox state parameters.
RESULTS: NMES-evoked contractions induced oxidative stress, demonstrated by an increase in lipid peroxidation and impairments in enzymatic antioxidant system. LLLT irradiations had a protective effect on NMES-induced decrease in enzymatic antioxidant defence and shortened the duration of inflammation. This effect of irradiations on redox state and inflammation did not affect lipid peroxidation, muscle damage, and muscle torque.
CONCLUSIONS: LLLT may protect from impairments in enzymatic antioxidant system and may shorten inflammation induced by a single NMES session in moderately active, healthy men. However, the effects of LLLT on redox state and inflammatory processes do not seem to affect muscle damage and recovery of muscle function after NMES.
BACKGROUND: The study was retrospectively registered in the Australian New Zealand Clinical Trials Registry (ANZCTR); The trial registration number: ACTRN12619000678190; date of registration: 6 May 2019.

BACKGROUND: Compression garment utilization is very popular among runners despite a lack of consensus in the literature regarding a beneficial impact. The aim of the study was to investigate the impact of training and competing with compression garments on exercise-induced muscle damage and performance in ultramarathon runners.
OBJECTIVE: Compression garments will reduce the severity of exercise-induced muscle damage and improve performance in long-distance runners compared with control conditions.
METHODS: Prospective, randomized controlled trial.
METHODS: Level 1.
METHODS: The study was conducted in healthy, uninjured endurance runners (n = 41) participating in a 56-km ultramarathon. The experimental group (n = 20; 14 males, 6 females) trained for 6 weeks and participated in the race wearing below-knee compression garments while the control group (n = 21; 15 males, 6 females) did not. Participants were tested on 4 occasions for various markers of exercise-induced muscle damage and running performance.
RESULTS: Ankle circumference measurements increased significantly less ( P = 0.01, Cohen d = 0.9) in the experimental group from immediately after until 2 days post-race compared with the control group. No further statistically significant changes were detected over time in midcalf circumferences, muscle architecture, or race performance. Selected pain ratings were statistically significant and worse in the experimental group.
CONCLUSIONS: There are limited indications of a beneficial impact of compression garments with improvements in ankle circumference measurements. No ergogenic impact was detected.
CONCLUSIONS: There is limited evidence to support the continued utilization of commercially available below-knee compression garments during running for the purpose of muscle recovery or as a performance aid.

BACKGROUND: Platelet rich plasma (PRP) therapy is widely used in enhancing the recovery of skeletal muscle from injury. However, the impact of intramuscular delivery of PRP on hematologic and biochemical responses has not been fully elucidated in exercise-induced muscle damage. The purpose of this investigation the effects of intramuscular delivery of PRP on hematologic and biochemical responses and recovery strategy muscle damage induced by high intensity muscle exercise (exercise-induced muscle damage, EIMD).
METHODS: Moderately active male volunteers participated in this study and were assigned to a control group (control, n = 6) and PRP administration group (PRP, n = 6). The subjects performed exercise with a load of 80% one repetition maximum (1RM) maximal voluntary contraction of the elbow flexors until point of exhaustion of the non-dominant arm was reached. The arms were treated with saline or autologous PRP post-24 h EIMD. Venous blood samples were obtained in the morning to establish a baseline value and 1-4 days post-exercise and were analyzed for serum ferritin, iron, iron binding capacity (IBC), creatinine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT).
RESULTS: The baseline levels of plasma iron, ferritin, IBC, CK, LDH, AST, and ALT were similar in both the control and PRP groups. However, 24-h following exercise a significant increase in these parameters was observed in both groups between 1 and 4 days during the recovery period. Interestingly, PRP administration decreased plasma iron levels compared to the control on the second day post-exercise. Plasma IBC increased in PRP group from Days 2 to 4 post-exercise compared to the control group whilst PRP administration had no effect on plasma ferritin, CK, AST, ALT, or LDH.
CONCLUSIONS: Acute exhaustive exercise increased muscle damage markers, including plasma iron, IBC, and ferritin levels, indicating muscle damage induced by exercise. PRP administration improves inflammation by reversing the increase in the iron levels post-exercise without displaying any myotoxicity and may have a role to play in the recovery of exercise-induced muscle damage.