The effectiveness of acupuncture for pain reduction in delayed-onset muscle soreness: a systematic review

Objective: The aim of this study was to systematically review the literature on acupuncture for delayed-onset muscle soreness (DOMS) and report upon study quality and treatment outcomes. Design: Systematic review. Data sources: Searches were conducted in the following electronic databases from their inception to 31 March 2018: CINAHL, MEDLINE, Allied and Complementary Medicine (AMED) and SPORTDiscus. Reference lists of all included studies and relevant reviews were hand-searched for additional studies. Eligibility criteria for selecting studies: Randomised controlled trials (RCTs) that evaluated the effectiveness of acupuncture in DOMS in adults measuring the pre-specified primary outcome (pain) were included. Data collection and analysis: Data were extracted using pre-defined extraction forms and the Standards for Reporting Interventions in Clinical Trials of Acupuncture (STRICTA) checklist. Quality of studies was evaluated based on the Cochrane risk of bias assessment. Results: Five RCTs investigating laboratory-induced DOMS in the upper limbs with a total sample size of 182 healthy participants were included. Of the included studies, three reported superiority of acupuncture over no treatment in DOMS pain reduction as measured by visual analogue scale, pressure pain threshold or electrical pain threshold, while two studies yielded non-significant results. All studies demonstrated risk of bias in one or more areas, commonly lack of blinding of participants and personnel. Summary/conclusion: There is conflicting to limited evidence to support the effects of acupuncture on the relief of pain associated with DOMS. The findings were confounded by methodological limitations and reporting insufficiency. More rigorous, high-quality, and well-reported RCTs are required to further evaluate the effectiveness of acupuncture for DOMS

Antioxidants for preventing and reducing muscle soreness after exercise

Background Muscle soreness typically occurs after intense exercise, unaccustomed exercise or actions that involve eccentric contractions where the muscle lengthens while under tension. It peaks between 24 and 72 hours after the initial bout of exercise. Many people take antioxidant supplements or antioxidant-enriched foods before and after exercise in the belief that these will prevent or reduce muscle soreness after exercise. Objectives To assess the effects (benefits and harms) of antioxidant supplements and antioxidant-enriched foods for preventing and reducing the severity and duration of delayed onset muscle soreness following exercise. Search methods We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, SPORTDiscus, trial registers, reference lists of articles and conference proceedings up to February 2017. Selection criteria 205 Antioxidants for preventing and reducing muscle soreness after exercise We included randomised and quasi-randomised controlled trials investigating the effects of all forms of antioxidant supplementation including specific antioxidant supplements (e.g. tablets, powders, concentrates) and antioxidant-enriched foods or diets on preventing or reducing delayed onset muscle soreness (DOMS). We excluded studies where antioxidant supplementation was combined with another supplement. Data collection and analysis Two review authors independently screened search results, assessed risk of bias and extracted data from included trials using a pre-piloted form. Where appropriate, we pooled results of comparable trials, generally using the random-effects model. The outcomes selected for presentation in the 'Summary of findings' table were muscle soreness, collected at times up to 6 hours, 24, 48, 72 and 96 hours post-exercise, subjective recovery and adverse effects. We assessed the quality of the evidence using GRADE. Main results Fifty randomised, placebo-controlled trials were included, 12 of which used a cross-over design. Of the 1089 participants, 961 (88.2%) were male and 128 (11.8%) were female. The age range for participants was between 16 and 55 years and training status varied from sedentary to moderately trained. The trials were heterogeneous, including the timing (pre-exercise or post-exercise), frequency, dose, duration and type of antioxidant supplementation, and the type of preceding exercise. All studies used an antioxidant dosage higher than the recommended daily amount. The majority of trials (47) had design features that carried a high risk of bias due to selective reporting and poorly described allocation concealment, potentially limiting the reliability of their findings. We tested only one comparison: antioxidant supplements versus control (placebo). No studies compared high-dose versus low-dose, where the low-dose supplementation was within normal or recommended levels for the antioxidant involved. Pooled results for muscle soreness indicated a small difference in favour of antioxidant supplementation after DOMSinducing exercise at all main follow-ups: up to 6 hours (standardised mean difference (SMD) -0.30, 95% confidence interval (CI) -0.56 to -0.04; 525 participants, 21 studies; low-quality evidence); at 24 hours (SMD -0.13, 95% CI -0.27 to 0.00; 936 participants, 41 studies; moderate-quality evidence); at 48 hours (SMD -0.24, 95% CI -0.42 to -0.07; 1047 participants, 45 studies; low-quality evidence); at 72 hours (SMD -0.19, 95% CI -0.38 to -0.00; 657 participants, 28 studies; moderate-quality evidence), and little difference at 96 hours (SMD -0.05, 95% CI -0.29 to 0.19; 436 participants, 17 studies; low-quality evidence). When we rescaled to a 0 to 10 cm scale in order to quantify the actual difference between groups, we found that the 95% CIs for all five follow-up times were all well below the minimal important difference of 1.4 cm: up to 6 hours (MD -0.52, 95% CI -0.95 to -0.08); at 24 hours (MD -0.17, 95% CI -0.42 to 0.07); at 48 hours (MD -0.41, 95% CI -0.69 to -0.12); at 72 hours (MD -0.29, 95% CI -0.59 to 0.02); and at 96 hours (MD -0.03, 95% CI -0.43 to 0.37). Thus, the effect sizes suggesting less muscle soreness with antioxidant supplementation were very unlikely to equate to meaningful or important differences in practice. Neither of our subgroup analyses to examine for differences in effect according to type of DOMSinducing exercise (mechanical versus whole body aerobic) or according to funding source confirmed subgroup differences. Sensitivity analyses excluding cross-over trials showed that their inclusion had no important impact on results. None of the 50 included trials measured subjective recovery (return to previous activities without signs or symptoms). There is very little evidence regarding the potential adverse effects of taking antioxidant supplements as this outcome was reported in only nine trials (216 participants). From the studies that did report adverse effects, two of the nine trials found adverse effects. All six participants in the antioxidant group of one trial had diarrhoea and four of these also had mild indigestion; these are well-known side effects of the particular antioxidant used in this trial. One of 26 participants in a second trial had mild gastrointestinal distress. Authors' conclusions There is moderate to low-quality evidence that high dose antioxidant supplementation does not result in a clinically relevant reduction of muscle soreness after exercise at up to 6 hours or at 24, 48, 72 and 96 hours after exercise. There is no evidence available on subjective recovery and only limited evidence on the adverse effects of taking antioxidant supplements. The findings of, and messages from, this review provide an opportunity for researchers and other stakeholders to come together and consider what are the priorities, and underlying justifications, for future research in this area

Effect of recovery on the treatment of delayed onset muscle soreness and muscle performance

La práctica de ejercicio físico intenso requiere de una adecuada recuperación para evitar el síndrome de sobre entrenamiento y la aparición de lesiones deportivas. La recuperación es esencial para ayudar a los atletas a manejar la fatiga mental y física sin comprometer el nivel de rendimiento cuando se reanuda la práctica y el entrenamiento. Se ha demostrado que la elección de una correcta recuperación posterior a un ejercicio intenso no habitual, juega un papel importante en el rendimiento de los deportistas y en la forma en que son capaces de manejar el dolor y otros síntomas relacionados como la inflamación, la disminución del rango de movimiento, de la fuerza, de la velocidad, y de la flexibilidad. La selección de un protocolo de recuperación específico y los correspondientes parámetros (intensidad, duración, frecuencia…) aún no está clara, y su impacto y eficacia en el trastorno muscular, la debilidad, el dolor y el rendimiento siguen siendo controvertidos y no concluyentes. En consecuencia, esta tesis doctoral tiene como objetivo identificar y desarrollar una visión profunda sobre los antecedentes científicos y la validez de los protocolos de recuperación reportados en la literatura y mostrar el efecto de protocolos de recuperación activos y pasivos sobre el dolor y el rendimiento muscular entre individuos jóvenes activos. Para dar respuesta a estos objetivos, se realizó una revisión sistemática, un ensayo de control aleatorizado y un estudio cuasi experimental. En el primer estudio se realizó una revisión sistemática de la literatura en cinco bases de datos, de acuerdo con las pautas descritas en la declaración de elementos de informes preferidos para revisiones sistemáticas y meta-análisis (PRISMA). En este trabajo se identifican los beneficios, y limitaciones, proporcionando un enfoque práctico para individuos activos, entrenadores y terapeutas acerca de qué tipo de recuperación activa podría mejorar el nivel de rendimiento después de actividades extenuantes. Adicionalmente, un estudio cuasi-experimental, en el que se examinó una muestra de 35 participantes durante tres días. La metodología del estudio se basó en la comparación intra-sujeto de ambas piernas, que permitiera demostrar la eficacia de una combinación de masaje e inmersión en agua fría sobre la percepción del dolor, la altura del salto, la fuerza isométrica máxima y variables cinemáticas de la marcha. Finalmente se diseñó un ensayo controlado aleatorio con un diseño cruzado incluyó a 31 jóvenes participantes activos. Se llevó a cabo un experimento de cuatro días, en dos sesiones idénticas separadas por un período de tres semanas, para probar un protocolo de recuperación activa que consistía en un ejercicio de intervalos de alta intensidad en pendiente positiva. En este estudio, se evaluaron y analizaron el dolor, la creatina-quinasa, la inflamación muscular, la altura del salto, la velocidad del sprint y la repetición máxima (1RM). Los resultados de esta tesis doctoral mostraron que la recuperación activa en general, incluyendo correr y trotar, ejercicio en el agua, yoga y contracciones musculares aisladas ofrece un manejo limitado del dolor. Además, la inflamación y la rigidez muscular después del ejercicio intensivo se redujeron con la actividad física general y el yoga, respectivamente, y la disminución de la fuerza muscular es menor después del ejercicio en el agua. Además, una combinación de masaje e inmersión en agua fría no parece disminuir significativamente el dolor, aumentar el rendimiento muscular o mejorar los parámetros de la marcha en comparación con ningún tratamiento. Y finalmente, un protocolo de recuperación activa que consiste en ejercicio en intervalos de alta intensidad cuesta arriba no ofrece un beneficio destacable en comparación con el descanso pasivo, sin embargo su implementación no aumenta el dolor ni agrava el rendimiento muscular, por lo que se puede realizar sin ningún daño. The practice of intensive physical exercise requires an appropriate recovery in order to avoid overtraining syndrome and the emergence of sports injuries. Recovery is highly essential in helping athletes to deal with mental and physical fatigue without compromising their performance level when practice and training are resumed. Following any unaccustomed activity, it has been demonstrated that the choice of the proper recovery plays an important role in athletes’ performance, and the management of soreness and other related symptoms such as inflammation, swelling and decrease in range of motion, strength, speed, and flexibility. The selection of a specific recovery protocol and the corresponding subsequent parameters, such as intensity, duration, and frequency, is still unclear, and its impact and efficiency on muscle disorder, weakness, pain, and performance remains controversial and inconclusive. Consequently, this doctoral thesis aims to highlight and to develop a deep insight into the scientific background and validity of recovery protocols reported in the literature. Moreover, the main objective is to demonstrate the effect of active and passive recovery protocols on pain and muscle performance among young active individuals. To respond to these objectives, a systematic review, a randomized controlled trial, and a quasi-experimental study were performed. The first study systematically reviewed the literature from five databases according to the guidelines outlined in the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. The benefits and limitations are identified in this paper, providing a practical approach for active individuals, coaches, and therapists regarding what type of active recovery could enhance performance level following strenuous activities. Moreover, a quasi-experimental study in which a sample of 35 participants was examined for three days. The methodology in this study was based on an intra-subject comparison of both legs, to investigate the effectiveness of a combination of massage and cold water immersion (CWI) on pain, jump height, maximum isometric force, and gait kinematic variables. Finally, a randomized controlled trial with a crossover design included 31 young active participants. A four-day experiment was conducted in two identical sessions separated by a three-week period, to test an active recovery protocol consisting of an uphill high-intensity interval exercise. In this study, pain, creatine kinase (CK), muscle inflammation, jump height, sprint speed, and one repetition maximum (1RM) were assessed and analyzed. The results of this doctoral thesis show that active recovery in general, including running and jogging, exercise in water, yoga, and isolated muscle contractions offers limited management on soreness. Furthermore, inflammation and muscle stiffness following intensive exercise were reduced by general physical activity and yoga, respectively, and the decrease in muscular strength is less following exercise in water. Additionally, a combination of massage and CWI does not seem to significantly decrease soreness, increase muscle performance, or improve gait parameters compared to no treatment. Finally, an active recovery protocol consisting of uphill high-intensity interval exercise does not offer a remarkable benefit in comparison with passive rest, however its implementation does not increase soreness nor aggravate muscle performance, thus it can be performed without any harm.<br /

Effect of Large Versus Small Range of Motion in the Various Intensities of Eccentric Exercise-Induced Muscle Pain and Strength

International Journal of Exercise Science 14(7): 1-18, 2021. The purpose was to investigate eccentric (ECC) exercise with full range of motion (FROM) induce a greater magnitude of delayed onset muscle soreness (DOMS), pain, functional limitations compared to partial range of motion (PROM; outer 60° of ROM). Thirty-four participants (men and women) aged between 18 and 30 years performed ECC exercise protocol on elbow and knee muscles (5 × 10 repetitions each session) using their 15%/25%/35% of maximal voluntary isometric contraction (MVIC) with PROM (week 2-4) and FROM (week 6-8). Two days a week, ECC exercises and remaining days the subjective and objective assessments were carried out (activities of daily living (ADL), pain (visual analogue scale (VAS), pain pressure threshold (PPT)), and MVIC. The ECC exercise with FROM showed moderate pain (0-3.5) in ADL (pulling a heavy object and descending stairs), VAS, and PPT for elbow extensors and knee flexors and showed a statistically significant difference (p ≤ 0.05) compared to PROM ECC protocol. The muscle strength was increased in FROM ECC exercise than PROM ECC exercise and ranged between 23.16% and 28.22%. ECC exercise performed with FROM induced a higher degree of DOMS, pain, ADL limitations than PROM. The study outcomes can be used for beginner sedentary older adults as well as young athletes

Pain assessment and possible mechanism of delayed onset muscle soreness

Muscle pain is felt during exercise or daily activities for several days after performing unaccustomed exercise, which is referred to as delayed onset muscle soreness (DOMS). Many people experience DOMS, but its underlying mechanisms are not fully understood. One of the challenges in the investigation of DOMS is its subjective nature, which makes the assessment ambiguous, thus establishing a standardised protocol is necessary. The present thesis scrutinised muscle pain assessments (Study 1, Study 2), developed a new assessment of muscle pain focusing on muscle fascia (Study 3), and investigated why DOMS is reduced after the second than the first bout of eccentric exercise (Study 4). From these studies, DOMS was thought to be more associated with connective tissue than muscle fibre damage and inflammation. In Study 1, the relationship between pain level assessed by a visual analogue scale (VAS) and pain sensitivity assessed by pressure pain threshold (PPT) was examined. Thirty-one healthy young men performed 10 sets of 6 maximal isokinetic eccentric contractions with their non-dominant arm. Before and 1 - 4 days after the exercise, muscle pain perceived upon palpation of the biceps brachii at three sites (5, 9, and 13 cm above the elbow crease) was assessed by VAS with a 100 mm line (0 = no pain, 100 = extremely painful), and PPT of the same sites was determined by an algometer. The VAS increased after exercise and peaked two days post-exercise, while the PPT decreased most at 1 day post-exercise and did not return to baseline for 4 days following exercise (P Muscle pain induced by elbow flexor eccentric exercise was investigated using different assessments in Study 2. Ten untrained men performed 10 sets of 6 maximal isokinetic eccentric contractions of the elbow flexors with one arm. Maximal voluntary isometric contraction torque (MVC), range of motion (ROM) and serum creatine kinase (CK) activity were measured before, immediately after, and 1 to 5 days after exercise as indirect markers of muscle damage. PPT of 50 sites over an exercised upper arm, VAS with a 100-mm line for pain level upon static pressure by a cuff and fingers, and palpation of the biceps brachii at three sites (3, 9, and 15 cm above the elbow crease) and different palpation methods (longitudinal, transverse and circular movements) on the mid-belly of biceps were assessed. Large decreases in MVC and ROM, and significant increases in serum CK activity indicated muscle damage. A significant difference (P In Study 3, changes in the electrical pain threshold (EPT) of the biceps brachii fascia, biceps brachii muscle and brachialis fascia following eccentric elbow flexor contractions, and the relationship between EPT and VAS or PPT were investigated. Ten healthy untrained men performed two eccentric exercise bouts (ECC1, ECC2) consisting of 10 sets of 6 maximal isokinetic eccentric contractions of the elbow flexors with the same arm separated by 4 weeks. Changes in MVC, ROM, VAS and PPT were smaller (P The purpose of Study 4 was to investigate the magnitude of muscle lengthening during the first and second bout of eccentric exercise bouts and whether the muscle length changes are associated with the magnitude of DOMS and changes in other indirect markers of muscle damages between bouts. Ten healthy untrained men performed two eccentric exercise bouts (ECC1, ECC2) consisting of 10 sets of 6 maximal isokinetic eccentric contractions of the elbow flexors using the same arm separated by 4 weeks. Changes in MVC, ROM, muscle thickness, ultrasound echo intensity, serum CK activity and muscle soreness (VAS) were smaller (

Perspectives on Exertional Rhabdomyolysis

© 2017, The Author(s). Exertional (exercise-induced) rhabdomyolysis is a potentially life threatening condition that has been the subject of research, intense discussion, and media attention. The causes of rhabdomyolysis are numerous and can include direct muscle injury, unaccustomed exercise, ischemia, extreme temperatures, electrolyte abnormalities, endocrinologic conditions, genetic disorders, autoimmune disorders, infections, drugs, toxins, and venoms. The objective of this article is to review the literature on exertional rhabdomyolysis, identify precipitating factors, and examine the role of the dietary supplement creatine monohydrate. PubMed and SPORTDiscus databases were searched using the terms rhabdomyolysis, muscle damage, creatine, creatine supplementation, creatine monohydrate, and phosphocreatine. Additionally, the references of papers identified through this search were examined for relevant studies. A meta-analysis was not performed. Although the prevalence of rhabdomyolysis is low, instances still occur where exercise is improperly prescribed or used as punishment, or incomplete medical history is taken, and exertional rhabdomyolysis occurs. Creatine monohydrate does not appear to be a precipitating factor for exertional rhabdomyolysis. Healthcare professionals should be able to recognize the basic signs of exertional rhabdomyolysis so prompt treatment can be administered. For the risk of rhabdomyolysis to remain low, exercise testing and prescription must be properly conducted based on professional standards

Modulation of exercise-induced muscle damage, inflammation, and oxidative markers by curcumin supplementation in a physically active population: A systematic review

Producción CientíficaPhysical activity, particularly high-intensity eccentric muscle contractions, produces exercise-induced muscle damage (EIMD). The breakdown of muscle fibers and the consequent inflammatory responses derived from EIMD affect exercise performance. Curcumin, a natural polyphenol extracted from turmeric, has been shown to have mainly antioxidant and also anti-inflammatory properties. This effect of curcumin could improve EIMD and exercise performance. The main objective of this systematic review was to critically evaluate the effectiveness of curcumin supplementation on EIMD and inflammatory and oxidative markers in a physically active population. A structured search was carried out following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines in the databases SCOPUS, Web of Science (WOS), and Medline (PubMed) from inception to October 2019. The search included original articles with randomized controlled crossover or parallel design in which the intake of curcumin administered before and/or after exercise was compared with an identical placebo situation. No filters were applied to the type of physical exercise performed, the sex or the age of the participants. Of the 301 articles identified in the search, 11 met the established criteria and were included in this systematic review. The methodological quality of the studies was assessed using the McMaster Critical Review Form. The use of curcumin reduces the subjective perception of the intensity of muscle pain; reduces muscle damage through the decrease of creatine kinase (CK); increases muscle performance; has an anti-inflammatory effect by modulating the pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-8; and may have a slight antioxidant effect. In summary, the administration of curcumin at a dose between 150–1500 mg/day before and during exercise, and up until 72 h’ post-exercise, improved performance by reducing EIMD and modulating the inflammation caused by physical activity. In addition, humans appear to be able to tolerate high doses of curcumin without significant side-effects

Effects of resveratrol supplementation on delayed onset muscle soreness and muscle recovery: A systematic review

Delayed onset muscle soreness (DOMS) and impaired muscle recovery significantly affect athletes and recreational exercisers, influencing their performance and training consistency. Resveratrol, a natural polyphenol known for its anti-inflammatory and antioxidant properties, is thought to mitigate these effects, yet its effectiveness remains to be fully verified. This systematic review evaluates the impact of RES supplementation on muscle recovery in adults by examining its influence on DOMS, oxidative stress, and inflammation, along with its interactions with other supplements. Three electronic databases and one registry were searched in October 2023. A total of 10 studies met the inclusion criteria, encompassing a combined participant count of 238 (N=238). The review encompassed diverse participant populations, exercise types, and resveratrol dosages. The findings indicated that resveratrol potentially reduces markers of muscle damage, such as creatine kinase and lactate dehydrogenase, and alleviates DOMS symptoms to varying degrees. However, results varied based on exercise intensity, participant demographics, timing of supplementations and dosages. Synergistic interaction studies suggested that resveratrol, in combination with other compounds, could be more effective in exerting its effects. Despite promising findings, the research was limited by diverse study designs and the absence of long-term impact assessments. Further studies should standardise methods and explore resveratrol’s long-term safety and effectiveness. Nevertheless, these results underscore resveratrol’s potential as a beneficial supplement in exercise and sports medicine, meriting additional detailed exploration to refine its use

Management strategies and contributory factors for resistance exercise-induced muscle damage: an exploration of dietary protein, exercise load, and sex

The World Health Organisation recommends that resistance exercise be performed at least twice per week to benefit general health and wellbeing. However, resistance exercise is associated with acute muscle damage that potentially can dampen muscle adaptations promoted by chronic resistance training. The extent to which muscle is damaged by exercise is influenced by various factors, including age, training status, exercise type, and – notable to this thesis – sex. To this end, establishing sex-specific management strategies for exercise-induced muscle damage (EIMD) is important to optimise the benefits of exercise. Two EIMD management strategies were focussed on in this thesis: dietary protein supplementation and exercise load manipulation. It was identified in this thesis that research into the impact both of protein supplementation and exercise load on EIMD heavily underrepresent female populations (chapters 3 and 5), despite well-documented sex differences in EIMD responses. Therefore, future research priority should be placed on bridging the sex data gap by conducting high-quality studies centralising around female-focussed and sex-comparative methodological designs. Both peri-exercise protein supplementation and exercise load manipulation in favour of lighter loads were revealed to be effective management strategies for resistance EIMD in males through systematic and scoping review of the current literature (chapters 3 and 5, respectively). Due to a lack of data from females, it is only appropriate for these strategies to be recommended for males at present. To decipher whether protein supplementation and lower exercise loads are beneficial for managing EIMD in females, a randomised controlled trial (RCT) (chapter 4) and a protocol for an RCT (chapter 6) involving male and female participants are presented in this thesis. The incorporation of ecologically-valid resistance exercise in the RCT in chapter 4 highlighted that even mild muscle damage is attenuated in females, reflected in diminished increases in post-exercise creatine kinase concentration and muscle soreness compared with males; however, the reason for this difference requires further investigation. This study, while supporting sex differences, contrasted previous studies, as neither males nor females experienced an attenuation of EIMD during milk protein supplementation. This difference likely owed to the lower severity of muscle damage induced in the current study relative to previous studies, and accordingly, future research should seek to discover alternative management strategies for mild EIMD. A protocol for an RCT examining the impact of exercise load on EIMD in untrained males and females is described in Chapter 6 of this thesis and may be used as guidance for researchers developing similar, sex-comparative studies. It was hypothesised that females will experience attenuated muscle damage relative to males and low-load exercise will induce less muscle damage than high-load exercise in both sexes. A lack of methodological consistency among EIMD studies was a recurring finding throughout this thesis, which posed an issue when attempting to compare between-study outcomes and reach a consensus. Achieving greater uniformity in study designs by adopting comparable methods relating to EIMD markers and time-points of assessment would help improve understanding of the factors influencing the magnitude of EIMD and effective management strategies. While there are limitations with several EIMD markers – for example the variability of biomarkers and subjectivity of perceptual assessments – once the optimal markers are determined, these should be consistently used moving forward. Overall, this thesis has contributed to the current body of knowledge by demonstrating that milk protein ingestion is not an effective management strategy for muscle damage following ecologically-valid resistance exercise; therefore, alternative strategies to mitigate mild muscle damage should be investigated. Further, this work supported previous reports of sex differences in EIMD and indicated that the attenuation of EIMD in females relative to males was not attributed to sex differences in body composition; thus, the aetiology of such differences necessitates further exploration by means of high-quality sex comparative research. Finally, this thesis reached the consensus recommendation that lower exercise loads can be utilised to reduce muscle damage in males; nonetheless, supporting evidence for the application of this recommendation to females is required

Modulation of Exercise-Induced Muscle Damage, Inflammation, and Oxidative Markers by Curcumin Supplementation in a Physically Active Population: A Systematic Review

[EN] hysical activity, particularly high-intensity eccentric muscle contractions, produces exercise-induced muscle damage (EIMD). The breakdown of muscle fibers and the consequent inflammatory responses derived from EIMD affect exercise performance. Curcumin, a natural polyphenol extracted from turmeric, has been shown to have mainly antioxidant and also anti-inflammatory properties. This effect of curcumin could improve EIMD and exercise performance. The main objective of this systematic review was to critically evaluate the effectiveness of curcumin supplementation on EIMD and inflammatory and oxidative markers in a physically active population. A structured search was carried out following Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines in the databases SCOPUS, Web of Science (WOS), and Medline (PubMed) from inception to October 2019. The search included original articles with randomized controlled crossover or parallel design in which the intake of curcumin administered before and/or after exercise was compared with an identical placebo situation. No filters were applied to the type of physical exercise performed, the sex or the age of the participants. Of the 301 articles identified in the search, 11 met the established criteria and were included in this systematic review. The methodological quality of the studies was assessed using the McMaster Critical Review Form. The use of curcumin reduces the subjective perception of the intensity of muscle pain; reduces muscle damage through the decrease of creatine kinase (CK); increases muscle performance; has an anti-inflammatory effect by modulating the pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-8; and may have a slight antioxidant effect. In summary, the administration of curcumin at a dose between 150–1500 mg/day before and during exercise, and up until 72 h’ post-exercise, improved performance by reducing EIMD and modulating the inflammation caused by physical activity. In addition, humans appear to be able to tolerate high doses of curcumin without significant side-effects.S