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Journal of Sport and Health Science Sep 2020The first report demonstrating that prolonged endurance exercise promotes oxidative stress in humans was published more than 4 decades ago. Since this discovery, many... (Review)
Review
The first report demonstrating that prolonged endurance exercise promotes oxidative stress in humans was published more than 4 decades ago. Since this discovery, many ensuing investigations have corroborated the fact that muscular exercise increases the production of reactive oxygen species (ROS) and results in oxidative stress in numerous tissues including blood and skeletal muscles. Although several tissues may contribute to exercise-induced ROS production, it is predicted that muscular contractions stimulate ROS production in active muscle fibers and that skeletal muscle is a primary source of ROS production during exercise. This contraction-induced ROS generation is associated with (1) oxidant damage in several tissues (e.g., increased protein oxidation and lipid peroxidation), (2) accelerated muscle fatigue, and (3) activation of biochemical signaling pathways that contribute to exercise-induced adaptation in the contracting muscle fibers. While our understanding of exercise and oxidative stress has advanced rapidly during the last decades, questions remain about whether exercise-induced increases in ROS production are beneficial or harmful to health. This review addresses this issue by discussing the site(s) of oxidant production during exercise and detailing the health consequences of exercise-induced ROS production.
Topics: Adaptation, Physiological; Animals; Antioxidants; Exercise; Humans; Muscle Contraction; Muscle Fatigue; Muscle Fibers, Skeletal; Muscle, Skeletal; Oxidation-Reduction; Oxidative Stress; Reactive Oxygen Species
PubMed: 32380253
DOI: 10.1016/j.jshs.2020.04.001 -
International Journal of Molecular... Oct 2021Muscle fatigue (MF) declines the capacity of muscles to complete a task over time at a constant load. MF is usually short-lasting, reversible, and is experienced as a... (Review)
Review
Muscle fatigue (MF) declines the capacity of muscles to complete a task over time at a constant load. MF is usually short-lasting, reversible, and is experienced as a feeling of tiredness or lack of energy. The leading causes of short-lasting fatigue are related to overtraining, undertraining/deconditioning, or physical injury. Conversely, MF can be persistent and more serious when associated with pathological states or following chronic exposure to certain medication or toxic composites. In conjunction with chronic fatigue, the muscle feels floppy, and the force generated by muscles is always low, causing the individual to feel frail constantly. The leading cause underpinning the development of chronic fatigue is related to muscle wasting mediated by aging, immobilization, insulin resistance (through high-fat dietary intake or pharmacologically mediated Peroxisome Proliferator-Activated Receptor (PPAR) agonism), diseases associated with systemic inflammation (arthritis, sepsis, infections, trauma, cardiovascular and respiratory disorders (heart failure, chronic obstructive pulmonary disease (COPD))), chronic kidney failure, muscle dystrophies, muscle myopathies, multiple sclerosis, and, more recently, coronavirus disease 2019 (COVID-19). The primary outcome of displaying chronic muscle fatigue is a poor quality of life. This type of fatigue represents a significant daily challenge for those affected and for the national health authorities through the financial burden attached to patient support. Although the origin of chronic fatigue is multifactorial, the MF in illness conditions is intrinsically linked to the occurrence of muscle loss. The sequence of events leading to chronic fatigue can be schematically denoted as: trigger (genetic or pathological) -> molecular outcome within the muscle cell -> muscle wasting -> loss of muscle function -> occurrence of chronic muscle fatigue. The present review will only highlight and discuss current knowledge on the molecular mechanisms that contribute to the upregulation of muscle wasting, thereby helping us understand how we could prevent or treat this debilitating condition.
Topics: Autophagy; COVID-19; Critical Illness; Humans; Insulin Resistance; Lysosomes; Muscle Fatigue; Muscle Proteins; Muscle, Skeletal; Muscular Atrophy; Sarcopenia
PubMed: 34769017
DOI: 10.3390/ijms222111587 -
Nutrients Jun 2022Recovery strategies, both in the general population and in athletes, must be aimed at the main causes of fatigue [...].
Recovery strategies, both in the general population and in athletes, must be aimed at the main causes of fatigue [...].
Topics: Athletes; Fatigue; Humans; Muscle Fatigue; Muscle, Skeletal; Nutritional Status
PubMed: 35745146
DOI: 10.3390/nu14122416 -
International Journal of Sports Medicine Dec 2022Fatigue is a phenomenon associated with decreases in both physical and cognitive performances and increases in injury occurrence. Competitive athletes are required to... (Review)
Review
Fatigue is a phenomenon associated with decreases in both physical and cognitive performances and increases in injury occurrence. Competitive athletes are required to complete demanding training programs with high workloads to elicit the physiological and musculoskeletal adaptations plus skill acquisition necessary for performance. High workloads, especially sudden rapid increases in training loads, are associated with the occurrence of fatigue. At present, there is limited evidence elucidating the underlying mechanisms associating the fatigue generated by higher workloads and with an increase in injury risk. The multidimensional nature and manifestation of fatigue have led to differing definitions and dichotomies of the term. Consequently, a plethora of physiological, biochemical, psychological and performance markers have been proposed to measure fatigue and recovery. Those include self-reported scales, countermovement jump performance, heart rate variability, and saliva and serum biomarker analyses. The purpose of this review is to provide an overview of fatigue and recovery plus methods of assessments.
Topics: Humans; Athletic Performance; Fatigue; Muscle Fatigue; Workload; Heart Rate; Athletes
PubMed: 35468639
DOI: 10.1055/a-1834-7177 -
Nutrients Sep 2019this study examined the effects of caffeine supplementation on anaerobic performance, neuromuscular efficiency and upper and lower extremities fatigue in Olympic-level... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
this study examined the effects of caffeine supplementation on anaerobic performance, neuromuscular efficiency and upper and lower extremities fatigue in Olympic-level boxers.
METHODS
Eight male athletes, members of the Spanish National Olympic Team, were enrolled in the study. In a randomized double-blind, placebo-controlled, counterbalanced, crossover design, the athletes completed 2 test sessions after the intake of caffeine (6 mg·kg) or placebo. Sessions involved initial measures of lactate, handgrip and countermovement jump (CMJ) performance, followed by a 30-seconds Wingate test, and then final measures of the previous variables. During the sessions, electromiography (EMG) data were recorded on the gluteus maximus, biceps femoris, vastus lateralis, gastrocnemius lateral head and tibialis anterior.
RESULTS
caffeine enhanced peak power (6.27%, < 0.01; Effect Size (ES) = 1.26), mean power (5.21%; < 0.01; ES = 1.29) and reduced the time needed to reach peak power (-9.91%, < 0.01; ES = 0.58) in the Wingate test, improved jump height in the CMJ (+2.4 cm, < 0.01), and improved neuromuscular efficiency at peak power in the vastus lateralis (ES = 1.01) and gluteus maximus (ES = 0.89), and mean power in the vastus lateralis (ES = 0.95) and tibialis anterior (ES = 0.83).
CONCLUSIONS
in these Olympic-level boxers, caffeine supplementation improved anaerobic performance without affecting EMG activity and fatigue levels in the lower limbs. Further benefits observed were enhanced neuromuscular efficiency in some muscles and improved reaction speed.
Topics: Boxing; Caffeine; Cross-Over Studies; Dietary Supplements; Double-Blind Method; Humans; Male; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Performance-Enhancing Substances; Physical Endurance; Time Factors; Young Adult
PubMed: 31492050
DOI: 10.3390/nu11092120 -
Journal of the International Society of... Apr 2021Although there is a plethora of information available regarding the impact of nutrition on exercise performance, many recommendations are based on male needs due to the... (Review)
Review
Although there is a plethora of information available regarding the impact of nutrition on exercise performance, many recommendations are based on male needs due to the dominance of male participation in the nutrition and exercise science literature. Female participation in sport and exercise is prevalent, making it vital for guidelines to address the sex-specific nutritional needs. Female hormonal levels, such as estrogen and progesterone, fluctuate throughout the mensural cycle and lifecycle requiring more attention for effective nutritional considerations. Sex-specific nutritional recommendations and guidelines for the active female and female athlete have been lacking to date and warrant further consideration. This review provides a practical overview of key physiological and nutritional considerations for the active female. Available literature regarding sex-specific nutrition and dietary supplement guidelines for women has been synthesized, offering evidenced-based practical information that can be incorporated into the daily lives of women to improve performance, body composition, and overall health.
Topics: Body Composition; Body Temperature Regulation; Contraceptives, Oral, Hormonal; Diet; Dietary Supplements; Energy Intake; Exercise; Female; Humans; Menstruation; Muscle Fatigue; Nutrition Policy; Sex Characteristics; Sports Nutritional Physiological Phenomena
PubMed: 33794937
DOI: 10.1186/s12970-021-00422-8 -
Journal of Sports Science & Medicine Mar 2020Different shoes and strike patterns produce different biomechanical characteristics that can affect injury risk. Running shoes are mainly designed as lightweight,...
Different shoes and strike patterns produce different biomechanical characteristics that can affect injury risk. Running shoes are mainly designed as lightweight, minimal, or traditional cushioned types. Previous research on different shoes utilized shoes of not only different mass but also different shoe structures. However, it is unclear whether biomechanical changes during running in different shoe types with differing mass are the result of the structural design or the mass of the shoe. Thus, the purpose of this study was to investigate the effect of shoes of different mass on running gait biomechanics. Twenty male runners participated in this study. The experimental shoe masses used in this study were 175, 255, 335 and 415 g. The peak vertical ground reaction force increased with shoe mass (p < 0.05), but the strike index, ankle plantarflexion at initial contact, peak moment of the ankle during the stance phase, and initial contact angles of the lower extremity joints did not change. During the pre-activation phase, the integrated EMG data showed that the tibialis anterior muscle was the most activated with the 175 g and 415 g shoes (p < 0.05). During the push-off phase, the semitendinosus, lateral gastrocnemius and soleus muscles displayed higher activation with the heavier shoes (p < 0.05). The center of pressure also moves forward; resulting in mid foot striking. The lightest shoes might increase gastrocnemius muscle fatigue during the braking phase. The heaviest shoes could cause semitendinosus and triceps surae muscle fatigue during the push-off phase. Therefore, runners should consider their lower extremity joints, muscle adaptation and cushioning to remain in their preferred movement path.
Topics: Ankle; Athletic Injuries; Biomechanical Phenomena; Electromyography; Equipment Design; Foot; Gait Analysis; Humans; Male; Muscle Fatigue; Muscle, Skeletal; Pressure; Running; Shoes; Young Adult
PubMed: 32132836
DOI: No ID Found -
International Journal of Environmental... Jan 2021The aim of this study was to compare the effects of various recovery techniques on muscle tissue after eccentric exercise-induced muscle fatigue (EIMF). Forty subjects... (Randomized Controlled Trial)
Randomized Controlled Trial
The aim of this study was to compare the effects of various recovery techniques on muscle tissue after eccentric exercise-induced muscle fatigue (EIMF). Forty subjects (24.3 ± 2.6 years; 77.45 ± 8.3 kg; 177.0 ± 6.4 cm; 24.66 ± 1.6 kg∙m) were randomly assigned to one of the following groups: manual therapy ( =10, MT), mechanical vibration ( = 10, MV), percussion therapy ( = 10, PT) or foam roller ( = 10, FR). The contraction time (Tc) and the radial displacement (Dm) of the gastrocnemius was evaluated through tensiomyography (TMG). The application of the different techniques had positive effects for Tc and Dm in the treated leg compared to the untreated leg (F = 50.01, < 0.01, ηp = 0.58 and F = 27.58, < 0.01, ηp = 0.43, respectively) and for the interaction of the factors (Time x Leg x Therapy: F = 5.76, < 0.01, ηp = 0.32 and F = 5.93, < 0.01, ηp = 0.33, respectively). The results of the various methods used were similar: Tc (F = 0.17, = 0.917; ηp = 0.01) and Dm (F = 3.30, = 0.031, ηp = 0.22). PT interventions show potential for restoring muscle compliance and reducing stiffness, similar to MT and possibly more effective (cost-time relationship) compared to MV or FR.
Topics: Humans; Muscle Contraction; Muscle Fatigue; Muscle, Skeletal; Vibration
PubMed: 33466606
DOI: 10.3390/ijerph18020647 -
Journal of Sport Rehabilitation Jan 2021Clinical Scenario: Endurance sports require a great deal of physical training to perform well. Endurance training and racing stress the skeletal muscle, resulting in... (Review)
Review
Clinical Scenario: Endurance sports require a great deal of physical training to perform well. Endurance training and racing stress the skeletal muscle, resulting in exercise-induced muscle damage (EIMD). Athletes attempt to aid their recovery in various ways, one of which is through compression. Dynamic compression consists of intermittent pneumatic compression (IPC) devices, such as the NormaTec Recovery System and Recovery Pump. Clinical Question: What are the effects of IPC on the reduction of EIMD in endurance athletes following prolonged exercise? Summary of Key Findings: The current literature was searched to identify the effects of IPC, and 3 studies were selected: 2 randomized controlled trials and 1 randomized cross-over study. Two studies investigated the effect of IPC on delayed onset muscle soreness and plasma creatine kinase in ultramarathoners. The other looked at the impact of IPC on delayed onset muscle soreness in marathoners, ultramarathoners, triathletes, and cyclists. All studies concluded IPC was not an effective means of improving the reduction of EIMD in endurance-trained athletes. Clinical Bottom Line: While IPC may provide short-term relief of delayed onset muscle soreness, this device does not provide continued relief from EIMD. Strength of Recommendation: In accordance with the Strength of Recommendation Taxonomy, the grade of B is recommended based on consistent evidence from 2 high-quality randomized controlled trials and 1 randomized cross-over study.
Topics: Creatine Kinase; Humans; Intermittent Pneumatic Compression Devices; Muscle Fatigue; Myalgia; Physical Endurance; Randomized Controlled Trials as Topic; Running
PubMed: 33418535
DOI: 10.1123/jsr.2020-0364 -
Journal of Applied Physiology... Dec 2019The study investigated the influence of β-alanine supplementation during a high-intensity interval training (HIIT) program on repeated sprint ability (RSA) performance.... (Randomized Controlled Trial)
Randomized Controlled Trial
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 (T) at baseline and followed by 4-wk HIIT (10 × 1-min runs 90% maximal T 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: ) T; ) supramaximal running test; and ) 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 (βm), 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%; > 0.01); only Gβ showed a time effect for total (-3.0 ± 2.0%; = 0.001) and best (-3.3 ± 3.0%; = 0.03) RSA times. A group-by-time interaction was shown after HIIT + Supplementation for muscle carnosine (Gβ: 34.4 ± 2.3 mmol·kg·dm and GP: 20.7 ± 3.0 mmol·kg·dm; = 0.003) and neuromuscular voluntary activation after RSA (Gβ: 87.2 ± 3.3% and GP: 78.9 ± 12.4%; = 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. 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.
Topics: Adult; Carnosine; Dietary Supplements; Double-Blind Method; Exercise; Exercise Test; High-Intensity Interval Training; Humans; Isometric Contraction; Male; Muscle Fatigue; Muscle, Skeletal; Oxygen Consumption; Running; beta-Alanine
PubMed: 31622158
DOI: 10.1152/japplphysiol.00321.2019