Background: The purpose of this systematic review was to determine the effect of antioxidant consumption on markers of oxidative stress and muscle damage after performing a muscle strength exercise. Methods: The Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed. Four databases were used: Scopus, PubMed, WOS and SportDiscus. Methodological quality was assessed using the PEDro scale. Results: A total of 1709 articles were retrieved and following duplicate removal and application of exclusion criteria seven articles were reviewed. Supplementation with pomegranate juice alleviates oxidative stress, taurine reduces muscle damage, melatonin protects the skeletal muscles, blueberries decrease oxidation and oats mitigate muscle damage. Conclusions: Acute administration of antioxidants immediately before or during an exercise session can have beneficial effects, such as delay of fatigue and a reduction in the recovery period. Administration of antioxidant susbtances may reduce muscle damage and oxidative stress markers.

Background: This study aimed to report, through a systematic review of the literature, the baseline and final reference values obtained by near-infrared spectroscopy (NIRS) of muscle oxygen saturation (SmO₂) during resistance training in healthy adults. Methods: Original research studies were searched from four databases (Scopus, PubMed, WOS, and SportDiscus). Subsequently, three independent reviewers screened the titles and abstracts, followed by full-text reviews to assess the studies’ eligibility. Results: Four studies met the inclusion criteria, data were extracted and methodological quality was assessed using the Downs and Black scale. Muscle oxygen saturation (% SmO2) during reported muscle strength exercises showed a decreasing trend after a muscle strength protocol; that is, before the protocol (range = 68.07–77.9%) and after (range = 9.50–46.09%). Conclusions: The trend of the SmO₂ variables is to decrease after a muscle strength protocol. Studies are lacking that allow expanding the use of these devices during this type of training.

Background: Older adults with hip osteoarthritis (OA) suffer a progressive loss of muscle quality and strength, affecting their daily activities and quality of life. The purpose of this study is to compare the levels of isometric strength among older adults with and without hip OA and healthy young adults, and to determine the relationship between muscle quality index (MQI) and isometric strength. Methods: Fourteen subjects with hip OA (65.6 ± 3.0 years), 18 healthy older adults (66.6 ± 6.5 years) and 32 young adults (20.7 ± 2.0 years) participated in the study. MQI, isometric muscle strength of the hip, ten time sit-to-stand tests, and body composition were measured. Results: The MQI was lower in subjects with hip OA, with no significant differences between groups (p > 0.054). Subjects with OA produced significantly less isometric strength in hip extension (p < 0.001), flexion (p < 0.001), abduction (p < 0.05), adduction (p < 0.001), external (p < 0.05) and internal rotation (p < 0.05). Subjects with OA demonstrated longer time in the execution of the sit-to-stand test (p < 0.001) in comparison with healthy older and young adults. High correlations between MQI, sit-to-stand (r = − 0.76, p < 0.01) and peak force during hip abduction (r = 0.78, p < 0.01) where found in subjects with OA. Moderate correlation between MQI and peak force during hip flexion (r = 0.55, p < 0.05) and external rotation (r = 0.61, p < 0.05) were found in the OA group. Conclusions: Subjects with OA have lower MQI than old and young healthy controls. In subjects with OA, there was a significant relationship between isometric strength of hip muscles and performance on the sit-to-stand test and the MQI.