Wouber Hérickson de Brito Vieira

Exercise-induced muscle damage (EIMD) occurs after unaccustomed eccentric exercise and may impair muscle recovery. Preconditioning with photobiomodulation (PBM) or ischemic preconditioning (IPC) may mitigate EIMD; however, no study has directly compared their effectiveness. This study aims to compare the effects of PBM and IPC applied prior to eccentric exercise on indirect markers of EIMD and associated perceptual responses. We hypothesized that MVIC trajectories would differ among the PBM, IPC, and sham groups, with PBM expected to provide greater preservation of MVIC than IPC. A prospective, randomized, placebo-controlled clinical trial with concealed allocation, blinded outcome assessors and statistician, and intention-to-treat analysis will be conducted. Healthy men (18–35 years) will be randomly allocated to PBM, IPC, or sham groups (n = 15 per group). After the intervention, participants will perform an eccentric exercise protocol for the elbow flexors consisting of 30 repetitions using a dumbbell load numerically matched to maximal voluntary isometric contraction (MVIC) values, with 45-second rest intervals. The primary outcome will be MVIC. Secondary outcomes include rate of force development, delayed-onset muscle soreness, pressure pain threshold, ultrasound echo intensity, range of motion, perceived exertion, and affective responses. Outcomes will be assessed at baseline, immediately after exercise (only MVIC), and at 24-, 48-, and 72-hours post-exercise. The primary analysis will assess the group × time interaction on MVIC using linear mixed-effects models, while secondary outcomes will be analyzed exploratorily. This study will provide, to our knowledge, the first direct comparison between PBM and IPC as preconditioning strategies to attenuate EIMD. The findings may help determine the most effective and clinically applicable intervention by considering both physiological and perceptual responses, thereby supporting decision-making in clinical and sports settings. Trial registration Brazilian Registry of Clinical Trials (REBEC), RBR-6gr5kf; registered February 19, 2020; amended August 26, 2026.

This study investigated additional and traditional variables from isokinetic test of thigh muscles in soccer players across different field positions. One hundred and eighty-nine athletes performed maximal concentric isokinetic knee contractions on dominant (DL) and non-dominant limb (NDL) at 60o/s and 240o/s. The additional outcomes peak torque angle (AngPT), acceleration time (AcT) and time to peak torque (TPT) and traditional outcomes Peak torque (PT), total work (TW) and power (Pw) were extracted from the exam. Goalkeepers (GK), side backs (SB), central backs (CB), central defender midfielders (CDM), central attacking midfielders (CAM) and forwards (FW) were considered. Comparisons between limbs and positions demonstrated that SB extensors of the DL presented TPT lower (p = 0.006) and AngPT higher (p = 0.011) than NDL at 60 degrees/s. CDM extensors of the DL showed lower TPT at 60 degrees/s (p = 0.003) and 240 degrees/s (p = 0.024). CAM flexors of the DL showed lower TPT (p = 0.026) and AcT (p = 0.021) at 240 degrees/s than NDL. CB, CDM and CAM extensors of the NDL showed higher PT, TW and Pw than DL (p < 0.05). In conclusion, there are muscle imbalances between limbs in SB, CDM and CAM and across different field positions.

Introduction Anterior cruciate ligament (ACL) tear and knee osteoarthritis (KOA) are the most prevalent musculoskeletal disorders of the knee. Rehabilitation with progressive resistance training is recommended for both disorders. Rating of perceived exertion (RPE) is widely used to prescribe, monitor, and control exercise load. However, the lack of detailed methodological description and variability in the use of RPE may hinder its validity. This scoping review summarises methodological aspects of the use of RPE in resistance exercises during ACL reconstruction and KOA rehabilitation. We also aim to identify possible methodological issues related to the use of RPE and provide recommendations for future studies. Methods and analysis This scoping review protocol was developed following the Joanna Briggs Institute and Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement extension for Scoping Reviews. The search will be conducted in Medline/PubMed, Embase, CINAHL, PEDro, Central and SPORTDiscus databases. The terms “anterior cruciate ligament rehabilitation”, “knee osteoarthritis” and “resistance exercise” and their synonymous will be used isolated and combined (boolean operators AND/OR/NOT). Two reviewers will independently conduct title and abstract screening and evaluate full texts of potentially eligible articles. Data related to study design, sample, intervention characteristics and RPE outcomes will be extracted, summarised and qualitatively analysed. Ethics and dissemination The proposed scoping review does not require ethical approval since it will synthesise information from publicly available studies. Regarding dissemination activities, results will be submitted for publication in a scientific journal and presented at conferences in the field.

Purpose: This study aimed to assess skin temperature (Tsk) changes after different magnitudes of exercise-induced muscle damage (EIMD) of the elbow flexor muscles and investigate whether Tsk is related to indirect markers of EIMD. Methods: Thirty healthy active men were randomly allocated to the mild (MiDG) (n = 15) or moderate (MoDG) (n = 15) muscle damage group. Muscle damage in elbow flexor muscles was induced by 10 (for MiDG) or 30 (for MoDG) maximal eccentric isokinetic contractions at 60 degrees/s. Tsk, maximal voluntary isometric contraction (MVIC), delayed-onset muscle soreness (DOMS), plasma creatine kinase (CK) activity, range of motion (ROM), and pressure pain threshold (PPT) were measured before and up to 72 hr after EIMD. Results: Tsk increased only immediately after EIMD (p < .05; f = 1.44) in the MoDG (4.2%) and MiDG (4.6%), returning to near baseline values 30 min after EIMD and remaining so thereafter. In addition, there was no intergroup difference (p > .05) at any of the times analyzed, or correlation between Tsk and most indirect markers of EIMD. Conclusions: In conclusion, Tsk should not be considered an indirect marker of mild or moderate muscle damage in active men, since alterations in this variable last less than 30 min after damaging exercise and showed no correlation with most indirect markers of EIMD.

Context: The rating of perceived effort (RPE) is a common method used in clinical practice for monitoring, loading control, and resistance training prescription during rehabilitation after rupture and anterior cruciate ligament reconstruction (ACLR). It is suggested that the RPE results from the integration of the afferent feedback and corollary discharge in the motor and somatosensory cortex, and from the activation of brain areas related to emotions, affect, memory, and pain (eg, posterior cingulate cortex, precuneus, and prefrontal cortex). Recent studies have shown that rupture and ACLR induce neural adaptations in the brain commonly associated with the RPE. Therefore, we hypothesize that RPE could be affected because of neural adaptations induced by rupture and ACLR. Study Design: Clinical review. Level of Evidence: Level 5. Results: RPE could be directly altered by changes in the activation of motor cortex, posterior cingulate cortex, and prefrontal cortex. These neural adaptations may be induced by indirect mechanisms, such as the afferent feedback deficit, pain, and fear of movement (kinesiophobia) that patients may feel after rupture and ACLR. Conclusion: Using only RPE for monitoring, loading control, and resistance training prescription in patients who had undergone ACLR could lead to under- or overdosing resistance exercise, and therefore, impair the rehabilitation process. Strength-of-Recommendation Taxonomy: 3C.

Es XX(X): 000–000, 2021—High-load and low-load resistance training (LL-RT) performed to failure are considered effective for improving muscle mass and strength. Alternatively, LL-RT with blood flow restriction (LL-BFR) may accelerate repetition failure and has been suggested to be more time efficient than LL-RT. This study explores the evidence for the effects of LL-BFR vs. LL-RT on repetition failure. A systematic literature search was conducted in the PubMed, CINAHL, Web of Science, CENTRAL, Scopus, SPORTDiscus, and PEDro databases. Meta-analyses of mean differences and 95% confidence intervals (CIs) were performed using a random-effects model. Subgroup analyses were conducted for both the high and low blood flow restriction pressures. The search identified n = 10 articles that met the inclusion criteria. The meta-analysis comprised a total of 218 healthy subjects. Low-load resistance training with blood flow restriction with high pressures (≥50% arterial occlusion pressure [AOP]) precipitate repetition failure in ∼14.5 fewer repetitions (95% CI −19.53 to −9.38) compared with LL-RT, whereas the use of low pressures (<50% AOP) stimulated repetition failure with ∼1.4 fewer repetitions (95% CI −3.11 to 0.37); however, this difference was not statistically significant. Repetition failure has been demonstrated to be an important normalizing variable when comparing the hypertrophic and strength effects resulting from resistance training and occurs earlier during low-load resistance exercise with high but not low blood flow restriction pressures. Address correspondence to Wouber Hérickson De Brito Vieira, hericksonfisio@yahoo.com.br. Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (http://journals.lww.com/nsca-jscr). Copyright © 2021 by the National Strength & Conditioning Association....

Background: The purpose of this review was to systematically analyze the evidence regarding the occurrence of muscle damage (changes in muscle damage markers) after resistance training with blood flow restriction sessions. Materials and methods: This systematic review was conducted in accordance with the PRISMA recommendations. Two researchers independently and blindly searched the following electronic databases: PubMed, Scopus, Web of Science, CINAHL, LILACS and SPORTdicus. Randomized and non-randomized clinical trials which analyzed the effect of resistance training with blood flow restriction on muscle damage markers in humans were included. The risk of bias assessment was performed by two blinded and independent researchers using the RoB2 tool. Results: A total of 21 studies involving 352 healthy participants (men, n = 301; women, n = 51) were eligible for this review. The samples in 66.6% of the studies (n = 14) were composed of untrained individuals. All included studies analyzed muscle damage using indirect markers. Most studies had more than one muscle damage marker and Delayed Onset Muscle Soreness was the measure most frequently used. The results for the occurrence of significant changes in muscle damage markers after low-load resistance training with blood flow restriction sessions were contrasting, and the use of a pre-defined repetition scheme versus muscle failure seems to be the determining point for this divergence, mainly in untrained individuals. Conclusions: In summary, the use of sets until failure is seen to be determinant for the occurrence of significant changes in muscle damage markers after low-load resistance training with blood flow restriction sessions, especially in individuals not used to resistance exercise. Trial registration: Register number: PROSPERO number: CRD42020177119.