The aim of this study was to verify whether physiological components [vertical jumps (Squat Jump-SJ and Countermovement Jump-CMJ), eccentric utilization ratio (EUR) of vertical jumps, running economy (RE), metabolic cost (C MET), first and second ventilatory threshold (VT 1 and VT 2) maximal oxygen uptake (VO 2MAX)] can predict maximal endurance running performance. Methods: Twenty male runners performed maximal vertical jumps, submaximal running at constant speeds, and maximal incremental running test. Before, we measured anthropometric parameters (body mass and height) and registered the training history and volume. SJ and CMJ tests were evaluated prior to running tests. Initially, the oxygen uptake (VO 2) was collected at rest in the orthostatic position for 6 min. Soon after, a 10-min warm-up was performed on the treadmill at 10 km•h −1 , followed by two 5-min treadmill rectangular tests at 12 and 16 km•h −1 monitored by a gas analyzer. After that, the runners performed a maximal incremental test, where the VT 1 , VT 2 , and VO 2MAX were evaluated, as well as the maximum running speed (vVO 2MAX). Thus, RE and C MET were calculated with data obtained during rectangular running tests. Multivariate stepwise regression analyses were conducted to measure the relationship between independent variables (height and power of SJ and CMJ, EUR; RE and C MET 12 and 16 km•h −1 ; VT 1 , VT 2 , and VO 2MAX), as predictors of maximal running performance (vVO 2MAX), with significance level at α = 0.05. Results: We found that VO 2MAX and RE at 16 km•h −1 predict 81% of performance (vVO 2MAX) of endurance runners (p < 0.001). Conclusion: The main predictors of the maximal incremental running test performance were VO 2MAX and RE.

Purpose: This study aimed to determine whether triceps surae’s muscle architecture and Achilles tendon parameters are related to running metabolic cost (C) in trained long-distance runners.Methods: Seventeen trained male recreational long-distance runners (mean age = 34 years) participated in this study. C was measured during submaximal steady-state running (5 min) at 12 and 16 km h–1 on a treadmill. Ultrasound was used to determine the gastrocnemius medialis (GM), gastrocnemius lateralis (GL), and soleus (SO) muscle architecture, including fascicle length (FL) and pennation angle (PA), and the Achilles tendon cross-sectional area (CSA), resting length and elongation as a function of plantar flexion torque during maximal voluntary plantar flexion. Achilles tendon mechanical (force, elongation, and stiffness) and material (stress, strain, and Young’s modulus) properties were determined. Stepwise multiple linear regressions were used to determine the relationship between independent variables (tendon resting length, CSA, force, elongation, stiffness, stress, strain, Young’s modulus, and FL and PA of triceps surae muscles) and C (J kg–1m–1) at 12 and 16 km h–1.Results: SO PA and Achilles tendon CSA were negatively associated with C (r2 = 0.69; p &lt; 0.001) at 12 km h–1, whereas SO PA was negatively and Achilles tendon stress was positively associated with C (r2 = 0.63; p = 0.001) at 16 km h–1, respectively. Our results presented a small power, and the multiple linear regression’s cause-effect relation was limited due to the low sample size.Conclusion: For a given muscle length, greater SO PA, probably related to short muscle fibers and to a large physiological cross-sectional area, may be beneficial to C. Larger Achilles tendon CSA may determine a better force distribution per tendon area, thereby reducing tendon stress and C at submaximal speeds (12 and 16 km h–1). Furthermore, Achilles tendon morphological and mechanical properties (CSA, stress, and Young’s modulus) and triceps surae muscle architecture (GM PA, GM FL, SO PA, and SO FL) presented large correlations with C.

Background: Face masks are widely used during the COVID-19 pandemic as one of the protective measures against the viral infection risk. Some evidence suggests that face mask prolonged use can be uncomfortable, and discomfort can be exacerbated during exercise. However, the acute responses of mask-wearing during exercise on affective/psychological and exercise performance responses is still a topic of debate.Purpose: To perform a systematic review with meta-analysis of the acute effects of mask-wearing during exercise on affective/psychological and exercise performance responses in healthy adults of different/diverse training status.Methods: This review (CRD42021249569) was performed according to Cochrane’s recommendations, with searches performed in electronic (PubMed, Web of Science, Embase, SportDiscus, and PsychInfo) and pre-print databases (MedRxiv, SportRxiv, PsyArXiv, and Preprint.Org). Syntheses of included studies’ data were performed, and the RoB-2 tool was used to assess the studies’ methodological quality. Assessed outcomes were affective/psychological (discomfort, stress and affective responses, fatigue, anxiety, dyspnea, and perceived exertion) and exercise performance time-to-exhaustion (TTE), maximal power output (POMAX), and muscle force production] parameters. Available data were pooled through meta-analyses.Results: Initially 4,587 studies were identified, 36 clinical trials (all crossover designs) were included. A total of 749 (39% women) healthy adults were evaluated across all studies. The face mask types found were clothing (CM), surgical (SM), FFP2/N95, and exhalation valved FFP2/N95, while the most common exercises were treadmill and cycle ergometer incremental tests, beyond outdoor running, resistance exercises and functional tests. Mask-wearing during exercise lead to increased overall discomfort (SMD: 0.87; 95% CI 0.25–1.5; p = 0.01; I2 = 0%), dyspnea (SMD: 0.40; 95% CI 0.09–0.71; p = 0.01; I2 = 68%), and perceived exertion (SMD: 0.38; 95% CI 0.18–0.58; p &lt; 0.001; I2 = 46%); decreases on the TTE (SMD: −0.29; 95% CI −0.10 to −0.48; p &lt; 0.001; I2 = 0%); without effects on POMAX and walking/running distance traveled (p &gt; 0.05).Conclusion: Face mask wearing during exercise increases discomfort (large effect), dyspnea (moderate effect), and perceived exertion (small effect), and reduces the TTE (small effect), without effects on cycle ergometer POMAX and distance traveled in walking and running functional tests. However, some aspects may be dependent on the face mask type, such as dyspnea and perceived exertion.Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021249569], identifier [CRD42021249569].

BACKGROUND: Achilles tendon pain is present in tendons’ non-rupture injuries usually exacerbated by mechanical loading (i.e., overuse injury).Photobiomodulation is a light therapy that may reduce pain in tendinopathy. AIM: This systematic review and meta-analysis of randomized clinical trials tested the acute and chronic effects of photobiomodulation on Achilles tendon pain. METHOD: Randomized clinical trials were included comparing photobiomodulation with a control group in patients with Achilles tendon pain.The search included MEDLINE (Pubmed), SCOPUS, EMBASE, Physiotherapy Evidence Database (PEDro), Cochrane Central Register of Controlled Trials (Cochrane CENTRAL), LILACS, and Science Direct databases, and manual search until November 2021.The bias’s risk was assessed by the Cochrane Collaboration bias risk assessment tool and PEDro scale, while the level of evidence strength by the GRADE. Quantitative analysis through meta-analyzes was performed. The protocol was registered (PROSPERO-CRD42018091509). RESULTS: The search yielded 3.239 papers in the seven databases. Five studies were included after screening, eliminating duplicates, and applying eligibility criteria, and three were included in the meta-analysis. The meta-analysis (n=79) showed no photobiomodulation acute and chronic effects compared with control group on Achilles tendon pain (p= 0.45, SMD: 0.28). In the qualitative analysis, three studies showed a high risk, and two studies a low risk of bias in all characteristics. GRADE analysis showed very low- to low-quality evidence of the studies. CONCLUSION: There is no photobiomodulation effect in Achilles tendon pain. Due to the very low and low strength of evidence, new studies with better methodological quality should be conducted to improve the level of evidence.