Introduction: Peripheral nerve adaptation is critical for strength gains. However, information about intensity effects on nerve morphology is scarce. Objective: To compare the effects of different intensities of resistance training on radial nerve structures. Methods: Rats were divided into three groups: control (GC), training with 50% (GF1) and training 75% (GF2) of the animal's body weight. The morphological analysis of the nerve was done by light and transmission electron microscopy. One-way ANOVA and the Tukey's post hoc test were applied and the significance level was set at p≤0.05. Results: Training groups had an increase of strength compared to GC (p≤0.05). All measured nerve components (mean area and diameter of myelin fibers and axons, mean area and thickness of the myelin sheath, and of neurofilaments and microtubules) were higher in GF2 compared to the other (p≤0.05). Conclusion: Results demonstrated greater morphological changes on radial nerve after heavier loads. This can be important for rehabilitation therapies, training, and progression.

Resistance exercise combined with testosterone triggered a response of compensatory adjustment in the increase of Nv [cap], collagen and interstitial space, increasing perfusion and nutrition to the heart.

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Introduction Throwing is considered the most important technical skill in Handball. However, it requires the athlete to perform this movement with maximum speed and accuracy, as it can define the final score of the game. Objective The aim of this study was to evaluate the effect of Proprioceptive Neuromuscular Facilitation, known as the Kabat method, on the throwing performance of handball athletes. Methods An experimental study of 18 male handball athletes with a mean age of 14 ± 1.13 years. The athletes were divided into two groups: control group (CG) and Kabat method group (KG). The athletes performed 16 training sessions, with analyses at the beginning and end of each session. Range of motion (ROM) of internal and external shoulder rotation, strength, muscle imbalance, throwing speed and accuracy were measured. The results were compared by the Student t-test of repeated measures. Results KG significantly increased external shoulder rotation and muscle strength in all the analyzed shoulder complex muscles. CG also increased strength, but not in all muscles. KG significantly increased the speed and accuracy of the pitch. Conclusion The Kabat method, through proprioceptive neuromuscular facilitation, significantly increased throwing performance, speed and accuracy in handball athletes when compared to the control group. Level of evidence III; Randomized Experimental Study.

Introduction It is indicated that aging reduces muscular vascularity. Thus, strategies that aim to reverse or decrease the progression of these changes are suggested. Therefore, the present study aimed to analyze the blood capillary density of the plantaris muscle (PL) of aged rats submitted to strength training and exogenous testosterone use. Methods A total of 30 rats were divided equally into the following groups: EA: 20 months old; OLD: 24 months old; OLD + S: testosterone; ST: strength training; and ST + S: strength training + testosterone. Strength training was performed 3 times a week for 15 weeks. Testosterone administration was performed by the intraperitoneal method 2 times a week at a dose of 10mg/kg. All of the morphological parameters were analyzed using morphoquantitative techniques. Results A significant increase in the capillaries numerical density of the OLD + S and ST + S groups. The OLD + S and ST + S groups demonstrated a higher ratio of capillaries per myofiber than the EA, OLD and ST groups. The OLD and ST groups had a higher ratio than the EA group. The OLD + S, ST and ST + S groups presented a statistically significant increase in the cross-sectional area in the type I fibers when compared with the EA and OLD groups. However, the ST group showed a significant increase compared with the OLD group. In type II fibers, the ST and ST + S groups showed a greater cross-sectional area than the EA group. As for the mean cross-sectional area, the ST and ST + S groups presented significantly larger areas than the other groups. Conclusion Anabolic steroid administration is crucial to increase the blood capillary density of the plantaris muscle of old rats, independently of the effects of strength training.