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The objective of this study was to compare the production of force and paraspinal muscle activity between deadlifts carried out in a standard way and with different instability devices (Bosu and T-Bow). Deadlifts involve the performance of muscle activities with dynamic and isometric characteristics. Thirty-one subjects participated voluntarily in the study. Initially, they performed an isometric test for 5 seconds in each condition. After that, they performed a set of 5 repetitions with 70% of the maximum isometric force obtained in each one of the previously evaluated conditions. During the isometric tests, records of electromyographic activity and force production were obtained, whereas during the dynamic tests, only the electromyographic activity was registered. The subjects produced more force and muscle activity on the stable surface than under the other conditions during the isometric test (p < 0.05), and the same differences in muscle activity were observed during the dynamic test (p < 0.05). These data show that the performance of deadlifts under stable conditions favors a higher production of maximum strength and muscle activity. Therefore, we conclude that the use of instability devices in deadlift training does not increase performance, nor does it provide greater activation of the paraspinal muscles, leading us to question their value in the performance of other types of exercises. KEY WORDS instability, core, Bosu, electromyography

The purpose of this study was to assess the effects of an 8-week integrative neuromuscular training (INT) program on physical fitness measures in young rugby players. A sample of 138 male rugby players (age range, 6-14 years) was divided into 5 age-related groups: group 1 (G1) (n = 20; age, 7.05 ± 0.58), group 2 (G2) (n = 27; age, 8.57 ± 0.49), group 3 (G3) (n = 31; age, 11.02 ± 0.56), group 4 (G4) (n = 33; age, 13.12 ± 0.58, and group 5 (G5) (n = 27; age, 14.85 ± 1.53 and additionally into 2 game position groups: forwards (FOR) (n = 69) and backs (BAC) (n = 69). Physical fitness measures included the Functional Movement Screen (FMS), dominant and nondominant hand-to-eye coordination, sprint capacity, core muscular endurance, and lower- and upper-body power. Integrative neuromuscular training (INT) included progressive strength, coordination, and speed exercises performed twice per week for 20 minutes. Following INT, significant improvements in selected age-related groups (p < 0.01) were found in total FMS score G3 (effect size [ES] = 0.47), G4 (ES = 0.88), and G5 (ES = 0.58); dominant hand-to-eye coordination G1 (ES 5 1.48), G2 (ES = 0.71), G3 (ES = 0.55), G4 (ES = 1.47), and G5 (ES = 1.15), nondominant hand-to-eye coordination G2 (ES = 0.74), G4 (ES 5 1.34), and G5 (ES = 1.09); lower-body power G2 (ES = 0.44), G4 (ES = 0.39), and G5 (ES = 0.43); core muscular endurance G1 (ES 5 0.82), G3 (ES 5 0.68), and G4 (ES 5 1.04); upper-body power G2 (ES 5 0.53); and sprint capacity G4 (ES 5 0.69). Significant improvements were also found between player's positions for all tests. These findings indicate that a progressive INT program can enhance functional movement abilities and selected physical fitness measures in young rugby players regardless of game position and age. [ABSTRACT FROM AUTHOR]

Pelvic floor dysfunction (PFD) in female athletes can have a negative impact on quality of life, athletic performance, and participation in sport. Research indicates that female athletes participating in sports that involve running, jumping, and high-impact landing are at a higher risk for PFD than nonathletic females. The stress and increased intra-abdominal pressure from high-impact forces, as well as neuromuscular fatigue of the pelvic floor musculature, may contribute to PFD in female athletes. Sport coaches, fitness professionals, and health care providers play an essential role in raising awareness about PFD and promoting pelvic floor fitness for female athletes. [ABSTRACT FROM AUTHOR]

Blood flow restriction training (BFRT) has been shown to be an effective alternative technique to conventional resistance training to increase skeletal muscle hypertrophy and strength. However, neuromuscular response to BFRT in combination with nutritional supplementation has rarely been studied. The purpose of this study was to investigate the effects of BFRT combined with creatine monohydrate (CrM) and/or hydroxymethyl butyrate (HMB) on skeletal muscle size and strength. Fift een healthy males were randomly divided into three groups: a) BFRT without supplementation (C-BFR); b) BFRT with CrM supplementation (0.3 g / kg-1) (CrM-BFR); and c) BFRT with CrM (0.3 g / kg-1) and HMB (3 g) supplementation (CrM + HMB-BFR). Participants performed elbow flexion exercise (30% of maximal isometric voluntary contraction (MIVC)) at 30% of total occlusion pressure, twice a week, for three weeks. MIVC of the elbow flexion and brachial biceps muscle thickness were assessed pre- and post-training. There was no significant group-by-time interaction for MIVC values (p>0.05). Biceps muscle thickness was significantly increased from pre- to post-test in all groups (p<0.05). The C-BFR group obtained a greater value of effect size (d=2.2). These findings suggest that 3 weeks of CrM and HMB supplementation had no influence on BFRT-induced neuromuscular adaptations. [ABSTRACT FROM AUTHOR]