The aim of this study was to investigate the effect of leg blood flow restriction (BFR) applied during a 3-a-side futsal game on strength-related parameters. Twelve male futsal players were randomly assigned into two groups ( n = 6 for each group) during 10 training sessions either with or without leg BFR. Prior to and post-training sessions, participants completed a series of tests to assess anabolic hormones and leg strength. Pneumatic cuffs were initially inflated to 110% of leg systolic blood pressure and further increased by 10% after every two completed sessions. In comparison with baseline, the resting post-training levels of myostatin ( p = 0.002) and IGF-1/MSTN ratio ( p = 0.006) in the BFR group changed, whereas no change in the acute level of IGF-1 and myostatin after exercise was observed. Peak torque of knee extension and flexion increased in both groups ( p < 0.05). A trend of increased neural activation of all heads of the quadriceps was observed in both groups, however, it was statistically significant only for rectus femoris in BFR ( p = 0.02). These findings indicated that the addition of BFR to normal futsal training might induce greater neuromuscular benefits by increasing muscle activation and augmenting the hormonal response.

The aim of this study was to describe the characteristics of jump capacity in a group of secondary school students and to develop 2 specific equations-applied to boys and girls, respectively, to estimate the jump power of secondary school students. Four hundred and fifty-six boys (age, 14.1 ± 0.8 years; mass, 61.9 ± 15.7 kg; height, 1.64 ± 0.10 m) and 465 girls (age, 14.1 ± 0.9 years; mass, 55.1 ± 10.0 kg; height, 1.58 ± 0.07 m), all of them secondary school students, volunteered to participate in this study. They performed a vertical jump test (Abalakov) on a force platform, and jump height and peak power were measured. Most importantly, peak power was also estimated through a series of previously established power equations. For the purpose of establishing statistically significant differences, a p value ≤ 0.05 was fixed. The equations proposed by Canavan and Vesconvi, and Harman were the most precise with respect to actual power, reaching a percentage of 1.9-2.1 and 3.6-4.1%, respectively. The equations by Sayers and Lara showed a greater difference in percentage (9.9-12.4 and 22.4-24.2%, respectively) with that of actual power. Similar results were not obtained in other studies, which means that a specific equation will be required according to the characteristics of the assessed sample. Two equations specifically addressed to secondary school students will be established in this article: boys: ([61.8 jump height (cm)] + [37.1 body mass (kg)] - 1,941.6); girls: ([31 jump height (cm)] + [45 body mass (kg)] - 1,045.4). Crossvalidation tests that were done to prove the validity of said equations showed positive results. Practical applications: Those teachers who wish to estimate the jump power of their pupils can use these equations and thereby calculate jump power by the indirect method from jump height and body mass index, without any need to use any expensive tools.

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Benito-Martínez E, Lara-Sánchez AJ, Berdejo-del-Fresno D, Martínez-López EJ. Effects of combined electrostimulation and plyometric training on vertical jump and speed tests. J. Hum. Sport Exerc. Vol. 6, No. 4, pp. 603-615, 2011. The aim of this study was to determine the performance evolution of a group of athletes after 8 weeks of training that combined electrostimulation (NM ES) and plyometrics (PT). 78 medium level sprinter athletes participated, 40 women and 38 men (age, 15.9±1.4 years old, body mass index, 20.5±1.68 kg/m 2 ; weight 58.53±8.05 kg; height, 1.68±0.07 m). The sample was randomized into four groups [Control (PT only), NM ES + PT, PT + NM ES, and Simultaneous (plyometric jumps were performed through the passage of current). Improvements were obtained in the Abalakov jump of 3.57% (p<0.01), 13.51% (p<0.001), 1.23% (p<0.01), and 0.77%, and in the sprint of 0.45%, 3.87% (p<0.05), 4.56% (p<0.01) and 7.26% p<0.001 for the control group, NM ES + PT group, PT + NM ES group, and Simultaneous group, respectively. It was concluded that a) improvement in vertical jump requires the application of the NM ES prior to PT; b) the sprinter athlete must combine the workout simultaneously or apply the ES after the PT training; and c) in sportspeople that require improvement in both the vertical jump and speed tests (e.g. basketball) the simultaneous method is not recommended, the order of application of NM ES and PT being non-determinant. Finally, the time needed to obtain significant improvement in strength training through a combination of NM ES and PT is substantially lower (15 days) than the time needed to improve speed (30 days).