Strength training for throwing velocity enhancement in overhead throw: A systematic review and meta-analysis

The overhead throw is a fundamental technical-tactical ability for overhead sports. The purposes of this review are to assess the effect of resistance training (RT) in enhancing throwing velocity in athletes and to investigate the relationships between age or gender in this effect. Control group trials were identified through looking up electronic databases with a search span of 10th December 2020. Only studies which have control groups within research design, subjects randomly assigned to groups, healthy athletes with experience in the sport, an intervention consisting of a supervised RT program of a minimum duration of 4 weeks, and assessment of sport-specific throwing velocity were taken into account for this meta-analysis. A total of 16 studies with 424 subjects were deemed eligible per the inclusion criteria. The overall pooled analysis demonstrated that a large effect was observed for throwing velocity outcomes (ES 1.10; 95% CI 0.64–1.57; p < 0.00001). Differences were due to gender, with male (ES 1.12; 95% CI 0.55–1.78; p < 0.0001) and female athletes (ES 1.22; 95% CI 0.25–2.20; p < 0.00001). And due to age, with teenager athletes (ES 0.49; 95% CI -0.18–1.17; p = 0.04) and adult athletes (ES 1.34; 95% CI 0.64–1.92; p < 0.00001). Throwing velocity enhancement after RT was greater for women than for men, and for adults more than underage subjects. RT should last at least four weeks, with 2–3 sessions each week, and with any available implement.

Registration of synchronous geomagnetic pulsations and proton aurora during the substorm on March 1, 2017

Data of synchronous geomagnetic pulsations and proton aurora registrations were analyzed during the substorm on March 1, 2017 at Zhigansk (L=4.5, induction magnetometer), Maimaga (L=4, all-sky imager and Yakutsk (L = 3.3, induction magnetometer) stations, simultaneously with satellite measurement of EMIC waves. Ground-based registration of proton aurora is very difficult due to the fact that their intensity is much lower than the aurora intensity caused by precipitations of electrons, but in the event of substorm activity at the zenith of Maimaga station, a narrow (1 degree in latitude) proton arc was observed. Irregular pulsations of the diminishing periods (IPDPs) in the range of Pc1 geomagnetic pulsations associated with the injection of energetic protons were recorded simultaneously at Zhigansk and Yakutsk stations. This is the first report when STEVE (Strong Thermal Emission Velocity Enhancement) was observed in the course of a substorm with the onset at 12:45 UT after the decay of Pc1-associated proton arc. It is shown that the proton arc and geomagnetic pulsations are a consequence of ion-cyclotron instability in the area of the outer plasmasphere overlapping by energetic protons.