Examinando por Autor "Herrera-Valenzuela, Tomás"

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    Ítem
    A Systematic Review with Meta-Analysis on the Effects of Plyometric-Jump Training on the Physical Fitness of Combat Sport Athletes
    (MDPI, 2023-02) Ojeda-Aravena, Alex; Herrera-Valenzuela, Tomás; Valdés-Badilla, Pablo; Báez-San Martín, Eduardo; Thapa, Rohit K.; Ramirez-Campillo, Rodrigo
    We aimed to assess the athletic performance changes in combat sport athletes (CoSAs) after plyometric-jump training (PJT), compared to control conditions, through a systematic review with meta-analysis. Following PRISMA guidelines, three electronic databases were searched for includable articles, according to a PICOS approach. Using a random-effects model, Hedges’ g effects sizes (ES) were calculated. Heterogeneity was assessed using the I2 statistic, with values of <25%, 25–75%, and >75% representing low, moderate, and high levels of heterogeneity, respectively. Statistical significance was set at p ≤ 0.05. The certainty of evidence was assessed using the GRADE approach. Twelve eligible articles were identified for systematic review, seven of high quality and five of moderate quality, according to the PEDro scale. The studies recruited taekwondo, silat, wrestling, judo, fencing, and karate athletes (292 total participants), including specific–active and active controls. Most participants had a mean age of <18 years and were males (n = 225). Compared to the control, PJT programmes, involving 4–12 weeks and 2–3 sessions per week, induced small to moderate improvements (ES = 0.47 to 1.04) in athletes’ maximal strength (e.g., 1RM squat), vertical jump height, change-of-direction speed, and specific performance (e.g., fencing movement velocity), although without meaningful effects on body mass, fat mass, and muscle mass (ES = 0.02 to −0.06). Most (7 of 8) outcomes attained low heterogeneity. The outcome-level GRADE analysis indicated a certainty of evidence from low to moderate. In conclusion, PJT, when compared to control conditions, may improve CoSA athletic performance. © 2023 by the authors.
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    Ítem
    Warm-up and handgrip strength in physically inactive chilean older females according to baseline nutritional status
    (MDPI, 2022-10) Hernandez-Martinez, Jordan; Castillo-Cerda, María; Vera-Assaoka, Tiago; Carter-Truillier, Bastian; Herrera-Valenzuela, Tomás; Guzmán-Muñoz, Eduardo; Magnani Branco, Braulio Henrique; Jofré-Saldía, Emilio; Valdés-Badilla, Pablo
    This study aims to analyze the effect of different types of warm-ups on handgrip strength (HGS) in physically inactive older females. Secondarily, it aims to compare HGS according to their baseline nutritional status. A randomized crossover trial study was conducted with 44 physically inactive older females distributed into normal weight (n = 12, BMI = 23.9 ± 3.2 kg/m2 ), overweight (n =16, BMI = 27 ± 4.7 kg/m2 ) and obese (n = 16, BMI = 31.6 ± 5.3 kg/m2 ), who participated in three warm-up conditions (static stretching condition, SSC; elastic band condition, EBC; and therapeutic compression ball condition, TCBC) and one control condition (CC, no warm-up). All participants performed the four randomized conditions with recovery within 72 h. A significant decrease (p < 0.05) in HGS for the dominant and non-dominant hands was observed when comparing SSC vs. CC. In contrast, comparing the warm-up conditions according to the baseline nutritional status, statistically significant differences (p < 0.05) were only reported in the obese group in the dominant and non dominant hand in favor of CC concerning SSC. In conclusion, warm-up with static flexibility led to a decrease in HGS in physically inactive older females. Only the obese group exhibited this result when analyzed by nutritional status.