Effects of Plyometric Jump Training on Measures of Physical Fitness and Sport‑Specific Performance of Water Sports Athletes: A Systematic Review with Meta‑analysis

Background: A growing body of literature is available regarding the effects of plyometric jump training (PJT) on measures of physical fitness (PF) and sport-specific performance (SSP) in-water sports athletes (WSA, i.e. those competing in sports that are practiced on [e.g. rowing] or in [e.g. swimming; water polo] water). Indeed, incoherent findings have been observed across individual studies making it difficult to provide the scientific community and coaches with consistent evidence. As such, a comprehensive systematic literature search should be conducted to clarify the existent evidence, identify the major gaps in the literature, and offer recommendations for future studies. Aim: To examine the effects of PJT compared with active/specific-active controls on the PF (one-repetition maximum back squat strength, squat jump height, countermovement jump height, horizontal jump distance, body mass, fat mass, thigh girth) and SSP (in-water vertical jump, in-water agility, time trial) outcomes in WSA, through a systematic review with meta-analysis of randomized and non-randomized controlled studies. Methods: The electronic databases PubMed, Scopus, and Web of Science were searched up to January 2022. According to the PICOS approach, the eligibility criteria were: (population) healthy WSA; (intervention) PJT interventions involving unilateral and/or bilateral jumps, and a minimal duration of ≥ 3 weeks; (comparator) active (i.e. standard sports training) or specific-active (i.e. alternative training intervention) control group(s); (outcome) at least one measure of PF (e.g. jump height) and/or SSP (e.g. time trial) before and after training; and (study design) multigroups randomized and non-randomized controlled trials. The Physiotherapy Evidence Database (PEDro) scale was used to assess the methodological quality of the included studies. The DerSimonian and Laird random-effects model was used to compute the meta-analyses, reporting effect sizes (ES, i.e. Hedges’ g) with 95% confidence intervals (95% CIs). Statistical significance was set at p ≤ 0.05. Certainty or confidence in the body of evidence for each outcome was assessed using Grading of Recommendations Assessment, Development, and Evaluation (GRADE), considering its five dimensions: risk of bias in studies, indirectness, inconsistency, imprecision, and risk of publication bias. Results: A total of 11,028 studies were identified with 26 considered eligible for inclusion. The median PEDro score across the included studies was 5.5 (moderate-to-high methodological quality). The included studies involved a total of 618 WSA of both sexes (330 participants in the intervention groups [31 groups] and 288 participants in the control groups [26 groups]), aged between 10 and 26 years, and from different sports disciplines such as swimming, triathlon, rowing, artistic swimming, and water polo. The duration of the training programmes in the intervention and control groups ranged from 4 to 36 weeks. The results of the meta-analysis indicated no effects of PJT compared to control conditions (including specific-active controls) for in-water vertical jump or agility (ES = − 0.15 to 0.03; p = 0.477 to 0.899), or for body mass, fat mass, and thigh girth (ES = 0.06 to 0.15; p = 0.452 to 0.841). In terms of measures of PF, moderate-to-large effects were noted in favour of the PJT groups compared to the control groups (including specificactive control groups) for one-repetition maximum back squat strength, horizontal jump distance, squat jump height, and countermovement jump height (ES = 0.67 to 1.47; p = 0.041 to < 0.001), in addition to a small effect noted in favour of the PJT for SSP time-trial speed (ES = 0.42; p = 0.005). Certainty of evidence across the included studies varied from very low-to-moderate. Conclusions: PJT is more effective to improve measures of PF and SSP in WSA compared to control conditions involving traditional sport-specific training as well as alternative training interventions (e.g. resistance training). It is worth noting that the present findings are derived from 26 studies of moderate-to-high methodological quality, lowto- moderate impact of heterogeneity, and very low-to-moderate certainty of evidence based on GRADE.Projekt DEA

Prevalence of Non-responders for Glucose Control Markers after 10 Weeks of High-Intensity Interval Training in Adult Women with Higher and Lower Insulin Resistance

Background: Exercise training improves performance and biochemical parameters on average, but wide interindividual variability exists, with individuals classified as responders (R) or non-responders (NRs), especially between populations with higher or lower levels of insulin resistance. This study assessed the effects of high-intensity interval training (HIIT) and the prevalence of NRs in adult women with higher and lower levels of insulin resistance.Methods: Forty adult women were assigned to a HIIT program, and after training were analyzed in two groups; a group with higher insulin resistance (H-IR, 40 ± 6 years; BMI: 29.5 ± 3.7 kg/m2; n = 20) and a group with lower insulin resistance (L-IR, 35 ± 9 years; 27.8 ± 2.8 kg/m2; n = 20). Anthropometric, cardiovascular, metabolic, and performance variables were measured at baseline and after 10 weeks of training.Results: There were significant training-induced changes [delta percent (Δ%)] in fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) scores in the H-IR group (−8.8, −26.5, −32.1%, p &lt; 0.0001), whereas no significant changes were observed in the L-IR. Both groups showed significant pre-post changes in other anthropometric variables [waist circumference (−5.2, p &lt; 0.010, and −3.8%, p = 0.046) and tricipital (−13.3, p &lt; 0.010, and −13.6%, p &lt; 0.0001), supra-iliac (−19.4, p &lt; 0.0001, and −13.6%, p &lt; 0.0001), and abdominal (−18.2, p &lt; 0.0001, and −15.6%, p &lt; 0.010) skinfold measurements]. Systolic blood pressure decreased significantly only in the L-IR group (−3.2%, p &lt; 0.010). Both groups showed significant increases in 1RMLE (+12.9, p &lt; 0.010, and +14.7%, p = 0.045). There were significant differences in the prevalence of NRs between the H-IR and L-IR groups for fasting glucose (25 vs. 95%, p &lt; 0.0001) and fasting insulin (p = 0.025) but not for HOMA-IR (25 vs. 45%, p = 0.185).Conclusion: Independent of the “magnitude” of the cardiometabolic disease (i.e., higher vs. lower insulin resistance), no differences were observed in the NRs prevalence with regard to improved HOMA-IR or to anthropometric, cardiovascular, and muscle performance co-variables after 10 weeks of HIIT in sedentary adult women. This research demonstrates the protective effect of HIIT against cardiometabolic disease progression in a sedentary population

A six-minute walking test: maximum oxygen consumption in physical education students

The Six-Minute Walking Test (SMWT) was completed just in few times in apparently healthy young individuals and university students, while the maximal volume of oxygen consumption (VO2max) prediction has not been taken into consideration. The aim of this study was to elaborate a prediction equation for VO2max from the heart rate recovery (HRR) after completion the SMWT. 127 young in the first stage completed the SMWT and Course Navette Test (CNT), 17 in the second stage (test-retest) completed the SMWT and CNT, and 20 subjects in the third stage completed the SMWT and Bruce test. All physical education students (PES) completions an informed consent. A significant correlation was observed between VO2max estimated trough the CNT and HRR after the SMWT (rho= -0.3; p= 0.001). The correlation between the same variables was r= -0.72 (p= 0.001) in the second stage, and a significant correlation (r= -0.65; p= 0.002) was observed between VO2max directly measured in Bruce test and HRR after the SMWT. From the correlation a prediction equation was elaborated is y= 92.468-(0.278*20-second-HRR) and the standard error of estimation (SEE) was 7.17 ml·kg-1·min-1. The HRR achieved after the SMWT may predict VO2max in PES

ACUTE RESPONSES TO 4 VS. 4 SMALL-SIDED GAMES IN FOOTBALL PLAYERS

The aim of this study was to examine acute physiological responses, physical fitness parameters and timemotion characteristics associated with a 4-a-side small-sided game in amateur level players. Sixteen male football players (age 23.9±4.2 years) completed one 4-a-side small sided game with the aim of maintaining ball possession as long as possible. The participants were monitored for external load and physiological parameters, and tested before and after for physical fitness assessment. A Student’s paired t-test was conducted to determine the differences in physical fitness assessment. A repeated measures analysis of variance (ANOVA), with Bonferroni post-hoc test, was used to determine the dynamics of physiological parameters in players, their RPE and time-motion characteristics of SSG. A significant difference was found in 20 m sprint time between before and after the SSG (Δ=+1.3%). No significant differences were found between bouts or recovery periods for THb and SmO2, nor between HR-related variables (ES=.005-.383). Compared to RPE in bout 1, greater values were observed in bouts 2, 3, and 4 (Δ=+5.3%, p=.008, ES=.40; Δ=+9.6%, p=.002, ES=.98; Δ=+15.1%, p=.000, ES=1.29; respectively). No significant differences were found between bouts for time-motion characteristics. The results demonstrated that RPE responses increased throughout bout periods, whereas the rest of physiological parameters were maintained over the entire protocol. Due to possible fatigue accumulation, physical fitness performance was impaired (sprint) and the external load was reduced over the course of the protocol

Características antropométricas, fuerza de prensión manual y asimetrías de miembros superiores en para-atletas chilenos de lanzamiento de bala altamente entrenados

Las características antropométricas, incluido el tamaño, forma y composición del cuerpo, pueden tener un impacto significativo en el rendimiento deportivo debido a su influencia en diversos factores fisiológicos y biomecánicos. Sin embargo, las investigaciones sobre las características antropométricas para-atletas de lanzamiento altamente entrenados son limitadas. El propósito de este estudio fue describir las características antropométricas, la fuerza de prensión manual y las asimetrías bilaterales de miembros superiores de paralanzadores chilenos altamente entrenados en lanzamiento de la bala. Se evaluaron las características antropométricas de cinco atletas masculinos chilenos de lanzamiento de bala (edad promedio de 38,8 ± 7,7 años), incluido el grosor de los pliegues cutáneos en seis sitios anatómicos, la circunferencia en cinco sitios y la anchura de los huesos en dos sitios. También se midieron la fuerza de prensión manual y las asimetrías bilaterales. Se encontró que la masa corporal y la altura de los atletas eran 90,5 ± 5,1 kg y 179,1 ± 8,9 cm, respectivamente. Los atletas tenían un somatotipo endo-mesomorfo (4.4-6.9-1.0) con altos niveles de masa grasa (25.7 ± 2.8 %) y masa muscular esquelética (39.1 ± 3.7 %). Se encontró además que la fuerza de prensión manual de los atletas era de 66,4 ± 6,7 kg con una asimetría bilateral de 6,5 ± 6,2 %, mostrando mayor fuerza la mano dominante. Los resultados indican que los atletas de lanzamiento de bala tienen un somatotipo caracterizado por una mayor musculatura y grasa corporal, junto con una estatura considerable. Aunque se encontró que la fuerza de agarre era alta, los atletas mostraron asimetría bilateral, lo que requiere de más investigaciones para determinar las causa e implicaciones.Anthropometric characteristics, including body size, shape, and composition, can have a significant impact on sports performance due to their influence on various physiological and biomechanical factors. However, limited research has been conducted on the anthropometric characteristics of highly trained throwing para-athletes. The purpose of this study was to describe the anthropometric characteristics, handgrip strength, and upper limb bilateral asymmetries of highly trained Chilean shot put para-throwers. Five male Chilean shot put para-athletes (average age of 38.8 ± 7.7 years) were assessed for their anthropometric characteristics, including skinfold thickness at six anatomical sites, girth at five sites, and bone breadth at two sites. Handgrip strength and bilateral asymmetries were also measured. The body mass and height of the athletes were found to be 90.5 ± 5.1 kg and 179.1 ± 8.9 cm, respectively. The athletes were found to have an endo-mesomorph somatotype (4.4-6.9-1.0) with high levels of fat mass (25.7 ± 2.8 %) and skeletal muscle mass (39.1 ± 3.7 %). The handgrip strength of the athletes was found to be 66.4 ± 6.7 kg with a bilateral asymmetry of 6.5 ± 6.2 %, with the dominant hand showing greater strength. The results indicate that the shot put para-athletes have a somatotype characterized by increased muscularity and body fat, along with a considerable stature. Although handgrip strength was found to be high, the athletes showed bilateral asymmetry, which requires further investigation to determine the cause and implications

Feasibility of the 2-point method to determine the load-velocity relationship variables during the countermovement jump exercise

Purpose: This study aimed to examine the reliability and validity of load−velocity (L–V) relationship variables obtained through the 2-point method using different load combinations and velocity variables. Methods: Twenty men performed 2 identical sessions consisting of 2 countermovement jumps against 4 external loads (20 kg, 40 kg, 60 kg, and 80 kg) and a heavy squat against a load linked to a mean velocity (MV) of 0.55 m/s (load0.55). The L–V relationship variables (load-axis intercept (L0), velocity-axis intercept (v0), and area under the L–V relationship line (Aline)) were obtained using 3 velocity variables (MV, mean propulsive velocity (MPV), and peak velocity) by the multiple-point method including (20–40–60–80–load0.55) and excluding (20–40–60–80) the heavy squat, as well as from their respective 2-point methods (20–load0.55 and 20–80). Results: The L–V relationship variables were obtained with an acceptable reliability (coefficient of variation (CV) ≤ 7.30%; intra-class correlation coefficient ≥ 0.63). The reliability of L0 and v0 was comparable for both methods (CVratio (calculated as higher value/lower value): 1.11–1.12), but the multiple-point method provided Aline with a greater reliability (CVratio = 1.26). The use of a heavy squat provided the L–V relationship variables with a comparable or higher reliability than the use of a heavy countermovement jump load (CVratio: 1.06–1.19). The peak velocity provided the load–velocity relationship variables with the greatest reliability (CVratio: 1.15–1.86) followed by the MV (CVratio: 1.07–1.18), and finally the MPV. The 2-point methods only revealed an acceptable validity for the MV and MPV (effect size ≤ 0.19; Pearson's product-moment correlation coefficient ≥ 0.96; Lin's concordance correlation coefficient ≥ 0.94). Conclusion: The 2-point method obtained from a heavy squat load and MV or MPV is a quick, safe, and reliable procedure to evaluate the lower-body maximal neuromuscular capacities through the L–V relationship