Squat Jump Test Research Articles

Post-activation performance enhancement of flywheel and traditional squats on vertical jump under individualized recovery time.

To explore the post-activation performance enhancement (PAPE) of flywheel and traditional squats on a series of vertical jumps, the loads of the two protocols were matched based on their linear velocities. In addition, we attempted to validate the effectiveness of determining individualized recovery time (IRT) between conditioning activities and explosive movements. Sixteen trained players participated in three main experiments: first, one-repetition maximum (1RM) assessment and intensity matching test; second, the weighted jump squat (WJS) test at baseline and at 2, 4, 6, 8, and 10min after flywheel and traditional protocols; and third, squat jump (SJ), countermovement jump (CMJ), and approach jump (AJ) tests incorporating IRT determined in the WJS sessions into both protocols. These protocols were standardized to 8 repetitions at 80% 1RM with equivalent concentric speed matched by a linear position transducer and conducted in a random order on separate days. In the WJS tests, both protocols exhibited significant increases on jump height (JH), peak force (PF), and peak power (PP) after 2 to 6min (all p < 0.05), and the time courses of changes in performance were in a similar trend. In the SJ, CMJ, and AJ tests, both protocols demonstrated highly significant increases on JH, PP, and reactive strength index (RSI) after incorporating IRT (all p < 0.01), with all participants exhibiting diverse improvement above the baseline levels. The potentiation percentages of the flywheel protocol on JH, PP, and RSI were higher than those of the traditional protocol across four jumping types (JH: 5.35%-9.79% vs. 4.13%-8.46%; PP: 4.16%-6.13% vs. 3.23%-4.77%; and RSI: 7.27% vs. 7.04%). High-intensity flywheel squats can produce jumping potentiation in neuromechanical factors comparable to, or even surpassing, those observed in traditional squats, potentially making them a more effective option for inducing PAPE. Additionally, incorporating IRT into potentiation protocols could further optimize the PAPE effects.

Can the Countermovement Jump or Squat Jump predict the kinematic performance of the rear Bandal Chagi kick?

This study aimed to measure the associative and predictive strength of biomechanical variables of the countermovement jump (CMJ) and squat jump (SJ), and performance of the bandal-chagi kick performed with the dominant (D) rear lower limb in elite Taekwondo Athletes. For this, a total of 27 international level athletes (15 males and 12 females) performed the CMJ and SJ on two force platforms. The bandal-chagi was monitored using a motion capture system (VICON). The main results indicated that non-dominant (ND) Stiffness for the CMJ showed predictive power alone (p=0.048) or in combination with eccentric breaking rating of force development (RFD) (p=0.031) for total hip angular speed. Takeoff peak force/BM for the SJ predicted total time (p=0.002). Concentric RFD/BM predicted total linear foot acceleration, either alone (p=0.001) or with vertical speed at takeoff (p=0.042). The total hip angular acceleration predictor was takeoff peak force D alone (p=0.019) or in combination with peak power/BM (p=0.041). In conclusion, CMJ and SJ tests showed specific associations with TKD kick performance. These analyses in this study indicated that they are good predictors for TKD athletes, producing results consistent with the participants’ levels. Keywords: Martial arts, Biomechanical Phenomena, Time-motion studies, Kinanthropometry, Motion Capture.

A comparative study of lower limb strength during vertical jump of male college students in table tennis, badminton and tennis

The objectives of this paper are to explore the correlation of kinetic indices of SJ (squat jump) and CMJ (counter-movement jump) and the differences of lower limb strength mechanics indexes of table tennis, badminton and tennis players under SJ and CMJ. This study included 60 male collegiate athletes, 20 each from table tennis, badminton, and tennis. Subjects performed SJ and CMJ tests on a force platform and the vertical jump data were analyzed. Table tennis, badminton and tennis players demonstrated significant differences in the SJ and CMJ assessments. Badminton players outperformed table tennis players in terms of peak power (PP) (p = 0.005) and peak velocity (PV) (p = 0.017). Badminton players beat table tennis players in PV (p = 0.028), PP (p = 0.022), fast twitch fibers (FTF) (p = 0.033) and pre-stretch effect (EP) (p = 0.0004). Tennis players exhibited lower peak force (PF) (p = 0.006) indicators than badminton players. For athletes in all three sports, the SJ test markers (vertical jump displacement, PF, PP and PV) demonstrated a strong positive correlation. There was a highly significant positive correlation between VJD and PF, PP, PV and FTF among badminton players. Significant positive connections were discovered between PF, PP, PV, FTF and EP, as well as between PP and PV and FTF and EP. PV and FTF had a very strong positive correlation, as did EP, PV and FTF. College badminton players had higher vertical jumps than table tennis and tennis players. In addition to vertical jump height, PP (power production), PV (power velocity) and FTF (force-time factors) are important markers for assessing the success of vertical jumps in athletes’ daily training. These findings can assist coaches and athletes develop better vertical jump training programs.

The relationships between ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms and athletic performance characteristics in professional soccer players

BackgroundCurrent research on athletic performance focuses on genetic variants that contribute significantly to individuals’ performance. ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms are variants frequently associated with athletic performance among different populations. However, there is limited research examining the pre-and post-test results of some variants of athletic performance in soccer players. Therefore, the presented research is to examine the relationships between the ACTN3 rs1815739 and PPARA-α rs4253778 gene polymorphisms and athletic performance improvement rates in adaptations to six weeks of training in elite soccer players using some athletic performance tests.MethodologyTwenty-two soccer players between the ages of 18 and 35 voluntarily participated in the study. All participants were actively engaged in a rigorous six-day-a-week training program during the pre-season preparation period. Preceding and following the training program, a battery of diverse athletic performance tests was administered to the participants. Moreover, Genomic DNA was extracted from oral epithelial cells using the Invitrogen DNA isolation kit (Invitrogen, USA), following the manufacturer’s protocol. Genotyping was conducted using real-time PCR. To assess the pre- and post-test performance differences of soccer players, the Wilcoxon Signed Rank test was employed.ResultsUpon analyzing the results of the soccer players based on the ACTN3 genotype variable, it was observed that there were no statistically significant differences in the SJ (Squat Jump), 30m sprint, CMJ (Counter Movement Jump), and DJ (Drop Jump) performance tests (p > 0.05). However, a statistically significant difference was identified in the YOYO IRT 2 (Yo-Yo Intermittent Recovery Test Level 2) and 1RM (One Repetition Maximum) test outcomes (YOYO IRT 2: CC, CT, and TT, p = 0.028, 0.028, 0.008, 0.000, respectively; 1RM: CC, CT, and TT, p = 0.010, 0.34, 0.001, respectively). Regarding the PPARA-α genotype variable, the statistical analysis revealed no significant differences in the SJ, 30m sprint, CMJ, and DJ performance tests (p > 0.05). Nevertheless, a statistically significant difference was observed in the YOYO IRT 2 and 1RM test results (YOYO IRT 2: CC, CG p = 0.001, 0.020; 1RM: CC, p = 0.000)ConclusionsThe current study demonstrated significant enhancements in only YOYO INT 2 and 1RM test outcomes across nearly all gene variants following the six-day-a-week training program. Other performance tests, such as the 30m sprint, SJ, CMJ, and DJ tests did not exhibit statistically significant differences. These findings contribute novel insights into the molecular processes involving PPARA-α rs4253778 and ACTN3 rs1815739 that underpin enhancements in endurance (YOYO INT 2) and maximal strength (1RM) aspects of athletic performance. However, to comprehensively elucidate the mechanisms responsible for the association between these polymorphisms and athletic performance, further investigations are warranted. It is thought that the use of field and genetic analyses together to support each other will be an important detail for athletes to reach high performance.

Effects of repetitive different jump pre-conditioning activities on post activity performance enhancement

Purpose: The purpose of this study was to investigate effects of repetitive different jump pre-conditioning activities on post activity performance enhancement (PAPE). Methods: Twenty-six male sports science faculty students who were physically active between the ages of 18-22 to participate in the study were divided into a squat jump group (SJG) (n= 14, age 20.0 ± 1.3 year, height: 175.1 ± 6.7 cm, body weight: 71.9 ± 6.9 kg) and a countermovement jump group (CMJG) (n= 12, age 20.1 ± .9 year, height: 175.3 ± 7.9 cm, body weight: 71.3 ± 8.2 kg). Squat jump (SJ) and countermovement jump (CMJ) tests were performed before the pre-conditioning activity, 4 min and 10 min after the pre-conditioning activity. SJG performed SJ and CMJG performed CMJ as the pre-conditioning activity with three reps. One-way repeated measures ANOVA was performed to determine the PAPE effect of pre-conditioning activities, SJ and CMJ on the variables flight time (FT), jump height (JH) and power (P) in SJ and CMJ tests after 4 min and 10 min. Significance level was taken as P&lt; .05. Results: Statistically significant differences were found as PAPE effect in SJ test FT, JH and P variables in the SJG at 4 min and 6 min after the pre-conditioning activity SJ (F(2;12)= 10.607; P= .002, η2= .639 for FT; F(2;12)= 9.323; P= .004, η2= .608 for JH and P). In CMJG, there were no statistically significant differences in PAPE effect in the CMJ test FT, JH, and P variables 4 min and 8 min after the pre-conditioning activity CMJ. Conclusions: In conclusion, the time-dependent differences in SJ and CMJ performance of PAPE effects caused by repetitive pre-conditioning activities, SJ and CMJ, showed the importance of determining the exercises that will create a pre-conditioning and optimal rest periods for post-PAPE performance. Keywords: Pre-conditioning activity, post activity performance enhancement, squat jump, counter-movement-jump

A comparative study of vertical jump parameters in men's college basketball and volleyball players

This study aimed to compare lower limb strength disparities between male college volleyball and basketball players in four distinct vertical jump types. We recruited 100 second-level (above the national standard) male college athletes (50 basketball and 50 volleyball players) from Capital University of Physical Education and Sports who volunteered to participate. We assessed the performance of each athlete with regards to the squat jump (SJ), countermovement jump (CMJ), continuous jump with straight legs (CJs), and continuous jump with bent legs (CJb). Data analysis was performed by independent samples t-tests in SPSS version 25.0. software. In the CMJ test, volleyball players had a significantly higher vertical jump displacement (VJD; p = 0.047, t = −2.018), squat displacement (SD; p = 0.005, t = −2.883), peak force (p = 0.023, t = −1.964), and peak velocity (p = 0.011, t = −1.687) than basketball players. In the SJ test, volleyball players had a significantly higher VJD (p = 0.041, t = −1.21) and SD (p = 0.008, t = −1.46) than basketball players. In the CJs test, volleyball players had a significantly higher average vertical jump displacement (AVJD; p = 0.042, t = −2.067) than basketball players. In the CJb test, volleyball players had a significantly higher AVJD (p = 0.001, t = −3.448), average squat displacement (p = 0.017, t = −2.44), and average contact time (p = 0.045, t = −2.038) than basketball players. The overall vertical jump ability of college volleyball players was better than that of college basketball players. CMJ, SJ, CJs and CJb training should be included in daily training sessions and considered in the selection of basketball and volleyball players. In addition, coaches can use fast twitch Fibers, the effect of pre-stretch and k as the main evaluation indicators to assess daily training progress.

Relationship between vertical jump tests and ice-skating performance in junior Polish ice hockey players

The aim of this study was to determine the relationships between vertical jumps (VJ) and various on-ice skating performances of junior ice hockey players (n = 19). The three modes of VJ or off-ice measures were countermovement jump with arm swing (CMJ), squat jump (SJ) and depth drop jump (DDJ). The on-ice skating performance was measured by the skating multistage aerobic test (SMAT), forward and backward acceleration test, top speed test, and repeated sprint ability (RSA) test. The relationships between the variables were quantified using Pearson's product-moment correlation. DDJ showed a significant positive correlation with forward average skating speed (FASS) (r = 0.62) and strong correlations with backward average skating speed (BASS) (r = 0.81), and maximum skating speed (MSS) (r = 0.71). SJ was found to be strongly correlated with BASS (r = 0.82) and MSS (r = 0.76), whereas the only on-ice performance that significantly correlated with CMJ was BASS (r = 0.68). All three modes of VJ were inversely and non-significantly correlated with performance decrement index and fatigue index, as determined by the RSA test. SMAT was not significantly correlated with either VJ or RSA. Correlations between all three modes of VJ tests were significant. Therefore, this study concludes that: (1) DDJ can be used as a predictor of all the ice skating speed tests, whereas SJ can predict BASS and MSS. CMJ, on the other hand, can predict the performance of only BASS. (2) RSA performance cannot be predicted from CMJ, SJ, or DDJ tests, and (3) neither any of the VJ nor RSA can predict skating endurance of junior ice hockey players.

Effects of 5-Week of FIFA 11+ Warm-Up Program on Explosive Strength, Speed, and Perception of Physical Exertion in Elite Female Futsal Athletes.

Futsal is a sport that originates from soccer and is increasingly practiced all over the world. Since training and warm-up protocols should be sport-specific in order to reduce injuries and maximize performance, this study aimed to evaluate the effects of 5 weeks of the FIFA 11+ warm-up program on explosive strength, speed, and perception of physical exertion in elite female futsal athletes. Twenty-nine elite female futsal athletes participating in the Italian national championships were divided into two groups: the experimental group (EG) underwent 5 weeks of the FIFA 11+ warm-up program, and the control group (CG) underwent 5 weeks of a dynamic warm-up. We evaluated any effect on explosive strength (by Squat Jump test), speed (by Agility T-test), and perception of physical exertion (by Borg CR-10 scale). All measurements were carried out by a technician of the Italian Football Federation before (T0), at the middle (T1), and at the end (T2) of the protocol. The EG showed significant improvements on performances between T0 vs. T1 and T0 vs. T2 both in the Squat Jump test (p = 0.0057 and p = 0.0030, respectively) and in the Agility T-test (p = 0.0075 and p = 0.0122). No significant differences were found in the Squat Jump test performances in the CG, while significant improvements were detected in the Agility T-test performances (p = 0.0004 and p = 0.0053, T0 vs. T1 and T0 vs. T2, respectively). As for the Borg CR-10 scale, we found a significant difference between T0 and T2 in the EG (p = 0.017) and no differences in the CG. This study showed that 5 weeks of the FIFA 11+ warm-up program improves the jumping performance of female futsal athletes without adversely affecting speed. These findings can be useful for coaches and athletic trainers in order to consider FIFA 11+ warm-up program also in female futsal athletes.

Inclusive Physical Activity to Promote the Participation of People with Disabilities: A Preliminary Study

Background: Physical activity brings improvements in the quality of life in all individuals, disabled and non-disabled. There is little evidence in the literature of inclusive physical activity in which disabled and non-disabled people participate at the same level.&#x0D; Objectives: The study aimed to demonstrate the effectiveness of an inclusive training program, structured in such a way as to encourage physical activity for all participants with and without disabilities, in improving body composition, explosive strength, and endurance.&#x0D; Methods: A sample of twenty-four subjects (mean age: 24.09±3.92 years), 12 disabled and 12 non-disabled, was selected. Quantitative input and output data were recruited at 16-week intervals using a battery of tests: anthropometric measurements, Vertec Squat Jump test, and Yoyo Endurance Test. During the 16 weeks, all participants followed an appropriately structured training program in four mesocycle without any differences. Input and output data were compared employing the t-test for dependent samples.&#x0D; Results and conclusions: The results showed statistically meaningful improvements at an alpha level set at 0.05 for the three parameters tested. These results confirmed the effectiveness of the proposed inclusive training protocol on the improvement of the tested parameters in all participants. These strategies didn't jeopardise the achievement of the overall objectives set; on the contrary, improvements in BMI, explosive strength, and endurance strength of 4.8%, 4.3%, and 56.2% respectively were observed.

Effects of COVID-19 Lockdown on Body Composition and Fitness Performance among Football Players in Negro African Environment

Context and Objective: The nutritional and sports dimension of the lockdown implemented during the COVID-19 pandemic is unexplored in the African environment. The purpose of this study was to assess the effects of COVID-19 lockdown on body composition and fitness performance in Congolese football players. Methods: This was an observational study carried out in Brazzaville between February 9 and October 30, 2020. It included 16 male players among Congolese senior national team and 11 male football players of first division Brazzaville clubs. Two types of measurements were carried out: anthropometric measures (height, body mass, total fat percent, lean body mass); physical capacities [30 m sprint, repeated sprint, aerobic endurance (Yo-Yo Intermittent Recovery test), vertical jump (Squat Jump test, Countermovement test)]. The measurements were realized at 4 times: before lockdown (month of february, T0), 1st week of june (T1), 1st week of september (T2), 1st week of october (T3). Data were compared using Student t test, Sokal S test, Anova, Newman-Keuls test (multiple contrasts) and correlation analysis. Results: A significant increase in body mass (p < 0.05), body mass index (p < 0.02) was observed in all subjects, compared to a less marked increase in muscle mass. Significant reductions in performance in the 30 m sprint, the 6-sprint series, the endurance event and the vertical jumps were noted. However, a significant effect of “practice level” on the changes in performance on Squat Jump and Countermovement Jump was only found, the maximum differences throughout experimental period being found among senior football players of Congolese national team. Conclusion: The present data suggest that COVID-19 lockdown promotes weight gain and decreased physical ability in football players.

Can a genetic profile be related to performance in young talent track and field athletes? A pilot study

Aim: This study analyzed the influences of ACE and ACTN3 gene variants in sprinters, jumpers, and endurance young athletes of track and field. Methods: 36 school-level competitors of both sex (15 girls and 21 boys; aged 16.4 ± 1.2 years; training experience 4 ± 1.2 years) practitioners of different sport disciplines (i.e., sprint, jump, and endurance athletes) participated in the study. The deoxyribonucleic acid (DNA) was extracted from peripheral blood using a standard protocol. Anthropometric measurements, 30 m sprint, squat jump (SJ), and maximal oxygen uptake (VO2max) tests were measured. Results: Genotype distribution of the ACE and ACTN3 genes did not differ between groups. In ACE DD and ACTN3 RX genotypes, the SJ test was bigger in sprinters and jumpers than in the endurance runners. In contrast, when analyzing the ACE ID genotype, sprinters had higher SJ than endurance athletes. Moreover, in the ACE DD genotype, the sprinters and jumpers’ athletes had lower time in 30 m tests compared to endurance runners. However, the ACE ID and ACTN3 RX genotypes was greater aerobic fitness in endurance runners than in jumpers’ athletes. Conclusion: Although the genetic profile is not a unique factor for determining athletic performance, the ACE DD and ACTN3 RX genotypes seem to favor athletic performance in power and sprint versus endurance sports. Thus, this study evidenced that assessing genetic variants could be used as an auxiliary way to predict a favorable profile for the identification of young talents of track and field.

Squat and countermovement jump performance across a range of loads: a comparison between Smith machine and free weight execution modes in elite sprinters.

The aims of this study were to: 1) provide and compare the height achieved during Smith machine (SM) and free weight (FW) loaded jumps executed over a wide spectrum of loads (40–120% of body mass [BM]); and 2) test the difference between loaded and unloaded squat jump (SJ) and countermovement jump (CMJ) attempts in ten highly trained male sprinters. On the first visit, athletes performed unloaded SJ and CMJ, loaded SJ with loads corresponding to 40, 60, 80, 100, and 120% BM, and loaded CMJ at 100% BM using an Olympic barbell (FW). On the second visit, they performed loaded SJ and CMJ tests under the same loading conditions on the SM device and, subsequently, a half-squat one-repetition maximum (1RM) assessment. The relative strength (RS = 1RM/BM) of the athletes was 2.54 ± 0.15. Loaded SJ performance was similar between SM and FW, and across all loading conditions. Differences in favour of CMJ (higher jump heights compared with SJ) were superior in the unloaded condition but decreased progressively as a function of loading. In summary, sprinters achieved similar SJ heights across a comprehensive range of loads, regardless of the execution mode (FW or SM). The positive effect of the countermovement on jump performance is progressively reduced with increasing load.

Sex and Age-Group Differences in Strength, Jump, Speed, Flexibility, and Endurance Performances of Swedish Elite Gymnasts Competing in TeamGym.

Purpose: To analyze sex and age group differences in strength, jump, speed, flexibility, and endurance performances of TeamGym athletes.Methods: A total of 91 Swedish elite gymnasts (junior female, n = 26, age = 15.4 y; senior female, n = 23, age = 20.0 y; junior male, n = 19, age = 15.6 y; senior male, n = 23, age = 20.6 y) participated in three testing sessions on three separate days. These were: (1) a series of flexibility tests for the lower- and upper-body; (2) strength tests for the lower- and upper-body; and (3) various types of jumps, a 20-m sprint-run, and a 3,000-m run test.Results: Males were 24% stronger in the back squat one-repetition maximum (relative to body mass) compared to females (P < 0.001, Hg = 1.35). In the pull-ups and dips, 2.4 and 2.3 times more repetitions were completed by the males compared to the females (both P < 0.001, 0.70 ≤ R ≤ 0.77). However, females were similarly strong as males in the hanging sit-ups test (P = 0.724). The males jumped 29, 34, 33, and 17% higher in the squat jump (SJ), countermovement jump (CMJ), countermovement jump with arm swing (CMJa), and drop jump (DJ), respectively, compared to the females (all P ≤ 0.002, 0.14 ≤ 0.60). In the 20-m sprint run, males were 4% faster than females (P < 0.001, R = 0.40). Moreover, the females had significantly better flexibility than the males in the trunk forward bending, front split, and side split tests (all P < 0.001, 0.24 ≤ ≤ 0.54). In the 3,000-m run test, males were 11% faster than females (P < 0.001, ≤ 0.54). Compared to junior athletes, seniors performed better in the pull-ups, dips, SJ, CMJ, CMJa, and 20-m sprint-run tests (all P ≤ 0.012, 0.31 ≤ R ≤ 0.56, 0.16 ≤ ≤ 0.25), with separate within-sex age-group differences (i.e., juniors vs. seniors) that were significant for the males but not for the females in the SJ, CMJ, CMJa, and 20-m sprint-run tests (males: all P < 0.001, 0.67 ≤ R ≤ 0.69, 1.37 ≤ Hg ≤ 2.01; females: all P = 0.298–732).Conclusions: Large sex and age-group differences were observed for most physical performance metrics with specific within-sex age-group differences only observed for male athletes, with male seniors performing better than juniors in the SJ, CMJ, CMJa, and 20-m sprint-run tests.

Sex Influence on the Functional Recovery Pattern After a Graded Running Race: Original Analysis to Identify the Recovery Profiles.

This study investigated the sex influence on the acute and delayed fatigue effects of a 20 km graded running race. Eighteen recreational runners, 10 women and 8 men, completed the race. The testing protocol included five sessions: a week before the race (PRE), 35 ± 15 min after (POST), 2 h, 2 and 4 days (2D and 4D) later. Each session included uni- and bilateral maximal isometric voluntary contractions of the knee extensors (MVC), a squat jump (SJ), and a drop jump (DJ). Acute and delayed muscle soreness (DOMS) were evaluated for the quadriceps, hamstring and triceps surae muscle groups. The 2D and 4D sessions included also a horizontal force-velocity test (HF-V) performed under five resistive conditions. For each test, a set of key variables was computed to characterize the lower limb functional recovery. Mixed ANOVA analyses revealed significant (sex × time) interactions, with larger acute drops for men in MVCs and earlier recovery for women in the bilateral MVC (p < 0.001) and DJ (p < 0.05) tests. Only women reported DOMS for the hamstrings at 2D (p < 0.001) and showed small improvements in pure concentric SJ (p < 0.05) and HF-V (p < 0.01) tests at 4D. As expected, DOMS disappeared prior to the complete functional recovery. These results confirmed the combined influence of testing task and sex on the functional recovery pattern while supporting a lesser and faster recovery in women. The originality of this study lies in the complexity and sex-dependence of the functional recovery pattern revealed by a multiple factorial analysis which was used to identify the most discriminating tests and variables in the recovery pattern. The obtained clusters highlighted some recovery profiles associated with greater risks of injury when starting to run again. However, the lack of sex × time interaction for normalized values emphasizes the major influence of men’s initially higher functional values compared to women.

Full Body Photobiomodulation Therapy to Induce Faster Muscle Recovery in Water Polo Athletes: Preliminary Results.

Objective: To investigate the recovery of male water polo athletes applying full body photobiomodulation therapy (PBMT) regarding inflammation and muscle damage markers, testosterone and cortisol hormonal responses, heart rate variability (HRV), maximal voluntary contraction, and squat jump (SJ) after official water polo matches. Background: PBMT has been applied locally on specific muscle groups to induce faster recovery and improve the performance of athletes and nonathletes. However, many sports modalities require movement of the whole body, and a full body PBMT could be more adequate to irradiate large muscle areas homogeneously and faster. Methods: In a randomized, parallel, and double-blinded design, 13 athletes (whole team) aged 18 years attended the study and were allocated into two groups: PBMT (dose of 6.9 J/cm2, irradiance of 46.17 mW/cm2, 5 min irradiation) and placebo treatment. The study was conducted during the 2019 Brazilian under 20 water polo championship. All athletes were assessed by blood samples and neuromuscular evaluation. Immediately after each match, all athletes received PBMT (effective or placebo). Results: No significant interactions (raw values and percentage related to baseline) were observed for testosterone and cortisol, tumor necrosis factor-alpha, interleukin-6, creatine kinase concentration, maximal isometric voluntary contraction, SJ test, and HRV. Only an isolated interaction (decrease) was found for lactate dehydrogenase (LDH) response after the first match (p = 0.004, post-hoc p = 0.038). Conclusions: The parameters of the full body PBMT of this study did not induce faster recovery of inflammatory, muscle damage (excepting LDH), testosterone, cortisol, HRV, and neuromuscular responses during repeated days of water polo matches.

Does Warm-up Type Matter? A Comparison between Traditional and Functional Inertial Warm-up in Young Soccer Players

Functional inertial training, a popular high-intensity training mode, provides high neuromuscular activation, developing proprioception, postural control, power, and sprint time. Aim of the study was to assess the acute effects of two types of warm-up (WU), inertial warm-up (IWU) vs. traditional warm-up (TWU), on explosive and reactive strength, sprint, and Change of Directions (COD) in young soccer players. In a randomized cross-over design study, twelve soccer players (aged 13.3 ± 0.7) performed 16 min of IWU and 16 min of TWU. IWU and TWU were spaced two weeks apart. Pre and post intervention tests, aimed at assessing explosive and reactive strength, sprint, and COD ability included: Squat Jump test (SJ), Countermovement Jump test (CMJ), Drop Jump test (DJ), Seven Repetition Hopping test (7R-HOP), 40 m-sprint test (40 m), and Illinois Agility Test (IAT). RM-ANOVA, used to compare differences between IWU and TWU effects (the level of significance set at ρ ≤ 0.05), showed enhanced performance after the IWU compared to the TWU. In addition, the effects of the IWU on performance lasted longer after the IWU than after the TWU. For IAT, the enhanced effects of IWU on performance lasted up to ten minutes after the administration of the IWU. Our results suggest that IWU affects functional changes displaying earlier adaptation in explosive and reactive strength with longer lasting effects compared to TWU and it could be recommended in young soccer athletes as a WU procedure.

EFICACIA DE LA PLIOMETRÍA EN LA FATIGA NEUROMUSCULAR EN TRIATLÓN: ESTUDIO PILOTO

Las transiciones en triatlón afectan al rendimiento y riesgo de lesión. El objetivo fue determinar la fatiga neuromuscular inducida por 40 km de ciclismo y la eficacia del entrenamiento pliométrico en la fatiga y rendimiento de la carrera a pie. Participaron doce triatletas, 5 realizaron un entrenamiento pliométrico y 7 continuaron su entrenamiento habitual. Se realizaron tests de salto antes y después de 40 km de ciclismo para determinar la fatiga y se registró el ritmo de 5 km de carrera. Se observaron diferencias significativas en la altura de salto (p&lt;0,05) indicando que 40 km de ciclismo inducen fatiga en la extremidad inferior. Tras el entrenamiento pliométrico se observaron mejoras significativas en el test Squat Jump posterior al ciclismo (p=0,038) y en el ritmo del primer kilómetro (p=0,015). El entrenamiento pliométrico parece ser más eficaz que el entrenamiento habitual para mejorar la fatiga neuromuscular y el ritmo del primer kilómetro.

Movement competency and measures of isometric and dynamic strength and power in boys of different maturity status.

An understanding of how movement competency, strength, and power interact with natural growth and maturation is required in order to determine meaningful changes with developing athletes. Isometric and dynamic testing in youth athletes provides insight into the natural development of the force-velocity (F-V) spectrum. Two-hundred and six young male athletes, aged 9-17years of age, were grouped according to stage of maturation based on their maturity offset which was determined as number of years from peak height velocity (PHV). All participants performed the back-squat assessment (BSA), isometric mid-thigh pull (IMTP), countermovement jump (CMJ), and squat jump (SJ) tests. Absolute and scaled force-time variables were collected from the IMTP, CMJ, and SJ. No significant differences were observed between maturational groups for squat movement competency (P>.05). One-way ANOVA with Bonferroni post-hoc analysis revealed that increasing maturity led to significant, moderate to large increases in allometrically scaled peak force (PFallo ) for all tests (P<.05). Multiple stepwise linear regression models revealed IMTP PFallo significantly predicted 34.8% and 41.3% of variance in SJ and CMJ jump height, respectively (P<.05). Natural growth and maturation induces positive adaptations to movement competency as well as isometric and dynamic strength and power. Trends from the IMTP, SJ, and CMJ tests indicate the largest differences in strength, and power may occur around the adolescent growth spurt despite the large variation in rates of change within the circa-PHV group.

SMALL SIDED GAMES VS REPEATED SPRINT TRAINING EFFECTS ON AGILITY IN FASTING BASKETBALL PLAYERS

ABSTRACT Introduction The coinciding of month of Ramadan with international basketball competitions could affect players’ performance. Objective This field investigation examined the impacts of a basic training program in small-sided games and repeated sprint ability during intermittent fasting for Ramadan (R) and one month after Ramadan (AR) [control month] on body composition, agility and lower limb power. Methods Sixteen basketball players (age, 23.4±2.3 years) performed two training programs [small-sided games (SSG) and repeated sprint ability (RSA)] during R and AR, interrupted by fifteen days of total recovery. The players were randomly allocated to two groups (GSSG, n=8 and GRSA, n=8). Body composition, agility T test, squat jump (SJ) test, countermovement jump (CMJ) test and five-jump (FJT) test performances were measured on four occasions: before R (P1) and at the end of R (P2),as well as before AR (P3) and at the end of AR (P4). Results The results showed that body mass (BM), body mass index (BMI) and body fat (BF %) decreased significantly at the end of R for both groups (all p &lt; 0.001). Moreover, the performances in the agility T test, SJ test, CMJ test and FJT test improved significantly at the end of R for both groups (p&lt;0.001 and p&lt;0.01). Also, by comparing R with the control month, we recorded significantly better agility and FJT performances in the R month (p &lt; 0.001). Conclusions This study indicated that Ramadan combined with RSA and SSG training may improve agility and lower limb power, enabling coaches and physical trainers to choose between these two training modalities, depending on the training objectives. Level of evidence II; Diagnostic Studies - Investigating a diagnostic test.

A Review of Countermovement and Squat Jump Testing Methods in the Context of Public Health Examination in Adolescence: Reliability and Feasibility of Current Testing Procedures.

BackgroundIn the context of a public health physical fitness (PF) examination in adolescence, a countermovement jump (CMJ) and a squat jump (SJ) are two vertical jump (VJ) tests widely used to evaluate lower limb muscle strength and power, respectively. The main criticism of both the CMJ and SJ test is the lack of test standardization. Therefore, the objectives of this review are: (a) to gather information about both jumps; (b) to investigate whether it is possible to identify common procedures referred to in the CMJ and SJ technical execution, and (c) to design standard operating procedures (SOPs) to promote CMJ and SJ standardization in an adolescent population aged 12–18 years.MethodsThe review partially adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement (PRISMA). Due to growing attention in monitoring physical health through field tests in recent years, articles were collected using the PubMed, Web of Science, and Scopus databases from January 2009 to July 2019. Original articles in which CMJ or SJ were used to assess the muscular strength in adolescents were eligible for further analysis. Articles written in English was imposed as a limit.ResultsA total of 117 studies met the inclusion criteria. The description of the CMJ and SJ test procedures was different within the literature, with discrepancies in the jump technique, number of jumps, and measurement devices used.ConclusionsA lack of method standardization for both the CMJ and the SJ test was identified. Based on the literature, SOPs for both VJs were proposed. These are useful in the context of public health PF examination in adolescents, as they facilitate an unbiased comparison of jump performance data between published studies.