Squat Jump Research Articles

Impact of the deep squat on articular knee joint structures, friend or enemy? A scoping review

BackgroundThe squat exercise has been shown to improve athletic performance. However, the use of the deep squat has been questioned due to claims that it may cause knee joint injuries. Therefore, the purpose of this scoping review was to synthesize existing literature concerning the impact of deep squats on knee osteoarticular health in resistance-trained individuals.MethodsThis study adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Scoping Reviews (PRISMA-ScR) guidelines. The original protocol was prospectively registered in Figshare (https://doi.org/10.6084/m9.figshare.24945033.v1). A systematic and exhaustive search was conducted in different databases: PubMed, Scopus, Web of Science, and SPORTDiscus. Additional searches were performed in Google Scholar and PEDro. The main inclusion criteria were the following: (1) Articles of experimental, observational, or theoretical nature, including randomized controlled trials, longitudinal studies, case reports, integrative reviews, systematic reviews, and meta-analyses(Primary studies were required to have a minimum follow-up duration of 6 weeks, whereas secondary studies were expected to adhere to PRISMA or COCHRANE guidelines or be registered with PROSPERO; (2) Peer-reviewed articles published between 2000 and 2024; (3) Publications written in English, Spanish and Portuguese; (4) Studies reporting the effects of deep half, parallel or quarter squats on the knee or evaluating squats as a predictor of injury.ResultsThe keyword search resulted in 2,274 studies, out of which 15 met all inclusion criteria. These 15 studies comprised 5 cohort studies, 3 randomized controlled trials, 4 literature or narrative reviews, 1 case study, and 2 systematic reviews, one including a meta-analysis. Overall, the risk of bias (ROB) across these studies was generally low. It is worth noting that only one study, a case study, associated deep squats with an increased risk of injury, the remaining 14 studies showed no negative impact of deep squats on knee joint health.ConclusionThe deep squat appears to be a safe exercise for knee joint health and could be included in resistance training programs without risk, provided that proper technique is maintained.

Acute Effects of Squat and Ballistic Jump Exercises on Judo-Specific Performance, Handgrip Strength, and Perceived Exertion in Young Male Judokas

This study aimed to examine the acute effects of squat and ballistic jump exercises during warm-ups on judo-specific performance in young male judokas. Using a randomized crossover design, 10 sub-junior male judokas (age: 12.9 ± 0.7 years) completed three conditions: a controlled warm-up with only judo-specific exercises and two experimental warm-ups including either a three-repetition maximum (RM) back squat (with ~90% 1RM load) or ballistic jumps (squat jumps, scissor jumps, and double-leg bounds) in addition to judo-specific warm-ups. Following each warm-up condition, participants performed the Special Judo Fitness Test (SJFT), with heart rate measured immediately and one minute post-test. Handgrip strength and ratings of perceived exertion (RPE) were recorded after the SJFT. Both squat and ballistic jump exercises significantly improved judo-specific performance compared to the control condition, with large effect sizes (ESs). The number of throws in set 2 (p = 0.001, ηp2 = 0.65, large ES), total throws (p < 0.001, ηp2 = 0.70, large ES), and the SJFT index (p < 0.001, ηp2= 0.65, large ES) all showed significant improvements. Regarding the throw in set 2, significant improvements were observed after both squat (p = 0.003, Hedge’s g = 1.78, large ES) and ballistic jump exercises (p = 0.010, Hedge’s g = 1.44, large ES) compared to the control condition. Similarly, total throws were significantly higher in the squat (p = 0.003, Hedge’s g = 1.51, large ES) and ballistic jump (p < 0.001, Hedge’s g = 1.37, large ES) conditions compared to the control condition. Furthermore, the SJFT index showed notable improvements following squat (p = 0.010, Hedge’s g = 0.80, moderate ES) and ballistic jump (p < 0.001, Hedge’s g = 0.90, moderate ES) conditions compared to control conditions. However, squat exercises led to a significant reduction in right-hand grip strength (p < 0.001, ηp2 = 0.58, large ES) [p = 0.008, Hedge’s g = 0.19, trivial ES for squat vs. control; p = 0.014, Hedge’s g = 0.23, small ES for squat vs. ballistic jump], with no differences observed in left-hand grip strength or RPE scores (p > 0.05). In conclusion, the integration of squat and ballistic jump exercises into warm-up protocols has been shown to significantly improve judo-specific performance in young male judokas without eliciting an increase in RPE values. However, careful consideration should be given when incorporating squat exercises, as they may lead to localized handgrip fatigue (reduced grip strength due to muscle exhaustion), which could affect performance in grip-dependent techniques.

Tropical Primary Pyomyositis of The Right Calf Muscle: A Rare and Unexpected Complication of Jump Squat Exercise

Diagnosing pyomyositis in its initial or invasive stages can pose a challenge due to its vague initial symptoms, which may mimic other conditions such as muscle strain, localized myositis, hematoma, deep vein thrombosis, cellulitis, or thrombophlebitis. A high index of suspicion for possible pyomyositis necessitates confirmation through radiographic imaging. A delayed diagnosis directly correlates with the time taken to commence treatment, thereby increasing the risk of patient morbidity and mortality. We present a case of a diabetic male who experienced bilateral calf muscle pain and right calf swelling after participating in jumping squat exercises, eventually developing right calf myositis and abscesses over a two-week period, which were initially overlooked by several general practitioners. This case underscores the crucial role of radiographic imaging in confirming the diagnosis, whether in the Emergency Department or any primary care setting. Prompt diagnosis and intervention, as demonstrated here, are imperative for minimizing the risks associated with this potentially severe disease. Knowledge of this condition and its diagnostic methods is highly advantageous for emergency physicians, primary care providers, and family physicians.

A comparative study of university training of sports and physical activity kinesiologist

BackgroundIn Italy, Legislative Decree No. 36/2021 and Ministerial Decree (MD) No. 1649/2023 have redefined the professional landscape of the physical activity and health sectors, emphasizing interdisciplinary and wellness-oriented education. The current disparity in the weighting of formative elements among the biomedical, psycho-pedagogical, and Exercise and Sport Sciences (ESS) fields in the configuration of degree courses in ESS has led to a need for reform. MD No. 1649/2023 offers an opportunity to reform these courses to emphasize interdisciplinary and wellness-oriented objectives, including at least 20 ECTS credits of practical activities in ESS disciplines. However, the impact of practical and laboratory activities on future kinesiologists has never been studied. This study aims to evaluate the impact of physical activity habits on the performance and self-assessment of ESS students.MethodA sample of 56 students enrolled in the Master of Science in Sport Science and Techniques at the University of Salerno was divided into “active” and “inactive” groups based on their physical activity levels, according to WHO guidelines. Both groups underwent anthropometric and functional tests, including the Squat Jump (SJ) and Countermovement Jump (CMJ). Descriptive statistics and t-tests assessed the differences between and within groups.ResultsThe “active” group exhibited significantly higher performance in SJ (15.7% higher) and CMJ (18.5% higher) compared to the “inactive” group. Both groups showed significant improvements in jump height from SJ to CMJ, with the “active” group improving by 11.04% and the ‘non-active’ group by 7.38%.ConclusionContinuous physical activity enhances functional efficiency, with significant gains in explosive and reactive strength. Practical, evidence-based training is crucial for future kinesiologists to provide specialized services and promote health, underscoring the importance of integrating substantial practical activities in ESS degree courses.

Force-velocity-power variables derived from isometric and dynamic testing: metrics reliability and the relationship with jump performance.

We investigated the convergent validity and intrasession reliability of force, velocity, and power (FVP) variables and the dynamic strength index (DSI) obtained from isometric midthigh pull (IMTP) and squat jump (SJ) testing. Fifteen male combat sports athletes (27 ± 5 years, 77 ± 9 kg, 1.76 ± 0.1 m, 14 ± 6% body fat) participated in a 2-days study. The first day involved testing familiarization, while the second was dedicated to IMTP and SJ testing. Maximal isometric force (Fiso ) was obtained from IMTP, while mean force, mean velocity, jump height, and jump impulse (J) were gathered from SJ. To analyze the FVP, we calculated the linear relationship between force and velocity, which allowed us to obtain the slope of the relationship (SFV ), the theoretical velocity at zero force (V0 ), and the theoretical maximal power (Pmax ). DSI was obtained as a ratio from SJ peak force and Fiso . The convergent validity was investigated using Spearman's ρ coefficients to assess the relationships between jump height and J with Fiso , V0 , SFV , Pmax , and DSI. The intrasession reliability was assessed using intraclass correlation coefficients (ICC) and coefficient of variations (CV). All variables demonstrated acceptable reliability scores. ICC ranged from moderate to excellent, and the mean CV was <10%. We found a "very large" correlation between jump J and Pmax , while jump height was not correlated with any variable. In conclusion, the IMTP and SJ combination is a practical way to determine FVP producing capacities that can be reliably measured (intrasession). The Pmax , derived from FVP, was correlated with jump performance, which might evidence the convergent validity of the method.

The Effect of High Interval Intensity Training (HIIT) on the Performance of Basketball Players 10-15 Years Old

Basketball is a game of seconds. A characteristic of this sport is the high intensity, the pressure of one or more different opponents, and very short recovery times. From a physiological-biomechanical point of view, basketball is classified among the sports activities with alternating aerobic-anaerobic energy commitment, with district demands of medium to high strength and endurance. Based on the High Interval Intensity Training Program (HIIT), in 8 weeks in a group of children aged 10-15, taking into account the efficiency of time, we look up to help the athletic youth progress, offering the improvement of other important skills, such as coordination skills, speed, and performance. This study aims to identify the biomechanical variables that directly affect their progress. In this study participated 15 subjects (age: 12.53 ± 2.09; height: 1.59 ± 0.10; body mass: 49.82 ± 16.78; BMI: 19.21 ± 3.98), basketball players of the basketball team "Sonia Basket." To achieve this aim, the CMJ (countermovement jump) and SJ (squat jump) vertical jump tests were performed on the force platform. The evaluation of the data was made using statistical analysis processing methods. The independent t-test results revealed a statistical improvement of 3 cm in the maximum height in the CMJ test and 90N in the maximum force in the SJ test due to the method called "HIIT." The results of this study of the HIIT method show a positive physical and physiological development of the players in such a way as to offer them the opportunity to express the highest level of performance in the game of basketball. If this training method is used for an even longer time, the results will be many times higher and will affect even more the improvements of all biomechanical parameters.

Investigation of muscle activation during kinetic chain based exercises in individuals with and without forward head posture.

The Band Pull-Apart (BPA) exercise is used to strengthen the periscapular muscles. It was recently stated that the lower extremity and trunk movements should be included in the shoulder rehabilitation programs to optimize an effective energy transfer throughout the kinetic chain. The aim of this study is to investigate the effects of kinetic chain based BPA exercise on the muscle activations of the sternocleidomasteideous (SCM) and the trapezius muscles in individuals with and without forward head posture (FHP). Eighteen individuals with FHP and 18 individuals without FHP were included. Photographic measurements were made to identify individuals with FHP. The muscle activations of SCM, Upper Trapezius (UT), Middle Trapezius (MT), and Lower Trapezius (LT) were measured with surface EMG. BPA exercise was performed in the standing, unipedal standing, squat, unipedal squat, and Bulgarian split squat (BSS). There was no Group × Exercise interaction for the SCM, UT, MT, LT muscle activations, or for the UT/MT and UT/LT ratios (p> 0.05). While there was a difference in the activation of all muscles between individuals with and without FHP (p< 0.05), both ratios were similar (p> 0.05). There was a statistically significant difference between exercises for SCM, MT, and LT muscle activations (p< 0.000 for these muscles), UT/MT (p< 0.000) and UT/LT ratios (p= 0.004). SCM muscle activation in squat was lower than activation in standing (Mean Difference (MD) = 2.5% Maximal Voluntary Isometric Contractions (MVIC); p= 0.004) and in unipedal standing (MD = 2.1% MVIC; p= 0.002). MT muscle activation in squat was higher than activation in standing (MD = 9.7% MVIC), unipedal standing (MD = 7.8% MVIC), unipedal squat (MD = 6.9% MVIC) and BSS (MD = 9.4% MVIC; p< 0.000 for these positions). LT muscle activation in the squat was higher than activation in the standing (MD = 8.5% MVIC) and unipedal squat (MD = 8.1% MVIC; p< 0.004 for these positions). UT/MT ratio in the squat was lower than standing (MD = 0.3), unipedal standing (MD = 0.2) and BSS (MD = 0.3; p< 0.000 for these positions). UT/LT ratio in squat was lower than unipedal squat (MD = 0.5) and BSS (MD = 0.6; p= 0.002; for these positions). Performing the BPA exercise in the squat position is suggested in cases where lower SCM and UT muscle activation, lower UT/MT, and UT/LT ratios and higher MT and LT muscle activations are needed for individuals with and without FHP.

Age- and Gender-Specific Reference Values for Physical Performance in Tunisian Youth Basketball Players.

Physical performance is becoming increasingly critical in basketball, as it directly influences players' agility, power, and endurance. This study aimed to assess the progression of body composition and physical performance metrics across different ages and genders, establishing age- and gender-specific reference values for Tunisian basketball athletes. A total of 469 Tunisian basketball players (239 boys and 230 girls) were assessed and grouped by age. Anthropometric measures-including standing and sitting height, body mass, leg length, body mass index, fat mass, fat-free mass, body fat percentage, wingspan, and leg muscle volume-were collected alongside physical performance metrics. Performance tests included countermovement and squat jumps, change-of-direction speed, maximal oxygen uptake, flexibility, the five-jump test, and 5 m, 10 m, and 20 m sprints with and without the ball. Normative data were generated based on age and gender categories. The findings revealed significant age-related improvements in both anthropometric and performance parameters. Boys consistently outperformed girls in physical and fitness-related measures, with gender differences becoming more pronounced with age. Stepwise regression analyses indicated that, for boys, body fat percentage, leg muscle volume, standing height, and wingspan were the best predictors of physical performance. For girls, body fat percentage, standing height, and sitting height were identified as key predictors. The newly established Tunisian reference values for physical performance in youth basketball provide valuable benchmarks that can support the development of explosive power and strength in players, aiding in talent identification and potentially enhancing individual and team performance outcomes.

Altered inter-segmental coordination in athletes with a history of concussion

ABSTRACT Concussion-recovered athletes have a higher risk of injury following return to sport. This study investigated the effect of history of concussion on the pattern and variability of inter-segmental coordination in athletes during squat jumps and timed squat and hinge tasks. A human pose estimation algorithm was applied to videos of 111 athletes (72 with no history of concussion (NOHX), 9 within 1 year of concussion (CONC1), 30 more than one-year post-concussion (CONC2) performing a series of movement tasks. Continuous relative phase metrics, calculated from phase angles of two contiguous segments, were used to evaluate inter-segmental coordination. Linear models were used to evaluate the causal effect of concussion group on hip, knee, and ankle coordination and repetition duration for each task. CONC1 affected repetition duration and knee and hip coordination and variability, while CONC2 influenced knee coordination. The findings suggest that concussion may have long-term persisting effects on lower-limb inter-segmental coordination in athletes.

Predict the musculoskeletal injuries in young skaters using Functional Movement Screen (FMSTM)

Background. Skating is a great way to improve heart rate, coordination, and strengthen the muscles, and burn calories. It works on the muscles of the legs, gluteus, and core and causes 50% less stress to the joints than running, along with improving flexibility and endurance. The FMS™ is a clinical screening tool used to assess seven fundamental movement patterns. It consists of overhead deep squats, hurdle steps, inline lunges, straight leg raises, trunk stability pushups, shoulder mobility, and rotary stability. Injuries are more common in sports, especially skating, where balance and coordination are required. A study like this is necessary to screen skaters, help predict injuries, and train them accordingly to prevent injuries. Objective. The objective is to predict musculoskeletal injuries in young skaters using the Functional Movement Screen (FMS™). Methodology. This is an observational cross-sectional study. Sixty-four skaters of both genders, aged between 6 and 18 years, were conveniently selected based on the inclusion and exclusion criteria and were assessed using FMS™. Outcome measures. Functional Movement Screening scores. Results. 31.3% of young skaters scored between 0 and 13 and are at high risk for musculoskeletal injuries, while 68.8% are at a low risk of injury with FMS™ scores ranging from 14 to 21. Conclusion. This study concluded that 31.3% of young skaters have a high risk for musculoskeletal injuries according to the Functional Movement Screen.

The relationship of foot anthropometry with countermovement jump and squat jump performance among male university-level athletes

This study assessed the relationship between foot anthropometry with countermovement jump (CMJ) and squat jump (SJ) performance among university-level male athletes. A total of 51 male athletes were selected from different sports. Various gross and acute anthropometric measurements were conducted. Each participant performed three CMJs and SJs each. Standing height has a moderate positive correlation with CMJ force (ρ = .368, p = .008) and power (ρ = .326, p = .019). Body mass demonstrated a high positive association with CMJ force (ρ = .568, p = .001) and a moderate positive correlation with power (ρ = .446, p = .001). The lower leg length was moderately positively correlated with CMJ flight time (ρ = .316, p = .024) (ρ = .311, p = .026), velocity (ρ = .304, p = .030), and power and showed a weak positive correlation with CMJ height (ρ = .290), p = .039). Foot length had a moderate positive correlation with CMJ force (ρ = .419, p = .002) and power (ρ = .377, p = .002). Conversely, a weak negative correlation was observed between foot arch height and both CMJ height (ρ = -.286, p = .042) and CMJ velocity (ρ = -.285, p = .043). These findings suggest the significant relationships between specific anthropometric characteristics with CMJ and SJ performance. However, the correlations showed moderate or lower strengths, underscoring the importance of further investigation.

Analysis of the relationship between upper body speed capacity and lower body strength of elite handball players specialized in winger position

Background and Study Aim. The physical demands of the winger position in elite handball require a unique combination of upper body speed and lower body strength. Therefore, identifying the optimal relationship between these two physical characteristics could improve performance for players in this role. This study aims to analyze the relationship between upper body speed capacity and lower body strength in elite handball players specializing in the winger position. Material and Methods. The study included 16 elite handball players specializing in the winger position from various teams in the National Handball League (Liga Zimbrilor). Four of these players were members of the Dinamo Bucharest team. Tests for evaluating the explosive strength of the lower limbs included the Squat Jump (SJ), Counter Movement Jump (CMJ), Counter Movement Jump with Free Arms (CMJb), and the maximum strength test (1RM) in squats. Specific technical training tests included triangular movement, a 30-meter sprint, and long-distance handball throws, focusing on speed and execution technique. Data analysis was conducted using KyPlot 6.0 software. Statistical indicators included median, standard deviation, coefficient of variation, and non-parametric Spearman correlation tests. Statistical significance was set at p &lt; 0.05. Results. The results show no statistically significant differences in lower limb strength between high-performance handball players (HPHP) and those specialized in the winger position (PSW) across various jump and squat tests (p &gt; 0.05). The Countermovement Jump (CMJ) test approached statistical significance (p = 0.084), while the CMJ with free arms (CMJb) and squat strength test did not show significant differences (p = 0.231 and p = 0.789, respectively). In the specific fitness tests, no significant differences were observed in the Triangle Movement test (p = 0.826), the 30-meter sprint (p = 0.404), or the handball throw test (p = 0.147). Correlation analysis indicated that squats and CMJb had positive correlations with improved performance in speed and distance tests, while CMJ showed a negative correlation with technical performance in agility tests. Conclusions. The findings suggest that lower limb strength and technical fitness are similar between elite handball players, regardless of specialization. This supports a unified training approach across player roles. However, targeted exercises like squats and CMJb may enhance specific performance aspects. These exercises improve dynamic strength and stability, which can benefit wingers' technical execution and speed.

Impact of three weeks of integrative neuromuscular training on the athletic performance of elite female boxers.

To investigate the effects of integrative neuromuscular training (INT) on the athletic performance of elite female boxers. A before-and-after controlled experiment was conducted on 37 elite Chinese female boxers (Age: 26.00±3.11 years). All included athletes have competed at the international level. The INT intervention was administered 11 times per week for 3 weeks. This training includes strength training, explosive training, core stability, agility exercises, high intensity intervals and sprint intervals. Basic physical fitness tests, including the deep squat and bench press one-repetition maximum (1RM), vertical long jump, 30 m sprint run, 400 m run, 3,000 m run, 1-minute hexagonal jump, and 3-minute double shake; as well as specialized striking ability tests, including single-punch striking and 10-second, 30-second, and 3-minute continuous punching, were conducted before and after the intervention. Compared with pre-intervention baseline data, significant differences were found in the athletes' post-intervention baseline physical fitness, including squat and beach press (1RM), vertical jump, 30 m sprint run, 400 m run, 3,000 m run, 1-minute hexagonal jump, and 3-minute double shake (p<0.05). Additionally, 10-second, 30-second, and 3-minute continuous punching were significantly different compared with pre-intervention (p<0.05). However, no significant differences were found in single punch power (p>0.05). The 3-week INT can significantly improve the maximum strength, vertical explosive power, linear acceleration, agility, and continuous punching abilities of Chinese elite female boxers. The use of INT in physical training may enhance their athletic performance.

Reliability and validity of My Jump 2® app to measure the vertical jump in visually impaired five-a-side soccer athletes.

Although My Jump 2 ® consistently presented excellent values of reliability and validity when compared to force platforms (FPs) and contact mats, to date no scientific investigation assessed the validity and reliability of My Jump 2 ® to measure jump height in visually impaired five-a-side soccer athletes. Thus, the study aimed at analyzing the validity and reliability of the My Jump 2® to measure the vertical jump of five-a-side soccer athletes. Twelve visually impaired five-a-side soccer athletes, volunteered for this study. Each player performed five countermovement jumps (CMJs) and squat jumps (SJs) on a contact platform (CP) while they were simultaneously recorded using My Jump 2 ®. There was almost perfect agreement between the My Jump 2® and the contact platform measurements of CMJ (intraclass correlation coefficient = 0.99; p < 0.001) and SJ (intraclass correlation coefficient = 0.99; p < 0.001), heights for athletes during the first and second measurement days. Bland-Altman analysis showed a bias of 0.25 ± 0.5 cm; maximum SD = 1.3; minimum SD = -0.88 for CMJ, while that Bland-Altman analysis showed bias 0.18 ± 0.5 cm; maximum SD = 1.3; minimum SD = -0.96, for SJ. We can conclude that the My Jump 2® is a valid and reliable method to measure CMJ and SJ in visually impaired five-a-side soccer athletes.

Effects of a Short-Term Detraining Period on the Physical Fitness in Elite Youth Soccer Players: A Comparison Between Chronological Age Groups.

Padrón-Cabo, A, Lorenzo-Martínez, M, De Dios-Álvarez, V, Rey, E, and Solleiro-Durán, D. Effects of a short-term detraining period on the physical fitness in elite youth soccer players: a comparison between chronological age groups. J Strength Cond Res XX(X): 000-000, 2024-The aim of this study was to examine the effects of a 2-week in-season training cessation on neuromuscular and endurance performance in 2 different age groups of elite youth soccer players. A total of 30 players belonging to the under-15 (U15, n = 17) and under-17 (U17, n = 13) age groups of a Spanish professional soccer academy participated in the study. The following tests were assessed before and after the training cessation period: squat jump (SJ), countermovement jump (CMJ), 20-m sprint with 5-m and 10-m split times, modified 505 change of direction, and 30-15 Intermittent Fitness Test (30-15 IFT). The results showed significant and similar performance impairments between the 2 age groups in SJ (p = 0.020), CMJ (p = 0.044), 20-m sprint (p < 0.001), and 30-15 IFT (p < 0.001). The U17 players evidenced greater impairment than the U15 players in 5-m (p = 0.006) and 10-m (p = 0.002) sprint performance. However, there was no significant change (p = 0.070) in the players' change of direction performance. These findings provide valuable information for strength and conditioning coaches, suggesting the need for targeted interventions to mitigate the effects of detraining on neuromuscular and endurance performance during short-term in-season training cessation periods in elite youth soccer players. Special attention should be paid to maintaining sprint performance during short-term detraining periods in U17 players.

The Effects of Combined Versus Single-Mode Resistance and Repeated Sprint Training on Physical Fitness, Hematological Parameters, and Plasma Volume Variations in Highly Trained Soccer Players.

We examined the effects of eight weeks of single-mode resistance, repeated sprint training, and the combination of the two programs on selected measures of physical fitness (muscle power, speed, and body composition), hematological parameters, and plasma volume variations in highly trained soccer players. Sixty male soccer players from the Tunisian national Ligue were randomly allocated to a resistance training group (RTG), a repeated sprint training group (RSTG), a combined resistance and repeated sprint training group (CTG), or an active control group (CG, soccer training only). The training volumes were similar between groups. Before and after training, we examined body composition, squat jump (SJ), countermovement jump (CMJ), sprint 30 m (S30), repeated-sprint sequences (RSSs), hematocrit, hemoglobin, mean hemoglobin concentration (MHC), and plasma volume. Significant group-by-time interactions were recorded for the RSS indices, SJ, and S30 (p < 0.039], 0.1< ηp2 < 0.49]), as well as the hematological parameters (p = 0.0001-0.045, 0.11 < ηp2 < 0.46). In terms of physical fitness, using post hoc tests, the CTG showed significantly greater gains compared to the RSTG, RTG, and the CG on the best time index of the RSSs (p = 0.008; d = 4.1), SJ (p = 0.004; d = 4.18) and 30 m linear sprint time (p = 0.008; d = 3.84). Body fat percentage also decreased significantly in the CTG compared to all other groups (p < 0.005, 0.21 < d< 0.35). Regarding hematological parameters (i.e., hemoglobin and hematocrit), the CTG, RSTG, and RTG showed significant decreases (p < 0.05) in their hemoglobin and hematocrit values compared to the CG (p < 0.05, 0.11 < d< 2.22]). Eight weeks of combined training compared to single-mode training was found to be more effective in improving fitness measures in highly trained soccer players. However, there appeared to be no consensus regarding the effect of single and combined repeated-sprint and resistance training on the hematological system.

Effects of hyperbaric oxygen therapy on recovery after a football match in young players: a double-blind randomized controlled trial.

Football is a physically demanding sport that requires effective recovery strategies to maintain performance level and prevent injuries. This study investigated if a single 1-h hyperbaric oxygen therapy (HBOT) session affects recovery and performance after a football match in elite youth players. Twenty elite youth football players (age 17.3 ± 0.5 years) were randomly assigned to a HBOT group or a control group (CON). They played a 90-min football game and underwent either a 60-min HBOT or placebo intervention. Before (T1), at the end of the match (T2), 1 h after HBOT or CON session (T3), and 12 h after HBOT session (T4), subjects underwent biochemical (serum samples (myoglobin (MB), creatine kinase (CK), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and aspartate aminotransferase (AST)) and performance measurements (linear speed at 5 m, 10 m and 20 m, squat jump (SJ), countermovement jump (CMJ) and countermovement jump with arm swing (CMJa)). The Hooper Index (HI) was collected and heart rate was measured during the game. The football match induced significant increases in all biochemical markers, but no significant differences were found between the HBOT and control group in biochemical or performance parameters at any time point. However, there was a significant interaction effect between time and group for HI (p = 0.012, η2 = 0.124), with the HBOT group showing significantly lower HI values (8.6 ± 2.41) than the control group (11.0 ± 3.23) at 1 h post-HBOT. A single 1-h session of HBOT did not significantly affect recovery or performance parameters in elite youth football players, though it did show a moderate positive affect on the HI at 1 h post-HBOT. Further studies should explore the impact of either longer or sequential HBOT sessions on recovery.

TMG Symmetry and Kinematic Analysis of the Impact of Different Plyometric Programs on Female Athletes’ Lower-Body Muscles

Asymmetries in sports are common and can lead to various issues; however, different training programs can facilitate change. This study aimed to assess the effects of opposing plyometric programs on tensiomyography lateral symmetry (TMG LS)/inter-limb asymmetry in female athletes’ lower-body muscles, alongside kinematic and body composition parameters. Twenty female subjects from basketball, volleyball, and track and field (sprinting disciplines) were divided into two experimental groups (n = 10 each). Two six-week plyometric programs (two sessions/week) were implemented: the first program (E1) focused on eccentric exercises, depth landings, while the second (E2) emphasized concentric exercises, squat jumps. TMG assessed LS in six muscles: vastus lateralis, vastus medialis, biceps femoris, semitendinosus, gastrocnemius lateralis, and gastrocnemius medialis. A kinematic analysis of the countermovement jump (CMJ) and body composition was conducted using “Kinovea; Version 0.9.4” software and InBody 770, respectively. The results showed significant increases in LS percentages (E1—VL 9.9%, BF 18.0%, GM 10.6% and E2—BF 22.5%, p &lt; 0.05), and a significant large effect in E1 for VL, and in E2 for BF, p &lt; 0.01). They also showed that E1 had a significant effect on VL, and that E2 had a significant large effect on BF (p &lt; 0.01). E1 also led to increased lean muscle mass in both legs (left: 1.88%, right: 2.74%) and decreased BMIs (−0.4, p &lt; 0.05). Both programs improved LS, with E1 enhancing muscle mass and lower-body positioning in CMJ. We recommend future studies use varied jump tests, incorporate 3D kinematic analysis, include male subjects, and examine more muscles to enhance TMG LS analysis.

Exploring Whole-Body Vibration Transmission Through the Human Body in Different Postures on a Large Vibration Platform

The positive effects of whole-body vibration exercise in rehabilitation, sport, fitness and preventive medicine have led to a proliferation of vibrating platforms. However, discrepancies have been claimed between the manufacturers’ vibration parameters and the vibration applied by the platforms. In addition, the dimensions, materials and motors used in their manufacture mean that each platform behaves differently. These factors can influence their transmission to the human body and, consequently, their effects. Thus, measured vibration parameters were recommended to report the vibration parameters as accurately as possible. Therefore, the present study aimed to determine the feasibility of a large vibration platform. Measurements of vibration parameters and their transmission were added. These parameters were measured using six accelerometers (platform, ankle, knee, hip, third lumbar vertebra, and head) throughout five postures (toe-standing, erect, high squat, deep squat, and lunge) and three vibration frequencies (20 Hz, 25 Hz, and 30 Hz). On the platform, peak accelerations of 1 ± 0.2 g, displacements of 1 ± 0.1 mm at 20 Hz and 25 Hz and 0.6 mm at 30 Hz, and a frequency from the setting of +0.5 Hz were obtained. In the human body, peak accelerations can exceed 2 g, and these transmissibility amplifications were found at the ankles and knees. However, at the hip, accelerations plummet and transmissibility attenuation occurs all the way to the head. The signal purity was highly satisfactory, although at the hip and third lumbar vertebra when adopting the toe-standing and lunge, some less satisfactory results were found—especially at 20 Hz and 30 Hz. Present data indicate that the long vibration platform can be used for exercise and health in a safe way, although its specific behaviours have to be taken into account in order to optimise its applicability.

Is the Rate of Force Development Produced in the Squat Jump a Reliable Metric and is it Related to Jump Height?

ABSTRACT This study aimed to analyze the intrasession reliability of the rate of force development (RFD) in different time windows in squat jumps (SJ) performed at different knee starting angles, and identify the relationship of RFD with vertical jump height (VJH). Twenty male volleyball and basketball players participated. Athletes randomly performed SJ from four different knee-flexion angles. The RFD was analyzed from six different windows, from force onset to instant peak force, in each position using the ground reaction forces. Reliability analysis was performed based on the intraclass correlation coefficient (ICC) and coefficient of variation (CV%); Spearman’s rho was used to test the relationship between RFD and VJH. The results demonstrated that RFD0-PF was the only variable assumed to be reliable, demonstrating an ICC > 0.84 and CV < 8.5% in all positions, and significant correlations between RFD metrics and VJH were observed at SJ70 and SJPREF. Some variables were underpowered due to the small sample size, as a limitation of the study.