Effectiveness of small-sided games vs high-intensity interval training on physical fitness in female soccer players: a systematic review and meta-analysis.

BackgroundThe aim of this study was to compare the effects of small-sided games (SSGs) and running-based high-intensity interval training (HIIT) on the body composition and physical fitness of youth female soccer players.MethodsThis study followed a randomized parallel study design. Twenty-four female soccer players (age: 18.63 ± 2.36 years) were randomly allocated to two training groups (SSG, n = 12; and HIIT, n = 12). The training intervention had a duration of eight weeks, consisting of three training sessions per week. Players were assessed twice (pre- and post-intervention) for anthropometrics, vertical (countermovement jumps, CMJ; and drop jumps, DJ) and horizontal jumping (single, triple and crossover hop), sprinting (10- and 30-m), change-of-direction (COD), COD deficit and final velocity at 30–15 Intermittent Fitness Test (VIFT). A covariance analysis (ANCOVA) was used to determine differences between the groups in the effect on post-intervention by controlling for covariates (pre-intervention). The within-group analysis (time) was performed using a paired t-test, while the between-group analysis per assessment moment was performed using an independent t-test.ResultsThe between-group analysis with ANCOVA revealed that there are no significant differences between the SSG and HIIT groups in the post-intervention for any outcome (p > 0.05). The within-group analysis revealed significant improvements in both the SSG and HIIT groups in CMJ (p < 0.05), single, triple and crossover hops (p < 0.05), RSI DJ 30-cm and RSI DJ 40-cm (p < 0.05), VIFT (p < 0.05) and COD (p < 0.05).ConclusionsSSG and HIIT are both effective for improving vertical and horizontal jumping ability, change-of-direction, and aerobic capacity status measured at a progressive and intermittent multistage test in youth soccer players.

Most of the research combining small-sided games (SSGs) with high-intensity interval training (HIIT) is using the short or long forms of HIIT. However, other types of HIIT as repeated sprint training (RST) could enhance different stimuli. The purpose of the current research was to analyze the within- and between-group variations of physical fitness and body composition of two combined training interventions: (i) SSGs combined with a short high intensity interval training (sHIIT); and (ii) SSGs combined with a RST. This study followed a randomized parallel study design. Twenty-eight youth soccer players (age: 17.3 ± 0.5) belong to the same team were assigned equally to two intervention groups: SSG + sHIIT versus SSG + RST. Training intervention lasted 4 weeks, with a 2-session/week frequency. The players were tested twice, once before and after the intervention with the following tests: skinfolds (fat mass); Sargent jump test (SJT); standing long jump; sprinting time at 10-, 20-, or 30-m; 5-0-5 for time and deficit; 30-15 intermittent fitness test (30-15IFT) based on the final velocity, and repeated sprint ability (RAST) for peak, minimum, average power, and fatigue index. A mixed analysis of variance was conducted to considering factor × time effect. Between-group analysis revealed no significant differences at baseline and post-intervention period for fat mass, sprinting time at 10-, 20-, and 30-m, change-of-direction (COD) time and deficit, SJT and standing long jump, final velocity at 30-15IFT and RAST peak, average power, and fatigue index ( p &gt; 0.05). Within-group analysis revealed that both groups significantly reduced fat mass ( p ≤ 0.001), SJT ( p ≤ 0.001), standing long jump ( p ≤ 0.001), sprint time at 10- and 20-m ( p ≤ 0.001), 30-m ( p = 0.002), COD time ( p ≤ 0.001) and deficit ( p &lt; 0.05), RAST average ( p &lt; 0.05), and final velocity 30-15IFT ( p ≤ 0.001). Only SSG + RST had significant improvements on COD deficit and peak power ( p &lt; 0.05). The result of the current research suggests that either SSG + sHIIT or SSG + RST are effective for improving physical fitness in youth soccer players, with a multiple beneficial effect on locomotor profile, speed and COD, jumping performance and repeated sprint ability.

Objective: To critically assess the literature focused on sex-specific trajectories in physical characteristics associated with anterior cruciate ligament (ACL) injury risk by age and maturational stage.Data Sources: PubMed, CINHAL, Scopus, and SPORTDiscus databases were searched through December 2021.Study Selection: Longitudinal and cross-sectional studies of healthy 8- to 18-year-olds, stratified by sex and age or maturation on 1 measure of body composition, lower extremity strength, ACL size, joint laxity, knee-joint geometry, lower extremity alignment, balance, or lower extremity biomechanics were included.Data Extraction: Extracted data included study design, participant characteristics, maturational metrics, and outcome measures. We used random-effects meta-analyses to examine sex differences in trajectory over time. For each variable, standardized differences in means between sexes were calculated.Data Synthesis: The search yielded 216 primary and 22 secondary articles. Less fat-free mass, leg strength, and power and greater general joint laxity were evident in girls by 8 to 10 years of age and Tanner stage I. Sex differences in body composition, strength, power, general joint laxity, and balance were more evident by 11 to 13 years of age and when transitioning from the prepubertal to pubertal stages. Sex differences in ACL size (smaller in girls), anterior knee laxity and tibiofemoral angle (greater in girls), and higher-risk biomechanics (in girls) were observed at later ages and when transitioning from the pubertal to postpubertal stages. Inconsistent study designs and data reporting limited the number of included studies.Conclusions: Critical gaps remain in our knowledge and highlight the need to improve our understanding of the relative timing and tempo of ACL risk factor development.Context: The risk of anterior cruciate ligament (ACL) injury in female athletes increases throughout the stages of maturation. Previous evidence has indicated a lack of dynamic knee control during double-limb jump landings throughout maturation, yet the extent of biomechanical changes that occur throughout maturation during single-limb landings are not well understood. A maturational analysis of high-risk biomechanics during single-limb landings may elucidate and inform injury risk reduction efforts.Objective: To determine differences in single-limb landing biomechanics between pre-pubertal, pubertal, and post-pubertal female soccer players.Design: Cross-sectional (pre-testing component of a randomized controlled trial)Setting: Research biomechanics laboratoryPatients or Other Participants: 151 competitive female soccer playersIntervention(s): Participants were categorized based on percent of adult stature into pre-pubertal (PRE: &lt;84% of adult stature, n=23), pubertal (PUB: 87%-94% of adult stature, n=36), and post-pubertal (POST: &gt;94% of adult stature, n=92) maturational groups.Main Outcome Measure(s): All participants were instrumented for standard three-dimensional motion analysis and completed three trials of an ipsilateral single-limb hop and land over a 4-inch hurdle. Variables of interest included peak landing kinematics (hip flexion, hip adduction, hip internal rotation, knee flexion, knee abduction, ankle dorsiflexion) and peak landing external moments and ground reaction forces normalized to body mass (hip flexion, knee flexion, knee abduction, vertical ground reaction force). Multivariate analysis of variance (MANOVA) was used to compare the biomechanical variables of the dominant limb (preferred kicking limb) between maturational groups (α=0.05). Pearson's correlational analyses identified the relationship between the estimated percent of adult stature and lower extremity biomechanical variables.Results: There were significant differences in lower extremity kinematics (λ=0.79, p&lt;0.001) and kinetics (λ=0.78, p&lt;0.001) between maturational groups. POST landed in less hip internal rotation (POST: -0.3±5.4°) than PRE (3.8±7.0°, d= 0.67, p=0.008) and PUB (3.4±6.0°, d= 0.65, p=0.004), and greater knee abduction (POST: 5.1±4.8°) than PUB (2.4±3.4°, d= 0.66, p=0.009). POST also landed with vertical ground reaction forces 14% lower (POST: 3.20±0.76 xBW) than PRE (3.69±0.78 xBW, d= 0.62, p=0.01) and 13% lower than PUB (3.65±0.47 xBW, d= 0.73, p=0.005). Weak relationships were identified between the estimated percent of adult stature and peak hip internal rotation angle (r=-0.26) and vertical ground reaction force (r=-0.31).Conclusions: Post-pubertal female soccer players performed single-limb landings with lesser hip internal rotation, greater knee abduction, and lower vertical ground reaction forces. These findings are inconsistent with previous evidence that indicates higher risk movement strategies in post-pubertal athletes. The single-limb landing over a standardized hurdle height may not provide a comprehensive biomechanical picture for which to assign injury risk profiles.Context: Researchers have identified modifiable biomechanical anterior cruciate ligament (ACL) injury risk factors in laboratory settings with change of direction tasks. To preserve athlete-environment relationship, it has been advocated to assess movement strategies on the field rather than only in the laboratory. However, the kinematic differences between laboratory and on-field settings have never been investigated.Objective: To investigate the knee kinematics of female soccer players during agility movements performed both in laboratory and in soccer field environments.Design: Observational.Setting: Research laboratory and field.Patients or Other Participants: Twenty healthy female soccer players (14.9 ± 0.9 years, height 167.9 ± 4.8 cm, mass 56.4 ± 7.3 kg) participated.Intervention(s): Unanticipated sidestep cutting tasks with the dominant leg (towards the non-dominant leg) were collected both in the laboratory and on the field. In the laboratory, the players used a 5m approach run followed by a 1-foot landing and a 40°-50° change of direction followed by running through a gate 5m away. On-field tasks were recorded during a game performed as part of their regular training session. Kinematics were collected through wearable inertial sensors (Xsens Technologies, Enschede, The Netherlands). One-way ANOVA was used to compare knee joint kinematics between the conditions, with level of significance set at p&lt;.05. Waveform consistency was investigated through Pearson's correlation coefficient and standardized z-score vector.Main Outcome Measure(s): For both conditions, 3D joint angles were defined using the Euler sequence ZXY and exported from the Xsens software (Xsens MVN Analyze 2020.0.1) to a customized Matlab (The MathWorks 2019a, Natick, Massachusetts, US) script. The ultimate foot contact before the change of direction was used and data were processed in a time-normalized interval from 50ms prior to the initial contact (0%) to 25ms after (100%). For the field, 40°-50° changes of direction were extracted for comparison with the laboratory condition.Results: On-field agility yielded vastly different knee kinematics compared to lab agility. At initial contact, the average knee flexion angle on-field was 31.96° - 36.92° versus 19.47° - 21.15° in the laboratory (p=.004). For the frontal plane at initial contact, we found -1.08° - -2.31° knee abduction in the field and 0.29° - 0.67° knee adduction in the laboratory (p=.007). The peak knee angles in frontal and sagittal planes were comparable among the two conditions. Waveform correlation was poor-to-excellent between laboratory and field (r: 0.20-1.00).Conclusions: Movement strategies used for changes of direction tasks in the laboratory were different from the on-field movement strategies in young female soccer players. This could be attributed to the differences in the environment and support the need for on-field injury risk screening.Context: Increased knee extensor moments relative to hip extensor moments during landing have been proposed as a risk factor for ACL injury in females. Diminished strength of the hip extensors relative to the knee extensors has been shown to predict an increased knee-hip extensor moment ratio during the deceleration phase of landing.Objective: To determine if decreased strength of the hip extensors relative to the knee extensors predicts re-injury in females who have returned to sport following ACL reconstruction (ACLR). Design: Retrospective, case-controlSetting: Patient clinicIntervention(s): Maximum isometric strength of the hip and knee extensors was measured using a motor-driven dynamometer (BTE Primus; BTE) as part of return to sport testing following ACLR. Patients were contacted to participate in an online survey concerning their return to sport and ACL injury status at least 12 months following testing.Patients or Other Participants: 345 females post ACLR who had previously undergone baseline strength testing were surveyed. The survey response rate was 54%. Respondents who sustained an ipsilateral ACL re-injury (non-contact) within 36 months of returning to sport were considered as cases.Main Outcome Measure(s): Twelve cases (14-22 years) were identified and matched with 2-4 non-injured controls (n = 41) based on sport level, athletic exposures, age, and graft type. Peak isometric strength for the hip and knee extensors was identified for each case and control from patient records. The hip-knee extensor strength ratio was calculated by dividing the peak strength of the hip extensors by the knee extensors (expressed as percentage). Logistic regression was performed to determine if the hip-knee extensor strength ratio predicted ACL re-injury, adjusted for known confounders (athletic exposures, age, graft type, months ACLR to return to sport). Receiver operator characteristic (ROC) curve analysis was conducted to determine the cutoff for the hip-knee extensor strength ratio that distinguished between high-risk and low-risk outcomes.Results: Cases had a lower hip-knee extensor strength ratio compared to controls (0.83 ± 0.16 vs. 0.98 ± 0.17, p = 0.007). The hip-knee extensor strength ratio significantly predicted ACL re-injury (p = 0.036, adjusted OR = 0.944, 95% CI: 0.894, 0.996). For every 1% increase in the hip-knee extensor strength ratio, there was 5.6% lower odds of re-injury. ROC curve analysis revealed an area under the curve of 74.8% [95% CI: 58.7%, 90.9%] (p=0.010), indicating fair prediction accuracy. The cutoff for the hip-knee extensor strength ratio to define high risk was &lt;= 97.1% (sensitivity: 91.7%, specificity: 51.2%).Conclusions: Female athletes with a lower hip-knee extensor strength ratio following ACLR are at greater risk of ACL re-injury (ipsilateral limb). These results suggest that return to sport testing to assess risk for ACL re-injury should consider the inclusion of hip and knee extensor strength.Context: Upwards of 30% of youth athletes sustain a repeat anterior cruciate ligament (ACL) injury after ACL reconstruction. While specific risk factors for re-injury and predictive models exist, these models are: 1) Limited in scope, failing to consider the large number of variables related to re-injury, 2) Overly simplistic, overlooking the interaction amongst variables, 3) Too broad, identifying risk factors within a group context and 4) non-actionable, utilizing risk factors that cannot be altered in recovery.Objective: The goal of this study was to develop an ACL re-injury prediction model capable of evaluating each patient's individual risk, identifying modifiable risk factors and ranking these factors on the order of importance and ability to be modified.Design: Retrospective database study of 432 patients (mean age 15.0, Female 50.7%) who underwent ACL reconstruction. This dataset represented a targeted extraction from a larger dataset and had a reinjury rate of 30%.Setting: The dataset included variables across the following categories: Demographics, injury information, family history of ACL injury, surgical variables, rehabilitation &amp; performance testing and re-injury information.Intervention(s): Machine learning (ML) techniques leveraging clinician domain knowledge were utilized to develop a model capable of determining a patient's risk for repeat ACL injury. Two highly experienced surgeons and a physical therapist independently assessed risk factors and ranked their contribution to injury and ability to be modified during recovery. These classifications were integrated into the modeling, allowing clinician expertise to improve upon standard ML methodologies. After patient risk classification, the model ranks the most significant risk factors according to impact and ease of modification.Main Outcome Measure(s): Multiple weighting methods and hyperparameter schemes were evaluated to obtain the highest accuracy classifying patients into high, medium or low risk categories, and weighting of modifiable risk factors. Model accuracy was determined using a 5-fold cross validation process over a 20% holdout dataset. An a-priori goal of classifying double the rate of re-injury across the entire dataset into high-risk patients (54%) and half this rate (13.5%) into low-risk.Results: The final model included 23 modifiable variables represented mostly by performance factors (e.g. normalized quad peak torque, quad/hamstring strength ratio, hop testing performance or time to return to sports). The model adjusts risk factor weight on a case-by-case basis. Performance goals were achieved with ACL re-tear rates of 58% in high-risk and 7% in low-risk categories, with sensitivity of 89% and specificity of 66% and verified within the cross-validation process.Conclusions: This ACL-Reinjury Risk Prediction Model can improve clinical care through accurate risk stratification and identification of patient specific modifiable risk factors, that can inform ongoing reinjury reduction or rehabilitation programs. Continued improvements in model accuracy will incorporate additional features, developing more intelligent labeling functions and adding confidence metrics.Context: The high incidence of anterior cruciate ligament (ACL) injuries in young female soccer players compared to their male counterparts has led to a large body of work aimed at reducing injury.Objective: To determine the effects of neuromuscular training using biomechanical biofeedback in order to reduce the risk of ACL injuries in adolescent female athletes.Design: Randomized controlled clinical trial; Level of evidence, 1.Setting: Research laboratoryPatients or Other Participants: 150 (age:13.3±2.2yrs; height: 156.1±10.6cm; mass:50.2±11.3kg) female soccer players.Intervention(s): A prospective, randomized, active comparator, open blinded, end-point trial was conducted. Participants were randomized into one of three study arms where each received neuromuscular training plus 1) sham biofeedback as an active control (NMT), 2) knee-focused biofeedback (NMT+K), and 3) hip-focused biofeedback (NMT+H).Main Outcome Measure(s): Each participant completed a pre-intervention baseline session and a post-intervention session to determine knee abduction moment (KAM) during a double leg drop vertical jump (DVJ) and an unplanned single leg cutting task at discrete time points and at specific time points during the stance phase. Athletic exposures and ACL injuries were tracked weekly for six months following the post-test session.Results: 140 participants (93.3%) completed the 6-week intervention and post-test. No ACL injuries were reported among any of the intervention groups six months following post-testing. Peak KAM was significantly improved in all three intervention groups from baseline to the post-test during the drop vertical jump (NMT: baseline -21.4Nm [95% CI: -25.4, -17.4], post -16.6Nm [95% CI: -19.7, -13.5], p=0.001, d=-0.48; NMT+K baseline -19.5Nm [95% CI: -23.2, -15.8], post -14.6Nm [95% CI: -17.6, -11.7], p=0.003, d=-0.42; NMT+H baseline -22.2Nm [95% CI: -26.9, -17.8]; post -17.6Nm [95% CI: -21.1, -14.1], p=0.002, d=-0.45). The primary outcome in this RCT, peak KAM, had mean improvement of 22.7% from baseline to post-testing which did not differ between groups during the DVJ (p&gt;0.05). However, statistically significant differences in peak KAM during the unanticipated cutting task were only found in the NMT+H intervention group (NMT: baseline -25.0Nm [95% CI: -30.4, -19.6], post -25.0Nm [95% CI: -29.6, -20.5], p=0.49, d=004; NMT+K baseline -23.6m [95% CI: -28.9, -18.3], post -22.8Nm [95% CI: -28.0, -17.6], p=0.377, d=-0.05; NMT+H baseline -29.5Nm [95% CI: -35.3, -23.8]; post -22.9Nm [95% CI: -27.8, -18.0], p=0.003, d=-0.44).Conclusions: While female soccer players involved in neuromuscular training programs regardless of intervention group exhibit significant improvements in KAM during a double leg landing, those that engage in hip-focused biofeedback compared to knee-focused or sham biofeedback exhibit decreased KAM during an unanticipated cutting maneuver. Neuromuscular training programs that aim to modify the high-risk biomechanics associated with ACL injury may benefit from targeting the underlying components of injury, such as underutilization of hip musculature during dynamic sport related movements.Context: Neuromuscular training (NMT) programs have been shown to modify high-risk biomechanics and ACL injury risk. However, it is unknown which neuromuscular factors are modified following the completion of NMT programs. Hip strength has been suggested to be an important factor in ACL injury risk and is commonly emphasized in NMT programs. Understanding the immediate effects and retention of hip strength following a NMT program will provide insight into the effectiveness of NMT programs in reducing ACL injury risk.Objective: To examine the increase and retention of isokinetic hip strength in female adolescent soccer players following a neuromuscular training (NMT) program.Design: Prospective cohort study.Setting: Research laboratory.Patients or Other Participants: 126 adolescent female soccer players (age=13.2±2.1yrs, height=156.4±10.2cm, mass=49.9±11.0kg) were included in this subgroup analysis that completed all isokinetic hip strength assessments.Intervention(s): Participants volunteered to complete 6 consecutive weeks of a neuromuscular training (NMT) program with a frequency of 3 times a week. The NMT program included progressive exercises that included components of lower extremity strengthening, plyometrics, and core strengthening. Using an isokinetic dynamometer, 5 repetitions of isokinetic concentric (CON) and eccentric (ECC) hip extension (HEXT) torque were measured at 60 deg•s−1 bilaterally prior to (PRE) and following (POST) the NMT program. Retention (RET) of hip strength was assessed 6-months following the completion of the NMT program.Main Outcome Measure(s): The average peak torque (Nm) of the middle 3 repetitions for CON and ECC HEXT strength measures of the right and left limb during each testing session were used for analyses. Separate repeated measures ANOVAs were used to compare differences in HEXT strength between PRE, POST, and RET. Post-hoc pairwise comparisons with Bonferroni correction were performed when appropriate.Results: HEXT strength (CON, ECC) were significantly different between testing sessions. Specifically, POST right (146.9±48.3 Nm, 150.0±57.9 Nm) and left (147.4±47.7 Nm, 144.2±52.7 Nm) were greater than PRE right (138.8±44.0 Nm, P=0.007; 139.6±56.5 Nm, P= 0.026) and left (138.4±45.0 Nm, P=0.009; 139.4±56.2 Nm, P=0.035). RET right (130.2±48.8 Nm, 133.5±50.2 Nm) and left (131.9±46.2 Nm. 133.2±50.2 Nm) were less than POST (Prange= &lt;0.001-0.007). However, neither right or left HEXT strength were different between PRE and RET (Prange=0.094-0.203).Conclusions: In female adolescent soccer players, increases in isokinetic HEXT strength were observed immediately following a 6-week NMT program. However, the increases in hip strength were not retained 6-months following the completion of the NMT program. While the immediate increases in hip strength may contribute to the effectiveness of NMT programs in reducing ACL injury risk, these positive changes appear to decrease over time. This suggests that adolescent athletes may need to continuously engage in NMT programs to maintain the immediate observed increases in hip strength.Context: Despite decades of research and innovation, primary and secondary ACL injury rates remain high. Traditional injury prevention programs focus on biomechanical-related outcomes, neglecting to maximize more cognitively-driven processes that capitalize on motor learning principles. The advent of virtual reality technology allows for seamless integration of targeted motor learning strategies into injury prevention regimens, which may lead to improved acquisition and retention of safe movement patterns.Objective: Determine the efficacy of a brief virtual-reality intervention to deliver specific motor learning of support or for retention of safe frontal plane We that and in greater improvements compared to a control repeated motion analysis laboratoryPatients or Other Participants: included participants cm, cm, kg) who frontal plane inclusion history of lower extremity or lower extremity injury for six months to data the final was Participants were to one of three groups or such that the ratio was across groups. All participants virtual reality that an plane Participants were to the 5 of 8 on the left The group their prior to each The group received positive biofeedback in the of when kinematics within Outcome Measure(s): Participants were for three-dimensional motion and completed repetitions of left leg Peak frontal plane and angles were measured before and immediately following the changes were assessed with A for time indicated that all groups increased hip adduction control by time revealed that the control group greater increases in knee abduction compared to and and that greater in ipsilateral compared to and control Hip adduction in all Despite and groups baseline knee the control group was through in ipsilateral of motor learning to the effects of increased and to athletes during increases and the motor learning on the timing of to movement The effects of on the of sidestep cutting a task that is highly related with ACL injury risk, are To investigate the of on was that the group more after the training than the Randomized controlled Research laboratory.Patients or Other Participants: healthy sport athletes years, cm, kg) were from on participants were to the or 1 and participants performed trials as and retention of three randomized an task and two in which participants had to and or and a to the All participants received and were to the movement of the to the of their The group was to for after every trial during of 1) the Movement 2) and sagittal of the trial and 3) an external focus on to improve their The goal was to lower the The counterparts received after the trial on which their in the group had Outcome Measure(s): between groups and were with repeated measures with level of significance set at between groups were of at were higher compared to training and retention to the group improved during training which was in the and retention The group higher in and retention compared to training The group their improved during the retention the group to their baseline may benefit and could be considered as a to in ACL injury prevention the years, have injury prevention programs capable of reducing the rate of ACL injury. However, youth sport have been to these programs and injury rates to Previous studies have focused on the efficacy of during controlled conditions. research that factors impact the effectiveness of in Understanding and on and may be important for the and effectiveness of in youth To and the and of youth sport Sources: An database search was conducted in using and A of search prevention and were were limited to in studies were following a search for those Selection: with data were and studies were that did not injury prevention in sport were as were and and the studies and those which did not did not focus on the and only included of youth sport Extraction: studies from sport female not were to knowledge and were reported in the included of studies was not Synthesis: to lack of knowledge and lack of to to increase knowledge to positive that youth athletes are at high risk of injury and that reduce injury The identified this literature support the need for and to knowledge and support of youth sport for of the evidence in the 13 of the studies from the the focused on soccer and when sex of was the were The of such as the for Research and the will be in identifying that and developing to the of individual program increases risk of lower extremity injury, to the anterior cruciate ligament in neuromuscular control following

The objective of this study was to compare the effectiveness of both small-sided games (SSG) and short interval running-based high-intensity interval training (HIIT) programs over an 8-week period in fostering adaptations in aerobic capacity, change-of-direction abilities, and jumping performances of youth female soccer players. The study involved 48 female youth participants under the age of 19, competing at the regional level, who took part in a randomized controlled trial. Participants were assigned to either the SSG group, the HIIT group, or a control group, which involved regular in-field sessions. Assessments were conducted at baseline and after the 8-week training intervention, measuring aerobic capacity using the 30-15 intermittent fitness test (VIFT), change of direction (COD) using the 5-0-5 test, and jumping performance using the countermovement jump test (CMJ). Time 5 group analysis revealed significant interactions in CMJ (p = 0.005; ηp2= 0.213) and VIFT (p < 0.001; ηp2 = 0.433), although no significant interaction were found in COD deficit (p = 0.246; ηp2 = 0.060). Within-group analysis revealed that SSG significantly improved CMJ (p < 0.001), COD deficit (p < 0.001), and VIFT (p < 0.001). HIIT group also significantly improved CMJ (p = 0.029), COD deficit (p = 0.001), and VIFT (p < 0.001). As conclusion, the study revealed that SSG promoted significantly improvements in VIFT, CMJ and COD deficit, being significantly better than control group, while HIIT was only significantly better than control in VIFT. SSG revealed to be effective approach for favoring key physical attributes of female soccer players, being an interesting and recommended training approach to increase the ecology of the training practice, while favoring physical positive adaptations.

The objective of this systematic review with meta-analysis was to compare the endurance performance chronic adaptations induced by running-based high-intensity interval training (HIIT), small-sided games (SSGs), and combined HIIT+SSGs in male and female youth and adult soccer players. The studies included in this review followed the PICOS criteria: (i) healthy soccer players; (ii) interventions based on SSGs; (iii) comparators exposed to only HIIT or combined SSGs+HIIT; (iv) endurance performance variables. Studies were searched for in the following databases: (i) PubMed; (ii) Scopus; (iii) SPORTDiscus; (iv) Web of Science. After conducting an initial database search that retrieved a total of 5,389 records, a thorough screening process resulted in the inclusion of 20 articles that met the eligibility criteria. Sixteen studies reported outcomes related to endurance performance measured through field-based tests, while five studies provided results from direct measurements of maximal oxygen uptake (VO2max). Results showed a non-significant small-magnitude favoring effect for the HIIT groups compared to the SSG groups (ES=0.37, p=0.074) for endurance, while a non-significant small-magnitude favoring SSGs was observed (ES=-0.20, p=0.303) for VO2max. Despite the very low certainty of evidence, the findings suggest similar effects induced by both SSG and HIIT on improving endurance performance and VO2max.

Previous studies have attempted to determine prognostic factors for predicting the occurrence of noncontact anterior cruciate ligament (ACL) injuries. However, studies on risk factors for noncontact ACL injuries in Asian female soccer players are limited. To identify intrinsic risk factors for noncontact ACL injuries among young female Asian soccer players. Cohort study; Level of evidence, 2. This study evaluated 145 female Japanese soccer players for potential risk factors for noncontact ACL injury during the preseason medical assessment. In total, 25 variables were examined-including anthropometric data, joint range of motion, muscle flexibility, muscle strength, and balance measurements. Participants were monitored throughout a single season for noncontact ACL injuries diagnosed by physicians. Noncontact ACL injuries occurred in 13 knees of 13 players (9%). Lower hamstring-to-quadriceps ratio (0.44 ± 0.07 vs 0.50 ± 0.10; P = .04), greater knee extension muscle strength (3.2 ± 0.5 vs 2.7 ± 0.5 N·m/kg; P < .01), and longer playing experience (10.8 ± 3 vs 8.1 ± 4.2 years; P = .02) were significantly associated with new-onset noncontact ACL injuries in young female soccer players. No statistically significant between-group differences were found for any other variables. New-onset noncontact ACL injury in young female soccer players was significantly associated with lower hamstring-to-quadriceps ratio, greater knee extension muscle strength, and longer soccer experience. These findings will help develop strategies for preventing noncontact ACL injuries among female soccer players.

&lt;p&gt;This study aimed to compare the effects of small-sided games (SSG) and high-intensity interval training (HIIT) on the physical health and fitness of sedentary, untrained young adults. A 16-week randomized controlled trial was conducted with 90 participants (mean age 19.82 ± 0.66 years; 45 males and 45 females), who were randomly assigned in a 1:1:1 ratio to either the SSG group, the HIIT group, or a non-training control group (CG). Each group included 30 participants, and all participants completed the intervention. All interventions were performed three times per week. The SSG group participated in 4v4 or 6v6 handball games, while the HIIT group completed 30-30 (30 s sprint/30 s active recovery) or 40-20 (40 s sprint/20 s active recovery) protocols on an outdoor rubber track at 80-85% of their maximum heart rate (HRmax). Measured outcomes included physiological indicators (body weight, body mass index [BMI], systolic/diastolic blood pressure [SBP/DBP], and resting heart rate [RHR]) and fitness indicators (grip strength, one-repetition maximum squat [1RM], 20-meter multistage fitness test [20 m MFT] performance, and maximal oxygen uptake [VO&lt;sub&gt;2&lt;/sub&gt;max]). Baseline characteristics were well balanced across groups (standardized mean differences &amp;lt; 0.50). After 16 weeks, both SSG and HIIT significantly reduced body weight, BMI, SBP, DBP, and RHR (p &amp;lt; 0.01), while significantly improving 1RM squat, 20 m MFT performance, and VO&lt;sub&gt;2&lt;/sub&gt;max (p &amp;lt; 0.01). In contrast, the CG group showed significant decreases in SBP, left-hand grip strength, and 1RM squat (p &amp;lt; 0.05). Between-group analyses indicated that SSG and HIIT produced substantially greater improvements than the CG in cardiometabolic outcomes, for example, VO&lt;sub&gt;2&lt;/sub&gt;max increased by approximately 7 mL·kg&lt;sup&gt;-1&lt;/sup&gt;·min&lt;sup&gt;-1&lt;/sup&gt; in both training groups, whereas it showed little or no change in the CG. For body weight and BMI, only body weight differed significantly between the SSG and CG groups (p &amp;lt; 0.05). No significant between-group differences were observed in grip strength (p &amp;gt; 0.05), and no significant differences were found between the SSG and HIIT groups across any indicators (all p &amp;gt; 0.05). In conclusion, both SSG and HIIT effectively improved physical health and fitness in sedentary young adults. SSG may be more suitable for individuals seeking an enjoyable, game-based approach that supports upper limb strength development, while HIIT may be preferable for those aiming to enhance aerobic fitness efficiently. Because SSG offers an enjoyable, socially interactive, game-based format and HIIT provides a time-efficient, highly structured format, both modalities may promote sustained participation beyond initial adoption in previously inactive young adults.&lt;/p&gt;

Introduction: High-intensity interval training (HIIT) and Sprint interval training (SIT) are effective training methods for soccer players. However, there is no clear indication which method is more effective to improve sprint performance, especially in young female soccer players. We hypothesized that a multi-component training model (HIIT+SIT) would improve soccer-specific sprint performance more effectively in young female soccer players. This study aims to investigate the effects of HIIT and SIT programs on soccer-specific sprint performance in young female soccer players. Methods: 30 trained female soccer players aged 14-16 from Çanakkale Youth and Sports Club’s 3rd League women's soccer team were included in the study. Participants were randomly divided into two groups: the training group (n = 15) and the control group (n = 15). Anaerobic power was evaluated using the Wingate test. Soccer-specific sprint performance was evaluated with a sprint test and with a ball. The training group was included in HIIT and SIT programs in addition to soccer training. The control group was included in soccer training only. The program was applied for 6 weeks and 3 days a week. Tests and measurements were repeated after 6 weeks. The Shapiro-Wilk test was used to assess normal data distribution, and the Levene test was used to assess equality of variances. The Mann-Whitney U test was used to determine the significance level of the difference between the means of the groups. The Wilcoxon test was used to determine the significance of the difference between the means of two groups. Results: Significant differences were found between the training group and the control group in the 30 m sprint (p = .000), 30 m sprint with ball (p = 0.001), and 41 m sprint with change of direction with ball (p = .002) tests. No significant differences were found in mean and peak anaerobic power (p &gt; .05). Conclusion: For young female soccer players, a combination of HIIT and SIT training is recommended to improve soccer-specific sprint performance.

Lesinski, M, Prieske, O, Chaabene, H, and Granacher, U. Seasonal effects of strength endurance vs. power training in young female soccer athletes. J Strength Cond Res 35(12S): S90-S96, 2021-This study examined the seasonal effects of strength endurance training (SET) vs. power training (PT) on physical fitness and body composition in young female soccer players. Thirty-six young female elite soccer players (15 ± 1 years; maturity offset +3 ± 1 years) were allocated to progressive SET (n = 19) or PT (n = 17). Over the course of one soccer season, SET performed slow movement velocity, moderate intensity (50-60% of the 1 repetition maximum [1RM]; 20-40 repetitions) strength exercises while PT performed moderate-to-high intensity (50-95% of the 1RM; 3-8 repetitions), high movement velocity strength exercises (2 sessions·wk-1). Before and after training, tests were performed for the assessment of muscle strength (1RM leg press), jump performance (countermovement jump [CMJ], drop jump [DJ]), muscular endurance (ventral Bourban test), linear speed (10 m, 20 m), change-of-direction (CoD) speed (T-test), dynamic balance (Y-balance test), sport-specific performance (kicking velocity), and body composition (lean body mass and fat mass). An analysis of covariance was used to test for between-group differences at post-test with baseline values as covariate. No significant between-group differences were observed in terms of total training volume over the respective soccer seasons (p = 0.069; d = 0.68). At post-test, SET showed significantly better ventral Bourban and T-test performances (d = 1.28-2.28; p = 0.000-0.001) compared with PT. However, PT resulted in significantly better 1RM leg press, DJ, 10-m, and 20-m sprint performances (d = 0.85-1.44; p = 0.000-0.026). No significant between-group differences were observed at post-test for CMJ, Y-balance test, kicking performance, and body composition (d = 0.20-0.74, p = 0.051-0.594). Our findings are mainly in accordance with the principle of training specificity. Both SET and PT are recommended to be implemented in young female elite soccer players according to the respective training period.

The aim of the study was to investigate the effects of 4-week small-sided games (SSG) and high-intensity interval training with changes of direction (HIT-COD) on physical performance and specific technical skills in female collegiate basketball players. Nineteen players were divided into SSG (n = 9) and HIT-COD (n = 10) groups, that performed either SSG or HIT-COD three times per week for 4 weeks during the pre-season. Players’ heart rate (HR) and perceived exertion responses (RPE) were assessed during the intervention. Before and after the intervention period, performances were assessed with 30-15 intermittent fitness test (30-15IFT), repeated sprint ability (RSA) test, modified agility T-test (MAT), countermovement jump (CMJ), 20-m sprint, shooting accuracy test, 1 min shooting test, passing test, defensive movement test and control dribble test. Both training interventions led to similar physiological and perceived exertion responses, showing no significant differences in HR ( P = .49, d = 0.2) and RPE ( P = .77, d = 0.1) between groups. Significant improvements were observed in 30-15IFT (SSG: 4.1%, d = 1.5; HIT-COD: 4.2%, d = 1.7), RSAmean (SSG: −2.2%, d = 1.0; HIT-COD: −1.9%, d = 1.0), RSAbest (SSG: −2.0%, d = 0.9; HIT-COD: −2.1%, d = 1.1), MAT (SSG: −7.2%, d = 1.7; HIT-COD: 5.7%, d = 1.5), defensive movement test (SSG: −5.1%, d = 2.1; HIT-COD: −5.8%, d = 1.8) and control dribble test (SSG: −3.4%, d = 1.0; HIT-COD: −2.6%, d = 1.0). The only significant group × time interaction was found ( P = .032, [Formula: see text] = 0.24), with SSG improving 1 min shooting (22.4%, d = 1.0) and HIT-COD performing slightly worse (−2.6%, d = 0.1) after a 4-week intervention. The current study suggests that using SSG is more effective than HIT-COD for female collegiate basketball players in pre-season, since SSG improves physical performance and basketball-specific movements as well as shooting abilities after a 4-week intervention.

ABSTRACTWe aimed (1) to test the acute impact of two high-intensity interval-training (HIIT) protocols differing in the level of effort on intraocular pressure (IOP) responses, and (2) to elucidate whether the IOP responses differ between men and women. Twenty-four physically active collegiate (12 men and 12 women) performed three protocols: low-fatigue HIIT (eight 30-m sprints with 60-s of rest), high-fatigue HIIT (eight 30-m sprints with 30-s of rest), and control (walking). IOP was taken at baseline, after sprints and recovery by rebound tonometry. Our data revealed an acute IOP reduction during both HIIT protocols compared to the control condition (effect size [ES]:0.81–1.65). The differences between both HIIT protocols were generally negligible (ES<0.30), however, the reduction of IOP was moderately higher for the low-fatigue HIIT protocol after the 7th (ES: 0.67) and 8th (ES: 0.74) sprints. Women showed a more prominent lowering effect on IOP during the control condition (ES: 0.42–1.02), and during the two first sprints of both HIIT protocols (ES: 0.54–1.03). These findings highlight that a time-efficient HIIT protocol may acutely reduce IOP levels, while low-fatigue HIIT protocol could be recommended since it induced a higher reduction on IOP than the high-fatigue HIIT protocol.

The objective was to systematically compare the effects of speed, agility, and quickness (SAQ) training, high-intensity interval training (HIIT), and small-sided games (SSG) training on sprint and change of direction (COD) performance in soccer players through pairwise and network meta-analyses. A comprehensive search of five electronic databases (PubMed, Web of Science, Embase, Cochrane, and EBSCO) was conducted during June 2025 to identify controlled trials involving SAQ, HIIT, or SSG training interventions. Studies meeting predefined eligibility criteria underwent pairwise meta‑analysis (PMA) to calculate standardized mean differences (SMDs) against control conditions, and network meta‑analysis (NMA) to estimate comparative efficacy across all three modalities. Surface under the cumulative ranking (SUCRA) values were computed to establish an intervention hierarchy. Twenty-three studies involving 914 participants were included. Pairwise meta-analysis (PMA) results showed that, compared with the control groups, only SAQ training significantly improved sprint (SMD = –1.23, 95% CI: –1.85 to –0.60, p&amp;lt;.001) and COD performance (SMD = –1.09, 95% CI: –1.69 to –0.48, p&amp;lt;.001). In network meta-analysis (NMA), SAQ ranked highest for sprint performance (SUCRA = 98.2%), followed by Conventional Training (CT) (57.0%), HIIT (36.7%), and SSG (8.1%). For COD performance, HIIT (SUCRA = 67.3%) ranked highest, followed by SSG (65.9%), SAQ (63.1%) and CT (3.7%). SAQ training demonstrated the most robust enhancement of sprint speed among the examined modalities. Although direct comparisons indicated benefits of SAQ for COD performance, its superiority was not confirmed in the network analysis, likely due to limited head-to-head data and study heterogeneity. A training strategy centered on SAQ, with supplemental HIIT and SSG components, is therefore recommended to optimize both sprint and COD adaptations in soccer players. PROSPERO: CRD42024583586

Wilmes, E, de Ruiter, CJ, van Leeuwen, RR, Banning, LF, van der Laan, D, and Savelsbergh, GJP. Different aspects of physical load in small-sided field hockey games. J Strength Cond Res 38(2): e56-e61, 2024-Running volumes and acceleration/deceleration load are known to vary with different formats of small-sided games (SSGs) in field hockey. However, little is known about other aspects of the physical load. Therefore, the aim of this study was to gain a more thorough understanding of the total physical load in field hockey SSGs. To that end, 2 different SSGs (small: 5 vs. 5, ∼100 m 2 per player; large: 9 vs. 9, ∼200 m 2 per player) were performed by 16 female elite field hockey athletes. A range of external physical load metrics was obtained using a global navigational satellite system and 3 wearable inertial measurement units on the thighs and pelvis. These metrics included distances covered in different velocity ranges (walk, jog, run, and sprint), mean absolute acceleration/deceleration, Hip Load, and time spent in several physically demanding body postures. The effects of SSG format on these external physical load metrics were assessed using linear mixed models ( p < 0.05). Running volumes in various speed ranges were higher for the large SSG. By contrast, mean absolute acceleration/deceleration and time spent in several demanding body postures were higher for the small SSG. This study shows that changing the SSG format affects different aspects of physical load differently.

This study aimed to compare the effects of a combined high-intensity interval training (HIIT) and small-sided games (SSG) training program (SSG + HIIT) with training programs consisting solely of either HIIT or SSG on the cardiometabolic and physical fitness of sedentary, overweight youth. A randomized, parallel-controlled study design was employed, with interventions lasting six weeks (twice a week, with each work time lasting 12-16 minutes). Fifty-seven sedentary, overweight male youth participants (15.1 ± 0.8 years) were assessed twice on anthropometric measures, blood pressure, endurance (using the Multi-Stage Fitness Test, MSFT), muscle power (countermovement jump and broad jump), and change of direction ability (using the 5-0-5 COD test). The session's ratings of perceived exertion (RPE) and scores on the Physical Activity Enjoyment Scale (PACES) were also monitored. The HIIT group exhibited a significantly smaller waist circumference compared to the control group (p = 0.041) after the intervention. The control group exhibited a significantly worst COD deficit compared to the SSG + HIIT (p = 0.002), SSG (p = 0.001) and HIIT (p = 0.048) after the intervention. In the case of MSFT, the group exhibited a significantly smaller distance covered than SSG + HIIT (p = 0.002), and SSG (p = 0.005). Moreover, significant differences on RPE (p < 0.001) and PACES (p < 0.001) was found between groups. The SSG + HIIT or SSG are effective for improving COD and aerobic capacity, while being more enjoyable and less intense than HIIT alone. However, HIIT is more effective in reducing waist circumference. The research limitations include the short intervention duration, lack of control for diet and external factors, and the need for longer-term research.

Background. The increase in young female soccer players requires understanding the adaptations determined by sport-specific exercises both to enable improvements in sports performance and to reduce injury risk in women’s soccer. Objectives. This study aimed to analyze the acute effects of Small-Sided Games (SSG) on landing technique control, lower limb strength and lower limb functional asymmetry in Under-15 female soccer players. Materials and methods. A total of 18 young female soccer players (age:14.04±0.26 years, weight: 51.56±2.9 kg; height: 146.9±3.22 cm) randomly performed hop test, Landing Error Scoring System assessment and vertical jump at the end of warm-up (pre-fatigue condition) and post SSG (3vs3, 4 x 4 min on field 24,5m x 24,5 m, post-fatigue condition). The inter-limb asymmetry value was calculated by comparing the two hop tests (left and right) using the formula: (highest performing limb – lowest performing limb/highest performing limb)×100. Results. The hop test and vertical jump results in the pre vs. post-SSG comparing showed a significant performance decrease (p&lt;0.001, ES:1.43 and 1.43, respectively). The inter-limb asymmetry value significantly increased (p&lt;0.001, ES:1.18) from 9.07±2.67% to 13.42±7.49%. The landing control value has undergone a substantial decrease from 5.72±0.67 to 7.83±0.86 (p&lt;0.001, ES:1.29). Conclusions. The findings indicate that high-intensity soccer drills have an impact on the landing control quality, decrease explosive strength performance, and increase inter-limb asymmetry value. Soccer-specific exercises must be carefully modulated within the training session.