Physical Performance Indicators Research Articles

Body Size Measurements and Physical Performance of Youth Female Judo Athletes with Differing Menarcheal Status.

Purpose: To compare body size measurements and physical performance among female youth judo athletes with differing menarcheal status and to identify indicators of physical performance in post-menarcheal girls. Methods: Nineteen young female judo athletes (age 13.9 ± 2.3 years) were divided into a pre-menarche (n = 7) and a post-menarche (n = 12) group. The athletes were evaluated through neuromuscular tests, including standing long jump (SLJ), medicine ball throw (MBT), and handgrip strength (HGS), and judo-specific assessments, including the Special Judo Fitness Test (SJFT) and the Judogi Grip Strength Test (JGSTISO). Furthermore, years of experience in judo and the age at menarche were determined. Results: The main results showed higher performance for the post-menarche group for most variables (p < 0.05) compared to the pre-menarche group. A multiple linear regression analysis demonstrated that age at menarche, chronological age, and body mass explained close to 70% of JGSTISO, while training experience, chronological age, and age at menarche explained close to 59% of SLJ. Additionally, chronological age and age at menarche explained 40% of MBT, and chronological age and height explained 52% of HGS. Conclusions: Age at menarche and somatic growth variables explained moderate proportions of the variance of physical performance, thereby providing evidence that these parameters are the primary indicators of physical performance in young female judo athletes.

Fibromyalgia status and depressive symptoms are linked to body mass index and physical performance in mid to late life

ABSTRACT Fibromyalgia (FM) is a chronic pain condition that is frequently accompanied by comorbid conditions, including depression. Depression is associated with reduced physical functioning and health, disproportionately affecting middle-aged and older adults with FM. This study examined associations between FM status and depressive symptoms with body mass index (BMI) and several physical performance indicators among middle-aged and older adults. Participants included 239 community-dwelling middle-aged and older adults with or without FM. Depressive symptoms were measured using the Beck Depression Inventory-II (BDI-II), BMI was objectively assessed, and physical performance was measured using the Fullerton Advanced Balance scale, 6-minute walk test, 30-second chair stand, and 8-foot up and go test. A path model using structural equation modeling yielded good fit and revealed that, compared to pain-free adult controls, participants with FM reported more depressive symptoms, which were in turn associated with reduced physical performance across all indicators except BMI, after adjusting for age and symptom severity. Findings suggest that individuals with FM demonstrate disproportionately higher depressive symptoms compared to non-FM controls, which may diminish physical performance after accounting for age and symptom severity. This study supports FM status and depressive symptoms as important considerations when evaluating the health and disability risk of aging adults.

Relationship of sagittal spinal alignment with low back pain and physical performance in the general population

Studies have suggested a relationship between sagittal spinal malalignment and low back pain (LBP). The current study investigated the relationship of spinal alignment with LBP and physical performance in 1491 individuals who attended the second follow-up visit of the Wakayama Spine Study. The sagittal vertical axis at C7 (C7 SVA) was measured by a spine surgeon. The occurrence of LBP within one month, pain intensity, Oswestry Disability Index (ODI), and physical performance (grip strength, 6-m walking time, chair stand test, one-leg standing test) were also evaluated. LBP in the previous month was determined using ODI, and indicators of physical performance were measured. The mean C7 SVA was 11.0 ± 42.7 mm and was significantly greater in older participants (p < 0.001). LBP was more prevalent in participants with a greater C7 SVA (< 40 mm, 35.7%; 40–95 mm, 47.3%; ≥ 95 mm, 59.4%; p < 0.001) and those with a higher ODI score (10.0%, 17.5%, and 29.4%, respectively; p < 0.001). Physical performance significantly decreased in participants with a greater C7 SVA (p < 0.001). Multiple linear regression analysis revealed that LBP and physical performance were significantly associated with C7 SVA (p < 0.001). Thus, sagittal spinal malalignment may lead to LBP and decreased physical performance.

Comparing the Effects of Eight Weeks of Whole Body Vibration Exercise Combined With Rope Skipping at Two Different Intensities on Physical Performance of Older Men: A Randomized Single-Blind Clinical Trial

Objectives: Whole-Body Vibration (WBV) exercise seems to be an effective alternative to improve physical performance in the elderly. This study aims to compare the effects of eight weeks of WBV exercise combined with rope skipping at two different intensities on physical performance of older men. Methods &amp; Materials: This is a randomized single-blind clinical trial. Participants were 30 older men (Mean±SD age= 65.83±4.16 years; Mean±SD height= 169.26±3.90 cm; Mean±SD weight= 77.04±4.62 kg; Body Mass Index= 26.86±0.69 kg/m2) living in Mashhad, Iran in 2019, who were selected by purposive and convenience sampling methods and randomly divided into three groups: high intensity (HI; n=12), low intensity (LI; n=12) and control (n=10). The WBV exercise was performed at a frequency of 25-40 Hz and amplitude of 3 mm. Rope skipping was performed based on the Borg scale at 13-14 level intensities with 30-35 jumps per minute. Physical performance indicators, body mass index, and fat percentage were measured before and after eight weeks of intervention. Repeated measures analysis of variance was used for data analysis in SPSS v. 20 software. The significance level was set at P≤0.05. Results: In HI and LI groups, body fat percentage (-4.50%, -5.99%), lower body flexibility (105%, 102%), upper limb muscle strength (42.43%, 42.93%), handgrip strength (43.38%, 39.45%), dynamic leg strength (36.47%, 26.43%), lower limb muscular endurance (27.20%, 26.10%), cardiorespiratory function (10.27%, 10.90%), and dynamic balance (-32.60%, -24.10%) showed a significant improvement compared to the control group (P&lt;0.05). There was no significant difference in body mass index between exercise and control groups (P&gt;0.05), and no significant difference between the two exercise groups in any of the study variables (P&gt;0.05) Conclusion: It seems that low intensities of the WBV exercise + rope skipping is effective in improving body composition and physical performance in older men. The selection of intensity level depends on the physical condition of the elderly.

Has India’s Employment Guarantee Program Achieved Intended Targets?

This paper explores the performance of the world’s largest employment guarantee program, the Mahatma Gandhi National Rural Employment Guarantee Scheme in India, both nationally and through a sub-national-level comparison based on key performance indicators viz. (i) financial indicators, (ii) physical performance indicators, and (iii) inclusiveness indicators. The paper is based on administrative data taken from the Ministry of Rural Development from 2006 to 2019. Despite sharp increases in fund allocation, total expenditures, and utilization rates, there was deceleration in majority of physical performance indicators after 2016, including total person-days employment and person-days of employment per household, with wide variation in sub-national level implementation capabilities. The finding also rejects the falsity of saturation of MGNREGA work in the rural areas, which is reflected in a strong positive correlation between fund allocation and employment generation. Its broader objective of social safety net for vulnerable people in rural areas shows an achievement, although with some gaps in implementation. JEL classification: H53, J43, P25

The Effect of Simulation-based Training on Athletic Performances among Female Basketball Players

Background: The effectiveness of simulation-based training has been examined in various sports. However, considering the effect of gender and sport on training, it would be interesting to evaluate simulation-based training in female basketball. Objective: The purpose of the study was to examine the effect of simulation-based training on physical fitness and performance indices in female basketball players. Methods: Sixteen female semi-professional basketball players were randomly assigned to experimental (n=8; age, 25±2 years; weight, 62±9 kg; height, 167±8 cm) or control (n=8; age, 24±1 years; weight, 57±9 kg; height, 170±8 cm) groups. The experimental group participated in a six week basketball simulation training program including running with different speeds (jogging to sprinting), agility, jumping, and shuffling. Both groups performed the Cooper 12 min run, line drill, an adjusted T-test, 20 ms print, the Sargent vertical jump and basketball exercise simulation test before and after six weeks of the study period. Control and experimental groups performed typical basketball training, three times weekly. The overall training volume was similar for both groups. Results: The perceived exertion was higher in the simulation-based training than control (p&lt;0.05) group. The findings of this study indicated a significant increase in VO2 max (p=0.001), anaerobic power (p=0.009), explosive leg strength (p=0.036), and total distance covered in basketball exercise simulation test (p=0.001) and decrease of the meantime of one round of basketball exercise simulation test (p=0.001) in the simulation training compared to the control group. Conclusion: Generally incorporation of the simulation-based training in conditioning programs is recommended for improving aerobic, anaerobic and leg explosive strength of basketball players.

Impact of Possession and Player Position on Physical and Technical-Tactical Performance Indicators in the Chinese Football Super League.

The purpose of this study was to investigate the impact of high (HPBPT) and low percentage ball possession teams (LPBPT) on physical and technical-tactical performance indicators in the Chinese Football Super League (CSL). Eight physical performance indicators and 26 technical-tactical performance indicators from all 240 matches from season 2018 were analyzed, as well as three contextual variables (team strength, quality of opposition, and match location). Players were divided according to five positions: fullbacks, central defenders, wide midfielders, central midfielders, and attackers. A k-means cluster analysis was conducted to classify all match observations into two groups: HPBPT (n = 229) and LPBPT (n = 251). A mixed linear model was fitted with contextual variables as covariates. When significant interactions or main effects were detected, a post hoc comparison was used to compare physical and technical/tactical differences between HPBPT and LPBPT. Results showed that central defenders and fullbacks covered more high-intensity and sprint running distance in the high possession teams, while wide midfielders and forward covered more high-intensity and sprint running distance in the low possession teams. Meanwhile, players from high ball possession teams were strong in technical indicators, especially in attacking organization. These results may help coaches to understand current football development trends and develop suitable training plans and tests for elite football players.

Iron deficiency anemia induces postural control disorders in young women

BackgroundDue to menstruation and restrictive dietary practices, women are at a particular risk of iron deficiency anemia (IDA). This hematologic manifestation could impair postural control as it induces fatigue, muscle weakness, cognitive and neurological functions alteration. AimThis study aimed to investigate IDA effects on postural control in young women in comparison to healthy counterparts. Material and methodsTwenty-four young women with IDA and twenty-four controls participated in this study. Center of pressure (CoP) excursions, in the bipedal and semi-tandem postures on the firm and foam surfaces in the eyes opened (EO) and closed (EC), were recorded, and Romberg index was calculated to evaluate postural control. Besides physical performance, attentional capacity, fatigue, and heart and respiratory rates were assessed. ResultsYoung women with IDA had significantly higher CoP velocity (CoPv) values in the bipedal posture in both vision and surface conditions (EO [firm: P < 0.001 and foam: P < 0.01]; EC: P < 0.001), as well as in the semi-tandem posture (EO [firm: P < 0.01 and foam: P < 0.001]; EC: P < 0.001) compared to controls indicating that they had worse postural control than their peers. In addition, values of the respiratory rate (P < 0.001), attentional capacity (P < 0.001), physical performance (P < 0.001), fatigue (P < 0.001), and Romberg index on the foam surface in both postures (P < 0.05) were significantly higher in young women with IDA compared to controls. ConclusionsPhysical performance, fatigue, tachypnea and attentional capacity resulting from IDA may explain postural control disorder in young women.

The increasing of the somatic health in students using differently directed fitness

The purpose of study is to scientifically substantiate the methodology of applying differently directed fitness tools to increase the level of somatic health, physical and mental workability of students. The experimental sampling consisted of 186 students (106 girls, 80 boys) of the Belgorod State National Research Institute and the Belgorod University of Cooperation, Economics and Law. Two groups of respondents were organized: control group (n=85; 47 girls, 38 boys) that included students involved into officially approved education program of the Chair of Physical Culture and experiment group (n=101; 59 girls, 42 boys) that included students involved into experimental program. It is established that Pilates stabilizes and topes up muscles of entire body, improves coordination abilities of students involved, improves body-build constitution, promotes reducing of back pain, improves cardio-respiratory system functioning and is the most called-for fitness direction for reducing psycho-emotional tension. The step aerobics positively effects on the cardio-respiratory system, the entire musculoskeletal system and physical workability. The level of somatic health in experiment group after the experiment improved from "below average" to "average". In control group both before and after the experiment, the level of somatic health corresponded to "below average". After the experiment, the physical performance indices in experiment group improved and remained at the same level in control group. In the experiment group all analyzed indices of mental workability increased and acquired measured character.

Evaluation of the effect of high air temperature on the behavioural activity and physical performance of animals (in a rat model)

Introduction. The profession of firefighters belongs to extreme activities. Fire hazards include flames, sparks, heat flow, elevated ambient temperatures, increased concentrations of toxic combustion and thermal decomposition products, decreased oxygen concentrations, and reduced visibility in smoke. High air temperature during fire extinguishing is one of the main adverse physical factors affecting firefighters’ bodies. Material and methods. The study was carried out on 124 outbred white male 3-month rats weighing 250-300 g, divided randomly into two groups: the first group (62 rats) underwent single hyperthermia. The second group (62 rats) experienced daily hyperthermia for 14 days. The study of the behavioural activity of animals was carried out after single and prolonged hyperthermia using the following methods: “Open field”, “Elevated cruciform maze”, Porsolt’s test, running on a treadmill. The tests were performed two times: the first time - before exposure, the second - after, with intervals between tests of at least two weeks. Results. The data obtained indicate that the high ambient temperature causes changes in the behavioural responses in animals, which is expressed by an increase in the level of anxiety, a decrease in motor and research activity, the development of depressive states, and a decrease in physical endurance. Conclusion. An experimental model of extreme heat exposure on animals showed the emergence and persistence of changes in animals’ behavioural activity and physical performance indicators. This experiment can be used to study the long-term effects of high temperatures on firefighters’ bodies.

Morning resistance exercise and cricket-specific repeated sprinting each improve indices of afternoon physical and cognitive performance in professional male cricketers

ObjectivesTo compare two modes (general and cricket-specific) of morning priming exercise on afternoon physical and cognitive performance, and subjective readiness to perform in professional male cricketers. DesignRandomised, crossover, counterbalanced. MethodsOn three occasions, 16 professional men's cricketers completed afternoon tests of countermovement jump height, cricket-specific sprint performance (running between the wickets, two runs), cognitive function (Stroop test, time taken), and subjective readiness to perform. Control (CON; passive rest), lower-body resistance exercise priming (LIFT; trap bar deadlifts, 6 × 4 repetitions up to 85% of one repetition maximum), or cricket-specific running priming (RUN; 6 × 35.36 m sprints including a 180° change of direction) interventions were implemented 5.5 h before testing. ResultsAfternoon sprint times were faster in RUN (−0.04 s, p = 0.013) and LIFT (−0.07 s, p < 0.001) versus CON, and faster in LIFT than RUN (−0.03 s, p = 0.032). Jump height (+1.1 cm, p = 0.021) and cognitive function (−3.83 s, p = 0.003) were greater in LIFT than CON, whilst RUN outperformed CON for cognition (−2.52 s, p = 0.023). Although perceived readiness was not influenced by trial (p > 0.05), players reported favourable responses on the “aggression” subscale in LIFT relative to CON (+1 arbitrary unit, p = 0.022). ConclusionsBoth general (lower-body resistance exercise) and cricket-specific (simulated running between wickets) morning priming are effective match-day strategies to improve afternoon markers of physical and cognitive performance in professional men's cricketers. Practitioners may thus be afforded flexibility in situations where resistance exercise is not feasible on the morning of a match.

Acceptance Test of Physical Properties of Perfexion Gamma Knife

Objective The acceptance test of the physical performance for the newly installed PFX Gamma knife was carried out to provide a reference for the quality assurance of the equipment. Method According to the manufacturer's acceptance manual and Chinese health industry standards, the dose rate of the PFX Gamma knife with maximum collimators in the calibration center point, the focal spot dose distribution with all three collimator sizes, the distance between the RFP and the PPS calibration center point, and the multi-target position accuracy were measured by means of the acceptance tools. Results The average absorbed dose rate, as measured in April 29, 2019, was 3.295 Gy/min in the calibration center point by the maximum collimators, which was better than acceptance standard of 2.5 Gy/min. The focal spot dosimetry data measured by the film were basically the same as the TMR-10 data stored in the LGP. The difference in FWHM was 0.18±0.13 mm, and the difference in penumbra was 0.15±0.25 mm, which was normal and as expected. The distance between the RFP and PPS calibration center point in the three-dimensional space was 0.24 mm, which was better than the recommended value of the factory standard and the national standard. The maximum position deviation of multiple targets was 0.16 mm, which was also better than the factory standard of 0.5 mm. Conclusion The various physical performance indicators of the PFX Gamma knife met the acceptance standards of manufacturers and industries.

Impact of technical and physical key performance indicators on ball possession in the Chinese Super League

ABSTRACT Ball possession an important key performance indicator (KPIs) in men’s soccer; thus, coaches and analysts have been interested in the technical and physical parameters resulting in different possession statuses. In this regard, this study aims to examine the relationship between match KPIs and ball possession in elite men’s soccer, and identify the suitable analysis method (multiple linear regression, MLR vs. quantile regression, QR) to model this relationship in the Chinese Super League (CSL). A total of 474 performance records from 237 matches during the 2019 competitive season in the CSL were selected, and analysed using MLR and QR using the 10th, 25th, 50th, 75th, and 90th quantiles. Several technical (foul, pass, air duel, tackle, shot, and corner kick) and physical (sprint and high-speed running distance) KPIs were associated with ball possession. Compared to the MLR model, the QR model identified additional physical KPIs, which are sprint, high-speed running, and high-intensity running efforts, that influenced ball possession. For the situational variables, the quality of the opposition affects the ball possession from the 25th to 75th quantiles. Therefore, QR modelling is a potential tool for performance analysts and coaches to strategise and monitor different parameters in a match.

ESTIMATION OF FUNCTIONAL AND PHYSICAL TRAINING OF WRESTLERS WITH THE USE OF INTERVALOMETRY AND LOADS OF SUBMXIMAL AND MAXIMUM INTENSITY

The methodology for determining the indicators of special physical and functional readiness of wrestlers, proposed by the authors, is distinguished by its simplicity and, at the same time, originality. The presence of a large number of discrete values makes the proposed method for determining indicators more sensitive and allows more accurate assessment of the results of maximum tests using loads of a specific nature of maximum and submaximal power, standard dosed load of a specific nature of submaximal power. It makes it possible to more accurately determine the degree of influence on the body of wrestlers of various qualifications, weight category and gender, the body's response to a specific load: heart rate, respiratory rate after exercise and the speed of recovery processes, indicators of physical performance and maximum oxygen consumption, as well as to carry out a comparative analysis efforts of wrestlers when performing physical activity of a specific nature of maximum and submaximum power. The data given by the authors allow to more effectively carry out operational and staged control over the process of training wrestlers of various styles, to make timely adjustments to the training plans of athletes

Four Weeks of Detraining Induced by COVID-19 Reverse Cardiac Improvements from Eight Weeks of Fitness-Dance Training in Older Adults with Mild Cognitive Impairment.

Physical training is considered as a low-cost intervention to generate cardioprotective benefits and to promote physical and mental health, while reducing the severity of acute respiratory infection symptoms in older adults. However, lockdown measures during COVID-19 have limited people’s opportunity to exercise regularly. The aim of this study was to investigate the effect of eight weeks of Fitness and Dance training, followed by four weeks of COVID-19-induced detraining, on cardiac adaptations and physical performance indicators in older adults with mild cognitive impairment (MCI). Twelve older adults (6 males and 6 females) with MCI (age, 73 ± 4.4 y; body mass, 75.3 ± 6.4 kg; height, 172 ± 8 cm; MMSE score: 24–27) participated in eight weeks of a combined Fitness-Dance training intervention (two sessions/week) followed by four weeks of training cessation induced by COVID-19 lockdowns. Wireless Polar Team Pro and Polar heart rate sensors (H10) were used to monitor covered distance, speed, heart rate (HR min, avg and max), time in HR zone 1 to 5, strenuousness (load score), beat-to-beat interval (max RR and avg RR) and heart rate variability (HRV-RMSSD). One-way ANOVA was used to analyze the data of the three test sessions (T1: first training session, T2: last training session of the eight-week training program, and T3: first training session after the four-week training cessation). Statistical analysis showed that eight weeks of combined Fitness-Dance training induced beneficial cardiac adaptations by decreasing HR (HR min, HR avg and HR max) with p < 0.001, ES = 0.5–0.6 and Δ = −7 to−9 bpm, and increasing HRV related responses (max and avg RR and RMSSD), with p < 0.01 and ES = 0.4. Consequently, participants spent more time in comfortable HR zones (e.g., p < 0.0005; ES = 0.7; Δ = 25% for HR zone 1) and showed reduced strenuousness (p = 0.02, Δ = −15% for load score), despite the higher covered total distance and average speed (p < 0.01; ES = 0.4). However, these changes were reversed after only four weeks of COVID-19 induced detraining, with values of all parameters returning to their baseline levels. In conclusion, eight weeks of combined Fitness-Dance training seems to be an efficient strategy to promote cardioprotective benefits in older adults with MCI. Importantly, to maintain these health benefits, training has to be continued and detraining periods should be reduced. During a pandemic, home-based exercise programs may provide an effective and efficient alternative of physical training.

ТИПОЛОГИЧЕСКИЕ ОСОБЕННОСТИ ЭНЕРГЕТИЧЕСКОГО ОБЕСПЕЧЕНИЯ МЫШЕЧНОЙ ДЕЯТЕЛЬНОСТИ ДЕВОЧЕК И МАЛЬЧИКОВ 9–10 ЛЕТ

Aim. The purpose of the study is to identify typological features of energy supply of muscle activity in 9–10 year-old children by means of cluster analysis. Materials and methods. The study involved apparently healthy girls (n = 201) and boys (n = 176) ages 9–10 years. A set of indicators of energy supply, physical performance, physical fitness and physical development was used for the study, as well as body types were determined. Results. Analysis of differences between groups showed that 9–10 year-old boys demonstrated higher values (p < 0.05–0.001) of energy supply and physical performance than girls. Four options for energy metabolism were revealed characterized by typical combinations of aerobic, anaerobic glycolytic and anaerobic alactate capabilities with physical performance, physical fitness and physical development. It was found that among children with aerobic metabolism, children with high endurance and leptosomic type were often found. Children with anaerobic metabolism were often characterized by high speed, strength, speed and strength abilities and eurysomic type. Conclusion. The selected options of energy supply must be taken into account in physical education, health and sports training for 9–10 year-old children.

Blood parameters as a measure for controlling physical performance of young Algerian cyclists (U23 category)

Background and Study Aim. The use of blood parameters in monitoring athletes is an essential but an unstandardized component of managing athletic preparation. This study aims to describe and evaluate typical measurements and responses observed while monitoring elite cyclist during a training camp. The reported observations might contribute in constituting a scientific support for other practitioners to employ. Material and Methods. 35 elite cyclists from the Algerian National team aged 16 – 23 years participated in this study. Peripheral fasting blood samples were collected in resting after 24 hrs of physical inactivity and outside competitions. Complete blood count (CBC) and hormonal index values (Cortisol, Testosterone, Probnp and TnT) were tested twice before and after the training camp. The statistical data were analysed by the SPSS software version 22.0. Results. The observed rates of change were significant (p&lt;0,01, p&lt;0,05) for most erythrocyte variables, except for leukocyte and platelet distribution levels. Hormonal values recorded for Troponin (↓92,78%, p=0,000) and Cortisol (↓11,85%, p=0,000) remained significantly as an anticipatory response to competition. The responses of the ProBnp and testosterone were not statistically significant and experienced a different response with regards to their kinetics. Conclusion. This study is further support suggesting a viable approach to monitoring physical performance index in elite athletes. The results imply that reducing volume while increasing intensity of training just before competition can enhance performance during short preparation periods.

Change in physical performance indicators of the progenies of rats with experimental preeclampsia in early and late pharmacological correction by GABA derivatives

Change in physical performance indicators of the progenies of rats with experimental preeclampsia in early and late pharmacological correction by GABA derivatives

The Effect of Growth Hormone Treatment on Physical Performance Indices in Children With Idiopathic Short Stature.

To examine the effect of growth hormone (GH) treatment on physical performance in children with idiopathic short stature and normal GH secretion. A total of 24 children participated in the study (13 GH-treated, 11 non-treated, aged 8-13y, 11 males and 13 females, Tanner stage 1-2). Participants performed a battery of motor skill performance tests (Eurofit), as well as the Wingate anaerobic test. No statistically significant differences in any of the Eurofit physical fitness test results (eg,20-m shuttle run 33.0 [15.1] vs 25.1 [21.0] laps in treated and nontreated participants, respectively, P = .25) or the Wingate anaerobic test were found between the groups (eg,peak power 5.0 [2.9] vs 3.9 [2.6]watts/kg in treated and nontreated participants, respectively, P = .2). Therapeutic usage of exogenous GH for pre and early pubertal children with idiopathic short stature and normal GH secretion was not associated with beneficial effects on physical performance indices. This suggests that the use of GH as a potential performance enhancing agent, in this age group, at least at commonly used doses, is not advantageous.

The effects of free weights and isoinertial resistance during semisquatting exercise on amateur soccer players' physical performance indicators: a randomized controlled study.

The aim of this study was to compare the effects of two lower extremity strengthening programs using isoinertial resistance or free weights on amateur soccer players' physical performance indicators. Thirty-five amateur soccer players (average age 22.6±5.1 years) were randomly assigned to isoinertial group (N.=11) or free-weight group (N.=11), or control group (N.=13). The groups performed two training sessions per week for six weeks. Before and after the strengthening implementation, physical performance indicators were evaluated, including the isokinetic knee extensors and flexors' strength, power, speed, and agility. The significance level was set at P<0.05. The isoinertial training resistance led to an increase in the hamstrings' eccentric strength at 60°/s and 150°/s (P<0.05) compared to the free-weight resistance (P>0.05) and the controls (P>0.05). No other significant adaptations were observed in the other isokinetic strength, power, speed (10-m, P=0.052) and agility measurements (Illinois Agility Test, P=0.059). In ratio (knee flexors/knee extensors) the only differences observed were at 150°/s for isoinertial group (P<0.05). Isoinertial resistance training during semisquatting can enhance the hamstrings' eccentric performance and the soccer players' speed and agility compared to the classic free-weight training program, which should consider when designing strength and injury prevention programs.