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ORIGINAL ARTICLE
Year : 2022  |  Volume : 22  |  Issue : 1  |  Page : 21-29

Comparison of endurance, agility, and core strength between national and state level female football players


Department of Physiotherapy, Faculty of Allied Health Sciences, Manav Rachna International Institute and Studies, Faridabad, Haryana, India

Date of Submission14-Jan-2022
Date of Acceptance02-Feb-2022
Date of Web Publication4-Apr-2022

Correspondence Address:
Moattar Raza Rizvi
Department of Physiotherapy, Faculty of Allied Health Sciences, Manav Rachna International Institute of Research and Studies, Faridabad - 121 001, Haryana
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/sjsm.sjsm_3_22

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  Abstract 


Objective: The present research was undertaken with the aim of evaluating and comparing the levels of performance in terms of aerobic endurance, agility, and core strength among female National and State level football players.
Methodology: Using a convenience-sampling method, 65 female football players were recruited in this study. These players were further divided into two groups: national level female players (N = 30) and state level female players (N = 35). Aerobic endurance was checked through Yo-Yo intermittent recovery test Level 1 (YYIRTL1), agility was measured through the change of direction ability test, and core strength was evaluated by the Plank test.
Results: Using YYIRTL1, we found that national level players (Mean = 16.67, standard deviation [SD] = 2.01) had greater aerobic endurance than state level players (Mean = 14.63, SD = 1.59). The national players (Mean = 15.81, SD = 1.71) had better agility than the state players (14.67, SD = 1.54). The duration of prone posture was longer in national players (86.93, SD 4.82) than in state players (79.89, SD 4.65).
Conclusion: Findings showed that state level players have low aerobic endurance, low agility, and less core strength as compared to national level players.

Keywords: Agility, change of direction ability, core strength, football player, endurance, plank test, yo-yo intermittent recovery test level 1


How to cite this article:
Zaidi Z, Rizvi MR, Sharma A, Saini P, Nigam S. Comparison of endurance, agility, and core strength between national and state level female football players. Saudi J Sports Med 2022;22:21-9

How to cite this URL:
Zaidi Z, Rizvi MR, Sharma A, Saini P, Nigam S. Comparison of endurance, agility, and core strength between national and state level female football players. Saudi J Sports Med [serial online] 2022 [cited 2022 Jun 28];22:21-9. Available from: https://www.sjosm.org/text.asp?2022/22/1/21/342525




  Introduction Top


Football is a sport, which involves intermittent high intensity physical activity, consists of continuous movement punctuated by bursts of intense activity. The activity further includes high aerobic load and extensive anaerobic energy turnover. Although performance in the sports like football is considered to be dependent on player's high aerobic ability and anaerobic ability which is essential for their better performance. Specially, VO2 max (maximum aerobic power) is believed to enhance the athlete's ability to recover from anaerobic efforts made throughout the match.[1]

According to prior research examining past sports injuries in male and female university football players, the incidence of sports injuries in high school tended to be higher for female players.[2],[3] Male players increase muscle strength during teenage growth, while female players do not, which is why the prevalence of sports injuries is higher in female players.[4] However, few researches examine the physical attributes that influence the prevalence of sports injuries during training.[3]

The Yo-Yo intermittent recovery (IR) tests are designed to determine an individual's capacity to perform repeated bouts of strenuous exercise over a short distance. There are two levels of Yo-Yo IR test, i.e., Yo-Yo Endurance Test Level 2 (YYETL2) and Yo-yo IR Test Level 1 (YYIRTL1). The YYIRTL1 is concerned in the capacity to perform intermittent exercise that results in the aerobic system being maximally activated. YYETL2 is intended to enhance an individual's capacity to recover from repeated exercise with a strong anaerobic component.[5],[6] Elite athletes in a variety of sports requiring intermittent activity were evaluated and it was discovered that the higher the level of competition, the better the athlete performs in the YYIRTL1[5],[7],[8]

The trunk is essential for energy transfer and connecting lower and upper extremity movements. The trunk contains several muscles, and appropriate activity of these muscles is essential to regulate the trunk's movement and posture during athletic activities.[8],[9] Core stability is explained in a sporting context as the capacity to control the position and motion of the trunk above the pelvis to optimize energy transmission from the torso to the extremities when conducting athletic activities that frequently include highly loaded movements.[10] The trunk is essential for energy transfer and connecting lower and upper extremity movements. The trunk contains several muscles, and appropriate activity of these muscles is essential to regulate the trunk's movement and posture during athletic activities.[8],[9] Core stability is described in a sporting context as the capacity to control the position and motion of the trunk above the pelvis to optimize energy transmission from the torso to the extremities, when conducting athletic activities that frequently include highly loaded movements.[10] Recent years have seen a substantial increase in core muscle training for both sports conditioning programs and the general population, owing to fitness experts prioritizing core training. Researchers have previously demonstrated that trunk exercises boost players' athletic performance. It is critical to evaluate trunk function in conjunction with an athlete's fitness level. The prone plank test has been utilized to assess trunk flexor endurance in recent research.[11],[12]

In football sport, players often have to repeatedly change the direction while sprinting by accelerating and suddenly braking. Players also require a sudden change of direction (COD) with minimal braking time. As a result, the ability to direction has been extensively explored across a variety of athlete populations using cross-sectional and intervention studies.[13],[14] In research and applied practice, the use of total time as a measure of COD performance has been overwhelmingly considered as a “valid” measure of performance.[13],[15]

This study was done to find the performance of both the level players to compare the aerobic endurance Yo-Yo IR test (YYIRTL1), agility COD ability (CODA) test, and core strength Plank test between the National and State level football players.


  Methodology Top


Samples were collected from sports complex, Saket (Delhi), DDA sports complex, Okhla using convenience-sampling method. The number of subjects was determined through G * Power 3.1.9.4, considering a moderate effect size of 0.5 using statistical test of mean difference between two dependent means (matched pair). The sample size of 38 was shown to be necessary based on the effect size of 0.5, an alpha level of 0.05, and power of 0.85. Therefore, seventy-six players were recruited in this study with 38 female football players both at National and state level. Female football players between the ages 12–19 years were included in this study. There were 17 players who competed at both the state and national levels; they were all assigned to the national level group.

The players having any injury of lower limb, unfit to perform the tests, were excluded from the study. The history of the injury was collected by inquiring about it at the time of signing the consent form. They were required to sign a statement asking informed consent, and the players were required to obtain consent from parents whose children were under the age of 18.

The subjects were informed of the study's purpose and procedures. A history and assessment were completed before to administering the examination, and anyone unwilling to perform the examinations was eliminated based on their choice. A history and assessment were completed before to administering the examination, and anyone unwilling to perform the examinations was eliminated based on their choice. We recorded demographic data such as body weight and height and calculated body mass index (BMI). The tests were conducted twice and best of 2 recording were taken as the final readings. The tests were repeated twice, with the best of the two results used as the final results. The tests were completed on a single day in the following order: Yo-Yo intermittent test first, capacity to change directions second, and plank fitness test third. The tests were performed with the help of the coach.

Yo-Yo intermittent recovery test

The YYIRTL1 was done by the method as described by Bangsbo et al.[5],[6],[7] Cones were utilized to denote three lines 20 m and 5 m apart in this test. When directed by the audio, subjects begin running 20 m (CD or team beep test software). When directed by a recorded beep, the subject then turns and returns to the beginning place. There was a 5–10 s active recovery interval during which the patient jogged down to the starting line. A warning was issued to the individual who initially failed to execute an out and return shuttle successfully within the allotted time. The individual was removed the next time they failed to successfully complete a shuttle.

Change of direction ability

The CODA test was performed on referees as per the method described by Castagna.[13],[15] Cones were used by marking three lines, i.e., line A, B, and C. The distance between lines A to B was 2 m and B to C was 8 meters. Start line was marked 0.5 m before the timing gate (A). Football players were line up at the start with their front foot touching the start line. Players started running when the signal was given that the electronic timing gate is set and players will start running.

Players sprint 10 m forward (A to C), 8 m sideways left (C to B), 8 m sideways right (B to C), and 10 m forward (C to A). This test was done one time. If a player failed the trial, they had given an additional trial. If they fail two trials, the match official has failed the test [Figure 1].
Figure 1: Schematic presentation of change of direction ability test

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Performance in football is determined by physiological, psychological, biomechanical, and environmental factors. Physiological factors include 5 components of health-related fitness (body composition, cardiorespiratory fitness, muscular strength and endurance, flexibility) and sport-specific characteristics such as speed and reaction time.

The plank fitness test

The Plank Test, also known as the Prone Bridge Test, is a simple fitness test for core muscular strength that can also be used as a fitness exercise for core strength improvement. The plank test assesses the back/core stabilizing muscles' control and endurance.[16] The plank test consisted of two postures in this test (i) Test of the Prone Plank (ii) Side Plank Test: right side plank and left side plank.

The prone plank test requires the athlete to maintain an elevated position for an extended period of time. The athlete begins with his or her upper body lifted off the ground by the elbows and forearms and his or her legs straight and weighted by the toes. A straight line from head to toe is created by lifting the hip off the floor. The athlete begins in a side plank position with one elbow and one foot supported on the ground. The side plank test was performed on both the right and left sides. The stopwatch is started as soon as the participant is in the proper position. When the person is unable to maintain a straight back and a depressed hip, the test is completed.

The score is based on the overall amount of time spent. The table below provides a rough estimate of male and female scores. The world record stands at more than 30 min. Plank test scores were classified as excellent if the total time was >6 min; very good if the total time was 4–6 min; above average if the total time was 2–4 min; average if the total time was 1–2 min; below average if the total time was 30–60 s; poor if the total time was 15–30 s; and very poor if the total time was 15 s.

Statistical analysis

Descriptive statistics was performed on all data. Data were checked for normality using Shapiro-Wilk's test as this provides better power than Kolmogorov–Smirnov test. Normally distributed data was expressed in Mean and standard deviation (SD) and median was used to represent the nonnormally distributed data. Following levene's test, independent t-test was applied for test variables having equal variances and Mann–Whitney U-test was applied for the data, which violated the assumption of equal variance. Statistical significances were set at P < 0.05. SPSS 25.0 software (SPSS Inc., Chicago, IL, USA) was used for all analyses.


  Results Top


This study involved 65 female football players in which 35 were from state level and 30 were from national level. Five players were dropped from the study after failing to complete the Yo-Yo IR test (3 national players; 2 state player). Six players were eliminated during the CODA, CODA (5 national players; 1 state player). In state level, there were 2 goalkeepers, 13 defender, 8 mid fielder, and 12 strikers whereas in national level, there were 2 goalkeepers, 8 defender, 12 mid fielder, and 8 strikers [Graph 1].



While taking history of past injuries of national and state level players, it was noted that ACL injury and ankle sprain were common in state and national level players. In national level players, the percentage of ACL injury (46.7%) was higher as compared to state level players (25.7%). Further, there was slight difference in percentage of knee injury between national (26.7) and state level players (34.3) [Graph 2].



The mean age of national player (Mean = 16.8, SD = 1.61) was found on a little higher side as compared to the state level players (Mean = 15.3, SD = 1.94). Mean height of national level player was 157.57 ± 7.56 and state level player was 177.12 ± 41.69. Mean weight of national level player is Mean = 44.97, SD = 7.26 and state level player is Mean = 43.93, SD = 8.45 did not differ on a large range. BMI was almost same in both the groups of players (National, Mean = 18.09, SD = 2.48 vs. State, Mean = 18.84, SD = 4.42) [Table 1].
Table 1: Physical characteristics of state and national player expressed as mean, median, and standard deviation

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A Shapiro–Wilk's test (P < 0.05) and a visual inspection of their histograms, normal Q-Q plots and box plots showed that the data of age, height, and BMI were not normally distributed for both state and national players, as reflected from the values of skewness and kurtosis of represented in [Table 1].

The core strength was measured by using plank test in three different positions, prone plank; side left plank, and side right plank. It was noted that the duration of prone position was more in national player (Mean = 86.93, SD = 4.82) as compared to state player (Mean = 79.89, SD = 4.65). However, there was not much difference in duration between the national and state players when they were assessed in side left and side right position [Table 2]. In this study, the combined score of plank test (Prone plank, Side left and Side right plank) was also calculated for both level of players and it was noted that the combined score of plank test was found to be higher in national players (Mean = 201, SD = 8.90) as compared to state players (Mean = 192, SD = 9.07). Further considering the classification of plank score into different category as mentioned in [Table 1], it was also observed that the combined score of both national and state level was above average (i.e., 120–240 s).
Table 2: Mean, standard deviation of plank test, change of direction ability, YYIRTL1

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The ability to change the direction among football players was performed using COD agility test. It was noted that the national players (Mean = 15.81, SD = 1.71) had improved agility as compared to the state level players (14.67, SD = 1.54).

Further, we compared aerobic endurance using YYIRTL1 in which it was observed that the national level players (Mean = 16.67, SD = 2.01) had increased aerobic endurance as compared to state level players (Mean = 14.63, SD = 1.59).

A Shapiro–Wilk's test with P < 0.05 and a visual inspection of their histograms, normal Q-Q plots and box plots showed that the data of Prone plank, side right plank, CODA, and YYIRTL1 were normally distributed for both state and national players, as reflected from the values of skewness and kurtosis of represented in [Table 2].

Levene's test verified the equality of variances

A Levene's test verified the equality of variances in the samples (homogeneity of variance) (P > 0.05). Levene's test for equality of variances was found to be violated for height F (1,63) = −2.5, P < 0.01. A levene's test found that the assumption of homogeneity of variance was met for age F (1,63) = 0.89, P = 0.35, weight F (1,63) = 0.78, P = 0.38, and BMI F (1,63) = 1.80, P = 0.18 [Table 3].
Table 3: Test of equality of variances (Levene's) for age, height, weight and body mass index

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A levene's test found that the assumption of homogeneity of variance was met for prone plank F (1,63) = 0.07, P = 0.80, side left plank F (1,63) = 0.35, P = 0.56, side right plank F (1,63) = 2.01, P = 0.16, combined score F (1,63) = 0.0055, P = 0.94, CODA F (1,63) = 0.59, P = 0.44, and YYIRTL1 F (1,63) = 3.20, P = 0.08.

Therefore, a two-tailed independent samples t-test based on equal variances was carried out [Table 4].
Table 4: Test of equality of variances (Levene's) for plank, change of direction ability and YY1RLT1

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Independent test for dependent variables

An independent t-test was conducted for age, weight, and BMI as the data was normally distributed. There was significant difference in age between the national and state players, t (63) =3.186, P = 0.002. Further, there was no significant difference in weight (63) =0.528, P = 0.599 and BMI t (63) =-0.825, P = 0.412 between national and state level players [Table 5].
Table 5: Independent samples t-test for age, weight, and body mass index

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Since the levene's test for equality of variance was violated for height, therefore, we applied Mann–Whitney U-test to see the relation of height between the national and state level football players. There was no significant difference in height (U = 402, 0.105) between national and state level football players (P > 0.05) [Table 5].

Independent-samples test for independent variables

An independent-samples t-test was performed, using an alpha level of 0.05 to examine the difference between the different tests variables used in this study among the state and national level football players.

In addition, endurance strength as measured using YYIRTL1 was significantly higher in national players (Mean = 16.7, SD = 2.01) as compared to state level football players (Mean = 14.6, SD = 1.59), t (63) = 4.56, P < 0.01. There was a difference in CODA between national (Mean = 15.8, SD = 1.71) and state level football players (Mean = 14.6, SD = 1.54), t (63) = 2.95, P ≤ 0.01 which indicates that national level players had significantly higher score in CODA as compared to state level players. There was a difference in prone plank test between national (Mean = 86.9, SD = 4.82) and state level football players (Mean = 79.9, SD = 4.65), t (63) = 5.99, P < 0.01 which indicates that national level players exhibit significantly higher score in prone plank test as compared to state level players. In addition, the overall core strength was calculated by combined score of plank test and was found that combined score was significantly higher in national players t (63) = 4.08, P < 0.01 [Table 6].
Table 6: Independent samples t-test for plank, change of direction ability and YY1RLT1

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The study also examined the difference in the positions of football players and different parameters studied at national and state level. In midfielders it was found that there is significantly higher (P < 0.05) core strength in national level players (86.67 ± 3.26) than state level players (79.88 ± 5.38). Position of player resulted in no significant difference in side left plank and side right plank between national and state level players. The midfielder player showed significantly higher aerobic endurance in national level players (16.13 ± 2.24) as compared to state level players (14.19 ± 1.16), P < 0.05. Further, there was no significant difference in agility of midfielder players between national and state level players.

In Defenders, higher core strength was noted in national level players (87.25 ± 6.16) than state level players (81.00 ± 4.90), P < 0.05. In addition aerobic endurance in defender at national level (15.95 ± 1.54) was comparatively higher (P < 0.05) than state level players (13.79 ± 0.85).

In Striker, it was reported that core strength was significantly higher (P < 0.05) in national level players (87.75 ± 6.16) than state level players (79.00 ± 4.37). The side left plank test resulted in significantly higher (P < 0.05) in national level players (57.50 ± 5.16) as compared to state level strikers (51.58 ± 3.73). In addition the aerobic endurance in strikers at national level (17.96 ± 1.80) was significantly higher (P < 0.05) as compared to the state level (16.01 ± 1.67). No significant difference was noticed in goalkeepers at national and state level, P > 0.05 [Table 7].
Table 7: Different playing position in national and state level female football players

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  Discussion Top


In this study, a comparison of CODA was tested between national and state level female football players. Further, aerobic endurance was tested using yoyo test and core strength was evaluated using plank test between national and state level female football players. We used the L1 version, YYIRT following Krustrup and Bangsbo[17] since this version is best suited for the debut of junior players. This is the first study to demonstrate the comparison of YYIRTL1, CODA test, and plank test between national and state level female football players.

All the participants in this study were females between age group of 13–19 years. In this study, we noted that the score of CODA test was significantly higher in national level players as compared to state level players. Our findings are consistent with another study in which a substantial difference in capacity to alter directions was identified between national and regional referees.[18] Numerous studies have demonstrated that good practical progression can increase agility.[19] In addition, we propose to administer the Modified Agility Test, which requires two sideways movements, due to the significance of this uncommon action.[20] Numerous authors have indicated that the capacity to change direction (CODA) is a necessary skill for football players, who are needed to turn, run, and change tempo during matches.[21]

Further, YYIRTL1 also showed higher score in national level players as compared to state level players. The YYIRTL1 was used to assess an athlete's capacity to do high-intensity aerobic runs repeatedly. It has been found to be a valid and accurate predictor of high-intensity aerobic capacity and VO2 max in athletes competing at a variety of sports and levels of competition. Bradley suggested that the submaximal YYIR1C testing can be utilized for routine, nonexhaustive fitness evaluations.[22]

The Yo-Yo IR test is currently used to evaluate athletes' endurance performance. Recently, Sandhu et al. conducted a study comparing Punjab women cricketers in India and Dhaka women cricketers in Bangladesh on the YYIRTL1.[23] The study concluded that substantial variations in YYIRTL1 performance were seen between Punjab women cricketers in India and Dhaka women cricketers in Bangladesh (YYIRTL1). Punjab women cricketers consistently perform at a greater level of high-intensity aerobic labor than Dhaka women cricketers, as measured by the Yo-Yo IR test.[23]

In 2012, a study was conducted on the YYIRTL1 in junior basketball players according to their performance level and age group. The purpose of this study was to determine the YYIRTL1 potential to discriminate between elite, sub-elite, and nonathletic healthy male athletes across three different age groups. The findings of this study indicated that elite athletes performed much better on the Yo-Yo than sub-elite athletes and the nonelite group. There were no statistically significant variations between participant performance levels and age groups in the YYIRTL1. When the influence of the participants' body mass was controlled for, this study indicated that the yo-yo test is accurate for discriminating elite junior basketball players but cannot be utilized to separate basketball-specific aerobic performance by age.[24]

In addition score of plank test was also significantly higher in national level players as compared to state level players. Plank test was used to find the core strength between national and state level players. Plank test is used in this study to assess the core muscle strength by requiring the subject to isometrically maintain the position as long as an athlete can. Controlling trunk movement is critical for running efficiency and COD performance; hence, core strength training is necessary to increase athletic performance.[12]

Football is a team sport, considered as a casually intermittent activity, which consists of sudden variation in respect to change in direction as well as change in intensity.[21] In 2014, a study has been conducted on repeated sprint (RS) ability in young basketball players: one verses two changes of direction.[25] The purpose of this study was to compare the effects of training on jump performance and aerobic fitness of RS ability (RSA) (with one direction change) and intense RSA (IRSA) (with two direction changes). Short-term repetitive sprint training with one versus two direction changes improves RSA and IRSA although jump performance with a greater increase has only a minor effect on sprint and endurance performance.[25]

RSs with a COD may be more relevant to football than linear RSs. A study was conducted to compare the effect of linear and COD RSs on intermittent high intensity running in the entire season of training. Result showed that there was no difference found in the effect of Yo-Yo IRTL2 or sprint tests and there was no change found between the groups. Further, this study also found that there was a main effect of time for Yo-Yo IRTL2 but there was no time effect found in sprints or VO2 max. This study also concluded that there is an improvement in intermittent HIR performance by using linear and COD RS exercises twice a week over 22 weeks but it does support enhanced sprint time or aerobic power in high-level junior football players.[26]

The trunk endurance plank test, as well as other trunk endurance tests, is utilized in this study to assess trunk muscle endurance by forcing the individual to maintain an isometrically stable posture for the duration of the test. Evans et al. discovered a correlation between COD performance and trunk angular displacement during the COD. In addition, excessive trunk motions, particularly trunk rotation, impair energy transfer efficiency during running-based sports activities.[27] Thus, trunk control is critical for running efficiency and direction change performance.

A study has been done to investigate the association between trunk endurance plank tests and physical performance tests in adolescent soccer players. The result showed that there was a high correlation between plank test and YYIRT, a moderate correlation of plank test with cooper test and a poor correlation was observed between prone plank test and step 50 agility test. The study concluded that result suggests that trunk endurance plank test is positively correlated with cooper test, YYIRT, and step 50 agility test.[16]

This study has four limitations: (1) it has a small sample size, (2) only female football players were included in this study, (3) development in female adolescents may differ considerably between players, (4) sample design was convenience sampling. Further research is needed to clarify the comparison in players related to development and injury risk during play in adolescent female players.


  Conclusion Top


Findings of this study concludes that female state level football players have comparatively low aerobic endurance, Agility and Core strength than National level female football players. State level players requires aerobic endurance training as well as agility and core strength training prior the competition season to increase performance level at the time of competition. It is important to make adequate training programs to enhance performance. Players must be aware of aerobic endurance, agility, and core trainings to set these trainings in their daily practice regimen.

Ethical approval

Ethical approval was obtained from the ethical committee at Faculty of Allied Health Sciences in accordance to Ethical Principles for Medical Research Involving Human (WMA Declaration of Helsinki) having reference No: MRIIRS/FAHS/DEC/2021-16 dated 10th April, 2021.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
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    Figures

  [Figure 1]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7]



 

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