Reliability of Change-of-Direction Economy in Soccer Players

Author(s):  
Filippo Dolci ◽  
Andrew E. Kilding ◽  
Tania Spiteri ◽  
Paola Chivers ◽  
Ben Piggott ◽  
...  

Purpose: To evaluate the reliability of new change-of-direction-economy tests (assessing energetic efficiency when performing continuous shuttle runs) compared with common running-economy tests in soccer players Methods: Sixteen subelite, male soccer players were recruited to perform a testing battery involving running economy (RE), 10-m shuttle-running economy (SRE10), and 20-m shuttle-running economy (SRE20) at 8.4 km·h−1 mean speed on 2 different days within 48 hours. SRE10 and SRE20 consisted of continuous shuttle runs interspersed with 180° directional changes. During the RE, SRE20, and SRE10 tests, respiratory exchange ratio and oxygen uptake were collected and used to calculate the movement-economy values over any running condition as oxygen cost and energetic cost. The secondary variables (carbon dioxide production, heart rate, minute ventilation, and blood lactate) were also monitored during all tests. Results: Depending on expression (oxygen cost or energetic cost), reliability was established for RE (CV: 5.5%–5.8%; ICC = .77–.88), SRE10 (CV: 3.5%–3.8%; ICC = .78–.96), and SRE20 (CV: 3.5%–3.8%; ICC = .66–.94). All secondary physiological variables reported good reliability (CV < 10%), except for blood lactate (CV < 35.8). The RE, SRE10, and SRE20 tests show good reliability in soccer players, whereas blood lactate has the highest variability among physiological variables during the economy tests. Conclusion: The assessment of change-of-direction economy through performing 20- and 10-m shuttle runs is reliable and can be applied to evaluate soccer players’ energetic movement efficiency under more soccer-specific running conditions.

Author(s):  
Filippo Dolci ◽  
Andrew E. Kilding ◽  
Tania Spiteri ◽  
Paola Chivers ◽  
Ben Piggott ◽  
...  

Purpose: To investigate the acute effect of repeated-sprint activity (RSA) on change-of-direction economy (assessed using shuttle running economy [SRE]) in soccer players and explore neuromuscular and cardiorespiratory characteristics that may modulate this effect. Methods: Eleven young elite male soccer players (18.5 [1.4] y old) were tested on 2 different days during a 2-week period in their preseason. On day 1, lower-body stiffness, power and force were assessed via countermovement jumps, followed by an incremental treadmill test to exhaustion to measure maximal aerobic capacity. On day 2, 2 SRE tests were performed before and after a repeated-sprint protocol with heart rate, minute ventilation, and blood lactate measured. Results: Pooled group analysis indicated no significant changes for SRE following RSA due to variability in individual responses, with a potentiation or impairment effect of up to 4.5% evident across soccer players. The SRE responses to RSA were significantly and largely correlated to players’ lower-body stiffness (r = .670; P = .024), and moderately (but not significantly) correlated to players’ force production (r = −.455; P = .237) and blood lactate after RSA (r = .327; P = .326). Conclusions: In summary, SRE response to RSA in elite male soccer players appears to be highly individual. Higher lower-body stiffness appears as a relevant physical contributor to preserve or improve SRE following RSA.


2000 ◽  
Vol 25 (4) ◽  
pp. 250-261 ◽  
Author(s):  
Claude Lajoie ◽  
Louis Laurencelle ◽  
François Trudeau

Changes in physiological variables during a 60-min continuous test at maximal lactate steady state (MLSS) were studied using highly conditioned cyclists (1 female and 9 males, aged 28.3 ± 8.1 years). To determine power at MLSS, we tested at 8-min increments and interpolated the power corresponding to a blood lactate value of 4 mmol/L. During the subsequent 60-min exercise at MLSS, we observed a sequential increase of physiological parameters, in contrast to stable blood lactate. Heart rate drifted upward from beginning to end of exercise. This became statistically significant after 30 min. From 10-60 min of exercise, a change of + 12.6 ± 3.2 bpm was noted. Significant drift was seen after 30 min for the respiratory exchange ratio, after 40 min for the rate of perceived exertion using the Borg scale, and after 50 min for % [Formula: see text] and minute ventilation. This slow component of [Formula: see text] may be the result of higher recruitment of type II fibers. Key words: Rate of perceived exertion, heart rate, oxygen consumption, blood lactate, cycling


Author(s):  
Filippo Dolci ◽  
Andrew E. Kilding ◽  
Tania Spiteri ◽  
Paola Chivers ◽  
Benjamin Piggott ◽  
...  

AbstractThis study aimed to evaluate the effect of high-intensity interval training shock microcycles (HIITSM) on endurance, running economy and change of direction economy in female soccer players. Nineteen sub-elite female soccer players were randomised to two groups: HIITSM (10 HIIT sessions over 13 days) or HIITTRAD (4 HIIT sessions over 13 days) interventions. Endurance performance was evaluated through the 30–15 intermittent fitness test (30–15IFT); running economy over a 5-min treadmill run; and change of direction economy over two conditions: (1) 5-min 20m shuttle run, and (2) 5-min 10m shuttle run. HIITSM significantly improved 30–15IFT scores compared to baseline (+4.4%, p=0.009; d=0.96) and 30–15IFT scores relative to HIITTRAD (p=0.002; d=2.01). There was no significant interaction (group×time) for running economy and change of direction economy. Pre- to post- intervention there was a significant main time effect for blood lactate over 20m and 10m shuttle runs (p<0.001 and p=0.037, respectively), with large (d=0.93) and moderate (d=0.53) changes observed for the HIITSM over the two distances, respectively. HIITSM may be more effective than HIITTRAD to improve 30–15IFT over shorter training periods but may not affect running economy and change of direction economy.


Author(s):  
Filippo Dolci ◽  
Andrew Kilding ◽  
Tania Spiteri ◽  
Paola Chivers ◽  
Ben Piggott ◽  
...  

2020 ◽  
Vol 73 (1) ◽  
pp. 193-201
Author(s):  
Yusuf Köklü ◽  
Utku Alemdaroğlu ◽  
Ramazan Demirhan ◽  
Yunus Arslan

AbstractThe purpose of this study was to compare the incremental running tests performed by young soccer players on a treadmill (Tr) and in the field (FTcod: 100 m change of direction and FTcir: 100 m circle). Nineteen players (average age 17.4 ± 1.1 years; body height 172.0 ± 5.7 cm; body mass 68.9 ± 6.7 kg) volunteered to perform incremental Tr , FTcod and FTcir running tests. In all three tests, players ran for 3 min at 8, 10, 12 and 14 km∙h-1 and were given a 1 min rest interval between subsequent stages. Blood lactate concentrations (La-) were measured at 1 min rest intervals and the heart rate (HR) responses of players were recorded during the tests. After a 5 min recovery period, the second part of the test started; players ran at 15 km∙h-1 with velocity increments of 1 km∙h-1 every 1 min until exhaustion. This part was performed to determine maximum HR, maximum La- and the players’ final velocities. The results showed that players had significantly lower La- (F = 6.93, p = 0.07, η2 = 0.46, 95%CI(TR-FTcir) = -1.91/-0.34, 95%CI(TR-FTcod) = -1.59/-0.05) and HR (F = 9.08, p = 0.02, η2 = 0.53, 95%CI(TR-FTcir) = -6.98/-1.68, 95%CI(TR-FTcod) = -7.19/1.08) responses in the Tr test than in the FTcir and FTcod tests at 14 km∙h-1. It was also found that players completed the Tr test (F = 58.22, p = 0.00, η2 = 0.87) at higher final running velocities than the FTcir (95%CI(TR-FTcir) = 1.67/2.78) and FTcod (95%CI(TR-FTcod) = 1.69/2.85) tests. In conclusion, when coaches or sports scientists plan to train at higher running velocities or according to the final velocity in the test, it is advisable to carry out testing in the circumstances under which training will be carried out (in the field or on a treadmill).


Sports ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 51 ◽  
Author(s):  
James H. Dugdale ◽  
Dajo Sanders ◽  
Angus M. Hunter

Considering the vast physical and neural developments experienced throughout adolescence, the reliability of physical performance may vary in youth populations. This study aimed to examine the reliability of change of direction (COD) and agility tests in youth soccer players. Altogether, 86 youth soccer players, aged 13.6 ± 2.0 years, volunteered to participate. Data were collected from a modified 505 COD test (m505COD) and the Y-sprint drill in both pre-planned (Y-SprintPRE) and reactive (Y-SprintREACT) conditions during 2 sessions, 7 days apart. Anthropometric data including body mass, standing stature, and sitting height were also collected. COD and agility tests demonstrated good reliability (ICC = 0.81–0.91; CV = 1.2–2.0; d = 0.00–0.31; p < 0.01) for our entire sample. However, we observed a small negative relationship between age and intersession differences for the Y-SprintPRE (r = −0.28; p = 0.04), and moderate negative relationships between both age (r = −0.41; p < 0.01), and maturity offset (r = −0.39; p < 0.01) for the Y-SprintREACT. Although the COD and agility tests adopted within this study possess good intersession reliability, we observed greater intersession differences for younger and less mature individuals. We suggest that while COD and agility tests may provide meaningful objective data for monitoring the development of youth soccer players, these tests should be used with caution when evaluating younger, more immature athletes.


Author(s):  
Javier Raya-González ◽  
Filipe Manuel Clemente ◽  
Daniel Castillo

Although asymmetries in lower limbs have been linked with players’ performance in male soccer players, literature that has been published addressing female soccer is scarce. Thus, the aim of this study was twofold: (i) describe the asymmetries of women soccer players during jumping, change-of-direction and range-of-motion tests; and (ii) test possible relationships between asymmetries and injury risk in female soccer players. Sixteen female players (15.5 ± 1.5 years) performed a battery of fitness tests (i.e., jump ability, change-of-direction ability and passive range-of-motion) and muscle mass analysis via dual-energy X-ray absorptiometry, through which the specific asymmetry index and the related injury risk were calculated. Significant (p < 0.05) lower asymmetries in the change-of-direction test were observed in comparison to those observed in jumping and range-of-motion tests; significant (p < 0.05) lower asymmetries in muscle mass were also reported compared to those found in the change-of-direction and countermovement jump tests. Additionally, increased injury risk for countermovement jump and hip flexion with extended knee range-of-motion (relating to asymmetry values) and for ankle flexion with flexed knee range-of-motion in both legs (relating to reference range-of-motion values), as well as increased individual injury risk values, were observed across all tests. These findings suggest the necessity to implement individual approaches for asymmetry and injury risk analyses.


Author(s):  
Elena Pardos-Mainer ◽  
Chris Bishop ◽  
Oliver Gonzalo-Skok ◽  
Hadi Nobari ◽  
Jorge Pérez-Gómez ◽  
...  

The association between asymmetries in jump and change of direction (COD) with physical performance in several sports show inconclusive results. The purposes of this study were to: (1) measure inter-limb asymmetries in three distinct groups in adolescent female soccer players and, (2) to determine the association between inter-limb asymmetries and physical performance in different age groups. Fifty-four players were distributed in three age groups: U-18, U-16 and U-14. All of them performed a series of jumps, sprints and change of direction speed tests. Asymmetries were assessed as the percentage difference between limbs, with the equation: 100/Max value (right and left) * in value (right and left) * −1 + 100. Mean inter-limb asymmetries were 2.91%, 4.82% and 11.6% for 180° COD, single leg hop and single leg countermovement jump tests respectively, but higher percentages of asymmetries were observed in many players individually. U-18 and U-16 showed significant differences on 180° left COD compared to U-14. Effect size (ES): 0.80 and 0.74, respectively; U-18 presented differences on single left leg hop test compared to U-14, ES: −0.72; U-16 also showed differences on 40 m speed compared to U-14, ES 0.87 (All p < 0.05). Jumping and COD physical tests show asymmetries in adolescent female soccer players, but these asymmetries do not interfere with physical performance. The largest asymmetry was observed in the single leg countermovement jump, and no asymmetries between groups were found. Due to the high variability in the direction of asymmetries, it is recommended to consider players’ individual asymmetries for designing specific training programs.


Author(s):  
Daniel Barbosa Coelho ◽  
Rodney Coelho da Paixão ◽  
Emerson Cruz de Oliveira ◽  
Lenice Kappes Becker ◽  
João Batista Ferreira-Júnior ◽  
...  

DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n6p621 The aims of the study were: 1) to analyze the exercise intensity in several phases (six phases of 15 min) of soccer matches; 2) to compare the match time spent above anaerobic threshold (AT) between different age groups (U-17 and U-20); and 3) to compare the match time spent above AT between players’ positions (backs, midfielders, forwards and wingabcks). Forty-four male soccer players were analyzed. To express players’ effort, the heart rate (HR) was continuously monitored in 29 official matches. Further, HR corresponding to the intensity at the onset of blood lactate accumulation (OBLA) was obtained in a field test. The highest exercise intensity during match was observed in the 15-30 min period of the first half (p< 0.05). Match time spent above AT was not different between players from U-17 and U-20. In the comparison among players’ positions, wingbacks showed lower time above AT (p< 0.05) than players of other positions. The intensity of effort is higher in the 15 to 30 minutes of play (intermediate phase), probably because the players are more rested in the beginning and wearing out is progressive throughout the game. It is also noteworthy that the intensity of exercise (HR and time above AT) of wingbacks was lower, probably because they usually are required to run a larger number of sprints and need more time below the AT to recover. 


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