The acute effect of different stretching methods on sprint performance in taekwondo practitioners.

BACKGROUND: The purpose of this study was to compare the acute effects of different stretching types on sprint performance in taekwondo practitioners. METHODS: Twelve male taekwondo practitioners performed stretching exercises using different types (ballistic, proprioceptive neuromuscular facilitation [PNF], static stretching) in a random order at three-day intervals; there was also a control condition involving no stretching exercises. The subjects performed 2 maximal 20-m sprints (with 10-m split times also recorded) with a recovery period of 1 minute immediately post stretching and at 5, 10, 15 and 20 minutes after stretching. They also performed these sprints before doing the stretching exercises. RESULTS: The study results showed that sprint times significantly increased after static stretching (10-m pre =1.84±0.07 s, 10-m post =1.89±0.08 s; 20-m pre =3.33±0.19 s, 20-m post= 3.38±0.2 s), PNF stretching (10-m pre =1.84±0.07 s, 10-m post =1.89±0.08 s; 20-m pre =3.33±0.19 s, 20-m post =3.38±0.20 s) and ballistic stretching (pre =1.84±0.08 s, post =1.86±0.07 s; 20-m pre =3.33±0.20 s, 20-m post =3.35±0.21 s) (P<0.05). In the static stretching condition, 10-m and 20-m sprint performance had fully returned to normal at 15 minutes after stretching. In the PNF stretching condition, 20-m sprint performance returned to normal levels at 15 minutes after stretching, while 10-m performance took 20 minutes to recover fully. In the ballistic stretching method, both 10-m and 20-m sprint performances had fully recovered at 5 minutes after stretching. CONCLUSIONS: It is therefore concluded that the acute effects of static, PNF and ballistic stretching may negatively affect sprint performance, although sprint performance is less affected after ballistic stretching than after the other stretching types. Therefore, it is not advisable to perform PNF or static stretching immediately before sprint performance

Effect of different recovery durations between bouts in 3-a-side games on youth soccer players' physiological responses and technical activities.

AIM: The aim of this study was to investigate the effects of the length of recovery durations between bouts in 4x4min 3-a-side small-sided games (SSG) on time-motion analysis, technical actions and physiological responses of players. METHODS: Twelve young soccer players participated in 4 different 3-a-side games in which the recovery durations between bouts were different (R1: 1 min, R2: 2 min, R3: 3 min, and R4: 4 min). Heart rate (HR), total distance covered in different speed zones, and technical performance were monitored during all SSGs, whereas the rating of perceived exertion (RPE, CR-10) and venous blood lactate were determined at the end of the last bout of each SSG. RESULTS: Results showed that SSGs-R1 induced higher %HRreserve and lower successful passes (vs. R3 and R4 conditions, P18 km.h-1), performed more tackles (vs. R1 condition, P<0.05) and had more ball contacts (vs. R1 and R2 conditions, P<0.05). CONCLUSION: According to these results, it is thought that R1 and R2 are suitable for inducing higher physiological responses, while R3 and R4 are more appropriate for training aim to improve technical skills in 4x4min 3-a-side SSGs among young soccer players. These findings provide evidence for coaches to justify the selection of recovery duration between bouts in 3-a-side SSGs among young soccer players

Comparison of the physiological responses to different small-sided games in elite young soccer players.

The purpose of this study was to compare the blood lactate (La-), heart rate (HR) and percentage of maximum HR (%HRmax) responses among the small-sided games (SSGs) in elite young soccer players. Sixteen players (average age 15.7 6 0.4 years; height 176.8 6 4.6 cm; body mass 65.5 6 5.6 kg; VO2max 53.1 6 5.9 ml · kg(-1) · min(-1); HRmax 195.9 6 7.4 b · min(-1)) volunteered to perform the YoYo intermittent recovery test and 6 bouts of soccer drills including 1-a-side, 2-a-side, 3-a-side, and 4-a-side games without a goalkeeper in random order at 2-day intervals. The differences in La-, HR and%HRmax either among the SSGs or among the bouts were identified using 4 x 6 (games x exercise bouts) 2-way analysis of variance with repeated measures. Significant differences were found on La-, HR, and %HRmax among the bouts (p ≤ 0.05). The 3-a-side and 4-a-side games were significantly higher than 1-a-side and 2-a-side games on HR and %HRmax (p ≤ 0.05), whereas the 1-a-side game significantly resulted in higher La- responses compared to other SSGs. This study demonstrated that physiological responses during the 1-a-side and 2-a-side games were different compared to 3-a-side and 4-a-side games. Therefore, it can be concluded that a decreased number of players results in increased intensity during SSGs including 6 bouts. These results suggest that coaches should pay attention on choosing the SSG type and the number of bouts to improve desired physical conditioning of elite young soccer players in soccer training

A comparison of heart rate response and frequencies of technical actions between half-court and full-court 3-a-side games in high school female basketball players.

The purpose of this study was to compare heart rate (HR) response and frequency of technical actions between half-court and full-court 3-a-side games in female high school basketball players. Twelve young female basketball players (age 15.5 ± 0.5 years; height 165.1 ± 5.7 cm; body mass 57.3 ± 7.2 kg; training age 4.2 ± 0.7 years; HRmax 202.9 ± 5.6 b·min(-1)) participated in this study voluntarily. On the first day, anthropometric measurements (height and body mass) were taken for each player; this was followed by the Yo-Yo intermittent recovery test (YIRT) level 1 for the subjects. Then, half-court and full-court 3-a-side games were organized in random order at 2-day intervals. The HRmax for each player was determined during the YIRT, after which the HR was measured during the 3-a-side games. In addition, the frequencies of different categories of technical actions were counted manually during the 3-a-side games. A paired t-test was calculated for each dependent variable, including HR, percentage of maximum HR (%HRmax), and the frequencies of different technical actions to compare half-court and full-court 3-a-side games. The study results indicate that the full-court 3-a-side games produced significantly higher responses than the half-court 3-a-side games in terms of HR and %HRmax (p < 0.05), whereas the half-court games resulted in significantly higher frequencies of technical actions (p < 0.05). The results of this study suggest that, if coaches want to achieve greater HR responses, coaches of female high school basketball players should organize full-court 3-a-side games, whereas coaches who want to focus on technical actions should arrange half-court 3-a-side games

A Comparison of Incremental Running Field and Treadmill Tests in Young Soccer Players.

The purpose of this study was to compare the incremental running tests performed by young soccer players on a treadmill (Tr) and in the field (FT(cod): 100 m change of direction and FT(cir): 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 , FT(cod) and FT(cir) 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, η(2) = 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, η(2) = 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 FT(cir) and FT(cod) tests at 14 km∙h(-1). It was also found that players completed the Tr test (F = 58.22, p = 0.00, η(2) = 0.87) at higher final running velocities than the FT(cir) (95%CI((TR-FTcir)) = 1.67/2.78) and FT(cod) (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)

Effect of different recovery durations between bouts in 3-a-side games on youth soccer players\u27 physiological responses and technical activities

The aim of this study was to investigate the effects of the length of recovery durations between bouts in 4x4min 3-a-side small-sided games (SSG) on time-motion analysis, technical actions and physiological responses of players.Twelve young soccer players participated in 4 different 3-a-side games in which the recovery durations between bouts were different (R1: 1 min, R2: 2 min, R3: 3 min, and R4: 4 min). Heart rate (HR), total distance covered in different speed zones, and technical performance were monitored during all SSGs, whereas the rating of perceived exertion (RPE, CR-10) and venous blood lactate were determined at the end of the last bout of each SSG.Results showed that SSGs-R1 induced higher %HRreserve and lower successful passes (vs. R3 and R4 conditions, P\u3c0.05), lower total passes (vs. R4 conditions, P\u3c0.05), and greater distance covered in walking zone (0-6.9 km.h⁻¹) (vs. other 3 conditions, P\u3c0.05). In addition, during the SSG-R3 players covered greater distances in high-intensity running zone (\u3e18 km.h-1), performed more tackles (vs. R1 condition, P\u3c0.05) and had more ball contacts (vs. R1 and R2 conditions, P\u3c0.05).According to these results, it is thought that R1 and R2 are suitable for inducing higher physiological responses, while R3 and R4 are more appropriate for training aim to improve technical skills in 4x4min 3-a-side SSGs among young soccer players. These findings provide evidence for coaches to justify the selection of recovery duration between bouts in 3-a-side SSGs among young soccer players

Accuracy and reliability of SPI ProX global positioning system devices for measuring movement demands of team sports.

AIM: The aim of this study was to determine the accuracy and reliability of SPI ProX global positioning system (GPS) devices for measuring movement at various speeds and movement patterns as evident in team sport demands. METHODS: Eleven amateur soccer players performed a 40 m straight sprint test (with 10-20-30 m split times), a zigzag test, 30 m walking, jogging and moderate intensity runs. RESULTS: Results indicated that the SPI ProX GPS measurements showed acceptable accuracy for all movement patterns for distance (coefficient of variation [CV]=0.14% to 3.73%; 95% ratio limits of agreement [95% ratio LOA]=0.97 x / ÷ 1.09 to 1.00 x / ÷ 1.05) and speed (CV=4.22% to 9.52%; 95%LOA=-0.17 ± 1.70 km h-1 to 2.30 ± 1.17 km h-1) compared with the measured distance and speed determined from timing gates, respectively. Furthermore, acceptable reliability of SPI ProX GPS measures for distance (CV=0.34% to 3.81%; 95%LOA=-0.09 ± 0.23 m to -0.34 ± 2.31 m) and speed (CV=3.19% to 6.95%; 95%LOA=-0.05 ± 3.90 km h-1 to 0.42 ± 3.68 km h-1) were also evident. CONCLUSION: Whilst SPI ProX GPS devices were within acceptable ranges of reliability, they remained significantly different to criterion measures of team sport movement demands

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The purpose of this study was to compare the percentage of maximum heart rate (%HRmax), blood lactate (La(-)), and rating of perceived exertion (RPE, CR-10) responses across different formats of small-sided games (SSG) in elite young soccer players. Fourteen players (average age 16.7 ± 0.6 years; height 177.6 ± 4.1 cm; body mass 66.3 ± 4.7 kg; average training age 6.7 ± 1.6 years; percentage of body fat 8.4 ± 2.6%) volunteered to perform the YoYo intermittent recovery test (level 1) and eight bouts of soccer drills including 2-a-side, 3-a-side, and 4-a-side games without goalkeepers in random order at two-day intervals. Heart rates were monitored throughout the SSGs, whereas the RPE and venous blood lactate were determined at the end of the last bout of each SSG. The differences in La(-), %HRmax, and RPE either across the different SSGs or between the bouts were identified using 3 × 8 (games × exercise bouts) two-way analysis of variance with repeated measures. Significant differences were found in terms of La(-), RPE, and %HRmax among the different types of SSG (p ≤ 0.05). 3-a-side and 4-a-side games elicited significantly higher responses than 2-a-side games in terms of %HRmax (p ≤ 0.05), whereas 4-a-side games resulted in significantly lower La(-) and RPE responses compared to 2-a-side and 3-a-side games. The results of this study show that physiological responses differ according to the numbers of players involved in small-sided games. Therefore, it can be concluded that 3-a-side and 4-a-side games could be more effective in improving high intensity aerobic performance than 2-a-side games, which in turn are more appropriate for developing anaerobic performance

Acute effects of small-sided games combined with running drills on internal and external loads in young soccer players.

The purpose of this study was to compare the effects of regular small-sided games (SSGreg) and SSGs combined with running drills (SSGcom) on players' internal and external loads. Eighteen young male soccer players (average age: 18.2 ± 0.5 years) participated in 3 vs. 3 and 4 vs. 4 games, under both SSGreg and SSGcom conditions. SSGreg bouts were played for 4 minutes without additional running drills, while SSGcom bouts consisted of 3 min 30 s SSG and 15 s running before and after the bout, making the duration of each bout 4 minutes. During all SSGs, measurements of heart rate (HR) responses as well as distances covered in four different speed zones - walking (WLK), low-intensity (LIR), moderate-intensity (MIR) and high-intensity running (HIR) - were recorded. Technical characteristics were monitored during the SSGs, and the rating of perceived exertion (RPE) and blood lactate (La-) responses were determined at the end of each SSG condition. Compared to the SSGreg in both 3 vs. 3 and 4 vs. 4 formats, the SSGcom condition resulted in higher La- and RPE responses (p < 0.05), greater distance covered at MIR and HIR speeds and greater total distance (p < 0.05). The results of this study show that replacing 30 s within the 4-min bouts of SSGs (both 3- and 4-a-side) by 2 x 15 s of running drills is effective in increasing internal (La- and RPE) and external loads (MIR and HIR) without a significant decrease in total passes and successful passes in young soccer players