Yusuf Köklü

Dr. Yusuf Köklü

orcid

Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2011 in Journal of Strength & Conditioning Research
Verified
Journal Article
Closed access
YKYusuf Köklü
Yusuf Köklü
AAAlper Asci
Alper Asci
FKFatma Ünver Koçak
Fatma Ünver Koçak
UAUtku Alemdaroğlu
Utku Alemdaroğlu
UDUğur Dündar
Uğur Dündar
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.

1 February 2015 in Science & Sports
Verified
Journal Article
Closed access
YKYusuf Köklü
Yusuf Köklü
UAU. Alemdaroğlu
U. Alemdaroğlu
AÖA. Özkan
A. Özkan
MKMitat KOZ
Mitat KOZ
GEG. Ersöz
G. Ersöz

1 December 2011 in Journal of Human Kinetics
Verified
Journal Article
Open access
PDF file
YKYusuf Köklü
Yusuf Köklü
UAUtku Alemdaroğlu
Utku Alemdaroğlu
FKFatma Koçak
Fatma Koçak
AEA. Erol
A. Erol
GFGülin Fındıkoğlu
Gülin Fındıkoğlu
Comparison of Chosen Physical Fitness Characteristics of Turkish Professional Basketball Players by Division and Playing Position: The purpose of the present study was to compare chosen physical fitness characteristics of Turkish professional basketball players in different divisions (first and second division) and playing positions. Forty-five professional male basketball players (14 guards, 15 forwards, 16 centers) participated in this study voluntarily. For each player, anthropometric measurements were performed, as well as a multi-stage 20 m shuttle run, isokinetic leg strength, squat jump (SJ), countermovement jump (CMJ), 10-30 meter single-sprint and T-drill agility tests. The differences in terms of division were evaluated by independent t-test and the differences by playing position were evaluated by one-way ANOVA with Post Hoc Tukey test. First division players' CMJ measurements were significantly higher than those of second division players' (p≤0.05), whereas second division players' 10 m sprint times were significantly better than those of first division players' (p≤0.05). In addition, forwards and centers were significantly taller than guards. Centers were significantly heavier and their T-drill test performances were inferior to those of forwards and guards (p≤0.05). Moreover, guards had a significantly higher maximal oxygen uptake (VO2 max) than centers. Guards and forwards showed significantly better performance in the 10 and 30 m sprint tests than centers (p≤0.05). Forwards and centers had significantly better left leg flexor strength at 180°.s-1(p≤0.05). In conclusion, the findings of the present study indicated that physical performance of professional basketball players differed among guards, forwards and centers, whereas there were not significant differences between first and second division players. According to the present study, court positions have different demands and physical attributes which are specific to each playing position in professional basketball players. Therefore, these results suggest that coaches should tailor fitness programs according to specific positions on the court.

1 March 2012 in Journal of Human Kinetics
Verified
Journal Article
Open access
PDF file
YKYusuf Köklü
Yusuf Köklü
A Comparison Of Physiological Responses To Various Intermittent And Continuous Small-Sided Games In Young Soccer Players: The purpose of this study was to investigate physiological responses to various intermittent and continuous small-sided games (SSGs) - including 2-a-side, 3-a-side, and 4-a-side games - in young soccer players. Twenty soccer players (average age 16.6±0.5 years; mean body height 176.2±4.6 cm; mean body mass 65.9±5.6 kg) voluntarily participated in this study. The subjects underwent anthropometric measurements followed by the YoYo intermittent recovery test. Then, they played intermittent (SSGint) and continuous (SSGcon) 2-a-side, 3-a-side, and 4-a-side soccer-specific SSGs in random order at 2-day intervals. Paired t-tests were used to assess differences between the training regimens (intermittent and continuous) in terms of heart rate (HR), percentage of maximum HR (%HRmax), and blood lactate concentration (LA). The differences in LA, HR and %HRmax between the 2-a-side, 3-a-side and 4-a-side SSGint or the 2-a-side, 3-a-side and 4-a-side SSGcon were identified using a one-way analysis of variance with repeated measures. The results demonstrated that the 3-a-side SSGint and SSGcon measurements were significantly higher than the 2-a-side and 4-a-side games in terms of HR and %HRmax, whereas the 2-a-side SSGint and SSGcon resulted in higher LA responses compared to other SSG types. The study results also demonstrated that SSGint and SSGcon are similar in terms of physiological responses except for 2-a-side game LA responses. The results of this study suggest that both SSGint and SSGcon could be used for the physiological adaptations required for soccer specific aerobic endurance.

1 February 2013 in Journal of Strength & Conditioning Research
Verified
Journal Article
Closed access
HAHalil Atl
Halil Atl
YKYusuf Köklü
Yusuf Köklü
UAUtku Alemdaroğlu
Utku Alemdaroğlu
FKFatma Ünver Koçak
Fatma Ünver Koçak
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.

1 April 2015 in Journal of Strength & Conditioning Research
Verified
Journal Article
Closed access
YKYusuf Köklü
Yusuf Köklü
ÖSÖzcan Sert
Özcan Sert
UAUtku Alemdaroğlu
Utku Alemdaroğlu
YAYunus Arslan
Yunus Arslan
The purpose of this study was to investigate the effect of "with goalkeeper" (SSGwith) and "without goalkeeper" (SSGwithout) conditions on players' physiological responses and time-motion characteristics in small-sided games. Sixteen young soccer players (age: 16.5 ± 1.5 years; height: 175.5 ± 5.2 cm; body mass: 63.0 ± 6.9 kg; training experience: 6.3 ± 1.3 years) participated in 2 different 2-a-side, 3-a-side, and 4-a-side games: SSGwith and SSGwithout. The players underwent anthropometric measurements (height and body mass) followed by the Yo-Yo intermittent recovery test (level 1). Then they played 2-a-side, 3-a-side, and 4-a-side SSGwith and SSGwithout soccer-specific SSGs in random order at 2-day intervals. Heart rate (HR) responses and distance covered in different speed zones (walking [WLK, 0-6.9 km·h(-1)], low-intensity running [LIR, 7.0-12.9 km·h(-1)], moderate-intensity running [MIR, 13.0-17.9 km·h(-1)], and high-intensity running [HIR, >18 km·h(-1)]) were measured during the SSGs, whereas the rating of perceived exertion (RPE) and blood lactate (La) were determined at the end of the last bout of each SSG. During the SSGwithout players showed higher %HR, La, and RPE (p ≤ 0.05), greater distance covered in LIR, MIR, HIR, and total distance (p ≤ 0.05) compared with the SSGwith during the 2-a-side, 3-a-side, and 4-a-side games. The results of this study suggest that both SSGwith and SSGwithout could be used for the physiological adaptations required for soccer-specific aerobic endurance. However, if coaches want both higher physiological responses and greater distance covered in the intensity running zone from their teams, SSGwithout should be organized. In addition, this study also suggests that smaller format games (i.e., 2-a-side) may promote some anaerobic adaptations for youth soccer players.