Introduction
Volleyball is one of the most popular competitive team sports in the world. Nowadays, young athletes should fulfill requirements to develop optimal competitive performance. Based on the literature, to achieve high performance, it is highly depend on several important factors such as physical, technique, tactics (Clemente et al., 2021; de Oliveira Castro et al., 2022; Halouani et al., 2023), and all of these aspects must be improved simultaneously (Trombiero et al., 2023). Most of previous studies claimed that high physical quality contributed to movements such as jumping (Khayati et al., 2024), run, agility in moving until endurance (Branquinho et al., 2020). In addition, technical execution and tactical behaviors were considered as important factors to achieve goal for young athletes in the future (Ferreira-Ruiz et al., 2022; Klingner et al., 2022; Poureghbali et al., 2020). For example, research by Rusmana et al. (2023) investigated the method to improve athletes’ techniques and tactics simultaneously, because both factors have a major contribution to achieve goal in competitive sports. In addition, Clemente et al. (2021) reported that through an improvement in technical execution and tactical behaviors could help athletes or teams in carrying out successful attacks or defenses. According to Ueda et al. (2023) high technical execution skills generated high quality motoric movements such as successful passing or shooting, while tactical behavior was an important tool to support athletes’ physical and technical performance during the competition. Thus, high performance of athletes depend on these factors (Modric et al., 2022). Thus, appropriate innovation training is needed, such as implementing coach’s verbal encouragement (CVE) during small-sided games (SSG). However, in this study, we combined these two methods turn into coach’s verbal encouragement during small-sided volleyball games (CVESSVG).
In order to understand the concept of CVESSVG, it is needed to comprehend the terms of CVE and SSG. CVE is interpreted as a training with verbal encouragement from a coach to young athletes while carry out a certain training session. SSG is interpreted as a training which has been minimized the number of players (e.g., 3v3, 4v4) (Sahli et al., 2023; Silva et al., 2022), the duration of the game (Arslan et al., 2022), and the size of the field (Faga et al., 2023), even the rules are changed (Gok et al., 2023), and adjusted to the needs of coach (Sahli et al., 2022). Thus, CVESSVG can be interpreted as a training condition with verbal encouragement from coach (e.g. “Good performance”, “Well done”), to athletes during a small-sided volleyball games (SSVG) session. Several previous studies had reported the effects of CVE during SSG, for example Khayati et al. (2024) applied CVE in small-sided basketball games with 8 male athletes, the result showed the improvement in game performance related to physiological, and psychological adaptation. Another study reported that CVE applied to SSG training for 6 weeks resulted in positive increase in aerobic performance, mood state, satisfaction and subjective effort among semi-professional soccer athletes (Romdhani et al., 2024b). Hammami et al. (2023) shows that CVE + SSG was applied in the context of physical education learning at school is able to change of physical fitness, technical skills and physiological responses of adolescent female students.
The best of our knowledge, it is the lack of research investigate the effects of CVESVG to improve the physical performance, technical execution, and tactical behavior of young athletes in volleyball that may be the basis for the gap. This study aims to investigate the effects of CVESSVG on improving specific physical performance, and technical-tactical behavior among youth athletes.
We hypothesize that:
Hypothesis 1: CVESVG has a higher effect than the control group (SSG-non CVE) in increasing specific physical performance among youth athletes.
Hypothesis 2: Technical-tactical behavior among youth athletes experienced higher improvement after participating in CVESVG compared to the control group (SSG-non CVE).
Methods
Ethics
This study has been approved by the local ethics committee of Surabaya State University, Indonesia (registration number: B/40962/UN38.6/LT.02.02/2024). In addition, all activities in this experimental study followed the Declaration of Helsinki (2013).
Sample Size
A priori sample size analysis was calculated with G*Power (v 3.1.9.4) through F test with ANOVA repeated measures with within-between interaction analysis (effect size f = 0.30, power 1– β err prob = 0.95 and α err prob = 0.05). The calculation results showed that the minimum participants (samples) needed were 40 youth athletes. These participants were arranged into 2 groups, namely experimental (CVESSVG, n = 20), and control groups (SSG-non CVE, n = 20) by using an online research randomizer (Table 1). To divide athletes into the second group involves the use of a random number generator application (Hasyim et al., 2024).
Table 1
Demographic information of the participant.
| VARIABLES MEASURED | |
|---|---|
| CVESSVG (n = 20) | |
| Age [years] | 18.9 ± 0.788 |
| Body height [cm] | 165 ± 3.89 |
| Body weight [kg] | 57.3 ± 1.45 |
| BMI [kg·m–2] | 21.9 ± 1.05 |
| Volleyball experience [years] | 1.74 ± 0.176 |
| CVESSVG experience [years] | 1.21 ± 0.174 |
| SSG-non CVE (n = 20) | |
| Age [years] | 19.3 ± 0.733 |
| Body height [cm] | 165 ± 3.52 |
| Body weight [kg] | 58.0 ± 2.84 |
| BMI [kg·m–2] | 22.4 ± 1.05 |
| Volleyball experience [years] | 1.83 ± 0.173 |
| CVESSVG experience [years] | 1.36 ± 0.314 |
[i] Note: CVESSVG = Coach’s verbal encouragement small-sided volleyball games, SSG-non CVE =Small sided game-non coach’s verbal encouragement, BMI = Body mass index.
Participants
After determined the minimum sample size, 40 youth male volleyball athletes from the faculty of sport and health science at Surabaya State University (Indonesia) involved as participants in this experimental study.
A total of 40 youth male athletes were selected using the following inclusion criteria: (i) youth volleyball athletes who have minimum 1.5 years of training experience; (ii) at least 1 year of CVESSVG experience; (iii) youth athletes who do not have any injuries in the last 1 month. While the exclusion criteria were: (i) athletes over 21 years old; (ii) youth athletes who do not have permission from their parents; (iii) youth athletes who are participate in national or international sports events. Detail information about the procedures, rules, risks and benefits in this study had been informed initially to the participants. All participants and their parents were required to sign a written consent form. We present participant demographic information between the two groups in Table 1.
Measurements
Physical Performance Tests
Agility T-Test (ATT)
ATT is an accurate test to measure the change direction rate of athletes (Hammami et al., 2023). First, participants were instructed to warm up (2 minutes). Next, they stood at the starting line (number 1). After the whistle sounded, the participants ran as fast as possible to cone 2, ran sideways to cone 3, ran sideways back to cone 4, ran to cone 5, and finally ran back to the finish line (Figure 1). Three opportunities were given to participants (Chuang et al., 2022). The shortest time in seconds (s) that needed to run was recorded for the final score.
Figure 1
Agility T-Test.
10-m Sprint Test (10-mST)
10-mST was used to measure the moving speed level from one point to another (Chuang et al., 2022; Trajković & Bogataj, 2020). First, participants performed a warm-up (2 min). Then, stand at the starting line. After the instruction “ready go”, the participants ran as fast as possible to the finish line (the distance from the start to the finish is 10 meters). Participants performed three trials of the 10-mST test. The shortest time in seconds (s) that needed to run was recorded and used for statistical analysis.
Countermovement Jump Test (CMJT)
CMJT has been acknowledged as an effective test for measuring leg power levels (Hernández-Davo et al., 2021; Masel & Maciejczyk, 2024). First, all participants were required to do a warm-up (2 minutes). Then, after the instruction ‘go’, participants squatted until their knees bent to 90º, and jumped vertically as high as possible. Participants performed this test for three times. The highest jump result (cm) was recorded for analysis.
Medicine Ball Throw Test (MBTT)
MBTT is a test to measure the arm power level among athlete (Nemati et al., 2023). Participants warmed up their arms for 2 minutes. Then, sat on the floor by leaning their bodies against the wall and both arms holding a medicine ball (Trident Premium Medicine Ball – 3 kg) on their chest (Tavares et al., 2020). After the whistle instruction, the participant threw the ball forward as far as possible. Participants were given 3 attempts and the furthest throw (m) were taken for statistical analysis purposes.
Multistage 20-Meter Shuttle Run Test (M20-MSRT)
20-MSRT has been used in previous studies to measure the VO2max endurance level of athletes (Zaharia et al., 2023). Participants were required to run back and forth for 20 meters while hearing the audio “beep”. This test ended when the participant was not able to run or could not follow the rhythm of the “beep”. The final score was converted into VO2max (mL/kg/min).
System of Technical-Tactical Behavior Assessment in Volleyball (STTBAV)
Previous studies had adopted STTBAV (Palao et al., 2023). A digital camera (JVC Gz E10), and 3 professional expert analysts were prepared to assess the recordings and observe the technical-tactical behavior of athletes while playing volleyball for 5 minutes. In this study, the technical-tactical performance index during offense and defense had been modified according to the needs of this study. The technical-tactical performance index during offense and defense that must be assessed (e.g., serve, reception, sets, attack, and defense). The technical-tactical quality of athletes during the competition was assessed using a scale of 0 (unsuccessful) to 5 (very successful).
Protocol
This study adopted an experiment method with a randomized control trial (RCT) design for 12 weeks, including.
Pre-Test
The first meeting in experimental research with RCT was a pre-test which included physical performance tests (ATT, 10-mST, CMJT, MBTT, M20-MSRT), and technical-tactical behavior (serve, reception, sets, attack, defense). Pre-test activities were carried out in the gymnasium field of Surabaya State University (Indonesia) from 06.00 to 09.00 am. Before the test began, all participants were instructed to carry out a warm-up (5 min), and the pre-test activities were supervised directly by the research team. After the activities were completed, participants carried out a cool-down.
CVESSVG and SSG-non CVE program
The CVESSVG program session was conducted in the gymnasium of Surabaya State University (Indonesia) from 08.00 to 09.00 am. Before the CVESSVG program began, all participants were instructed to do a warm-up (5 min). There were some modifications in the CVESSVG program, included the number of players, positions, duration and rules (Table 2). The 3v3 and 4v4 formats were applied in CVESSVG and control group (SSG-non CVE), which lasted for 25 minutes in each session and 5 minutes for the recovery phase. The reason for using the 3vs3 and 4vs4 format is that it reflects the characteristics of a small game in volleyball. Apart from that, this format will provide many physical and movement experiences for youth male athletes, so that they have the potential to develop higher physical abilities and technical-tactical behavior. When the experimental group (CVESSVG) played, coach also provided verbal encouragement. On the other hand, the control group did not receive verbal encouragement or SSG-non CVE (Figure 2). During the games session, the coach stood beside the field and gave verbal encouragement to the athletes (e.g., “Come on, you can do it”, “Good movement” (Table 2). Verbal encouragement is spontaneous based on the game situation. All athletes were required to compete with maximum effort. This activity ended with a cool-down (5 min). The CVESSVG and SSG-non CVE program was ended in week 12.
Table 2
CVESSVG program.
| WEEKS | SESSION | FORMATCVE | FORMATSSVG | DURATION | REST | POSITION |
|---|---|---|---|---|---|---|
| Games Rules: Each team is allowed twice to touch until the ball is touched by the opponent team. One player is not allowed to touch the ball 2 times in a row (net height: 2.10 m and field size: 9 × 9 m.) | ||||||
| 1–2 | 1 | “Come on” “You can do it” | 3v3 | 25 min | 5 min | Libero |
| 2 | “Good movement” “Good job” | 4v4 | 25 min | 5 min | ||
| 3–4 | 1 | “Show your ability” “Good serve” | 4v4 | 25 min | 5 min | Tosser |
| 2 | “Good reception” “Don’t give up” | 3v3 | 25 min | 5 min | ||
| 5–6 | 1 | Do harder punches “Good sets” | 3v3 | 25 min | 5 min | Spiker |
| 2 | “Come on jump higher” “Good attack” | 4v4 | 25 min | 5 min | ||
| 7–8 | 1 | “Block well” “Good defense” | 4v4 | 25 min | 5 min | Libero |
| 2 | “Earn more points” “Maintaining victory” | 3v3 | 25 min | 5 min | ||
| 9–10 | 1 | “Good performance today” “Thank you for your efforts” | 3v3 | 25 min | 5 min | Tosser |
| 2 | “Don’t give up” “Don’t lose” | 4v4 | 25 min | 5 min | ||
| 11–12 | 1 | “Do harder punches” “You have to win” | 4v4 | 25 min | 5 min | Spiker |
| 2 | “Block well” “Focus on the game” | 3v3 | 25 min | 5 min | ||
Figure 2
Study design.
Post-Test
The last meeting in this experimental research was to conduct a post-test, namely re-conducting the physical performance test (ATT, 10-mST, CMJT, MBTT, M20-MSRT), and technical-tactical behavior (serve, reception, sets, attack, defense). This activity were carried out in the gymnasium field of Surabaya State University (Indonesia) from 06.00 to 09.00 am. Before the test began, all participants were instructed to do a warm-up (5 min). After the activity was completed, participants carried out a cool-down (5 min).
Statistical analysis
Mean ± standard deviation and normality (Shapiro-wilk’s) tests are presented in the results section. The reliability value of the variables was analyzed using the intraclass correlation coefficient (ICC). Student’s Paired t-test was used to test the difference scores between these two groups in the pre- and post-test on the dependent variables (Selmi et al., 2023). Effect sizes (ES) was calculated using Cohen’s d: <0.2 (trivial), 0.2–0.6 (small), 0.6–1.2 (moderate), 1.2–2.0 (large), >2.0 (very large), and >4.0 (extremely large) (Trajković & Bogataj, 2020). 2-Way ANOVA repeated measures analysis was chosen to investigate the effects of time factors (pre- and post-test) and time*group interactions towards physical performance variables (ATT, 10-mST, CMJT, MBTT, M20-MSRT), and technical-tactical behavior (serve, reception, sets, attack, defense). If the results of time effects and time*group interactions were significant, Bonferroni post-hoc analysis would perform to test the group effects (CVESSVG and SSG-non CVE). The rate of time effects, group and interaction factors was calculated with Partial eta squared (η²p): 0.01 (small), 0.06 (medium), 0.14 (large) (Cohen, 2013). The percentage of delta (%Δ) was calculated with the follwong formula: (posttest–pretest/pretest) × 100. Finally, the significance level was p < 0.05, and all statistical analyses were performed with Jamovi v. 2.3.28.
Results
Table 3 presents the reliability testing results with ICC (0.893-0.980), and normality with Shapiro-Wilk analysis (all, p > 0.05).
Table 3
Results of intra-class correlation coefficient (ICC) dan Shapiro-wilk’s (SW).
| VARIABLES MEASURED | ICC | SW- CVESSVG(PRE – POST) | SW- SSG-NON CVE(PRE – POST) |
|---|---|---|---|
| Physical Performance | |||
| ATT [s] | 0.980 | 0.092 | 0.321 |
| 10-mST [s] | 0.987 | 0.079 | 0.115 |
| CMJT [cm] | 0.925 | 0.940 | 0.159 |
| MBTT [m] | 0.896 | 0.066 | 0.054 |
| M20M-SRT [ml/kg/min] | 0.893 | 0.502 | 0.341 |
| Technical-Tactical Behavior | |||
| Serve [score] | 0.971 | 0.063 | 0.078 |
| Reception [score] | 0.963 | 0.090 | 0.064 |
| Sets [score] | 0.948 | 0.082 | 0.057 |
| Attack [score] | 0.952 | 0.135 | 0.072 |
| Defense [score] | 0.970 | 0.139 | 0.061 |
[i] Note: CVESSVG = Coach’s verbal encouragement small-sided volleyball games, SSG-non CVE =Small sided game-non coach’s verbal encouragement, ATT = Agility t-test, 10-mST = 10-m sprint test, CMJT = Countermovement jump test, MBTT = Medicine ball throw test, M20M-SRT = Multistage 20 meter-shuttle run test, ICC = Intra-class correlation coefficient, SW = Shapiro-wilk’s.
Effect of CVESSVG and SSG-non CVE on physical performance
Table 4 and Figure 3 shows that there are differences between the pre- and post-tests in both groups on the physical performance variable (all, p < 0.05). It can be seen that the higher increases are indicated in CVESSVG (ATT: %Δ = –13.0; ES = 2.49[very large], 10-mST: %Δ = –34.2; ES = 1.87[large], CMJT: %Δ = +71.1; ES = –3.80[very large], MBTT: %Δ = +35.3; ES = –1.72[large], and M20M-SRT: %Δ = +30.3; ES = –2.65[very large]), compared to the SSG-non CVE group (ATT: %Δ = –8.4; ES = 1.07[moderate], 10-mST: %Δ = 15.0; ES = 1.14[moderate], CMJT: %Δ = +12.0; ES = –2.17[very large], MBTT: %Δ = +28.6; ES = –1.70[large], and M20M-SRT: %Δ = +16.0; ES = –2.36[very large]).
Table 4
Effect of coach’s verbal encouragement small-sided volleyball games (CVESSVG) and small sided game-non coach’s verbal encouragement (SSG-non CVE) on physical performance.
| VARIABLES MEASURED | GROUPS | N | PRE | POST | %Δ | P | ES (D) | 2-WAY ANOVA REPEATED MEASURES |
|---|---|---|---|---|---|---|---|---|
| PHYSICAL PERFORMANCE | ||||||||
| ATT [s] | CVESSVG | 20 | 11.50 ± 0.642 | 10.00 ± 0.524 | –13.0 | <.001* | 2.49 [very large] | Time: F(1.38) = 103.10; p < .001; η2p = 0.731 Interaction: F(1.38) = 4.67; p = 0.037; η2p = 0.109 Group: F(1.38) = 13.8; p < .001; η2p = 0.267 |
| SSG-non CVE | 20 | 11.9 ± 0.618 | 10.9 ± 0.900 | –8.4 | <.001* | 1.07 [moderate] | ||
| 10-mST [s] | CVESSVG | 20 | 4.07 ± 0.647 | 2.68 ± 0.492 | –34.2 | <.001* | 1.87 [large] | Time: F(1.38) = 94.9; p < .001; η2p = 0.714 Interaction: F(1.38) = 12.9; p < .001; η2p = 0.254 Group: F(1.38) = 14.0; p < .001; η2p = 0.269 |
| SSG-non CVE | 20 | 4.27 ± 0.552 | 3.63 ± 0.637 | –15.0 | <.001* | 1.14 [moderate] | ||
| CMJT [cm] | CVESSVG | 20 | 24.6 ± 2.39 | 42.1 ± 4.26 | +71.1 | <.001* | –3.80 [very large] | Time: F(1.38) = 367; p < .001; η2p = 0.906 Interaction: F(1.38) = 175; p < .001; η2p = 0.822 Group: F(1.38) = 40.3; p < .001; η2p = 0.514 |
| SSG-non CVE | 20 | 26.7 ± 2.45 | 29.9 ± 2.73 | +12.0 | <.001* | –2.17 [very large] | ||
| MBTT [m] | CVESSVG | 20 | 2.15 ± 0.273 | 2.91 ± 0.456 | +35.3 | <.001* | –1.72 [large] | Time: F(1.38) = 116.424; p < .001; η2p = 0.754 Interaction: F(1.38)= 0.771; p = 0.385; η2p = 0.020NS Group: F(1.38) = 0.135; p = 0.715; η2p = 0.004NS |
| SSG-non CVE | 20 | 2.24 ± 0.190 | 2.88 ± 0.416 | +28.6 | <.001* | –1.70 [large] | ||
| M20M-SRT [ml/kg/min] | CVESSVG | 20 | 35.7 ± 3.13 | 46.5 ± 2.91 | +30.3 | <.001* | –2.65 [very large] | Time: F(1.38) = 240.5; p < .001; η2p = 0.864 Interaction: F(1.38) = 25.7; p < .001; η2p = 0.404 Group: F(1.38) = 37.3; p < .001; η2p = 0.495 |
| SSG-non CVE | 20 | 33.7 ± 3.05 | 39.1 ± 2.56 | +16.0 | <.001* | –2.36 [very large] | ||
[i] Note: CVESSVG = Coach’s verbal encouragement small-sided volleyball games, SSG-non CVE =Small sided game-non coach’s verbal encouragement, ATT = Agility t-test, 10-mST = 10-m sprint test, CMJT = Countermovement jump test, MBTT = Medicine ball throw test, M20M-SRT = Multistage 20 meter-shuttle run test, %Δ = Delta percentage, ES = Effect size, η2p = Partial eta squared. NS = Not significant. *Significant difference between pre- and post-test. Bold indicates significant differences in time, interaction and group factors in 2-Way ANOVA repeated measures analysis.
Figure 3
Changes in pre- and post-test between CVESVG and SSG-non CVE on (a) ATT, (b) 10-mST, (c) CMJT, (d) MBTT, and (e) M20M-SRT.
Meanwhile, the results of 2-Way ANOVA repeated measures test, shows that there are significant differences in the effects of the time factor on ATT (p < .001; η2p = 0.731), 10-mST (p < .001; η2p = 0.714), CMJT (p < .001; η2p = 0.906), MBTT (p < .001; η2p = 0.754), and M20M-SRT (p < .001; η2p = 0.864). There are differences in interaction factors on the ATT variables (p = 0.037; η2p = 0.109), 10-mST (p < .001; η2p = 0.254), CMJT (p < .001; η2p = 0.822), M20M-SRT (p < .001; η2p = 0.404), but it is not found in MBTT (p = 0.385; η2p = 0.020). There are group factor differences on ATT (p < .001; η2p = 0.267), 10-mST (p < .001; η2p = 0.269), CMJT (p < .001; η2p = 0.514), M20M-SRT (p < .001; η2p = 0.495), but there is no differences on MBTT (p = 0.715; η2p = 0.004) (Table 4).
Effect of cvessvg and ssg-non cve technical-tactical behavior
Table 5 and Figure 4 shows that there are differences between the pre- and post-tests in both groups towards the p technical-tactical behavior variable (all, p < 0.05). Higher improvement is indicated in CVESSVG (serve: %Δ = +33.1; ES = –2.43[very large], reception: %Δ = +41.7; ES = -2.24[very large], sets: %Δ = +55.6; ES = –2.13[very large], attack: %Δ = +57.6; ES = –1.98[large], defense: %Δ = +102.4; ES = –1.94[large]), compare to the SSG-non CVE group (serve: %Δ = +31.9; ES = –1.62[large], reception: %Δ = +30.3; ES = –1.87[large], sets: %Δ = +34.4; ES = –1.59[large], attack: %Δ = +42.6; ES = –1.44[large], defense: %Δ = +43.7; ES = –1.86[large].
Table 5
Effect of coach’s verbal encouragement small-sided volleyball games (CVESSVG) and small sided game-non coach’s verbal encouragement (SSG-non CVE) on technical-tactical behavior.
| VARIABLES MEASURED | GROUPS | N | PRE | POST | %Δ | P | ES (D) | 2-WAY ANOVA REPEATED MEASURES |
|---|---|---|---|---|---|---|---|---|
| TECHNICAL-TACTICAL BEHAVIOR | ||||||||
| Serve [score] | CVESSVG | 20 | 7.70 ± 0.801 | 10.25 ± 1.333 | +33.1 | < .001* | –2.43 [very large] | Time: F(1.38) = 152.694; p < .001; η2p = 0.801 Interaction: F(1.38)= 0.829; p = 0.368; η2p = 0.021NS Group: F(1.38) = 10.4; p = 0.003; η2p = 0.215 |
| SSG-non CVE | 20 | 6.90 ± 1.17 | 9.10 ± 1.17 | +31.9 | < .001* | –1.62 [large] | ||
| Reception [score] | CVESSVG | 20 | 6.35 ± 0.671 | 9.00 ± 1.124 | +41.7 | < .001* | –2.24 [very large] | Time: F(1.38) = 170.62; p < .001; η2p = 0.818 Interaction: F(1.38) = 5.39; p = 0.026; η2p = 0.124 Group: F(1.38) = 9.24; p = 0.004; η2p = 0.196 |
| SSG-non CVE | 20 | 6.10 ± 0.912 | 7.95 ± 0.686 | +30.3 | < .001* | –1.87 [large] | ||
| Sets [score] | CVESSVG | 20 | 4.95 ± 1.32 | 7.70 ± 1.30 | +55.6 | < .001* | –2.13 [very large] | Time: F(1.38) = 140.67; p < .001; η2p = 0.787 Interaction: F(1.38) = 8.79; p = 0.005; η2p = 0.188 Group: F(1.38) = 5.23; p = 0.028; η2p = 0.121 |
| SSG-non CVE | 20 | 4.80 ± 0.768 | 6.45 ±1.050 | +34.4 | < .001* | –1.59 [large] | ||
| Attack [score] | CVESSVG | 20 | 6.25 ± 0.786 | 9.85 ± 1.565 | +57.6 | < .001 | –1.98 [large] | Time: F(1.38) = 119.26; p < .001; η2p = 0.758 Interaction: F(1.38) = 7.58; p = 0.009; η2p = 0.166 Group: F(1.38) = 47.1; p < .001; η2p = 0.554 |
| SSG-non CVE | 20 | 5.05 ± 1.395 | 7.20 ± 0.951 | +42.6 | < .001* | –1.44 [large] | ||
| Defense [score] | CVESSVG | 20 | 4.10 ± 0.852 | 8.30 ± 2.029 | +102.4 | < .001* | –1.94 [large] | Time: F(1.38) = 129.7; p < .001; η2p = 0.773 Interaction: F(1.38) = 18.4; p < .001; η2p = 0.327 Group: F(1.38) = 10.3; p = 0.003; η2p = 0.213 |
| SSG-non CVE | 20 | 4.35 ± 0.933 | 6.25 ± 0.550 | +43.7 | < .001* | –1.86 [large] | ||
[i] Note: CVESSVG = Coach’s verbal encouragement small-sided volleyball games, SSG-non CVE = Small sided game-non coach’s verbal encouragement, %Δ = Delta percentage, ES = Effect size, η2p = Partial eta squared. NS = Not significant. *Significant difference between pre- and post-test. Bold indicates significant differences in time, interaction and group factors in 2-Way ANOVA repeated measures analysis.
Figure 4
Changes in pre- and post-test between CVESVG and SSG-non CVE on (a) Serve, (b) Reception, (c) Sets, (d) Attack, and (e) Defense.
Meanwhile, the results of 2-Way ANOVA repeated measures test show that there are significant differences in the effects of the time factor on serve (p < .001; η2p = 0.801), reception (p < .001; η2p = 0.818), sets (p < .001; η2p = 0.787), attack (p < .001; η2p = 0.758), defense (p < .001; η2p = 0.773). There iss no differences in interaction factors for serve (p = 0.368; η2p = 0.021), but significant differences are found in reception (p = 0.026; η2p = 0.124), sets (p = 0.005; η2p = 0.188), attack (p = 0.009; η2p = 0.166), defense (p < .001; η2p = 0.327). In addition, there are differences in group factors in the serve variables (p = 0.003; η2p = 0.215), reception (p = 0.004; η2p = 0.196), sets (p = 0.028; η2p = 0.121), attack (p < .001; η2p = 0.554), and defense (p = 0.003; η2p = 0.213) (Table 5).
Discussion
The current study aims to investigate the effects of CVESSVG on improving specific physical performance, and technical-tactical behavior among young athletes.
The main findings in this study confirmed all hypotheses. The first finding in this study showed that the CVESSVG and control (SSG-non CVE) groups both had positive effects on improving specific physical performance related to ATT, 10-mST, CMJT, MBTT, M20-MSRT. However, we observed that higher improvements were found in CVESSVG compared to SSG-non CVE after the intervention program was completed. This is because the CVESSVG program has the advantage of presenting a modified small-sided volleyball game situation (e.g., number of players, positions, duration, rules), and combined with positive verbal encouragement from the coach for young athletes during the game session, as a stimulus for them to be more optimal in improving the quality of specific physical performance. This was also reported by a previous study, verbal encouragement from beginning until the end of SSG training, had a positive value for the development of physical quality related to aerobic endurance among soccer athletes (Romdhani et al., 2024b). Consistent results were also reported by several previous studies, for example Ouertatani et al. (2022) investigated that training with SSG+CVE for 6 weeks was an important tool to trigger improvements in lower extremity power, aerobic speed, and agility among young soccer players. In addition, Sahli et al. (2020) reported that verbal encouragement from coach during SSG cause a higher level of physical performance (VO2max) compared to SSG without CVE. A recent study reported results consistent with the findings in our study, where physical fitness among sixty school girls in Tunisia significantly improved after participating in a CVE program during SSG (Mekni et al., 2024). Meanwhile, another study revealed that implementing CVE during certain training sessions showed positive impacts on physical performance (Romdhani et al., 2024a). Hammami et al. (2023) used small-sided soccer games with a 5 vs 5 format combined with coach encouragement, and the results showed that the physical fitness levels of soccer athletes indicated positive changes.
Previous studies had highlighted the importance of technical-tactical behavior factors for athletes in competitive sports (Hintermann et al., 2021; Palao et al., 2023; Pizarro et al., 2019; Tassi et al., 2024). The second finding in this study showed that CVESSVG had a positive effect on the development of technical-tactical behavior in young athletes. We believe that the 12-week CVESSVG program provides training that focuses on the development of technical-tactical behavior in young athletes. This is also in line with study from Sahli et al. (2023) which mentioned that the application of verbal encouragement during small-sided handball games generate a high positive effect towards offensive performance related to an increase in the number of goal shots. Meanwhile, it was reported that twenty high school students carried out handball games with an SSG session combined with verbal encouragement, showed that students were able to generate more passing (Sahli et al., 2022). Other studies also reported similar results, the application of CVE during SSG training sessions was an effective way that can be used by coaches to improve the quality of technical-tactical behavior among young soccer athletes (Jumareng et al., 2024). The CVESSVG program applied in this study presented a stimulus in the form of verbal and auditory information in game situations, so that athletes could process all this information directly. Eventually, this program triggers an improvement in technical-tactical behavior. Main of the previous studies have proven and reported similar results, the application of CVE during training sessions could provide positive benefits for the development of athlete performance in competitive sports (Khayati et al., 2024; Sahli et al., 2024).
The main strengths of this study included following points: (i) creating a CVESSVG program for young athletes to improve specific physical performance and technical-tactical behavior, (ii) creating a CEFCT program that is easy to implement daily by coaches and young volleyball athletes, (iii) this study is the first finding that uses the CVESSVG program to improve specific physical performance and technical-tactical behavior in young athletes.
Meanwhile, this research still has several limitations in terms of: (i) a few number of participants (athletes) who came from one faculty of sport and health science at Surabaya State University (Indonesia), (ii) only involved male participants. Future research should overcome the limitations in this study by involving more participants who coming from several other universities in Indonesia or other countries. In addition, involving young female volleyball athletes in the research.
Conclusion
Based on the results of this study, it can be concluded that CVESSVG for 12 weeks is able to improve specific physical performance, and technical-tactical behavior of young athletes. In addition, this study clearly shows that CVESSVG has a higher impact than SSG-non CVE. This study contributes as an innovation in the development of a training program using CVESSVG, so that it is expected to be used by volleyball coaches continuously in the future to fulfill the high requirement of physical performance and technical-tactical behavior. In addition, in the future trainers will integrate the CVESSVG program into their regular training routine and continue to evaluate the achievements that can be obtained from implementing the CVESSVG program.
Data Accessibility Statement
All data supporting the findings of this research are available from the author and stored at Surabaya State University.
Acknowledgements
We would like to thank Surabaya State University for providing facilities to carry out this research.
Funding Information
Surabaya State University supports this research by providing research equipment facilities.
Competing Interests
The authors have no competing interests to declare.
Author Contributions
All authors had access to the data used in this research and are responsible for the integrity and authenticity of the data. This research was designed by TH, IF, S, AK and HW. Meanwhile ES, AK, AT, JL, JM, BY were responsible for data analysis. All authors are responsible for data interpretation and manuscript preparation. Final approval of the manuscript was given by all authors.