1. Introduction
Basketball is a dynamic sport and is the second most popular sport in many countries around the world [
1]. In basketball, success is determined by the individual performance of each player, as well as body dimensions, technical and tactical components, psychological development, and the physiological potential of players [
2]. Therefore, physical fitness, including muscular strength, endurance, flexibility, and speed, as well as jumping and agility, all contribute to basketball performance [
3,
4]. Physical fitness tests should be based on multidirectional movements similar to those occurring during the game, such as dribbling, running, shuffling at different velocities, and jumping [
5,
6,
7]. The ability to perform these movements involves both anaerobic and aerobic systems. Generally, basketball involves about 20% aerobic and 80% anaerobic [
8] energy systems. In fact, during matches, players cover distances of between 4400 and 7500 m, consisting of jogging, jumping, sprinting, and changes in direction [
9]. Aerobic capacity has been found to be essential for maintaining a high level of activity during the game and enhancing rapid recovery in basketball players [
10]. However, the relative contribution of each energy source varies according to the intensity and duration of the exercise [
8].
Muscular performance of the lower limbs is essential for functional capacity across various contexts [
11,
12]. Muscular strength improves with chronological age during middle childhood and adolescence, but the pattern of improvement is influenced by many components, such as gender, growth maturity, body size, height, mass, and, to a certain degree, motor competence and the level of physical activity. Neural, structural, and metabolic changes in the skeletal muscle occur during growth and development [
13]. Notably, biological maturation in basketball is associated with adolescent growth and functional performance [
14]. The age period from 11 to 14 years is a time of intense development for athletes and talent identification [
15]. This period should take biological maturity into account.
Biological maturation has been described as the time required and the process of change until the adult stage of development is reached. Among the methods used to monitor biological maturation, the calculation of the age at peak height velocity (APHV) is one of the most used indicators. Indeed, peak height velocity (PHV) is an important non-invasive maturational event that occurs during adolescence. The mean age range for PHV in boys is from 13.8 to 14.2 years [
16]. It is used to describe changes in body composition instead of chronological age. Biological maturation not only affects the physical performance of a player but is also a good predictor of a basketball team’s performance. The timing and tempo of maturation have been shown to exert significant effects on an athlete’s development and progression. For example, early-maturing players tend to be heavier, taller, possess greater lean mass, and perform better on physical tests compared to average- and late-maturing players [
7]. However, early-maturing players do not demonstrate important basic basketball skills, such as shooting, dribbling, passing, and defensive movements [
14]. In other studies, the findings favored late-maturing basketball players in some biological and physical performance parameters and technical skills [
17,
18].
In addition, in some studies and in studies across various sports, inter-individual differences in biological maturation are rarely considered. Significant differences were found in the physical and anthropometric parameters in favor of early-maturing players among male volleyball players [
19]. In youth soccer players, early- and average-maturation groups were heavier, taller, and faster in sprints than a late-maturation group [
20]. Moreover, the advancement of biological maturation increased levels of muscle power and sport performance in young swimming athletes [
21]. Conversely, post-pubertal groups outperformed pre-pubertal groups in jumping, change in direction, and aerobic performance among Tunisian handball players. Additionally, this recent study provided maturity- and gender-specific reference values for physical performance in Tunisian handball players aged 13–19 years [
22].
Previous and subsequent research has examined the effect of maturation on jump performance and anthropometric parameters in players classified by chronological age groups. In basketball, Gryko et al. [
7] showed that average-maturing players obtained higher values in an endurance test compared to their early-maturing peers. Furthermore, maturity differentiation in under-14- and -15-year-old groups significantly affected body size, sprinting time, and the results of all jumping tests in male Polish basketball players aged 13 to 15 years. Guimarães et al. [
23] found that differences in biological maturity affected muscular power and height but not technical skills in male Portuguese basketball players.
It is crucial to establish locally derived reference values of physical performance parameters for adolescent players. This allows coaches and other practitioners working with adolescent players to make informed decisions about a player’s physical performance in relation to their development stage. The relationships between maturation, gender, and performance capacities of adolescent players, as well as their implications for athlete selection, are discussed in the context of early talent identification and the prediction of success. Additionally, these insights can help individualize training programs that are relevant to the stages of biological development rather than being based solely on chronological age. Percentile values may also serve as a source of reference and comparison for performance in similar population. Therefore, we sought to examine how anthropometric and performances parameters varied when Tunisian players were classified by maturation status. To the best of our knowledge, no study has yet established percentile reference values for performance parameters relevant to the Tunisian population.
The aims of the study were as follows: (1) Evaluate the influence of maturity status on anthropometric parameters and physical characteristics of Tunisian basketball players. (2) Establish percentile values for physical performances in Tunisian basketball players according to maturity status and gender.
2. Materials and Methods
2.1. Participants
A total of 470 Tunisian basketball players (240 males and 230 females) were included in this study. We used a sample size calculation formula to determine the optimal sample size. Players aged between 9 and 21 years were randomly selected from various basketball teams across Tunisia, representing the northern, central, and southern regions. The sample included players who participated in the national championship leagues on a weekly basis. All players, in good health, were examined by the medical team and cleared for participation in team activities. Physical and physiological tests were conducted on 502 basketball players. Of these, 32 players who were unable to perform the tests adequately were excluded. As a result, 32 players (15 males and 17 females) were excluded from the initial sample of 502. Ultimately, the analysis included 240 males and 230 females. Prior to the study, the athletes and their parents were fully informed of the study’s aims, protocol, and procedures before signing a written consent form.
Prior conducting this research, the study protocol was approved (CEFMS: 213/2023) by the research Ethics Committee of the Faculty of Medicine of Sousse (Tunisia). The study adhered to the ethical standards of the Declaration of Helsinki of the World Medical Association, which was initially established in 1964 [
24].
2.2. Anthropometric Measurements
Subjects were weighed in minimal clothing using a digital scale (Harpenden Balance Scale, International Trade Instruments Ltd (ITI), Harpenden, UK) with precision to the nearest 0.1 kg. Standing and sitting heights were collected using a stadiometer (Harpenden Portable Stadiometer, UK), and lengths were measured with a non-elastic measuring tape to the nearest 0.1 cm. The difference between standing and sitting heights was used to calculate leg length. Body mass index (BMI) was determined by dividing weight (kg) by the square of height (meters). Lower-body impedance was measured using a Tanita TBF-604 Body Fat Monitor/Scale (Tokyo, Japan). This device required input data, including the subject’s body mass, standing height, and gender. The subject then stood on the scale, which had source and detector electrodes on the plantar surfaces of both feet, to measure lower-body impedance and calculate body fat percentage.
Absolute body fat weight was calculated using the following formula: fat weight (kg) = %fat × (weight/100). Fat-free weight (kg) was determined by subtracting fat weight from total body weight.
Wingspan was measured using a tape measure, from fingertip to fingertip, with the arms held parallel to the ground. Players stood upright with their backs against a wall and their arms extended to the sides, perpendicular to their bodies [
25].
Leg muscle volume of the dominant leg, which refers to the leg a basketball player prefers to use and that provides greater stability and control during various competitive activities such as rebounding, blocked shots, and lay-ups at higher positions, was estimated anthropometrically using the method described by Jones and Pearson [
26]. This method involves summing the volume of truncated cones. Seven circumferences were measured at pre-determined sites: the maximum gluteal furrow, maximum mid-thigh, minimum above the knee, maximum knee, minimum below the knee, maximum calf, and minimum ankle. Heights were measured above the floor level for each circumference. Moreover, anterior and posterior skinfold thicknesses were measured at the second circumference (thigh) and the sixth circumference (calf) [
26].
All anthropometric measurements were performed in the afternoon at the end of the week.
2.3. Procedure
The experimental part of this study was conducted during a 3-day vacation period in March of the previous competitive season. All participants completed two preliminary familiarization sessions to minimize learning effects and to receive pretest instructions. Prior to the experiments, players were instructed to refrain from strenuous physical workout for 24 h before the tests and to avoid heavy meals and caffeinated beverages for at least 4 h before testing. The performance tests, including the sprint, jump, agility, and aerobic tests, were conducted indoors, with the ambient temperature ranging from 18 to 20 °C and relative humidity between 35% and 50%. Participants wore the same type of standard sports shoes and indoor sportswear to ensure consistency and minimize any variation in test performance due to differences in footwear or clothing. Before each test, participants performed a standard 20 min warm-up. All tests were conducted in a single afternoon (4 pm) session to control for potential circadian rhythm effects on performance. This timing was selected based on studies showing that anaerobic performance peaks in the late afternoon [
27,
28]. The aerobic test, however, was conducted in a separate session. The test–retest intra-class correlation coefficients (ICC) of the testing procedure variables used in this study ranged from 0.98 to 0.99 ICC with the within-trial variation (CV = 1.1–1.9%).
2.3.1. Jump Assessments
All jumping data were collected using an Optojump Next device (Microgate SRL, Bolzano, Italy) (connected to a portable computer. All basketball players performed the squat jump (SJ) and countermovement jump (CMJ) with and without an arm swing under the supervision of the same investigator. The players were given two practice jumps before the specific jump tests were conducted. For the SJ, the players were instructed to sink into a 90-degree knee-bent position and hold it for three seconds before jumping as high as possible. The CMJ assessment required the athlete to start in a standing position, then sink as quickly as possible and jump as high as possible. These tests were conducted either with or without the use of an arm swing. Performing a CMJ and SJ with an arm-swing action has been shown to increase performance by 10% or more [
29]. All jumps were performed according to the guidelines given by Komi and Bosco [
30]. The best of three attempts, measured to the nearest centimeter, was recorded.
2.3.2. Five-Jump Test (5JT)
A multiple-5-jump test was used to assess horizontal jumping. The target of this test was to perform five consecutive double-leg hops as far as possible. The participants started by standing behind a line with their feet shoulder-width apart. When ready, they performed five consecutive broad jumps without stopping, using a combination of forward and vertical jumps to maximize distance [
31].
2.3.3. Modified Agility t-Test
The modified agility test, commonly used to assess an athlete’s ability to change direction rapidly by moving forwards, backward, and side to side, was timed using a Photocells Witty system (Microgate). To perform the modified agility
t-Test, a player runs 5 m forward from the start point to point one, sidesteps to point two, then sidesteps to point three, sidesteps back to point one, and finally runs back to the finish. The process is then repeated, starting by sidestepping in the opposite direction. The fastest time is recorded on an assessment form and used as a baseline for future performance comparisons. Besides testing an individual’s ability to move quickly in all directions, it also evaluates agility [
32].
2.3.4. Sprint Tests
Running speed tests were conducted during 5 m, 10 m, and 20 m linear sprint tests both with and without the ball. Sprint times were recorded using photocell gates from the Witty System, a portable timing system from Microgate (Bolzano, Italy). The starting position for each sprint was standardized by placing the dominant foot at the front. All athletes performed the linear sprints three times with a 1 min passive recovery period between each set to ensure reliable results. The best sprint time was used for further analysis [
33].
2.3.5. Flexibility
The flexibility test was carried out using a digital anteflexion meter (TKK-5403, Takei, Niigata, Japan) to assess the flexibility of the hamstring and lower back muscles. A TKK-5403 FLEXION-D, a digital device specifically designed for measuring forward body bending, displayed each measured value and the larger of two measurements, with a range from −20.0 cm to +35.0 cm. Players performed the test barefooted, with their legs extended and feet close together while standing on a platform. They were instructed to bend forward to their maximum range of motion, keeping their knees, arms, and fingers extended for at least 2 s during the test [
34].
2.3.6. Aerobic Power Test: Twenty-Meter Shuttle Run Test
The 20 m shuttle run test, described by Léger and Lambert, involves continuous running between two lines 20 m apart, timed to recorded beeps [
35]. Participants start behind one line, facing the other, and begin running when instructed by the recording. The initial speed is set at 8.5 km·h
−1. Participants run between the lines, turning when signaled by the beeps. Approximately every minute, a sound indicates an increase in speed, with beeps becoming closer together. The athlete’s score is based on the level and number of shuttles (20 m) completed before they can no longer keep up with the recording. This level score can be converted to maximal oxygen uptake (VO
2max), expressed in milliliters of oxygen consumed per kilogram of body mass per minute [
36]. Maximal aerobic speed (MAS) is defined as the lowest running speed at which the maximum oxygen uptake (VO
2max) is achieved [
37].
2.4. Maturity Status
Biological maturity was assessed using the maturity offset equation developed by Mirwald et al. [
38], which is a simple and non-invasive method. This method estimates the years from the peak height velocity (PHV) as a measure of maturity offset, combining anthropometric parameters with the player’s chronological age. The regression equations are as follows [
38]:
For males: Maturity offset = −9.236 + (0.0002708 × leg length × sitting height) − (0.001663 × age × leg length) + (0.007216 × age × sitting height) + (0.02292 × weight by height ratio).
For females: Maturity offset = −9.376 + (0.0001882 × leg length × sitting height) + (0.0022 × age × leg length) + (0.005841×age × sitting height) − (0.002658 × age × weight) + (0.07693 × weight by height ratio).
A maturity offset value of >−1 years was classified as pre-PHV, −1 to 1 years indicated that the player was circa-PHV, and a score of >1 years indicated that the player was post-PHV [
38].
A total of 470 Tunisian basketball players (boys and girls) were categorized among the maturity groups (n = 111 pre-PHV, n = 170 circa-PHV, and n = 189 post-PHV).
2.5. Statistical Analysis
Descriptive statistics, including mean and standard deviations, were calculated for all anthropometric and physical performance parameters. Data from males and females were analyzed separately. The normality of all anthropometric and physical performance parameters was checked by the Shapiro–Wilk test. Comparisons between boys and girls at the same maturity status were carried out using Student’s unpaired
t-tests. Comparisons between maturity status groups were analyzed using one-way ANOVA with Bonferroni’s correction. A repeated-measures multivariate analysis of variance (MANOVA) was applied to analyze within-subject changes and interaction effects (chronological age × maturity status) [
39]. Effect sizes for the MANOVA test results were calculated in terms of eta squared values (η
2) and categorized as follows: <0.06 as a low effect, 0.06 to 0.14 as a moderate effect, and >0.14 as a high effect. Percentile analyses were computed separately for boys and girls according to maturity status, calculating the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles. All statistical procedures were performed using SPSS for Windows (version 26.0). A 0.05 probability level was used for statistical significance.
6. Strengths and Limitations
This research establishes normative performance values based on gender- and maturity-specific benchmarks for Tunisian young basketball players, helping to deepen the understanding of their potential and development. By considering maturity as a factor in performance, we can reduce the risk of disadvantaging or misjudging athletes who may be on a slower, but ultimately more successful, developmental trajectory. More precisely, understanding the developmental trajectory of female athletes is vital for creating effective training programs. Moreover, the large sample size enhances the reliability of the reference values, reinforcing their applicability across different maturity statuses and gender groups. One limitation of this study is its focus on a specific population—Tunisian youth basketball players—which may limit the generalizability of the results to other populations with different training practices and social, ethnic, and genetic factors. Moreover, while this study includes basic anthropometric and performance parameters, future research could benefit from incorporating more advanced psychological and physiological parameters to provide a more comprehensive view of athletic development. Lastly, as a cross-sectional study, it does not account for longitudinal changes within individuals, which would be important for understanding the development of physical performance over time.