## 2 Materials and Methods
### Participants  
This study recruited 15 male college basketball players as participants, meeting the required sample size [12]. To ensure the representativeness of the sample, this study utilized the quantile-quantile plot (Q-Q Plot) for normality testing [13], as shown in Figure 1. The results showed that the pre-test means and standard deviations of the participants' background variables all exhibited a linear normal distribution, including age (\(21.4\pm 1.29\) years), height (\(180\pm 8.70\) cm), weight (\(78.2\pm 7.68\) kg), body mass index (\(24.1\pm 1.78\) kg/m\({}^{2}\)), skeletal muscle mass (\(37.9\pm 4.75\) kg), and body fat mass (\(13.3\pm 3.79\) kg). Additionally, all values fell within the 95% confidence interval (CI) range [14]. All participants voluntarily joined the study and signed informed consent forms before the research commenced to ensure that the study adhered to academic ethical standards. To ensure the representativeness of the sample and the reproducibility of the study, the inclusion criteria consisted of adult males aged 20 years or older who were in good health, without severe sports injuries or chronic diseases. Additionally, participants were required  
Figure 1: Normal distribution of participants’ background variables. Note: The horizontal axis represented “observed values”, while the vertical axis indicated “deviation from normality”. The abbreviation for body mass index was BMI; skeletal muscle mass was abbreviated as SMM, and body fat mass was abbreviated as BFM. to have at least two years of formal basketball training and competitive experience to meet the research requirements. The exclusion criteria included injuries that could impair athletic performance, such as recent severe strains, fractures, or muscle tears, as well as the use of medications that could affect sports performance. Psychological factors that might influence athletic ability, such as severe stress or anxiety disorders, were also considered. Additionally, participants who were unable to complete the required training and testing or failed to comply with the research guidelines were excluded. Intervention Measures  
The participants in this study undergo two hours of basketball training per day (Monday to Friday), including technical training and team practice games. This study employed a progressive training program (PTP) as an intervention measure. The training team consisted of basketball coaches, strength training coaches, and sports protection specialists. Based on the relevant literature [15; 16; 17; 18; 19; 20] and the expertise of the research team members, a customized PTP was developed to meet the specific demands of basketball and align with the physical and skill attributes of the study participants. Because the participants already possessed a fundamental level of strength, the PTP intervention lasted for 12 weeks, aligning with the physiological adaptation cycles observed in trained individuals [21; 22; 23]. Additionally, the participants' background variables exhibited normal distribution, and the PTP incorporated diverse movement types while rationally distributing training intensity, effectively minimizing physiological deviations. PTP twice a week for 12 weeks [24]. Each training session lasted for a total of 60 min [25], consisting of 10 min of warm-up (dynamic stretching and low-intensity aerobic exercises), 40 min of main training (circuit training), and a 10 min stretching session (static stretching and relaxation). The circuit training was designed with each movement being performed for 40 s, followed by 20 s of rest, completing three cycles. A 2 min rest period was provided between cycles [26]. The training intensity was set to moderate to high levels (70-85% of maximum effort), with intensity being controlled based on heart rate monitoring or perceived exertion (RPE scale) [27]. The training content included movements such as squat jumps, box jumps, single-leg hops, lateral bounds, split jumps, and broad jumps.