During the 6-week intervention period, the combined training group performed 2 sessions per week of lower-body strength training and 2 sessions per week of small-sided games training in different formats. The combined training group also participated in their team's regular soccer training, which focused on technical and tactical skills, with 5 sessions per week (60-90 minutes each).

The small-sided games group performed 2 sessions per week of small-sided games training program in different formats, without participating in any strength training. The combined training group also participated in their team's regular soccer training, which focused on technical and tactical skills, with 5 sessions per week (60-90 minutes each).

During the 6-week intervention period, the combined training group performed 2 sessions per week of lower-body strength training and 2 sessions per week of small-sided games training in different formats. The strength training was performed on Tuesdays and Thursdays. This training was finished at least one hour before the team's technical and tactical soccer training. The strength training program is designed to include movements for bilateral hip dominant, bilateral knee dominant, unilateral hip dominant, unilateral knee dominant and calf muscles. The exercises were selected to allow players to perform them on the field with minimal equipment, without the need for machines. In addition, small field games training was practiced two days a week. Repetitions in reserve and resistance training-specific ratings of the perceived exertion scale were used to determine training intensity and load.

Height (in cm) was measured using a stadiometer (SECA, Hamburg, Germany). These measurement was taken in the morning, before breakfast, while the players wore light clothing and no shoes. Measurement was performed twice to reduce the margin of error.

Body weights (in kg) were measured using a body mass measuring device (Fakir, Germany). These measurement was taken in the morning, before breakfast, while the players wore light clothing and no shoes. Measurement was performed twice to reduce the margin of error.

Body mass index (BMI) (kilograms/m2) was calculated from height and body weight values.

The sprinting performance was assessed using the 20-m linear sprint test. The test was conducted using two pairs of photocells (Smartspeed, Fusion Sport Pty Queensland, Australia). The starting point was placed 70 cm behind the first pair of photocells. First, a familiarization trial was conducted at low intensity. The test was then performed twice, with two-minute passive recovery intervals. The best result was used for analysis.

To assess agility performance, the Illinois Agility Test (IAT), a valid and reliable test for male team athletes, was used. Prior to starting the test, the player lies in a prone position, with the chin touching the surface of the starting line. After the researcher's command started, the player quickly stood up and ran in the indicated direction, avoiding contact with the placed cones. First, a familiarization trial was conducted at low intensity. Two trials were then performed, with two-minute passive recovery intervals. The best time was used for analysis.