## 2 Materials and Methods
### Outcome Measures  
The effects of the fitness programs were assessed through changes in body weight, height, BMI, waist circumference, skinfold thickness (upper arm, abdomen, thigh), body fat percentage, muscle mass percentage, and blood lipid parameters (HDL, LDL, total cholesterol, and triglycerides). Anthropometric measurements were conducted according to the International Standards for Anthropometric Assessment (ISAK) [36], using standardized procedures and equipment, including a Harpenden skinfold caliper and the TANITA UM-72 bioelectrical impedance analyzer [37]. Standing height was measured with [PERSON]'s anthropometer with participants standing barefoot, heels together, arms at their sides, and the head positioned in the Frankfurt horizontal plane. The measurement was taken from the vertex to the floor and recorded to the nearest 0.1 cm. Waist circumference was measured at the midpoint between the lower margin of the last palpable rib and the top of the iliac crest, using a flexible, non-elastic anthropometric tape, with the participant in a standing position after a normal expiration. Skinfold thicknesses were measured at the triceps, abdomen, and thigh using a Harpenden caliper, on the right side of the body. The skinfold was grasped firmly between the thumb and index finger, and the caliper was applied 1 cm below the fingers, perpendicular to the fold. Readings were recorded 2 s after application, in accordance with ISAK guidelines. Body composition parameters (body fat and muscle mass percentages) were assessed using the TANITA UM-72 device (Tanita Corporation, Tokyo, Japan), which applies bioelect  
Figure 1: Participant randomization. trical impedance analysis (BIA). Standardized pre-test conditions were ensured, including assessments conducted in a hydrated state and during morning hours. All instruments were calibrated before the assessment phase, and anthropometric measurements were conducted by ISAK-certified technicians. To evaluate intra-rater reliability, the Intraclass Correlation Coefficient (ICC) was calculated for all anthropometric variables. Venous blood samples for lipid profile analysis (total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides) were collected in the morning, between 8:00 and 10:00 a.m., after a fasting period of 9 to 12 h, from the antecubital vein while participants were in a seated position, in cooperation with the Bosfor Polyclinic in Novi Pazar. The analyses were conducted in their accredited medical-biochemical laboratory using a standardized and validated direct enzymatic method on the automated biochemical analyzer Roche Cobas C311 (Roche Diagnostics, Mannheim, Germany), with original Roche reagents, in accordance with the manufacturer's recommendations and international laboratory standards. Total cholesterol and triglycerides were determined using the classical colorimetric method, while HDL and LDL cholesterol were analyzed using the direct enzymatic method, which provides higher accuracy in determining these fractions due to the variability of lipoprotein subfractions. When applicable, LDL cholesterol values were also automatically calculated by the analyzer using a validated formula based on the concentrations of total cholesterol, triglycerides, and HDL: LDL-C (mmol/L) = total cholesterol - HDL-C - (triglycerides/2.2). This formula is valid only when triglyceride levels are below 4.5 mmol/L. The laboratory is also equipped with reagents for direct LDL cholesterol determination, further enhancing the reliability of the results. All samples were processed within two hours of collection and analyzed under the same laboratory conditions by licensed professionals. Participants were advised to refrain from consuming alcohol, carbonated beverages, and fatty foods during the 48 h prior to blood sampling. All analyses were consistently performed at the same time of day (8:00-10:00 a.m.), within five days before the beginning and after the completion of the twelve-week intervention, to ensure maximum reliability and repeatability of measurements.