## 1 Introduction  
Modern lifestyles, which are characterized by increased reliance on technology and enhanced comfort, have significantly reduced physical activity levels, with participation rates falling below 50% [1]. Additionally, poor dietary habits and the rise in sedentary behaviors affect a substantial proportion of the population, with approximately 50% of individuals engaging in minimal physical activity, further amplifying health risks [1]. According to the World Health Organization (WHO) [2], approximately 1 in 4 adults and over 80% of adolescents fail to meet the physical activity guidelines necessary for maintaining optimal health. This lack of activity has been strongly associated with increased morbidity and mortality from non-communicable diseases. The WHO recommends that adults engage in muscle-strengthening exercises at least twice per week to mitigate these risks [2]. Resistance training, in particular, is recognized as a highly effective strategy for improving both physiological and physical health across all age groups [3]. Emerging evidence supports its efficacy, demonstrating substantial gains in muscle mass and strength [4,5]. In recent years, high-intensity interval training (HIIT) has gained prominence due to its adaptability to diverse individual characteristics and fitness levels [6]. Among HIIT methodologies, CrossFit(r) has emerged as a popular and effective training approach, as highlighted by [PERSON] and [PERSON] [7] and [PERSON] et al. [8]. CrossFit emphasizes general physical fitness by optimizing multiple fitness dimensions, including cardiorespiratory fitness, muscle strength, power, flexibility, speed, agility, and balance [7]. The workouts integrate elements from gymnastics, Olympic weightlifting, endurance exercises, resistance training, and other athletic disciplines [8,9]. The defining characteristic of CrossFit is its focus on high-intensity functional movements, often structured as the \"workout of the day\" (WOD), which involves rapid, repetitive execution with minimal rest periods [7,10]. The methodology used by CrossFit optimizes exercise efficiency, generating significant physiological adaptations and improving overall physical performance [11, 12, 13]. A systematic review has demonstrated the effectiveness of CrossFit on increasing maximal oxygen consumption (VO\({}_{2}\)max), improving muscle mass and strength, and enhancing cardiorespiratory fitness [13]. In addition, scientific evidence indicates that CrossFit significantly increases fat-free mass [9]. When appropriately tailored to individual needs, CrossFit can serve as an effective exercise strategy for healthy adults [8,10]. Among training methodologies for improving muscle strength and overall physical fitness, CrossFit is distinctive for avoiding a linear programming structure, instead prioritizing constant variation in stimuli through WODs [10,14]. This variability promotes simultaneous and comprehensive improvements in fitness domains. WODs are highly diverse, targeting cardiorespiratory fitness, muscle strength, or a combination of both, with durations that fluctuate significantly [13]. Research on training and performance processeshas explored the impacts of these variations on physical adaptation and performance outcomes. For example, a six-month intervention comparing novice and advanced CrossFit practitioners showed significant improvements in both groups. Females exhibited gains in flexibility, power, muscular endurance (push-ups), and muscle strength (back squat, bench press, and deadlift). Notably, the novice group exhibited greater improvements in running speed (1.5-mile run) [15]. Similarly, another study comparing novice and advanced practitioners with physically active individuals found that the advanced CrossFit group exhibited a lower body fat percentage, greater fat-free mass, higher quadriceps isometric strength, and superior VO2 max and cycling performance [16].