Validity of a User-Friendly Spreadsheet Designed for an In-Depth Analysis of Countermovement Bipodal Jumps  
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1 SER Research Group, Physical Activity and Sport Sciences Department, CESAG, Comillas Pontifical University, 07013 Palma de Mallorca, Spain 1  
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2 Department of Education, Faculty of Education Sciences, University of Almeria, 04120 Almeria, Spain; alexperez@uales 23 SPORT Research Group (CTS-1024), CIBIS Research Center, Faculty of Education Sciences, University of Almeria, 04120 Almeria, Spain 3  
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4 Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, 18011 Granada, Spain; [EMAIL_ADDRESS] (FJ.R.-); [EMAIL_ADDRESS] (I.N.-M.) 4  
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4 Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, 18011 Granada, Spain; [EMAIL_ADDRESS] (FJ.R.-); [EMAIL_ADDRESS] (I.N.-M.) 4  
5 Human Lab, Sport and Health University Research Institute (IMUDS), Faculty of Sport Sciences, University of Granada, 18007 Granada, Spain; [PERSON]  
-port performance [4]. Furthermore, asymmetries in jump performance, where one limb generates more force than the other, often reflect underlying muscular imbalances or compensatory mechanisms that disproportionately overload one limb, thereby exacerbating the risk of injury in sports and other high-intensity physical activities [5]. These studies emphasize the significance of jump tests as essential tools in both athletic and public health evaluations. An in-depth analysis of the countermovement bipodal jump (CMJ) requires analyzing each leg's variables in isolation, not only taking into account the magnitude of the ground reaction forces but also the temporal offset between each phase of the dominant and non-dominant leg. In this context, force platforms are frequently regarded as the benchmark instrument for assessing the kinetic and kinematic variables associated with jumping [6; 7]. The accuracy and reliability of the data obtained from these platforms are contingent upon the software employed, as the precision of variable calculations hinges on the formulas utilized [8]. A notable example is Measurement, Analysis, and Reporting Software [MARS 4.0], developed by the esteemed brand Kistler. MARS 4.0 is a comprehensive solution that requires no specialized programming knowledge, making it accessible for broad use in both research and practice [9]. This software facilitates the extraction of a wide array of parameters, including kinematical and temporal parameters or kinetics ones [10]. Among these, two of the most widely used in research are jump height calculated via take-off velocity or flight time [8; 11; 12; 13; 14] and propulsive impulse [15; 16], which directly influences take-off velocity and, consequently, jump height. One of the primary challenges associated with software specifically designed to evaluate jumps is its prohibitive cost, with most brands exceeding one thousand euros. Consequently, many coaches and research laboratories with limited budgets find it unaffordable. This underscores the need to develop cost-effective solutions for assessing bipodal CMJs, given the considerable amount scientific literature dedicated to this jumping skill. Conventional spreadsheet-based software (such as Microsoft Excel) offers an alternative, given its widespread availability and user-friendly interface and has been used for complex sport sciences applications [17; 18]. Furthermore, Excel includes features that are particularly advantageous in academic settings, such as customizable formulas that can be easily modified and automated (even including more sophisticated script in VBA computer programming language). Indeed, few authors have developed spreadsheets enabling the straightforward calculation of bilateral CMJ parameters, including eccentric and concentric phase impulses, as well as jump height derived from flight time or take-off velocity [19; 20].