## 1 Introduction
(2013) assessed the physiological responses and performance variables during RAST and WAnT in collegiate-level soccer players, finding little correlation between the two, which suggests that different combinations of metabolic contributions exist between the protocols [10]. Moreover, a study by [PERSON], [PERSON], and [PERSON] (2009) investigated the validity of RAST for assessing anaerobic power and predicting short-distance performances in athletes from the armed forces. They demonstrated that RAST is a reliable and valid tool for evaluating anaerobic power, with significant correlations found between the RAST and WAnT results, as well as with actual running performances over distances ranging from 35 to 400 m. The study highlights RAST's practicality for field tests, reinforcing its relevance for sports that utilise running as the primary form of locomotion [5]. These findings underscore the need for the careful selection of the appropriate test protocol based on specific sport requirements, highlighting the variability in how different tests might align or diverge in terms of assessing specific performance metrics relevant to various sports disciplines. This variability influences the choice of the most appropriate test protocol for assessing repeated sprint ability in athletes. Understanding the contribution of different energy systems in RSA tests is vital for targeted training. Studies have quantified these contributions, revealing significant differences in how energy systems are taxed during cycling versus running. For example, [PERSON] et al. (1993) underscored the predominance of the ATP-PCr and glycolytic systems, attributing 55.9% and 44.1% of energy production to these pathways, respectively, during initial sprints [16]. This distribution shifts as the duration of the activity extends, with [PERSON] et al. (2005) noting that a 3 s sprint utilises the ATP-PCr and glycolytic pathways for 65% and 32% of energy, respectively, indicating a higher reliance on immediate energy systems for shorter bursts [9]. Further studies, such as those by [PERSON] et al. (2011), expand on this by quantifying the oxidative system's contribution, which, while minimal (8%) during short 6 s cycles, plays a crucial role in recovery processes and sustaining performance over successive sprints [8]. This observation aligns with [PERSON] et al. (2017), who explored the nuanced contributions of oxidative phosphorylation, glycolysis, and phosphagen systems, highlighting their interdependent roles in facilitating recovery and performance sustainability [12]. Moreover, innovative methodologies, such as the use of the oxygen consumption (VO\({}_{2}\))-time integral to estimate the phosphocreatine (PCr) replenishment during rest intervals, as noted in these studies, underscore the importance of aerobic recovery mechanisms between high-intensity efforts [16; 17; 18]. This body of evidence not only enhances our understanding of energy system dynamics during RSA but also suggests that tailored training strategies that consider these diverse energy contributions could significantly benefit athletic performance in intermittent sports. Despite the extensive use of cycling tests due to their convenience, there is a gap in understanding how well these tests translate to performance in field sports where running is more prevalent. Research suggests that performance outcomes from cycling tests may not correlate strongly with those from running tests [5; 10; 15]. This discrepancy points to a need for more comparative studies to validate the appropriateness of these tests in different sports contexts. This study aims to address a critical gap in sports science by comparing physiological and performance variables between cycling and running repeated sprint tests. Specifically, the study objectives are as follows: (1) Assess the differences--to evaluate and compare the physiological and performance variables between similar cycling and running repeated sprint tests.