# The Role of Physical Fitness on FRAN CrossFit(r) Workout Performance
## 1 Introduction  
During the past 25 years, CrossFit(r) has become a well-known training method which is followed by several people who want to enhance their fitness levels. CrossFit(r) is a high-intensity sport which includes both aerobic and anaerobic exercises combining different athletic skills which are organized in training sessions called the workout of the day. This training scheme has several positive effects on the physiology, physical fitness, psychology, and performance of participants [1, 2]. During a CrossFit(r) workout, the training volume and intensity can be adjusted to each individual's needs, which makes it an essential training method for participants looking for an individualized and diverse training modality [3]. CrossFit(r) includes several workouts with different physical fitness determinants [4, 5, 6]; however, it remains unclear what physical abilities an athlete should have developed in order to have a high performance in specific CrossFit(r) workouts. One of the most well-known workouts in CrossFit(r) is FRAN [7, 8]. FRAN consists of two multi-joint movements: front squat thrusters with a barbell of 43.2 kg and body mass pull-ups. Both exercises are performed alternately for three rounds of 21, 15, and 9 repetitions for each round. The aim is to complete the workout as fast as possible. Performance in FRAN depends largely on the tolerance of the athlete to fatigue, which may be reflected by muscle buffer capacity [9]. Muscle buffer capacity works as a system to reduce the accumulation of H\({}^{+}\) and therefore reduce the perception of fatigue during high-intensityexercises [9]. From a practical point of view, muscle buffer capacity shows the ability of an athlete to maintain power against repeated high-intensity exercises such as the repeated sprints or the Wingate anaerobic test [10; 11]. Indeed, several studies have shown that the Wingate anaerobic test may significantly predict CrossFit(r) performance [11; 12] but not performance in FRAN [4]. More specifically, a study on 17 participants (12 males and 5 females) showed that anaerobic peak and mean power in the Wingate test were not correlated with performance in FRAN (r = \(-\)0.317 and \(-\)0.399, respectively), probably because of the level and mixed gender of the participants [4]. Although the correlation between the Wingate anaerobic test and CrossFit(r) performance has been previously investigated, it would be interesting to investigate the connection between continuous jumping (CJ) with FRAN. More specifically, the CJ anaerobic test refers to several maximum countermovement jumps with arms akimbo with a duration of 1 min or 30 s [13; 14]. It has previously been proposed that the CJ test may be a better anaerobic test compared to Wingate for evaluating performance in trials with several stretch-shortening cycle (SSC) movements like FRAN [15]. However, whether performance in CJ may separate faster from slower athletes in FRAN may provide useful information to coaches in order to design more effective training programs and enhance performance in FRAN. In addition, a possible connection between CJ and FRAN may suggest that CJ can also be used as a laboratory tool to predict performance in FRAN. Nevertheless, such a premise needs further investigation. Systematic CrossFit(r) training may lead to several significant changes in body composition, including fat mass, lean mass, and bone mineral density [16]. More specifically, 10 weeks of CrossFit(r)-based training may improve body composition in individuals of all fitness levels and genders [17]. Furthermore, more experienced athletes in CrossFit(r) possessed greater lean mass and lower body fat compared to their recreational counterparts [18], although such a comparison between faster and slower athletes in FRAN is unclear.