Evaluation of Body Composition in CrossFit ® Athletes and the Relation with Their Results in Official Training

s a high-intensity sport that combines weightlifting, gymnastic skills, and cardio- vascular exercises. To nd the anthropometric references that de ne the optimal body composition, it is essential to rst nd an optimal body composition for one's physical preparation. The objective of this study is to describe the anthropometric characteristics of 27 Spanish CrossFit ® athletes, 19 males aged 39 years old (24–44) and 8 females aged 28 years old (23–40), and how these characteristics in uenced their performance. The athletes performed the Fran, Cindy, and Kelly workouts, estab- lishing minimum marks, and the CrossFit Total workout to assess maximum strength. Signi cant differences were not found in time and repetitions between sexes in skill training, although there was a positive correlation r = 0.876 (p< 0.001) between muscle mass and the Total CrossFit result. We can conclude that the CrossFit ® athlete has a low amount

workouts, estab- lishing minimum marks, and the CrossFit Total workout to assess maximum strength. Signi cant differences were not found in time and repetitions between sexes in skill training, although there was a positive correlation r = 0.876 (p< 0.001) between muscle mass and the Total CrossFit result. We can conclude that the CrossFit ® athlete has a low amount of fat mass and a small relative size, which is an advantage when training with bodyweight exercises, and a high muscle mass that provide bene ts when strength training. In addition, despite executing movements from a multitude of disciplines, the physical demands for lifting heavy loads resulted in the anthropometric values of athletes being more similar to elite weightlifting athletes than in other sports. Keywords:CrossFit; cross-training; anthropometry; body composition; somatotype; athletic performance 1. Introduction CrossFit ® is a high-intensity sport created by Greg Glassman and Lauren Jenai [1,2] that combines weightlifting, typical of sports such as weightlifting and powerlifting, movements with body weight from artistic gymnastics, cardiovascular exercises, and various skills from other sports [3]. Since its creation, the presence of CrossFit ® has increased in the world of sports, with more than 13,000 official sports centers (boxes) around the world, 499 of them in Spain [4]. In addition, there are countless unofficial boxes where the same type of sports practice is carried out, commonly known as cross-training, but without the official license from the brand; so we can consider it as one of the sports that has grown the most in number of athletes in the last 20 years [ CrossFit ® workouts, called Workout of the Day (WOD), are extremely varied and can focus on one of the sports modalities that CrossFit ® is composed of or be a compendium of them. Thus, an athlete can perform both a WOD with their body weight that lasts no more than 5 min [6] and another workout that lasts 30–40 min that combines powerlifting, running, and movements on rings [7]. Therefore, this is a sport that not only builds an enormous physical capacity but also has a fairly high technical

a compendium of them. Thus, an athlete can perform both a WOD with their body weight that lasts no more than 5 min [6] and another workout that lasts 30–40 min that combines powerlifting, running, and movements on rings [7]. Therefore, this is a sport that not only builds an enormous physical capacity but also has a fairly high technical component from different sports modalities. Int. J. Environ. Res. Public Health2022,19, 11003.

Int. J. Environ. Res. Public Health2022,19, 11003 2 of 11 In competition, unlike in most sports, the athletes do not know which tests they are going to face until a few hours or minutes before it. Therefore, training, rest, feeding, and hydration in the days before and during the competition cannot be oriented towards speci c parameters, as it is often found with athletes of more speci c sports such as endurance [8]. Thus, the athletes must focus on maintaining an optimal general physical condition [9]. It should be noted that in CrossFit ® , there is a single weight category, and all athletes have to perform the same exercises with the same loads regardless of their size, so it is not easy to nd an ideal body composition (BC) as excess fat mass, or even muscle mass, could weigh you down in gymnastic movements, although they could be an advantage in heavy lifting of weightlifting [10]. Anthropometry is one of the tools used to estimate BC. It is a science that studies size, shape, proportionality, composition, biological maturation, and bodily function in order to understand the processes involved in growth, exercise, nutrition, and sports performance [11]. Today there is a standardized protocol created by the International Society for the Advancement of Kinanthropometry (ISAK) so that measurements are carried out with the highest possible validity and precision; which consists of taking anthropometric measurements: weight (kg), height (cm), sitting height (cm), arm span (cm), skinfolds (mm), girths (cm), lengths (cm) and bone diameters (mm); in order to assess people's health status, body composition and somatotype [12]. Despite the growing interest of the sports population for CrossFit ® , there are no studies that describe their athletes anthropometrically or that refer to BC or somatotype [13], and the suitability of one compared to another for the practice of this sport, as with other classic sports such as athletics [14], artistic gymnastics [15] or weightlifting [10,16]. It is considered that establishing anthropometric references that de ne the body composition of the athletes with the best marks is essential for the physical preparation of

BC or somatotype [13], and the suitability of one compared to another for the practice of this sport, as with other classic sports such as athletics [14], artistic gymnastics [15] or weightlifting [10,16]. It is considered that establishing anthropometric references that de ne the body composition of the athletes with the best marks is essential for the physical preparation of elite athletes [17]; however, we do not have that tool for CrossFit ® . The aim of this study is to describe the anthropometric characteristics, body composi- tion, and somatotypes of CrossFit ® athletes from southeast Spain and how these parameters in uence the performance of this sport. The main hypothesis of this research is that the studied sample will show differences according to sex and that CrossFit ® athletes will have a low amount of fat mass and a high muscle mass. 2. Materials and Methods 2.1. Design An observational and descriptive pilot study of the anthropometric characteristics, body composition, and somatotype of CrossFit ® athletes from southeast Spain to nd a correlation with their results in of cial WODs. 2.2. Sample The study population was selected through non-probabilistic convenience sampling. The sample was made up of 19 men and 10 women, with an age range between 23 and 44 years, with high physical and technical levels, and an experience of >2 years in the practice of CrossFit ® . In addition, the sample performs an average of 3 training per week. All athletes participated voluntarily, being informed of the entire process and methodology used, providing their consent in writing in accordance with the Declaration of Helsinki 2013 and the Ethics Committee from the University of Alicante (File UA-2020–03–29). For the selection of athletes, we counted different of cial boxes that agreed to partici- pate in the study. Athletes who met the inclusion criteria were recruited through the boxes and voluntarily accepted to participate. The training sessions were carried out by the participating athletes at of cial CrossFit ® boxes, having the possibility of repeating some or all of the WODs, and only delivering the best mark for each

boxes that agreed to partici- pate in the study. Athletes who met the inclusion criteria were recruited through the boxes and voluntarily accepted to participate. The training sessions were carried out by the participating athletes at of cial CrossFit ® boxes, having the possibility of repeating some or all of the WODs, and only delivering the best mark for each of them at the end. Both the training and the anthropometric measurements were carried out in the months of February and March 2020.

Int. J. Environ. Res. Public Health2022,19, 11003 3 of 11 2.3. Inclusion and Exclusion Criteria For the selection of the sample, as CrossFit ® did not have of cial regional or national competitions with which to establish the minimum requirements of physical performance and experience in athletes, we decided to use of cial WODs, also known as Benchmark Workouts [18], which utilize standards de ned by CrossFit ® , both for technical execution and load (Rx). Training sessions were held on Mondays for four consecutive weeks as part of the participants' pit schedule. This day was chosen since the schedules of these boxes consist of ve pieces of training that take place from Monday to Friday, and in this way, it was guaranteed that the athlete carried out the training after having rested two days and not another day of the week when accumulated fatigue would interfere with their performance. For the selection of the of cial WODs, and considering the objective of this study, WODs chosen did not have high technical demand, and the physical abilities of the athletes were evaluated based on their body composition in addition to their skills or experience. The WODs were selected to cover the full range of CrossFit ® 100 workouts. These were: “Kipping Fran” [19], oriented towards strength/endurance, “Cindy” [19], which is performed with body weight, and “Kelly” [19], focused on aerobic endurance. In addition to these three WODs, which de ned the suitability of the athletes for the study, another WOD, called “CrossFit Total” [19], was performed to assess maximum strength, in which the athletes had 15 min to perform three basic strength training exercises in one single repetition (1RM): Shoulder Press, Back Squat, and Dead Lift, recording the maximum weight lifted in each exercise and the total sum. We used the execution standards established by CrossFit ® through a CrossFit ® certi ed trainer and set the maximum execution times that would ensure an advanced physical level of the athletes in the sample. The data obtained were used to carry out the analysis (Table). Table 1.WODs requirement for sample selection.

lifted in each exercise and the total sum. We used the execution standards established by CrossFit ® through a CrossFit ® certi ed trainer and set the maximum execution times that would ensure an advanced physical level of the athletes in the sample. The data obtained were used to carry out the analysis (Table). Table 1.WODs requirement for sample selection. (Kipping 1 ) Fran Kelly 21-15-9 Repetitions per Time 5 Rounds for Time - - - - - Time Cap 2 : 9 0 Time Cap: 30 0 Cindy CrossFit Total AMRAP 3 in 20 0 Sum of the Best of Each Lift - - - - 4 Back Squat - - Minimum 12 sets Time Cap: 15 0 1 . Kipping: Hanging pull-up exercise with momentum. 2 . Time Cap: time limit. 3 . AMRAP: As Many Reps As Possible. 4 . 1RM: 1 repetition maximum. 2.4. Materials and Procedures To carry out this study, the following sociodemographic variables were collected for statistical or descriptive purposes, as well as for their use in the anthropometric formulas that required them: sex (male or female), age, ethnicity, and country of origin. For taking the anthropometric values, the standards and measurement techniques rec- ommended by the ISAK were used. The measurements were taken by an anthropometrist accredited in the ISAK level 2 who worked under the supervision of a level 3 accredited anthropometrist. We took into account the intraobserver technical error of measurement (ETM) indicated by the ISAK (5% for skinfolds and 1% for girths and diameters). Thus, the anthropometric measurements taken were those established by the ISAK [20] restricted pro le: Basic (body mass, height, sitting height, arm span), Skinfolds (triceps, subscapu-

Int. J. Environ. Res. Public Health2022,19, 11003 4 of 11 laris, biceps, iliac crest, supraspinal, abdominal, thigh, leg), Girths (relaxed arm, exed and contracted arm, waist, hips, middle thigh, leg) and Bone breadth (humerus, bistyloid, femur), in addition to the biacromial and biiliocrestal breadth, belonging to the complete pro le of the ISAK, for a total of 23 anthropometric measurements. For the calculation of BC, a four-component system was used through the application of the equations from Lee et al. [21] for muscle mass, Faulkner [22] for fat mass, Rocha [23] for bone mass. The residual mass was calculated as the remaining body mass minus the other three components, as recommended for use for adult athletes in the consensus document of the Spanish Federation of Sports Medicine [24]. These data were calculated both in kg and in percentages of total weight. To calculate the somatotype, the three-component system (mesomorphy, endomorphy, and ectomorphy) proposed by Heath and Carter [13] was used, thereby establishing the mean somatotype and position in the somatochart of the high-level CrossFit ® athlete, for both men and women. The proportionality of the athletes in the sample was assessed using the Phantom [25] methodology, which allows describing which anthropometric values stand out with respect to a phantom human being, a mixture of a metaphorical woman and man. In addition, the sum of the values of the 8 skinfolds, corrected girth of the relaxed arm, corrected girth of the middle thigh, corrected girth of the leg, body mass index (kg/m 2 ), waist-height index (waist girth/height), relative size and acromio-iliac index (biacromial breadth/biiliocrestal breadth) [12,17,26] were calculated. The number of times, repetitions performed, and weights used in the WODs were recorded in a sheet, which indicated in detail what the athlete had to do in each training session. The exercises were supervised by trainers or judges, all certi ed by CrossFit ® , to ensure that they were performed in compliance with the standards mentioned. Variables such as diet control, sleeping time, hydration, or use of ergogenic sports supplements were not studied because the aim of the study was

the athlete had to do in each training session. The exercises were supervised by trainers or judges, all certi ed by CrossFit ® , to ensure that they were performed in compliance with the standards mentioned. Variables such as diet control, sleeping time, hydration, or use of ergogenic sports supplements were not studied because the aim of the study was to describe anthropometric variables and how they can affect performance, but not to analyze what results were obtained depending on the lifestyles of the athletes. The equipment used for the anthropometric measurements consisted of a Harpenden skinfold caliper (precision 0.2 mm), Cescorf anthorpometric tape (precision 1 mm), Cescorf segmometer (precision 1 mm), RealMet small sliding caliper (precision 1 mm), RealMet large sliding caliper (precision 1 mm), RealMet dermographic pen, Seca standing height rod (1 mm precision), Ozeri scale (100 g precision) and anthropometric drawer (40 50 30 cm); all of which were approved, correctly calibrated, and checked every six months. 2.5. Statistical Analysis The statistical analysis was carried out through a descriptive and association study by sex of the anthropometric variables and the results of the training. Given the sample size, it was assumed that the values obtained did not have a normal distribution. Thus, we obtained the mean, standard deviations, median, minimum, and maximum for all values. Likewise, in order to nd a relationship between the anthropometric values and the training results, the Spearman correlation was used. To nd the statistical differences between sexes and the results of the WODs Fran, Cindy and Kelly, a Spearman correlation was calculated. All mathematical and statistical analyzes were performed with Microsoft Of ce Excel 2019 (Redmond, WA, USA) programs for MacOS, and IBM SPSS 24 (Armonk, NY, USA). 3. Results Of the initial sample of 19 men and 10 women, 2 women were discarded because they did not meet the minimum physical level requirements (WODs) for participation in the study, nally leaving a sample of 19 men aged 39 (24–44) years old, and 8 women aged 28 years-old (23–40).

initial sample of 19 men and 10 women, 2 women were discarded because they did not meet the minimum physical level requirements (WODs) for participation in the study, nally leaving a sample of 19 men aged 39 (24–44) years old, and 8 women aged 28 years-old (23–40).

Int. J. Environ. Res. Public Health2022,19, 11003 5 of 11 In relation to the results of the WODS, to find the statistical differences between sexes and the results of the WODs Fran, Cindy, and Kelly, a Spearman correlation was calculated, and it was observed that the significance between each of the WODs and sex was greater than 0.05 (p> 0.05), so we conclude that there are no differences between sexes. It was not the same with Crossfit Total, in which the significance of the correlation wasp< 0.001. Table that there were no significant differences between sexes in the training sessions that required technical skills (Kipping Fran r = 0.056, Kellyr = –0.297, Cindyr = 0.006). However, there was a significant correlation between the results in CrossFit Total and gender (r = –0.792); but since it is a maximum strength exercise, regardless of gender, this correlation is more related to muscle or bone mass, r = 0.876 (Figure Table 2.Results of the WODs for the selection of the sample. Male Female n Mean Std Dev. Median Min–Max n Mean Std Dev. Median Min–Max Kipping Fran (s) 18 372 78 349 233–523 6 375 534 393 292–430 Kelly (s) 18 1806 174 1795 1373–2082 7 1712 180 1660 1472–2027 Cindy (reps) 19 577 85 555 470–801 7 566 85 605 453–660 Shoulder Press (kg)19 63.8 7.3 63,0 52.5–80.0 8 43.3 4.2 42,8 37.5–50.0 Back Squat (kg) 19 126.2 11.4 125.0 110.0–160.0 8 89.8 5.5 90.0 83.0–100.0 Dead Lift (kg) 19 165.8 16.6 170.0 140.0–190.0 8 109.7 10.4 110.0 97.5–125.0 CrossFit Total (kg) 19 355.8 29.1 355.0 305.0–420.0 8 242.7 15.9 244.0 222.5–260.0Int. J. Environ. Res. Public Health 2022, 19, x FOR PEER REVIEW 5 of 12 3. Results Of the initial sample of 19 men and 10 women, 2 women were discarded because they did not meet the minimum physical level requirements (WODs) for participation in the study, finally leaving a sample of 19 men aged 39 (24–44) years old, and 8 women aged 28 years‐ old (23–40). In relation to the results of the WODS, to find the statistical differences between

This research establishes a descriptive basis for the body composition of CrossFit athletes.