Prevalence of dietary supplements consumption among CrossFit practitioners

doi:10.21203/rs.3.rs-2084649/v1

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Research Article

Prevalence of dietary supplements consumption among CrossFit practitioners

https://doi.org/10.21203/rs.3.rs-2084649/v1

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Purpose: We aimed to determine the prevalence of the use of supplements among CFPs. Moreover, we sought to elucidate which factors may be associated with dietary restraint, a dimension of eating behavior that seems to be crucial for food intake, energy availability, fatigue, and performance.

Methods CFPs aged 18-64 years (n = 112; 57 male; 55 female) were included in this cross-sectional, exploratory, and descriptive study. They answered an online questionnaire containing questions to assess prevalence, type, and reasons for supplements use, besides information about sociodemographic variables and prevalence of the main chronic morbidities. To analyze aspects of eating behavior, the “Three-factor eating questionnaire (TFEQ) - R21" was used. The Pittsburgh Sleep Quality Index questionnaire (PSQI) was used to assess sleep time and quality.

Results: Eighty-seven CFPs (50 male; 37 female) reported currently use of dietary supplements. Whey protein was the most used supplement (n = 70), followed by creatine (n = 54). Eating behavior dimensions of emotional eating, binge eating, and cognitive restraint displayed no differences between genders and CFPs of levels.

Conclusion: CFPs seem to be using some supplements with purposes which conflict with those supported by scientific evidence. Regarding eating behavior dimensions, physical exercise may be able to suppress emotional eating, possibly justifying the lack of difference in our results. The use of supplement is prevalent among CF practitioners, but it seems they need nutrition education.

CrossFit®

Dietary Supplementation

Three-factor eating questionnaire

Sleep Quality

High-intensity functional training regimens such as CrossFit® (CF) consist of a training methods comprising several physical exercises including weightlifting, powerlifting, sprints, plyometrics, calisthenics, gymnastics, and running [1]. In the past few years, CF training has become very popular. Considering the high energy demand required to perform the high-intensity workouts known as "workout of the day" (WOD) [1], practitioners commonly follow diets that promise performance improvement (i.e., Zone diet and Paleo diet) [2] or take pre- or post-exercise dietary supplements as ergogenic aids.

According to the CF founders’ recommendations, high amounts of protein should be consumed, representing up to 30% of total energy intake. Likewise, the dietary intake of fat should cover 30% of the daily energy requirements (mainly as mono- and polyunsaturated fatty acids). Carbohydrates’ contribution in the diet was initially recommended at a low level (about 40% of the daily energy requirements) [3].

Interestingly, these recommendations do not have sufficient scientific support and differ from the latest recommendations proposed by the consensus widely followed by nutritionists and exercise professionals [4]. Previous studies suggest that it is common to find inappropriate eating practices among CF practitioners (CFPs) and most of them are characterized as low energy intake [5, 6]. Restrictive eating behaviors are common in sports that involve the necessity to control body mass or to lose weight [7–9], tending to be associated with greater body image concern [10, 11].

Considering the high energy expenditure of athletes such as CFPs, dietary restraint can lead to low energy availability (LEA), resulting in poor sport-performance, besides worsening several health outcomes [12]. In CFPs, LEA may be expected, although little has been identified [6]. It is believed that a balanced diet is usually sufficient for athletes to obtain appropriate amounts of required nutrients [13, 14]; however, the use of dietary supplements is common among athletes who aim to minimize nutrient inadequacies in their diet plan, increase performance, improve body composition, or improve specific health outcomes [14]. The main sport-specific reasons for supplement use include the belief that stress of intense training/competition (load) cannot be met by food only [14]. At the highest levels of competition, athletes already train intensely and are highly motivated, so marginal advantages obtained can be decisive for winning the competition [14]. On the other hand, supplement use may be frequent even for those who are not elite CF athletes (i.e., athletes following scale and RX prescriptions). The combination of high energy demand generated by WODs, the desire to lose weight and to lower food intake can encourage the individual to start or increase the use of supplements for weight loss or improvement of body composition.

CFPs' prevalence of use of supplements and its relationship with behavioral aspects are currently unclear. Recently, our group published a systematic review investigating nutritional interventions on CFPs' performance [15]. Few studies have been found, showing that little is known about the topic [15]. Furthermore, few cross-sectional studies have investigated the relationship between nutrition and CF.

This study aimed to determine the prevalence of the use of dietary supplements and its associated factors among CF-athletes and CF practitioners.

2.1 Study type, sample and Ethics

This is a cross-sectional, exploratory, and descriptive study. Data were collected through online questionnaires, using the Google Forms® tool. Inclusion criterion comprised CrossFit practice for at least one year. Diseases were not considered as exclusion criteria. In fact, the prevalence of the main chronic morbidities (type 1 and type 2 diabetes, systemic arterial hypertension, and dyslipidemias) was assessed. Participants were aged 18–64 years. The survey was made available online, via social media, and randomly dispersed to as many people as possible from August 1st, 2020 to Sept 31st, 2020. Snowball sampling method was applied to recruit additional participants. Due to the COVID-19 pandemic, participants were asked to answer the questions without considering social isolation changes.

The sample was composed exclusively of male and female CrossFit practitioners of different levels (Scale, RX, or Elite). Athletes are placed in Scale category when workout is performed with adaptation in at least one movement or load, regardless total time or performance. RX athletes perform workouts with no adaptation. Elite athletes perform workouts with no adaptation and aim to compete at a high level. The explanation of the categories was provided so that participants could respond adequately.

Informed consent was obtained along with the questionnaire. The study was approved by the local Ethics Committee (4.165.399) and it was carried out in accordance with the procedures approved by the Declaration of Helsinki.

2.2 Questionnaire

The first questionnaire used in this investigation was applied according to Navarro et al. [16], containing questions to assess prevalence, type, and reasons for supplements use, besides information on sociodemographic variables.

2.3 Analysis of dietary supplements by group

According to Baltazar-Martins et al. [17], each supplement was individually notated and grouped according to the groups of the IOC consensus statement [18], as follows:

(i) “Performance enhancement”, which included caffeine, beta alanine, creatine, sodium bicarbonate, beet root juice (nitrate), carbohydrate drink or gel.

(ii) “Immune health”, which included antioxidant supplements, vitamin D, Vitamin E, probiotics, and vitamin C.

(iii) “Micronutrients”, which included iron supplements, magnesium, folic acid, calcium, zinc, selenium, multivitamin supplements, and electrolytes.

(iv) “Improve recovery & injury management”, which includes joint support supplements (glucosamine, chondroitin, collagen), recovery supplements (mixes of carbohydrate and protein powders labelled as a “recovery product”), omega- 3 &- 6 polyunsaturated fatty acids, and curcumin.

(v) “Body composition changes”, which includes protein powders (whey protein mixes, casein, calcium caseinate, plant/meat/egg-based protein powders).

(vi) “Low level of evidence supplements”, which includes glutamine, single amino acids/branched-chain amino acids (BCAA), beta-hydroxy beta-methylbutyrate (HMB), L-carnitine, spirulina, royal jelly, citrulline, taurine, conjugated linoleic acid, co-enzyme Q10, and fat burners, among others.

2.4 Eating behavior

To analyze aspects of eating behavior, we used the “Three-factor eating questionnaire (TFEQ - R21)" [19], which was translated and validated to the Brazilian population [20]. TFEQ-21 evaluates three human eating behavior dimensions: emotional eating score (EEs), cognitive restraint score (CRs), and binge eating score (BEs). EEs includes six items that assess the propensity to overeat in response to negative emotions, such as anxiety, depression, and loneliness. CRs includes six items that assess several factors involving food intake and concerns about body mass changes. BEs includes nine items to provide analysis on the individual's tendency to lean toward high food intake during a short period of time, generally triggered by some external stimuli.

2.6 Statistical analysis

Data are presented as means and standard deviation (mean ± SD) or frequency (%). Independent t-test was used to determine the difference between continuous variables according to CFPs' gender. Analysis of variance (ANOVA) was used to determine the difference between continuous variables according to CFP's levels. The relationship between categorical variables was tested using Chi-squared test. Pearson's coefficient was used to determine the correlation between continuous variables. Effect sizes were estimated by Cohens'd for independent t-test and by partial eta squared for ANOVA. All statistical analyses were performed using Jamovi® 1.2.27 version. The significance level was set at p < 0.05.

3.1 Sample characteristics

All answers to the questionnaire were carefully screened for coherence with their respective proposed questions. All subjects who answered the questionnaire were included in the present study. The sample consisted of 112 CFPs (57 male; 55 female). Mean age was 28.9 ± 7.64 (28.1 ± 7.64 male; 29.7 ± 7.62 female) with no difference between genders (t = -1.13; p = 0.259). Most of the participants were employed (n = 93; 47 male; 46 female) at the time of data collection.

Regarding CF levels, 20 subjects (17.9%; 8 male and 12 female) declared pertaining to Scale category, 57 subjects (50.9%, 20 male and 37 female) declared pertaining to RX category, and 35 subjects (31.3%; 29 male and 6 female) declared pertaining to Elite category. According to this categories, mean age was 31.2 ± 10.1 years (Scale), 29.2 ± 7.0 years (RX), and 27.1 ± 6.71 years (Elite), with no difference between groups (F _(2,107) = 1.97; p = 0.144; η_p² = 0.036). Athletes' current use of supplements statement, CF levels, income, and presence of diseases are displayed in Table 1.

Table 1

Sociodemographic characteristics of the participants and distribution of CF- athletes who reported current use/not use of supplements.
	Frequency % (n)
	Yes	No	p-value
Use of supplements	77.7 (87)	22.3 (25)
Gender
Male	44.64 (50)	6.25 (7)	0.009
Female	33.03 (37)	16.07 (18)
Type of supplements
Performance enhancement	34.9 (65)	-
Micronutrients	7 (13)	-
Improve recovery	7.5 (14)	-
Body composition changes	38.7 (72)	-
Low level of evidence supplements	11.8 (22)	-
CF levels
Scale	8.92 (10)	8.92 (10)	0.002
RX	40.17 (45)	10.71 (12)
Elite	28.57 (32)	2.67 (3)
Salaries
< 1 Salaries	11.6 (13)	0.89 (1)	0.204
1–2 Salaries	14.24 (16)	4.46 (5)
3–4 Salaries	23.21 (26)	8.92 (10)
5–9 Salaries	18.75 (21)	6.25 (7)
≥ 10 Salaries	9.82 (11)	1.78 (2)
Diseases
Type 2 Diabetes Mellitus	0.9 (1)	99.1 (111)
Type 1 Diabetes Mellitus	0	0
Systemic arterial hypertension	0.9 (1)	99.1 (111)
Dyslipidemias	1.8 (2)	98.2 (110)
Smoking	2.7 (3)	97.3 (109)
Legend: Description of socio-demographic data. Chi-square test. CF = CrossFit. Salary (193.87 USD) in local currency was calculated considering the average exchange rate in the data collection period. N = 112.

3.2 Use of dietary supplements

Out of all 112 athletes, 87 (77.7%; 50 male; 37 female) reported currently use of dietary supplements, while 25 (22.3%; 7 male; 18 female) reported no use of supplements. Analyzing by participant's levels, statistical difference was found (X² = 12.7; p = 0.002): 45 RX CFPs, 32 Elite CFPs, and 10 Scale CFPs reported using supplements. However, no difference was found when data were analyzed according to their monthly income (X² = 5.93; p = 204). Considering the reasons why those 87 athletes started using dietary supplements, we found goals of increasing exercise performance (n = 47; 54%), increasing muscle mass (n = 29; 33.3%), reducing body fat (n = 8; 9.2%), and preventing injuries (n = 3; 3.4%). Difference was found when these data were analyzed according to participant's levels (X² = 37.3; p < .001). RX CFPs use supplements for muscle hypertrophy (n = 20) and performance enhancement (n = 19), whereas Elite CFPs use them for performance enhancement (n = 25).

Concerning frequency, CFPs reported using supplements 5 or more times per week (n = 57; 65.5%; 33 male; 24 female), 2–5 times per week (n = 22; 25.3%; 10 male; 12 female), less than twice a week (n = 1; 1.1%; 1 female), and rarely (n = 7; 8.0%; 7 male). Difference was found when data were analyzed according to CFPs' levels (X² = 13.5; p = 0.036). Four Scale CFPs, 14 RX CFPs, and 4 Elite CFPs reported using supplements 2–5 times per week. Four Scale CFPs, 27 RX CFPs, and 25 Elite CFPs reported using supplements 5 or more times per week.

Regarding supplement prescription, 69 CFPs' (61.6%; 37 male; 32 female) reported using supplements without professional support and 43 athletes (38.4%; 20 male; 23 female) reported having nutritionist or sports physician counseling. No statistical difference was found (X² = 7.68; p = 0.465).

Screening for types of supplements was performed individually, due to the possibility of one individual use more than one supplement. Seventy-two CFPs (38.7%) use Body composition changes supplements. Sixty-six CFPs (35.5%) use Performance enhancement substances. Twenty-one CFPs (11.3%) used low level of evidence supplements. Fourteen CFPs (7.5%) use improve recovery supplements, and thirteen CFPs (7%) use micronutrients, with no difference between CFPs of different levels (Fig. 1.) Whey protein was the most used supplement (n = 70), followed by creatine (n = 54), omega-3 (n = 12), glutamine (n = 11), BCAAs (n = 9), beta-alanine (n = 7), caffeine, carbohydrate powder, pre-workouts and multivitamin (n = 5), isomaltulose (n = 4), vitamin D, magnesium and collagen (n = 2), meat protein, vegetable protein, vitamin E, nitrate, sodium bicarbonate and B-12 vitamin (n = 1). Nineteen CFPs reported the use of more than one performance enhancing supplement. Two CFPs reported the use of more than one supplement with low level of evidence (Fig. 2).

3.3 CF practice goals

Subjects reported practicing CF to improve body composition (n = 69; 70.4%; 29 male; 40 female), to improve performance (n = 25; 25.5%; 18 male; 7 female), and to improve quality of life (n = 4; 4.1%; 1 male; 3 female).

3.4 Injury history

Forty-three CFPs (38.4%; 25 male, 18 female) reported having had at least one injury during CF practice and 69 CFPs (61.6%; 32 male; 37 female) reported never having had injuries during CF practice. Injuries did not differ between genders (X² = 1.47; p = 0.226).

3.5 Eating behavior

No difference between genders was found concerning TFEQ-R21 dimensions of EE (t = 1.328; p = 0.187; Cohen’s d = 0.25), BE (t = 0.527; p = 0.599; Cohen’s d = 0.10), and CR (t = 0.463; p = 0.644; Cohen’s d = 0.08). Moreover, no differences were found when data were analyzed according to CFPs' levels (EE: F _{(2, 107)} = 1.37; p = 0.258; η_p² = 0.025; BE: F _{(2, 107)} = 0.07; p = 0.932; η_p² = 0.001; CR: F _{(2, 107)} = 2.79; p = 0.066; η_p² = 0.050). Correlation analysis showed positive correlation between EE e BE (r = 0.49; p < 0.001).

3.6 Life habits and illness

On average, CFPs sleep 7.09 ± 1.35 hours (6.90 ± 1.38 for men and 7.28 ± 1.30 for women) per night, without significant difference between genders (t = -1.498; p = 0.137; Cohen’s d = 0.28; small). The average sleep efficiency was 91.0 ± 11.4% (91.2 ± 12.5 for men; 90.8 ± 10.5 for women) without significant difference between genders (t = 0.166; p = 0.868; Cohen’s d = 0.03; insignificant). Data analysis according to CFPs' levels showed that Scale CFPs sleep 6.45 ± 1.54 hours per night, with sleep efficiency of 84.8 ± 15.3%; RX CFPs sleep 7.41 ± 1.22 hours per night, with sleep efficiency of 92.7 ± 10.7%; and Elite CFPs sleep 6.92 ± 1.29 hours per night, with sleep efficiency of 91.9 ± 8.51%. Differences were found between groups regarding hours of sleep (F _{(2, 105)} = 4.41; p = 0.014; η_p² = 0.078) and sleep efficiency (F _{(2, 105)} = 3.80; p = 0.025; η_p² = 0.068). Scale CFPs sleep less than RX CFPs (Mean = − 0.962; SE = 0.339; t = − 2.84l p = 0.015; Cohen’s d = 0.73), having lower sleep efficiency (Mean = − 7.933; SE = 2.90; t = − 2.704 p = 0.022; Cohen’s d = 0.70). No significant differences were found between CFPs of different levels concerning sleep quality assessed through PSQI (X² = 6.31; p = 0.177). Negative correlation was found between age, hours of sleep (r = − 0.209; p < 0.001) and sleep quality (r = − 0.197; p = 0.043).

One hundred and nine CFPs declared themselves as non-smokers (57 male; 52 female; X² = 3.81; p = 0.537), 111 CFPs (56 male; 55 female; X² = 0.974; p = 0.324) reported not having diagnosis of systemic arterial hypertension, 109 CFPs (57 male; 52 female; X² = 2.15; p = 0.143) reported not having diagnosis of diabetes dyslipidemias (hypercholesterolemia and hypertriglyceridemia), 111 CFPs (57 male; 54 female; X² = 1.05; p = 0.306) reported not having diagnosis of type 2 diabetes mellitus, and none reported having diagnosis of type 1 diabetes mellitus.

3.7 Socioeconomic status

Regarding monthly income, CFPs reported receiving less than 1 minimum wage (n = 14; 12.7%), between 1 and 2 minimum wages (n = 21; 19.1%), between 3 and 4 minimum wages (n = 36; 32.7%), between 5 and 9 minimum wages (n = 28; 25.5%), and more than ten minimum wages (n = 11; 10%). Analysis according to CFPs' levels showed differences (X² = 17.7; p = 0.024): 36 CPFs (10 Scale; 17 RX; 9 Elite) receive 581.61–775.48 USD and 28 CFPs (4 Scale; 18 RX; 6 Elite) receive 969.35–1.755,83 USD.

The present study aimed to determine the prevalence of use of dietary supplements among CFPs of different levels. In addition, we aimed to determine whether the use of supplements was associated with aspects involving eating behavior or not, particularly concerning the dimension of dietary restraint, culminating in energy imbalance and, ultimately, worsening performance and health.

The frequency of use of supplements was 77.7% (n = 87), mainly represented by men 44.64% (n = 50). Body composition changes supplements are the most used among CFPs (n = 72; 38.7%), represented by whey protein (n = 70) and other proteins (i.e., meat or vegetable proteins). Performance enhancement substances are the second most used (n = 65), especially creatine (n = 54) (Fig. 3).

The dietary supplement prevalence among sportspeople and athletes is higher when compared to the general population. While non-athletes believe that using supplements will confer benefits for health [23], athletes' use rely mainly on performance improvement [14]. In the present study, several CFPs who use supplements (n = 47; 54%) reported exercise performance improvement. Moreover, the relationship between dietary supplements and training load is well described. Due to higher energy expenditure, athletes consume supplements which allow them to sustain the training load [14]. According to our findings, the most used supplement was whey protein (n = 72; 64.28%), which is used primarily to increase adaptations mediated by resistance exercise, despite the different effects on the body [24]. However, some CFPs may attribute performance improvement to whey protein, despite being used after training sessions to improve muscle recovery [25, 26]. Proteins and amino acids represent the most consumed ergogenic aids, with a frequency of 35–40% [17]. It seems that some people are using whey protein in an incorrect manner, believing it is an ergogenic aid. In this sense, our findings suggest that nutrition education, especially concerning supplement use, would be very important and necessary to CFPs.

The second most used supplement was creatine (n = 54; 48,21%). Creatine is an organic nitrogen compound found in muscle or available in the diet [27]. It is a classic supplement for those who aim to increase intramuscular stores of phosphocreatine, to improve ATP synthesis and high-intensity exercises performance [28–30]. Furthermore, creatine is able to increase lean body mass and strength of upper [29] and lower [30] limbs. According to Momaya, Fewal, Estes [31], creatine is one of the most popular sports dietary supplements on the market, with more than $ 400 million in annual sales. The use of creatine varies according to the public. Some studies found prevalence of 14% among college student athletes [32], 34.1% among children and adolescents [33], and 27% in the military [34], with the purpose of enhancing sports performance)

CF comprises several movements, often performed in a short period of time with, characterized as high intensity exercise, especially in Olympic weightlifting. In this sense, it is intuitive to believe that creatine supplementation can positively affect performance, despite the lack of studies conducted with CFPs [15]. In fact, 29 CFPs (33.3%) use supplements for muscle hypertrophy (whey protein and creatine), an outcome scientifically supported [18]. Fifty-seven CFPs (65.5%; 33 male; 24 female) reported using dietary supplements 5 or more times per week, a high frequency attributed to whey protein and creatine, which are generally used on a daily basis by athletes. In Brazil, the practice of CF has an intense appeal for changes in body composition, especially weight loss, while evidence on this and other topics is scarce [35].

Some athletes understand that avoiding injuries or illnesses reduces interruptions during preparation for competitions [36]. Although injuries [37] and rhabdomyolysis [38] were reported in CF, in the present study only 3.4% of CFPs reported using supplements to reduce the frequency of injuries. This probably means that they do not consider the use of supplements to be an important factor for reducing the risk of injuries. The relationship between nutrition and injuries has been widely explored [39–41]. In this context, the necessity of nutrition education also applies to CFPs.

Recently, a systematic review including 165 studies showed that the primary users of supplements are soccer players and bodybuilders. Also, the most used supplements were vitamins and minerals. The prevalence of supplement use varies widely, mainly due to the period of use. While some studies have assessed the use of supplements in the past few days, others do not clarify when these supplements were being used. In our study, CFPs were asked about their current use of supplements, according to 14 studies included in the meta-analysis [42].

Analysis of eating behavior dimensions, such as BE, EE, and CR, showed no differences between genders or CFPs of different levels, although women commonly display greater EE than men [43, 44]. Physical exercise may be able to suppress EE [45], possibly justifying this results. It is important to consider, however, that BE and EE were positively associated in CFPs of the present study.

Lower food intake directly relates to CR [46], which involves restrictive food practices. CR is defined as the cognitive effort exerted by an individual to eat less than they would like, with self-monitoring, self-evaluation, and self-reinforcement [47]. Intensification of this dimension could contribute to promote imbalances between energy intake and expenditure [48, 49]; however, the relationship between supplements and CR is unclear. Supplements are commonly used to correct inadequacies in food intake [42]. Restrictive behaviors are exacerbated in the sports scenario, especially when body composition is crucial for performance. For CFPs, gymnastic movements are better performed when subjects are lighter. It is possible that, for this reason, the dietary restraint may be pronounced among them. We could speculate on the use of weight loss supplements and partial meal replacements, but we did not identify the use of these products in the present study. No previous studies have investigated these food behavior dimensions in CFPs. Therefore, it is not possible to compare our findings with other studies. CFPs were asked if they followed some diet plan and used supplements.

Finally, analysis of sleep variables showed that Scale CFPs get less hours of sleep and have lower sleep efficiency than RX CFPs. The impact of sleep on health parameters has been increasingly explored in the past few years [50]. Even though only subjective parameters are normally used to assess different aspects of sleep (i.e., PSQI), available evidences suggest positive and bidirectional relationship between sleep and exercise performance [51]. Positive effects of exercise on sleep were previously demonstrated in other populations [52–54]. Nevertheless, the relationship between sleep and CF remains unexplored, as far as we are concerned. In this context, age is an important factor to be considered. In contrast to our findings of negative correlation between age, hours of sleep, and sleep quality, young athletes may have short sleep duration, low sleep quality and delayed sleep onset, which may affect exercise performance [55]. Due to its diversity of exercise intensities and its dynamicity, CF may exert positive effects on sleep. Kirmizigil & Demiralp [56] showed that functional exercises, which share significant similarities with CF, may significantly improve sleep quality in women diagnosed with primary dysmenorrhea. The importance of sleep seems to be fundamental to athletes' recovery and performance [57]. Interestingly, diverging from society's belief, recent evidence showed that poor sleep quality is not an independent risk factor for physical training-related injuries in adult athletic populations [58].

This study brings out unreported information regarding CFPs' practices. However, our data should be analyzed cautiously, due to some limitations, such as small sample size, cross-sectional design, snowball sampling method to collect data, and the sole use of questionnaires.

CrossFit practitioners reported prevalent (77.7%) use of dietary supplements, especially among RX and Elite athletes, 5 or more times per week. Main reasons for using dietary supplements included increasing exercise performance and increasing muscle mass. Whey protein was the most used supplement, followed by creatine. However, CrossFit practitioners lack nutrition education regarding the appropriate use of dietary supplements. Eating behavior dimensions of emotional eating, binge eating, and cognitive restraint displayed no differences between genders and CFPs of levels. Given the exploratory and descriptive nature of the study, more research is necessary to elucidate aspects related to dietary supplements and CrossFit practitioners.

Ethical Approval

The Ethics Committee of Centro Universitário São Camilo approved this study. The committee's statement number is 4,165,399.

Conflict of interest

None of the authors has any conflict of interest to disclose.

Author contributions

MVLSQ and FPN generated the research question. MVLSQ, LC, RBC and LSO planned the collection. MVLSQ, CGM and ACOM performed the literature search. MVLSQ and ACOM tabulated the data. MVLSQ performed the analysis statistic. MVLSQ, CGM and FPN interpreted the findings. MVLSQ, CGM and FPN wrote the first draft of the manuscript. RVTS critically reviewed this and previous drafts. All authors contributed and approved the final draft for submission.

Funding statement

It was not supported by any funding agency.

Availability of data and materials

The data is available from the corresponding author and can be accessed upon request.

Acknowledgment

All authors are grateful to the research participants and the Centro Universitário São Camilo.

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No competing interests reported.

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Prevalence of dietary supplements consumption among CrossFit practitioners

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Version 1

Abstract

Figures

1 Introduction

2 Methods

2.1 Study type, sample and Ethics

2.2 Questionnaire

2.3 Analysis of dietary supplements by group

2.4 Eating behavior

2.6 Statistical analysis

3 Results

3.1 Sample characteristics

3.2 Use of dietary supplements

3.3 CF practice goals

3.4 Injury history

3.5 Eating behavior

3.6 Life habits and illness

3.7 Socioeconomic status

5 Discussion

6 Limitations Of The Study

7 Conclusions

Declarations

References

Additional Declarations

Status:

Version 1