Speed Track Events: Development and Validity of Exercise Catalog

Through interviews, a group of expert coaches elaborated a catalog of exercises. Two groups of raters evaluated the content validity of these exercises, producing a coefficient of content validity (CCV) for such validity indicators as clarity of language, practical pertinence and theoretical relevance. Additionally, raters assessed the specificity level of each exercise by deciding if the exercise was general, special or specific to speed track events.


INTRODUCTION
Track and field athletics are a collection of sports contests that basically involve contests of running, jumping and throwing, and it is one of the most popular and global sports domains worldwide [1]. Track events involve running in contests of different distances, with the fastest sprints. Sprints are also considered the most popular athletics events [2]. The speed track events in the Olympic program are currently the [7 -9]. Following the systemic approach, a theoretical training system model named "Planning, Registration and Analysis of Sports Training Load" (PRACTE in Portuguese) was developed by Szmuchrowski & Couto [10] with the purpose of better planning, executing and controlling the variables that influence the training process.
The PRACTE model suggests a simplified process of planning, registration, and analysis of training load, and the development of catalogs of exercises for each individual and team sport. These catalogs are instruments that contain codified exercises organized and subdivided according to their specificity, as proposed by Pedrosa et al. [11] and Silva et al. [12] for judo and taekwondo, respectively. A catalog containing exercises in a codified way can be a quick solution to record the exercises performed in the training session if you have an organized training sheet, as the one designed by Kalina [13]. This registration allows a posterior analysis of training load parameters as magnitude, structure and dynamic as proposed by Szmuchrowski & Couto [10] and performed by Pedrosa et al. [14].
Development of an instrument as an exercise catalog that is able to improve the training planning, its execution and control is important for achieving better results in the sports, but it is important and necessary to assess the content of the instrument. There is no one validated exercise catalog for speed track events. Thus, this study aims to elaborate and assess the content validity of a catalog of exercises for speed track events.

METHODS
The methodological approach adopted for the elaboration and content validation process was guided by literature recommendations [15,16] and this study was divided into two phases; the first phase for the development of items (catalog elaboration) and the second phase for evaluation of items (content validation); both are described below.

Catalog Elaboration
In order to achieve a high level of physical and technical performance in speed track events, the training planning might contain exercises that aim to improve some capacities as speed, strength, endurance, flexibility, motor coordination and specific technique [17 -24]. These are important capacities for the speed track training adopted in this study.
In this phase, the sample was composed of ten experienced Brazilian speed track coaches (mean ± SD: age 45 ± 12,2 years; time as coach 17,9±7,9 years) ( Table 1). As inclusion criteria, coaches must have been coaching for at least ten years continuously, must have done graduation in physical education, registered at Athletics Brazilian Confederation and have won relevant national or international tournaments. These coaches responded, through an individual semi-structured interview, what exercises are used during a training routine that aim at the development of the capacities previously cited (Appendices 1-5). After the interviews, the answers of all coaches were recorded in a file, and then similar exercises were grouped and repeated exercises were excluded . The items of this file were based on the exercises that were submitted for content validation.

Content Validation
To assess content validation, Pasquali [16] suggested inviting raters from the area of concern to evaluate each item by the analysis of three indicators and one dimension. The indicators were Clarity of Language (CL), Practical Pertinence (PP) and Theoretical Relevance (TR). According to Dunn et al. [15], the number of raters to assess content validity should be dictated by the availability of experts who are willing to participate in the evaluation process and who possess the knowledge and skills necessary to make valid judgments. However, the items need to be comprehensible to all members of the population to which the instrument is intended and thus, it must be checked by a group of raters with a low level of academic education [25].
Thus, the raters were composed of two groups. The first group, named Judges, was based on individuals with a high level of academic education, and they had, at least, a master's degree in sports science or related areas, besides a minimum of ten years of experience in athletics, whether as a coach, athlete or referee (mean ± SD: age 40,6 ± 7,9 years; time of expertise in athletics 18,6 ± 7,5 years). The other group, named Instructors, was composed of individuals with a lower level of academic education, and they have been currently working as running coaches for at least the past two years and do not have reached the academic education level above than regular graduation (mean ± SD: age 31,2±9,4 years; time as coach 5,2±2,7 years). Judges were composed of six raters and Instructors by five raters ( Table 2).
All raters received the file of the exercises and an explanatory manual about how to evaluate the items. The raters were asked to read and rate each exercise using a five-point Likert scale, regarding the content validation indicators [12,16,26] known as CL, PP, and RT. Besides, they also rated the dimension of the items by using a four-point scale. The CL checks if the language is written clearly and appropriately for the athletics coach. Thus, each rater responded to the following question: "At which level do you believe the description of this exercise is sufficiently clear, understandable and suitable for athletics coaches?" Ratings ranged from 1 (not very clear) to 5 (very much clear).
The PP considers if the item is indeed important for the speed track training. Thus, each rater responded to the following question: "At which level do you believe this exercise is important for speed track training?" Ratings ranged from 1 (not very important) to 5 (very much important).
The TR analyzes the relation of the exercise with the catalog and one of its dimensions. Thus, each rater responded to the following question: "At which level do you believe this exercise is representative of a catalog of exercises?" Ratings ranged from 1 (not very representative) to 5 (very much representative).
Dimension, in this study, is the classification of the exercises into groups, according to their specificity level related to modality, as suggested by Sozanski & Sledwieski [27] and Szmuchrowski & Couto [10]. These groups of exercises may be named as general, special and specific. According to these authors, general exercises are those that aim at the development of basic fitness, without requiring any specific motion from a determined modality, e.g. stretching exercises are considered general for judo training [26]. Special exercises are those that aim at the development of physical capacities such as strength or speed, using activities that have similar energetic demands, but not requiring reproduction of the technical motion from a determined modality, e.g., squats are considered special exercises for taekwondo training [12]. Specific exercises are those that aim at the development of technical motions required during the competition, as well as their energy demand, e.g., loaded jumps are considered specific exercises for improvement of the vertical jump [28]. Each rater responded to the following question: "At which level does this exercise can be considered specific for speed track training?" Ratings ranged from 1 (not specific) to 4 (very specific).
Considering the higher academic level and the high complexity of the task, only the judges evaluated the items on the three indicators and the dimensions [26,29], while the instructors evaluated the items only by the CL [26].

Analysis
To verify statistically the ratings of CL, PP and RT, the Coefficient of Content Validity (CCV) was adopted as suggested by Hernandez-Nieto [30].
Initially, the CCV was calculated for each item separately for an indicator, with Eq. (1). Then, each item has a CCV for CL, for PP and for TR.

(1)
In sequence, the CCV was calculated for each indicator of the catalog and for the catalog as a whole, with Eqs. (2 and 3), respectively. (2)

(3)
The catalog should present values above 0.8 for all indicators to have your content considered validated [16]. The items should present values above 0.8 for indicator CL and values above 0.6 for the indicators PP and TR [26]. Items with CCV CL value below 0.8 were rewritten and reevaluated by the raters and if these items do not achieve the minimum rate of 0.8, they were excluded from the catalog [30].
To verify statistically the dimension of each item, based on the responses from the judges who used a four-point scale, the average value of each item was used, by calculating the sum of the scores divided by the corresponding number of judges. In this way, each item could have a minimum value of 1 and a maximum value of 4. For standardization, if the result of the average was less than two, this item was classified as general; if presented average between two and three, it was classified as special, and if it presented results higher than three, it was classified as specific.

RESULTS
From the interview process, 85 exercises were transcribed by expert trainers and they contemplated all the finalities proposed at the beginning of the study. No exercise presented CCV CL below than 0.8 and thus, a second evaluation by the judges for this indicator was not necessary. However, ten exercises were not included in the final catalog because they presented CCV PP or CCV TR less than 0.6 (in Appendix).
Thus, from the 85 exercises initially developed, only 75 were included in the final catalog, with 16 general, 24 special and 35 specific exercises ( Table 3). The catalog shows satisfactory CCV values for all indicators, meaning the exercises are understandable for athletic coaches (CCV CLj =0,93 and CCV CLi =0,95), pertinent for speed track training (CCV PP =0,84) and relevant (CCV RT =0,83) ( Table 4). Run from the starting block using strategies to achieve greater movement of the lower limb responsible for the first contact with the ground. e.g. Place a 40 cm cone in front of the starting block and at the start signal, the athlete should raise the knee trying to overpass the cone and hit the ground in front of the cone. Set of submaximal sprints in greater distance than the distance that the athlete compete with incomplete rest. e.g. Five races of 500m in intensity close to 90% of the maximum with rest of three minutes for of recovery for a 400-meter dash athlete.

DISCUSSION
Studies that used CCV as a statistical tool to assess content validation of different instruments, including catalogs, have shown satisfactory results for the instrument, with CCV above 0.8 for them [12,26].
The results of CCV CL showed that the exercises described in the catalog are sufficiently clear and adequate for the target population. As the catalog is intended for athletics coaches, it is recommended that this population evaluates the language of the instrument and not just people with a higher degree of ability to perform this task [29]. Judgesbesides possessing expertise in the modality, have a high level of academic training in the sports field and this may influence their understanding of the description of the exercises [31]. For general and special exercises, a discrepancy was observed concerning the mean CCV CL values between the group of judges and the group of instructors; however, regarding the group of specific exercises, this value was similar, corroborating with the one proposed by Pedrosa et al. [26]. In another similar study, Silva et al. [12] did not perform the CL evaluation with a population with a lower degree of ability. The degree of the academic rigor of the judges can influence this kind of analysis since a panel of experts with a higher level of academic experience tends to require greater details in the description of the items when compared to the group of instructors who have a lower academic degree. However, in both cases, the values obtained in this analysis were higher than those established at least in the literature [30], indicating that the items in the catalog are clear and understandable for the population of athletic trainers.
The results of CCV PP indicate that judges considered that the exercises evaluated are relevant and important for the training of speed track events. Exercises 1-3 and 65-75 were considered the least and most important exercises in the catalog, respectively. A possible explanation for these findings is associated with the principle of specificity, which shows that the adaptations resulting from the training are specific to the applied stimuli [32]. Confirming this, CCV PP value for the specific exercises was higher than the value for the special exercises, which was higher than the value for the general exercises, corroborating with the findings of Pedrosa et al. [11]. As described in the catalog, exercises 1-3 are focused on strength training through exercises with movements characteristic of other modalities or are preparatory activities used as a warm-up for the main part of the training session and are not used in specific situations during competitions. Other exercises with a similar purpose obtained higher scores for PP (for e.g, 34 for strength training and 19 for warm-up) because they are more similar to the demand for speed track events. Strength training and activities of warm-up are important for the training of speed track events; however, how these exercises are executed in a session can increase or decrease the perception of their importance by an evaluating judge. Wilson et al. [33] analysed the effects of various types of strength exercises on the performance of dynamic activities and showed that training with exercises considered specific resulted in a greater improvement in performance compared to training with other types of exercises, suggesting that specific exercises are more efficient and pertinent to achieve better performance.
The values of CCV RT showed that exercises have a relation with the instrument and its dimensions, being classified in general, special or specific, and thus, confirming its relevance to the catalog. CCV RT values, as well as CCV PP , were higher for the exercises classified as specific. As for the PP indicator, the specificity principle may be associated with the RT indicator, since specific exercises can be interpreted as more relevant for the training, as in the study of Franchini & Takito [34], where athletes answered a questionnaire and the results pointed out that the exercises considered specific were classified as more relevant than the non-specific exercises. Understanding exercise as a component of the training load, exercises could be divided into different dimensions that tend to help coaches in the planning of these loads [10,35]. Baker [28] presents a training progression to vertical jump through groups of general, special and specific exercises and directs that, for the beginning of the physical preparation, more general exercises than specific ones are used. Nuñez et al. [36], investigating soccer, also used exercises divided into three dimensions for the planning of strength and endurance training for 48 weeks that were divided into four macrocycles. It was observed that all four macrocycles of the cited study had predominantly classified exercises as general in their first-week and in their last week exercises were classified as specific.
The division into dimensions also allows a facility for recording and analysing the loads performed during training. Tota et al. [37], in mixed martial arts, recorded 11 training micro cycles where the exercises used were previously divided into three dimensions by the coaches. Thus, after the registration, it was possible to verify the total and relative time of exercises of each dimension executed in each micro cycle and to analyse if the training was following the one initially planned by the trainers. In judo training, Pedrosa et al. [14] recorded, using video analysis, 14 training sessions and investigated how long general, special and specific exercises were performed throughout these sessions. Thus, it would be possible to identify the need to increase or decrease a type of stimulus during training.
Although the specific means of training are the ones that most resemble the demands of competition and that can generate a transference that may result in better performance, the excessive use of this type of stimulus can generate negative results like overtraining, muscular imbalance, increased risk of injury and monotony [32]. Thus, exercises considered general are important throughout the training process.
How the dimension of the items was analysed in this study has not been discussed in the literature. Catalogs elaboration studies adopted the majority choice of raters to determine the exercise dimension classification and measured Cohen Kappa Coefficient to show an agreement among the evaluators [11,12]. In these studies, the concordance values presented were 0.533 [11] and 0.441 [12], values that represent a moderate agreement. However, both studies mentioned above show that this is not the best way to determine the dimension of an item, because according to these authors, the means of training should be placed on a continuum, where at one end they would be classified as extremely general or nothing specific and at the other end as completely specific. Finally, they suggest that more research needs to be done to verify this possibility of classification [11,12]. The present study adopted the option to classify the dimension of the items based on a continuum. Thus, most of the judges' choices were not taken into account, but rather the average score based on scores on a four-point scale. This form has limitation because if a judge disagrees with others who agree with each other, it may suggest that the mean score of an item represents a dimension that may not be the most appropriate for it. More studies using this format to choose the dimension of an item are necessary to confirm its suitability and to determine what would be an ideal or suitable number of points on a scale.
A few number of studies related to content validation in instruments, such as an exercise catalog, make it difficult to compare and discuss some data. Furthermore, if this study had been realized in another country, the results of content validation could be different due to the influence of sports culture. Different exercises could be reported by the coaches in the interview, and local language maybe influence the form that the exercises were described in the catalog. Additionally, some adjustments may be made in the catalog based on an ecological validation assessment. However, the content of the present instrument has validity, and it may contribute to speed track exercise selection and registration.

CONCLUSION
The content validation assessment performed in this study by two groups of raters confirmed that the catalog of speed track exercises was pertinent, representative of training and had suitable language for athletics coaches. According to the presented results, athletics coaches can use this instrument to guide them in the moment of the selection, recording and control of the training (Fig. 1).

ETHICS APPROVAL AND CONSENT TO PARTI-CIPATE
This study was approved by the Ethics Committee of Federal University of Minas Gerais, Brazil (CAAE -26729814.7.0000.5149).

HUMAN AND ANIMAL RIGHTS
No animals were used in this research. All human research procedures were followed in accordance with the ethical standards of the committee responsible for human experimentation (institutional and national), and with the Helsinki Declaration of 1975, as revised in 2013.

CONSENT FOR PUBLICATION
All participants signed informed consent prior to participating in the study.

AVAILABILITY OF DATA AND MATERIALS
The data supporting the findings of the article is available in the Figshare at: https://figshare.com/s/4508034a92ed596ae515 Reference number: 10.6084/m9.figshare.16799452.

FUNDING
None.

CONFLICT OF INTEREST
The authors declare no conflicts of interest, financial or otherwise.