1. Introduction

It is well known that professional soccer includes lower limb power and proper strength and conditioning demands (Barnes, Archer, Hogg, Bush, & Bradley, 2014). Diverse global training methods with the ball have been applied for developing the above mentioned variables. In Brazil, an interesting sport modality called “footvolley” is largely practiced by soccer athletes as a leisure moment (Figure 1). However, this specific modality has been growing in the last 10 years and became an official regional sport with relevant competitions in Brazil. The “footvolley” is applied in a sand environment with volleyball net in an area of 18x9 meters (Figure 2). The rules are the same of volleyball (i.e., 3 touches, point is gained when the ball touches the ground), the difference is that only two participants play for each side and the ball cannot touch hands.

Figure 1. Brazilian soccer players (Daniel Alves and Neymar Junior) playing footvolley – by Gaspar Nóbrega

Figure 2. Footvolley environment and training (Villeroy Team) – by Vicente Vaccaro

Regarding footvolley environment and prescription research, the literature has been focused on physical training (i.e., sand jumps, sprints, and short displacements) with general implications for different sports modalities (Gaudino et al., 2013; Impellizzeri et al., 2008). However, there is no specific investigation concerning footvolley practice and its singular physical demands.

Although this modality is well known in Brazil, there is a lack of data (i.e., no study of our knowledge) in relation to displacement parameters and neuromuscular fatigue in response to a professional match. In fact, the coaches who try to develop footvolley athletes performance have been working with no representative data to help training prescription. Thus, important practical questions emerge: which is the total travelled distance in a match? Which is the maximal velocity in a match? Which is the average velocity in a match? What is the intensity compared to atheltes’ maximal velocity? Does acceleration capacity decrease in a match? In this context, the present study aimed to screen and describe these singular displacement and neuromuscular parameters in response to an official match in the professional Brazilian championship.

2. Methods

Participants

The sample was three professional footvolley players from Villeroy Team (33 ± 5 years old; 79 ± 6 kg; 179 ± 4 cm), who were asked to voluntarily participate of the assessments in the official match day. After recruitment and acceptance, individuals received a consent form to read and sign if they agreed. This study was performed in accordance with the Helsinki Declaration. The inclusion criteria were (a) men between 18 and 40 years (b) without neuromuscular, cardiovascular, pulmonary, or metabolic diseases, (c) no use of any type of substances that could improve the neuromuscular performance, and (d) with no training interruptions during the past year. The participants played the same match (Athlete 1 and 2 vs. Athlete 3 and other who did not participate).

Acceleration capacity and GPS parameters

Before and immediately after the match, participants executed three 10-meter sprint bouts with 30 seconds of rest between each attempt for measuring maximal acceleration capacity utilizing photocells (Speed Test 6.0 Std, São Paulo, Brazil). They warmed up during 5 minutes of skeeping and submaximal sprints. All athletes were familiarized with the test. The maximal sprint bouts were conducted in the same environment condition of the match (i.e., sand). Maximal (all-out) effort was required for each participant, being verbal encouragement implemented during all repetitions. Furthermore, the athletes used a specific trunk vest for coupling the GPS (QStartz 5Hz, BT-Q1300ST, Taiwan) during all match’s time (i.e., 20 minutes).

3. Results

Because of the descriptive study’s purpose and reduced sample, we did not use statistical analyze. Moreover, the current data are specific for practical implications and only suggestive for training considerations. All data are showed with mean and standard deviation (SD). Table 1 presents individual physical characteristics. Table 2 presents pre- to post-match 10-meter sprint performance and fatigue index. Table 3 presents GPS parameters. Table 4 presents match’s intensity data.

Table 1. Physical characteristics

Table 2. 10-meter sprint bouts (Sand)

Table 3. GPS parameters

Table 4. Match's intensity

4. Discussion and Conclusions

The current investigation proposed to identify displacement characteristics of a premature and great sport modality in Brazil in which coaches have no representative neuromuscular data to help training prescription. Despite our reduced sample, the present study aimed to only offer practical and experienced information of a growing sport. One of our main results was the fatigue index information because athletes showed 5.96% of acute velocity decreases in response to a match of 20 minutes (Figure 3). In comparison to soccer, this is an interesting fatigue index value, once elite soccer players may show an acute sprint performance decrease of 2.6% after playing 45 minutes (Edholm, Krustrup, & Randers, 2014). Furthermore, maximal knee extension torque seems to decrease approximately 8% after 90 minutes in professional soccer matches (Nédélec et al., 2012). Of course, present study did not evaluate maximal single-joint moment and the fatigue indexes can be completely different between maximal knee extension torque, jumps, and sprint performance (Sánchez-Medina & González-Badillo, 2011; Haugen, Tønnessen, Hisdal, & Seiler, 2014; Morin, Samozino, Edouard, & Tomazin, 2011; Pinto, Blazevich, Andersen, Mil-Homens, & Pinto, 2017).

Figure 3. Individual sprint performance decreases

Besides that, other important match’s information were traveled distance and the prevalent playing intensity. The athletes displaced an average distance of 633 meters and the average intensity was 39.4% of the maximal acceleration capacity. Taking into account the association between total distance, fatigue index, and intensity, we could conclude that, although the reduced distance and intensity, the fatigue index was relevant in the match. An assumption about this observed relationship could be in relation to the environment condition (i.e., sand). In this context, Gaudino et al. (2013) showed that on sand it is possible to perform maximal intensity sprints with higher energy expenditure and metabolic power values, without reaching maximum speed and with smaller impact shocks. Furthermore, exercises with change of direction carried out on this surface allow to reach higher deceleration values. In addition, sprinting on sand potentially entails a limited stretch of the involved muscles. It can therefore offer a valid alternative to traditional training, injury prevention and rehabilitation programs. In this way, it is possible to conclude that, although reduced intensity, on sand actions need greater effort than in traditional surface, possibly promoting interesting neuromuscular adaptations. Furthermore, although we did not asses jump performance and quantity in match, footvolley demands many jumps. In this sense, Impellizzeri et al. (2008) demonstrated that on sand plyometric training improved both jumping and sprinting ability and induced less muscle soreness than on grass training. Moreover, sand surface showed greater improvement in Squat Jump than grass surface.

The present study has some limitations. We did not evaluate a specific sport action as jump performance and fatigue, prevalent in match and the most appropriate practical neuromuscular fatigue indicator (Jimenez-Reyes et al., 2016). Moreover, we had a reduced sample. In summary, the current study brings important practical suggestions regarding an official and leisure modality.

ACKNOWLEGMENTS

We gratefully acknowledge to the subjects who participated in this research and made this project possible. Moreover, we acknowledge all Villeroy Team collaborators.