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Journal of Science and Medicine in Sport 12 (2009) 490–494

Original paper

Match demands of professional Futsal: A case study Carlo Castagna a,∗ , Stefano D’Ottavio a , b ´ Juan Granda Vera b , Jos`e Carlos Barbero Alvarez a

Corso di Laurea in Scienze Motorie, Universit`a di Roma Tor Vergata, Italy b Departamento de Educaci´ on F´ısica y Deportiva Universidad de Granada, Spain

Received 22 June 2007; received in revised form 2 February 2008; accepted 8 February 2008

Abstract Despite its popularity and competitive status there have been only few scientific studies that have examined Futsal in professional players. Consequently the aim of this study was to examine the physiological responses and activity pattern to Futsal simulated game-play in professional players. Eight full-time professional outfield Futsal players volunteered for this study: age 22.4 (95% CI 18.8–25.3) years, body mass 75.4 (60–91) kg, height 1.77 (1.59–1.95) m and VO2max 64.8 (53.8–75.8) ml kg−1 min−1 . Physiological measurements were assessed during highly competitive training games (4 × 10-min quarters) and consisted of game VO2 , game blood-lactate concentration ([la]b ) and game heart rates (HRs). Game activities were assessed using a computerised video-analysis system. During simulated game-play players attained 75% (59–92) and 90% (84–96) of VO2max and HRmax , respectively. Mean game VO2 was 48.6 (40.1–57.1) ml kg−1 min−1 . Peak game VO2 and HRs were 99% (88–109) and 98% [90–106] of laboratory maximal values, respectively. Players spent 46 and 52% of the playing time at exercise intensities higher than 80 and 90% of VO2max and HRmax , respectively. Mean [la]b was 5.3 (1.1–10.4) mmol l−1 . Players covered 121 (105–137) m min−1 and 5% (1–11) and 12% (3.8–19.5) of playing time spent performing sprinting and high-intensity running, respectively. On average players performed a sprint every ∼79 s during play. These results show that Futsal played at professional level is a high-intensity exercise heavily taxing the aerobic and anaerobic pathways. © 2008 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved. Keywords: Soccer; Training; Physiology; Oxygen consumption; Lactic acid; Exercise

1. Introduction Futsal is the indoor version of soccer that is officially sanctioned by soccer’s international governing body (Federation de Football Association, FIFA). The game is growing in popularity all over the world and since 1989 the world championships have been contested by 16 national teams every 4 years. Futsal is played 5-a-side and during the competitions unlimited substitutions are permitted. Consequently game physical demands may result very high.1 Analysis of movement demands has shown that Futsal is an intermittent high-intensity exercise mode locomotor activities changing every 3.28-s.2 Dragomaci and Watsford2 estimated that dur∗

Corresponding author. E-mail address: [email protected] (C. Castagna).

ing competitive matches Futsal players cover at high intensity 26% of total game distance or time. Recently Castagna et al.3 showed that recreational 5-aside soccer elicited in young players (age 16.8 ± 1.5 years) a heart rate (HR) of 84 ± 5.4% of HRmax and an oxygen consumption (VO2 ) of 75 ± 11.2% of VO2peak . Higher average physiological responses (91 and 85% of HRmax and VO2max , respectively) were reported by Hoff et al.4 in adult professional soccer players playing training 5-a-side drills (2 × 4 min with 3 min active rest) over a 50 m × 40 m football pitch. Potential reasons for the elevated intensity reported by these authors include that players were strongly encouraged to keep exercise intensity high by coaches and ball was replaced as fast as possible to avoid intensity decrements.4 In contrast, Castagna et al.3 reported that the mean intensity of young non-elite soccer players during a 12-min 5-a-side

1440-2440/$ – see front matter © 2008 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.jsams.2008.02.001

C. Castagna et al. / Journal of Science and Medicine in Sport 12 (2009) 490–494

training drill (30 m × 15 m court) was 52 ± 11% of VO2peak . Probably skill level and motivation may be the cause of the reported difference in play intensity.5 Despite its popularity and competitive status there have only been a few scientific studies that have examined Futsal.6,7 Furthermore the papers that are available in the international literature have only addressed game analysis or the physiological demands of small-sided versions of soccer played at recreational level1,3 and with no standard rules. Consequently the actual physiological demands imposed to professional Futsal players during the game are unknown. Given that the aim of this study was to examine the VO2 , HR and blood-lactate concentration ([la]b ) and game activities in professional Futsal players playing on standard-sized courts and official rules. It was hypothesised that Futsal match play under standard rules may induce different physiological responses from those previously reported.3

2. Methods Eight fulltime well-trained (nine training sessions per week plus competition) professional Futsal players: age 22.4 (95% CI 18.8–25.3) years, body mass 75.4 (59.9–91) kg, height 177 (159–195) cm, from the Spanish second division volunteered to participate in this study. The local Institutional Review Board approved this study design and informed written consent was obtained from all players. The present study was completed during the regular competitive season and the team involved were successful (finished in third position). All the players were familiar with the testing procedures used in this investigation. The demands of Futsal were established by analysing simulated games and physiological testing. Players were observed during highly competitive games (4 × 10 min with 5-min recovery) in a friendly setting to assess physiological variables without restriction. This activity pattern was used as preliminary studies (unpublished pilot data) showed that players were involved for an average of 10 min (total-time) during official championship games before being substituted. Game VO2 demands were assessed in each players using a portable gas analyser (K4b,2 COSMED, Rome, Italy) according to Castagna et al.3 procedure. Blood sampling was taken in a random order during the 4 × 10 min bouts for each player according to the methods described by Krustrup et al.8 Heart rate monitoring was performed throughout the 4 × 10 min games in all players. Prior to the commencement of this investigation a systematic analysis of championship game demands was performed. This involved collecting HR from the players involved in this investigation during four official championship games over the month preceding this study. Analysis of game activities was performed using a video computerised system.1 Data was analysed according to the following match activity categories:

1. 2. 3. 4. 5. 6.

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sprinting (speed >18.3 km h−1 ); high-intensity running (speed >15.5 km h−1 ); medium-intensity running (12.1–15.4 km h−1 ); low-intensity running (6.1–12 km h−1 ); walking (0.5–6 km h−1 ); standing (0–0.4 km h−1 ).

Sprinting cut-off speed was chosen as average treadmill speed at VO2max was 18.3 (15.5–21) km h−1 . High-intensity running speed was considered as average speed between speed at VT and VO2max (12.9 (10.2–15.5) and 18.3 (15.6–21) km h−1 , respectively). Maximum oxygen uptake (VO2max ) was determined using an incremental running test on a motorised treadmill (RunRace, Technogym, Gambettola, Italy). After an individually adjusted warm-up (5-min) players ran for 6-min at 8 km h−1 , then the velocity was increased by 1 km h−1 every minute until exhaustion (within 8–12 min). Achievement of VO2max was considered as the attainment of at least two of the following criteria: (1) a plateau in VO2 despite increasing speeds, (2) a respiratory exchange ratio above 1.10, (3) a HR ±10 beats min−1 of age-predicted maximal HR (220-age) and (4) a blood-lactate concentration higher than 7 mmol l−1 3 min after the end of the test. Expired gases were analysed using K4b.9,10 Before each test flow and volume were calibrated using a 3-L capacity syringe (Sensormedics, Yorba Linda, CA). Gas analysers were calibrated using gases of (O2 and carbon dioxide) of known concentrations (Sensormedics, Yorba Linda, CA). Ventilatory threshold (VT) was assessed according to Beaver et al.11 Running economy (RE) was considered as average VO2 during the final minute of the 6-min run at 8 km h−1 . Maximal aerobic speed was calculated using the relationship between VO2 and running speed.12 Maximal HR was considered as the highest 5 s mean during the treadmill test. In this study [la]b measurements were performed sampling players’ earlobe blood using a miniphotometer (Doctor Lange Plus LP20, Dr. Lange, Germany). Blood was collected in a capillary and then stored in a heparinised probe for later analysis. Before each testing session the lactate analyser was calibrated according to manufacturer guidelines using a calibration solution of a known concentration. In this research HRs were monitored and analysed with a short-range telemetry system (Polar Team System, Polar Electro Oy, Kempele, Finland).

3. Statistical analyses Data is reported as mean and 95% confidence intervals (95% CI). Before using parametric tests, the assumption of normality was verified using the Shapiro–Wilkes W-test. One-way ANOVA with repeated measurements were used to assess group differences. Relationship between variables was assessed using Pearson’s coef-

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Table 1 Treadmill testing results Variables (ml kg−1

Mean (95% CI) min−1 )

VO2max Speed at VO2max (ml kg−1 min−1 ) Peak treadmill speed (km h−1 ) RE at 8 km h−1 (ml kg−1 min−1 ) VO2 at VT (ml kg−1 min−1 ) %VO2max at VT Speed at VT (km h−1 ) HR at VT (beat min−1 ) %HRmax at VT VEmax (l min−1 ) HRmax (beat min−1 ) [la]bmax (mmol l−1 )

64.8 (53.8–75.8) 18.3 (15.5–21) 18.7 (15.9–21.5) 33.7 (30–39) 46.0 (36–56) 71.0 (65–77) 12.9 (10.2–15.5) 162 (148–176) 84.8 (80.3–89.3) 162 (132–191) 191 (175–206) 11.3 (6.4–16.2)

VO2max = maximal oxygen uptake; RE = running economy; HR = heart rates; VT = ventilatory threshold; VE = ventilation; [la]b = blood-lactate concentration; 95% CI = 95% confidence interval.

ficient. Significance was assumed at 5% (p ≤ 0.05) a priori.

4. Results The results of the treadmill test are shown in Table 1. Game mean VO2 and HR were 76% (59–92) and 90% (84–96) of maximal treadmill test values. The peak VO2 and HRs during the simulated game-play were 99% (88–109) and 98% (90–106) of VO2max and HRmax , respectively. Mean game VO2 was 48.6 (40.1–57.1) ml kg−1 min−1 . Players spent 46 and 52% of the playing time at exercise intensities higher than 80 and 90% of VO2max and HRmax , respectively (see Fig. 1). Mean blood-lactate concentration was 5.3 (1.1–10.4) mmol l−1 . The mean HR during the experimental games were significantly lower (169 vs. 176 beats min−1 , p < 0.01) than the correspondent HR values attained during championship games by the same players. However, no significant differences (p > 0.05) were found for time spent with HR above 90% of HRmax between the two conditions. No mean differences across game periods were detected for mean HR (p > 0.05).

Fig. 1. Percentage of game time spent in selected VO2 and HR intensity zones (mean and 95% confidence interval).

Fig. 2. Profile of Futsal game activities (% of game total distance, mean and 95% confidence interval).

An inverse significant relationship was found between VO2max level and time spent above 90%HRmax (r = −0.79, p < 0.01). The activity profile of game activities is presented in Fig. 2. Analyses of game activities showed that players covered 121 (105–137) m min−1 per playing minute. Sprinting and high-intensity running accounted for 5% (1–11) and 12% (3.8–19.5) of total playing time, respectively. During each game period players performed 26.4 (13–39) high-intensity running bouts of which 7.2 (1.5–12.9) were sprints. Accordingly, mean players performed a sprint bout every ∼79 s of play. However, during the game 54% of the recovery bouts between sprints were less than 40 s. Mean sprint bout distance and duration were 10.5 m (6.2–14.8) and 1.95 s (1.4–2.5), respectively. Distance covered per minute significantly decreased during the third and fourth period (p < 0.05). High-intensity distance significantly decreased during the fourth period (p < 0.05). No significant correlations were found between match performance and physiological variables.

5. Discussion The main finding of this study was that during a Futsal game played by professional players, aerobic power was heavily taxed accounting for 76% of maximal individual values. The substantial physical demands of Futsal were evidenced by VO2 requirements in the range of 45–50 ml kg−1 min−1 and repeated high-intensity efforts (a sprint bout every 79 s of play). Game intensity elicited average HR and VO2 values that were approximately 6% higher than the corresponding values at VT. These exercise intensities are higher than those found in competitive soccer,13 but similar to values reported for professional basketball.14 The mean HR found in this investigation were significantly lower than that showed by the same players during championships

C. Castagna et al. / Journal of Science and Medicine in Sport 12 (2009) 490–494

games. Although the higher championship game mean HR may be due to competitive stress,3 it could be speculated that in competitive Futsal aerobic involvement may be even higher.1 The %VO2max attained by professional Futsal players was similar to that reported by Hoff et al.4 but higher than those found by Castagna et al.3 in professional and young regional-level soccer players during 5-a-side drills, respectively. Consequentially, it could be speculated that along with court dimensions,5 competitive level and skill level may play inherent roles in game demands in 5-a-side soccer. Conversely to what was reported by Castagna et al.3 for recreational 5-a-side players an inverse significant relationship was found between VO2max level and time spent above 90%HRmax . This may suggest that Futsal players with higher aerobic power may play more economically given the mean game demands experienced of 48.6 (40.1–57.1) ml kg−1 min−1 .5,7 Therefore it appears that Futsal coaches and fitness trainers should consider this when implementing small-sided games with aerobic fitness development aims.4 In this regard variation in players number and/or court dimensions may result useful in ball-drill intensity.4 This study players showed VO2max values that were within the ranges that Reilly et al.15 and Barbero et al.16 considered to be advisable to play soccer and Futsal at elite level, respectively. A recent study showed that VO2max may be considered as a discriminative physiological variable in Futsal of different competitive levels.16 As a consequence of VO2 game demands and the individual level of VO2max a well developed maximal aerobic power seems to be advisable in professional Futsal players. It is in this study authors’ opinion that given the mean VO2 game demand of (48.6 (40.1–57.1) ml kg−1 min−1 ) professional players should possess VO2max levels of at least 55 ml kg−1 min−1 (mean + 1S.D.) to cope with game physiological requirements. In this study anaerobic involvement was examined considering [la]b derived from random blood sampling during actual game-play.8 The results [la]b were similar to those previously reported in soccer by several authors.13 We normalised [la]b data according to maximal values obtained at the end of exhaustive treadmill tests. As a consequence of that players attained during the game [la]b that at times were close to 80–85% of exhaustion values. The present results show that professional Futsal may elicit high blood-lactate levels and suggests that anaerobic metabolism can be an important contributor to energy provision during games. In fact analysis of game activities showed the existence of sprint bouts sequences (3–4 bouts) with very short recovery time (20–30 s of lower intensity activity) occurring during crucial phases of the game. Consequently the ability to repeat sprint with short recovery time (20–30 s) may be considered as a Futsalspecific physical ability to be trained. As in this study

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only random blood sampling was used therefore it is not possible to establish a clear cause-effect between

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