Handball is a team sport with two opposing teams, which alternately take the role of either attacker or defender, depending on who has possession of the ball. The work-rate intensity and volume of the external load in handball are highly heterogeneous. During games, players are exposed to both high- and low-level intensities of external load. External load in handball can be divided into acyclic and cyclic activities. In a match, acyclic activities (e.g., passing the ball, various kind of shots, jumps, body contacts, falls) occur along with the player's cyclic movements (running, walking, jogging, cruising, and moving sideways or backwards) (Sibila et al., 2004). Data on cyclic movements show a greater distance travelled for the wings, with a higher percentage of time spent sprinting (running speed above 5.2 m x [s.sup.-1]); this trend was also confirmed during 2 x 20 minute matches (Sibila et al., 2004). Other studies, utilizing time-motion analysis, revealed significant differences in the total distance travelled (Bon, 2001; Luig et al., 2008). Differences in acyclic activities are also apparent among the players with different playing positions: significantly more passes and shots are executed by the back players compared with others (Pori et al., 2009). In order to evaluate the internal load in handball, the most frequently used methods are analyses of heart rate (HR) and blood lactate concentrations (LA). Average HR during official matches has been reported to be approximately 82% of maximal HR (HRmax) (Povoas et al., 2012). Blood lactate ranges between 2 and 6 mmol x [l.sup.-1] (Pori et al., 2007).
To cover the specific game demands, more specific training methodologies have been developed. Following these developments, several authors have now focused their attention on investigating physiological and technical activities of specific drills. For example, when many games were investigated, these drills were performed with different court dimensions and number of players (Abrantes et al., 2012; Aroso et al., 2004; Da Silva et al., 2011; Dellal et al., 2011; Gabbett et al., 2012; Hill-Haas et al., 2011; Jones and Drust, 2007; Katis and Kellis, 2009; Kelly and Drust, 2009; Kennett et al., 2012; Koklu et al., 2011; Rampinini et al., 2007; Tessitore et al., 2006) and different duration (Fanchini et al., 2011; Hill-Haas et al., 2011; Tessitore et al., 2006). In particular, the main question of several studies in different team sports was whether exercises performed with the ball can be used as a substitute of traditional training methods without the ball (Hill-Haas et al., 2011; Impellizzeri et al., 2006; Kelly et al., 2013; Little and Williams, 2006; Sassi et al., 2004).
Compared with generic training methods, those reproducing specific game situations may provide a useful conditioning stimulus, together with technical and tactical training components (Hill-Haas et al., 2011; Impellizzeri et al., 2006; Sassi et al., 2004). In handball, there is a lack of scientific knowledge about how to set up small-sided games (SSGs), in terms of the number of players involved, court dimensions, and duration. In spite of substantial growth in research related to specific training methods in many team sports, only two studies on SSGs in handball have been published (Buchheit et al., 2009a; 2009b). The first study of Buchheit et al. (2009a) compared a traditional intermittent running exercise with a specific four-a-side drill played on a regular court dimension, reporting greater time spent close to maximal oxygen update, lower HR and blood lactate levels, and a similar rating of perceived exertion (RPE) during the handball-specific condition. The second study of Buchheit et al. (2009b) highlighted the improvement of repeated sprint ability (RSA) and high-intensity intermittent running performance in young players (as measured by 30-15 Intermittent Fitness Test) following both high-intensity interval training and specific game-based handball training. While both methods were equivalent to improve most of the performance test measures, SSGs could be preferred due to their greater specificity. However, only one type of SGG (i.e. 4vs4 on the entire handball court) was used during these two studies. Whether the variations in player numbers and court dimensions could be as efficient at developing physical performance is presently unknown.
Beside the data about metabolic response of the players, during the SSGs, researchers also attempt to obtain data about cyclic activities (e.g., running and walking with different intensity) and acyclic activities (e.g., jumps, shots, passes, changes of directions) performed during the game. With this purpose, a wide range of different measurement methods of notational and time motion analysis were introduced. In this field, the introduction of GPS technology has been a significant innovation. In recent years, GPS systems have been adopted to track time-motion characteristics for all kind of games (Brewer et al., 2010; Castellano and Casamichana, 2010; Macutkiewicz and Sunderland, 2011).
The aim of this study was to investigate the effect of three different court dimensions on the internal load (assessed by heart rate and rate of perceived exertion) and external load (assessed by running intensity and the number of technical actions) during SSGs in handball. Based on previous studies in soccer (Casamichana and Castellano, 2010; Rampinini et al. 2007), we expected to observe both greater internal and external loads when increasing the court dimensions.
Six amateur players (age 28 [+ or -] 3 years, range 24-33 years) belonging to an Italian Serie A1 league team (second tier championship in Europe) were recruited to participate in this study. Players had at least six years of experience in handball training (four times per-week) and competitions; they also took part in national championships at the time of the investigation. Participants were volunteers and took part in the present study after giving their written consent. All of the procedures received the approval of the ethics committee of the Faculty of Sports, at the University of Ljubljana.
Three court dimensions were used: 24 x 12m, 30 x 15m and 32 x 16m. For each court condition, an eight-minute drill of continuous exercise without substitutions was performed. This drill duration was chosen on the basis of previous studies (Buchheit et al., 2009a; Tessitore et al., 2006). Consistent verbal encouragement provided by the coach, to ensure the maintenance of a high work-rate, was allowed (Ramipinini et al., 2007).
The study was conducted over a 12-week period, with all experimental sessions scheduled at the same time of the day, (on a Tuesday once every two weeks during normal training) to avoid any effect of circadian rhythms on the measured variables (Drust et al., 2005). Before each experimental session, players wore a specific vest to support the GPS and heart rate devices, after which they performed a standardized 20-minute warm-up. During the SSGs, the defence in front of the goalkeeper was a zone-defence that reproduced the central part of a hypothetical 5-1 defence, with the centre back and two half defenders, and without the front centre defender. The opponent at the beginning of each action held the positions of left, right and central backcourts, independent of their real role. The rules of the drills were the same as for normal handball with the exceptions of:
1) throw-in after a goal was immediately made by the goalkeepers from their 6-m area, and the investigator was always available to immediately replace the ball when it was thrown out of the playing area (Buchheit et al., 2009a),
2) the 2-min exclusions were not present, but the referee only sanctioned "normal" faults.
The referee for all of the drills was always an official referee of the Italian handball federation.
By means of a SPI pro elite GPS system 15hz (GPSports), the cyclic movements were categorized as: 1) total distance in the drills; 2) percentage of time spent from 0 to 1.4 m x [s.sup.-1]; 3) percentage of time spent...