Thursday, March 14, 2013

Small-Sided Games. Part I: Do They Improve Fitness?

Written By Jeremy Williams

There is no doubt that success in soccer requires players to have a high level of physical fitness. For any athlete, maintaining fitness throughout the competitive season can be challenging. This is especially true for those who do not receive much playing time during contests (i.e. reserve players). It is common for coaches to implement lower volume and intensity training sessions on the days before and after match day so those who play the majority of minutes do not begin the match fatigued. Also, “light” training days allow players to recover the day following a match. Unfortunately, players who do not receive significant playing time can very quickly lose fitness. To combat this, many coaches will subject these players to some sort of fitness training the day after a match. This can serve as a way to replicate the physical and technical demands of competition that are missed on game days. However, the extent to which small-sided training improves and maintains fitness is somewhat unclear. Part I of this two-part series takes an evidence-based look at small-sided games and asks the question, “Does small-sided training improve endurance capacity?” In the Part II, a second question will be addressed, “What are the best configurations to optimize training load?”

Traditional ways to increase endurance capacity in athletes include training regimens such as a long distance run and interval-type or sprint workouts. Coaches in all sports routinely use these workouts as part of their fitness program. However, when examining the physical demands of a soccer match, it is difficult to create a workout that mimics the workload and movements experienced when playing a 90-minute soccer match. Due to the randomness of sprint lengths, running intensities, changes of direction, and recovery times between runs, many players feel that a simple distance or interval workout does not adequately prepare them to be “match fit”.  Due to this inadequacy, the concept of “small-sided” training in soccer has emerged as an alternative to long training runs or interval training as a way to increase and maintain fitness levels in soccer players.

Small-sided games involve from two- to eight-player “teams” competing against one another on a field with reduced dimensions. Multiple games lasting several minutes are typically played with short recovery intervals. These games provide high-intensity activities, directional changes, and intermittent recovery times between movements that are more consistent with the natural flow of the game. Many coaches favor this alternative form of training because it is thought to improve and maintain fitness. Small-sided games also offer training in both the skill and tactical areas of the game that traditional endurance and interval sprinting cannot provide.  Given this, it seems logical that players would benefit from this type of training program

The desired characteristics of any training program is the ability to produce an overload and to maintain specificity to the sport that is being trained for. In order for a system to adapt, it must be overloaded or stressed beyond the level that it is accustomed. For maximum benefits, the training load should be greater than that which is experienced during competition. With regard to specificity, the muscles exercised, typical movements associated with the sport, and energy systems involved during training should mimic those of competition. Thus, for small-sided training to be effective, the work load should be greater and movements similar to those of a competitive match.

The average youth and professional player may cover anywhere from 3-6 miles over the course of a match. Also, players typically exercise at approximately 75-85% of their maximal oxygen consumption (VO2max) and 80-85% of maximal heart rate. Thus, soccer has major endurance and aerobic requirements built into the game.  It is easy to see why many coaches have used distance running or interval training to increase VO2max and develop fitness in soccer players. However, the movements in soccer also include sprinting, high intensity running, jogging and walking. A competitive game also requires players to change directions more than 1000 times. Thus, a training program of distance running or interval training may not provide the necessary overload to maximize soccer fitness. Also, it does not simulate the types of movements experienced in a match and therefore, lacks the specificity component.

Several studies have compared the movement patterns encountered during small-sided games and during full-sided, 11v11 competitive matches. The key difference between full-sided matches and small-sided games is that the work rate in small-sided games is higher than a full-sided match. This is due to greater individual player involvement in the smaller game format (Casamichana et al., 2012; Gabbetti & Mulvey, 2008). The smaller number of players increases the probability of each player being directly involved in defending or attacking at any moment. For example, 3v3 games have a greater work-rest ratio, player workload per minute, and exertion per minute than full-sided matches, (Casamichana et al., 2012). On the other hand, due to the smaller field dimensions, small-sided games do not replicate the repeated long sprints seen in full-sided matches.

Despite the interest in small-sided game training and the physical demands associated with it, only a few research studies have examined training-induced adaptations and directly compared them to other forms of training. A study in Lyon, France compared the effects of small-sided games and high-intensity interval training on aerobic capacity and ability to perform intermittent exercises (Dellal et al., 2012). By the end of the 6-week training period, both groups showed improvements in the VAMEVAL test (an incremental running test of VO2max); 5% for the HIT group, compared to 7% for those who participated in the small-sided games. An intermittent running test that incorporated directional changes was also improved, with the HIT group showing a 5% increase, and the small-sided group showing a 6% improvement. The researchers concluded that both training programs were equally effective with regard to improving fitness.

In professional players, small-sided training used during a four-week, in-season break improved sprint time, repeated sprint ability and running economy (Owen et al., 2011). The improvements found in running economy were considered large, but changes in other parameters, while statistically significant, were considered small. In a similar study, exercising heart rates were compared in elite level soccer players who trained with short-duration, intermittent runs and in various configurations of small-sided games (Dellal et al., 2008). The overall finding was that heart rate responses during small-sided games were similar to that of short intermittent runs, and in some cases exceeded the responses of those during the intermittent runs. However, there was significant variance in heart rate responses between the sizes of the small-sided games.

With regard to the size of teams in the small-sided games, 3v3 was the most commonly used amongst the training studies. The games included goalkeepers and field dimensions were adjusted to obtain approximately 125m2 per player, which is the approximate ratio that occurs in a full-sided match. Owen et al. (2012) looked at elite soccer players in the Scottish Premier League during a mid-season break. Players competed in small-sided games for a total of seven sessions over a four-week period. The games lasted three minutes and were interspaced with a two-minute passive recovery. The number of games per training session ranged from 5-11, with more games being played per session as the study went on. Repeated sprint ability, which consisted of six trials of 20-meter sprints, showed small increases in fastest sprint time, total sprint time, and percentage decrement score. However, the largest changes were reduced VO2 and heart rates at running speeds of 9, 11, and 14 km/h. This suggests that a training program that includes small-sided games can improve exercise economy and may reduce the overall energy expended during a match.

As for youth players, two studies specifically compared small-sided games to “generic” or endurance training. Hill-Hass et al. (2009) showed that seven weeks of training failed to improve VO2max or repeated sprinting ability in either group. However, the generic training group perceived their training to be more intense than that of the small-sided games. It is important to point out that neither group showed declines in VO2max or sprint ability, suggesting that fitness was maintained. In contrast, Impellizzeri et al. (2006) found significant improvements in aerobic fitness and match performance using both the generic training and small-sided training programs. Training took place over a 12-week period, training twice per week. Four of the weeks were during the team’s pre-season training period, while the next eight weeks took place during the regular season. Four, four minute bouts of either interval training or small-sided games were conducted, with three-minutes of active recovery placed between bouts. VO2max increased in the generic training group and in the small-sided group by approximately 8% and 7%, respectively. The authors conclude that small-sided games used twice per week could be used as an effective training mode to enhance aerobic fitness.

Using these studies, two important conclusions can be reached. First, small-sided games, used as a training tool, mimics the workload as well as specific movements encountered during a full-sided competitive match. Thus, both overload and specificity requirements of a training program are met. Second, the use of small-sided games for training over 4-12 weeks can maintain and improve fitness. Further, the adaptations are similar in magnitude to interval training. Given this, coaches should be confident in using small-sided games as an effective training tool for soccer players. Not only will small-sided games help players get match fit, they will also train the technical and tactical aspects of the game.

The next question is how best to implement small-sided training. What configurations should be used? How many players per game, what pitch size to use? Also, what about the number of games, game length and rest interval? These questions well be addressed in Part II of this series by taking a look at the physiological responses of players to various training configurations.

Jeremy Williams is currently the Volunteer Assistant with the Florida State Women’s team. He is also a graduate student in the FSU sport science program.

References

Casamichana, D, Castellano, J, Castagna, C. Comparing the physical demands of friendly matches and small-sided games in semiprofessional soccer players. Journal of Strength Conditioning Research, 2012, 26: 837-843.

Dellal, A, Chamari, K, Pintus, A, Giroud, O, Cotte, T, Keller, D. Heart rate responses during small-sided games and short intermittent running training in elite soccer players: A comparative study. Journal of Strength and Conditioning Research, 2008, 25: 1449-1457.

Dellal, A, Varlette, C, Owen, A, Chirico, E, Pialoux, V. Small-sided games versus interval training in amateur soccer players: Effects on the aerobic capacity and the ability to perform intermittent exercises with changes of direction. Journal of Strength and Conditioning Research, 2012, 10: 2712-2720.

Gabbett, TJ, Mulvey, MJ. Time-motion analysis of small-sided training games and competition in elite women soccer players. Journal of Strength and Conditioning Research, 2008, 22: 543-552.

Hill-Haas, SV, Coutts, AJ, Roswell, GJ, Dawson, BT. Generic versus small-sided game training in soccer. International Journal of Sports Medicine, 2009, 30: 636-642.

Impellizzeri FM, Marcora SM, Castagna C, Reilly T, Sassi A, Iaia FM, Rampinini E. Physiological and performance effects of generic versus specific aerobic training in soccer players. International Journal of Sports Medicine, 2006, 27: 483-492

Owen, A, Wong, D, McKenna, M, Dellal, A. Heart rate responses and technical comparison between small- vs. large-sided games in elite professional soccer. Journal of Strength and Conditioning Research, 2011, 25: 2104-2110.

Owen, A, Wong, D, Paul, D, Dellal, A. Effects of periodized small-sided game training intervention on physical performance in elite professional soccer. Journal of Strength and Conditioning Research, 2012, 26: 2748-2754.