Small-Sided Games in footballFrom a scientific point of view, Small-Sided-Games (SSG) provide reliable internal- (such as HR, RPE, and blood lactate concentration) and external responses (such as total distance covered) and therefore can be used as a conditioning format (46).

As mentioned on previous sites, SSG seem to have many advantages (such as football specific movement, technical training, possible tactical improvements and inherent high motivational factors for training) over other conditioning formats (19, 22, 26, 31, 42). It seems that coaches, who in particular have only limited amount of time with the players, might benefit from SSG as they might increase the efficacy of training (46) and even reduce the total training time because of the multi-functionality of SSGs (19, 45), especially in youth players (47).

Besides improvements in the aerobic endurance (12, 31, 34, 35, 43), and anaerobic endurance (35) changes were also seen in change of direction performance (24) of players and technical abilities in youth players (47).

As an initial paragraph regulations and rules that will influence (the efficacy of) the training (14) need to be discussed.Regulations and rules that affect outcome of SSGa) Regulations of the gamePitch-sizeCertainly, the pitch-size needs to be linked to the amount of players involved.Table in accordance to (1, 19, 32, 38).Numberof playersPitch-area(meter)Pitch-area(m squared)(16)

GeneralSmall (11)Medium (11)Large (11)

1 vs. 110105 10

10 15

15 20

100

2 vs. 220-2820-21 (32)10 15

15 20

20 25

400-800

3 vs. 32518 (44)12 20

15 25

18 30

240-2500

4 vs. 430-4020-30 (23, 32, 36, 46)16 24

20 30

24 36

240-2208

5 vs. 5*32-6223-44 (7)20 28

25 35

30 42

240-2500

6 vs. 6493724 32

30 40

36 48

240-2500

7 vs. 75035-45 (27)875-2200

8 vs. 86040-45 (36)2400-2700

9 vs. 9*6050 (46)3000

10 vs. 109045~4000

*Note: games were played with goalkeeperWhen the number of players are kept constant and the pitch-size is increased, exercise intensity increases as well (48).

A smaller pitch size affect physiological aspects of the game (6, 7, 20) and technical training compared to a larger pitch size (7, 38, 53). Curiously, while a smaller pitch size seems to decrease the possibility to maintain ball possession (53), an increase in pitch size resulted in a decrease of passes, turns, dribbles, interceptions, target passes and changes were significantly different for shots and tackles (38, 46) and heart rate response (45).

Generally, an increase of up to 10 meters caused heart rates to increase (and therefore the intensity), while a change of only 5 meters did not alter intensity (45).

Similar responses were seen in youth players and an increase in pitch-size increased heart rate (39).

Amount of playersIn order to compare the effect of different amount of players during SSG, the relative pitch size (the square area of the pitch divided by the number of players) was kept identical whilst changing number of players (32). There were no goalkeepers involved, no restriction on the number of touches, mini goals to score and all players needed to be in the oppositions half (32).

The smaller SSG (2 vs. 2) showed greater physiological demands (heart rate, lactate accumulation (4) and RPE) compared to bigger SSG (4 vs. 4; 6 vs. 6; 8 vs. 8), although the players had lower sprint duration, lower average maximal sprint duration, lower sprint distance and greater time between sprints (31, 32, 37, 41, 42, 48).

GoalkeepersIf coaches include goalkeepers in SSG, players heart rate responses and therefore the intensity of the game was lower (3, 43) compared to no goalkeeper involvement or possession games (27). Similar results were seen in youth footballers (40). We believe that the lower intensity is not only due to the goalkeepers, but as a result of specific direction of play. Therefore, a lower intensity will also be present if no goalkeepers are involved and the game has a specific direction of play.Rules of SSGOffside vs. no offsideIncluding offside rule will lower the intensity non-significantly (Unfortunately I cannot find that reference again!)

Number of touchesIf coaches incorporate a restriction about the amount of touches per players, some effects will result from this restriction (9, 21, 23). However, the outcome of the SSG session for the players aerobic endurance will also depend on a) the technical ability of the players, b) the fitness level of the players.

If the technical level of the players is not sufficient enough for the restriction demanded, no real play will result and therefore no/lesser outcome for the players aerobic endurance will be achieved (21).

The fitness level of players will also have an impact on the flow of a SSG (21). If the player inherent no or limited aerobic endurance capacity (for example during pre-season or lower level players) a low amount of touches might result in a bad flow and possible no outcome for the aerobic endurance.

Nevertheless, a restriction of number of passes will increase the intensity of the game (9, 15).

Player numbers up or down/neutral playersMost of the time, games with uneven numbers (such as floaters and/or attacking team can add players to attack) did not change the physiological responses of the players, however increasedRPE( meaning how the players perceived the intensity) for the team with lower number of players (30). Contrarily it increased the physiological demands (52).

Neutral players outside the pitch lowered the intensity of the game (52). However, for the neutral players, game formats also had an impact on their demands and it seems that the bigger formats (4 vs. 4 compared to 2 vs. 2 for example) elicited greater physiological responses (16).

Man-marking increased the intensity of the game in 3 vs. 3 (44).

Man-marking increased the intensity of the game in 3 vs. 3 (37).

Scoring rulesRules that require the attacking team to have ALL players in a specific pitch was also shown to increase lactate production, however did not change heart rate or high intensity running. The pitch size was divided into thirds and in order to score a goal ALL attacking players had to be in the front two thirds (30).

MiscellaneousCoaches encouragement was also shown to increase the effect intensity of SSG (15, 48, 51).

Fitter players will cover more distance and get greater conditioning in SSG compared to un-fitter players (18, 21).It seems that SSG inherent greater density of acceleration and deceleration compared to normal match-play (33) and friendly games (11) and therefore seem to display a very effective training option.

In order to replicate game demands, training tactical aspects in SSG should incorporate specific aspects about individual pitch size area. Depending on different zones, individual pitch-size should range from 65 110 (m2) and length to width ratio of 1:1 and 1:1.3 (25). Furthermore, it seemed that number of players affected the distance to the teams centroid (kind of the middle/centre point of team players) (2). For example the distance decreased with increasing number of players (2-4 players), meaning the players stay closer together, however increased in the 5-a-side, suggesting a greater positional organization (2).

Intensity is increased if an end-zone is utilized compared to goals in youth soccer players (28). Furthermore, in less skilled youth footballers, the physiological demand and therefore the possible training benefit of a non-football specific game (such as handball/bucketball) might be of greater a benefit to the players (29). However, it seemed that SSGs were more efficient to improve the ball handling/dribbling capacities of youth players compared to pre-planned agility courses (13).

Interestingly, the number of players had no significant impact on total distance covered, high-intensity distance and RPE in untrained/amateur soccer players (49).ProtocolsMost (nearly all) of the SSG reviewed, utilized a 4 4 minutes with passive recovery (2-4 minutes) protocol. However, a 3 5 minutes with a passive recovery of 4 minutes (46) or 10 4 minutes with 3 minutes passive recovery (37) protocol was also used.

Pacing strategies during intermittent activities are influenced by the number and duration of exercise bouts. Practitioners should consider within-game bout durations when prescribing game-based activities to improve aerobic capacity (50). It seemed that continuous formats produced higher load on the players (8).In a nutshell SSG as a tool to train multi-functional (technical and physiological) Pitch-size changes the technical aspect of the game and the actions performed during the SSG Amount of players on similar pitch-size changes technical aspect as well. The lower the amount of players the greater the amount of dribblings, shots, tackles and touches for each player Direction of play results in a decrease of intensity Restriction of touches will change the demands of the SSG. The lower the technical ability the lower the effect on the physiological system Interval training was proven to be more controlled and training can be prescribed more individually (19)References1. Aguiar, M., et al. A review on the effects of soccer small-sided games. 2012. 33, 103-113.

2. Aguiar, M., et al., Footballers' movement behaviour during 2-, 3-, 4- and 5-a-side small-sided games. J Sports Sci, 2015. 33(12): 1259-66.

3. Allen, J.D., et al., The physical and physiological value of 5-a-side soccer training to 11-a-side match play. Journal of Human Movement Studies, 1998. 34: 1-11.

4. Aroso, J., A.N. Rebelo, and J. Gomes-Pereira, Physiological impact of selected game-related exercises. Journal of Sport Sciences, 2004. 22(6): 522.

5. Beato, M., L. Bertinato, and F. Schena, High volume training with small-sided games affects technical demands in football - a descriptive study. Sport Sci Health, 2014.

6. Bondarev, D.V. Factors influencing cardiovascular responses during small-sided soccer games performed with recreational purposes. 2011.

7. Casamichana, D. and J. Castellano, Time-motion, heart rate, perceptual and motor behaviour demands in small-sides soccer games: effects of pitch size. J Sports Sci, 2010. 28(14): 1615-1623.

8. Casamichana, D., J. Castellano, and A. Dellal, Influence of different training regimes on physical and physiological demands during small-sided soccer games: continuous vs. intermittent format. J Strength Cond Res, 2013. 27(3): 690-7.

9. Casamichana, D., et al., Effect of number of touches and exercise duration on the kinematic profile and heart rate response during small-sided games in soccer. J Hum Kinet, 2014. 41: 113-23.

10. Castelao, D., et al., Comparison of tactical behaviour and performance of youth soccer players in 3v3 and 5v5 small-sided games. International Journal of Performance Analysis in Sport, 2014. 14(3): 801-813.

11. Castellano, J. and D. Casamichana, Differences in the number of accelerations between small-sided games and friendly matches in soccer. Journal of Sports Science and Medicine, 2013. 12: 209-210.

12. Chamari, K., Hachana, Y., Kaouech, F., Jeddi, R., Chamari-Moussa, I., and Wislff, Endurance training and testing with the ball in young elite soccer players. British Journal of Sports Medicine, 2005. 39: 24-28.

13. Chaouachi, A., et al., Multidirectional sprints and small-sided games training effect on agility and change of direction abilities in youth soccer. J Strength Cond Res, 2014. 28(11): 3121-7.

14. Clemente, F., et al., The usefulness of small-sided games on soccer training. Journal of Physical Education and Sport, 2012. 12(1): 99-102.

15. Clemente, F.M., F.M. Martins, and R.S. Mendes, Developing aerobic and anaerobic fitness using small-sided soccer games: Methodological proposals. Strength and Conditioning Journal, 2014. 36(3): 76-87.

16. Clemente, F.M., et al., Inspecting the performance of neutral players in different small-sided games. Motriz Rio Claro, 2015. 21(1): 45-53.

17. Clemente, F.M., F.M.L. Martins, and R.S. Mendes, Periodization based on small-sided soccer games: Theoretical considerations. Strength and Conditioning Journal, 2014. 36(5): 34-43.

18. Dellal, A., et al., Comparison of physical and technical performance in European professional soccer match-play: The FA Premier League and La LIGA. Eur J Sport Sci, 2010. 25(25): 93-100.

19. Dellal, A., et al., 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. 22(5): 1449-1457.

20. Dellal, A., B. Drust, and C. Lago-Penas, Variation of activity demands in small-sided soccer games. Int J Sports Med, 2012. 33(5): 370-375.

21. Dellal, A., et al., Small-sided games in soccer: Amateur vs. professional players' physiological responses, physical, and technical activities. J Strength Cond Res, 2011. 25(9): 2371-2381.

22. Dellal, A., et al., Physiologic effects of directional changes in intermittent exercise in soccer players. J Strength Cond Res, 2010. 24(12): 3219-3226.

23. Dellal, A., et al., Effect of the number of ball contacts within bouts of 4 vs. 4 small-sided soccer games. Int J Sports Physiol Perform, 2011. 6(3): 322-333.

24. Dellal, A., et al., Small-sided games vs. interval training in amateur soccer players: Effects on the aerobic capacity and the ability to perform intermittent exercises with changes of direction. J Strength Cond Res, 2011. 25(9): 2371-2381.

25. Fradua, L., et al., Designing small-sided games for training tactical aspects in soccer: extrapolating pitch sizes from full-size professional matches. Journal of Sports Sciences, 2013. 31(6): 573-581.

26. Gabbett, T.J. and M.J. Mulvey, Time-motion analysis of small-sided training games and competition in elite women soccer players. J Strength Cond Res, 2008. 22(2): 543-552.

27. Gaudino, P., G. Alberti, and F.M. Iaia, Estimated metabolic and mechanical demands during different small-sided games in elite soccer players. Human Movement Science, 2014. 36: 123-33.

28. Halouani, J., et al., Physiological responses according to rules changes during 3 vs. 3 small-sided games in youth soccer players: stop-ball vs. small-goals rules. J Sports Sci, 2014. 32(15): 1485-90.

29. Harrison, C.B., et al., Small-sided games for young athletes: is game specificity influential? J Sports Sci, 2014. 32(4): 336-44.

30. Hill-Haas, S.V., et al., Time-motion characteristics and physiological responses of small-sided games in elite youth players: The influence of player number and rule changes. Journal of Strength and Conditioning Research, 2010. 24(8): 2149-2156.

31. Hill-Haas, S.V., et al., Generic versus small-sided game training in soccer. Int J Sports Med, 2009. 30(9): 636-642.

32. Hill-Haas, S.V., et al., Physiological responses and time-motion characteristics of various small-sided soccer games in youth players. J Sports Sci, 2009. 27(1): 1-8.

33. Hodgson, C., R. Akenhead, and K. Thomas, Time-motion analysis of acceleration demands of 4v4 small-sided soccer games played on different pitch sizes. Hum Mov Sci, 2014. 33: 25-32.

34. Impellizzeri, F.M., et al., Physiological and performance effects of generic versus specific aerobic training in soccer players. International Journal of Sports Medicine, 2006. 27(6): 483-492.

35. Jensen, J.M., et al., Effect of additional in-season aerobic high-intensity drills on physical fitness of elite football players. Journal of Sports Science & Medicine, 2007. Suppl 10: 79.

36. Jones, S. and B. Drust, Physiological and technical demands of 4 vs. 4 and 8 vs. 8 in elite youth soccer players. Kinesiology, 2007. 39: 150-156.

37. Katis, A. and E. Kellis, Effects of small-sided games on physical conditioning and performance in young soccer players. Journal of Sports Science and Medicine, 2009. 8: 374-380.

38. Kelly, D.M. and B. Drust, The effect of pitch dimensions on heart rate responses and technical demands of small-sided soccer games in elite players. Journal of Science and Medicine in Sport, 2009. 12(4): 475-479.

39. Kkl, Y., et al., Comparison of the physiological responses to different small-sided games in elite young soccer players. Journal of Strength and Conditioning Research, 2011. 25(6): 1522-1528.

40. Koklu, Y., et al., Comparison of the physiological responses and time-motion characteristics of young soccer players in small-sided games: the effect of goalkeeper. J Strength Cond Res, 2015. 29(4): 964-71.

41. Little, T. and A.G. Williams, Measures of exercise intensity during soccer training drills with professional soccer players. J Strength Cond Res, 2007. 21(2): 367-371.

42. Little, T. and A.G. Williams, Suitability of soccer training drills for endurance training. J Strength Cond Res, 2006. 20(2): 316-319.

43. Mallo, J. and E. Navarro, Physical load imposed on soccer players during small-sided training games. Journal of Sports Medicine and Physical Fitness, 2008. 48(2): 166-171.

44. Ngo, J.K., et al., The effects of man-marking on work intensity in small-sided soccer games. Journal of Sports Science and Medicine, 2012. 11: 109-114.

45. Owen, A., C. Twist, and P. Ford, Small-sided games: The pysiological and technical effect of altering pitch size and players numbers. Insight, 2004. 7(2): 50-53.

46. Owen, A.L., et al., Heart rate Responses and technical comparison between small- vs. large-sided games in elite professional soccer. J Strength Cond Res, 2011. 25(8): 2104-2110.

47. Radziminski, L., et al., A Comparison of the Physiological and Technical Effects of High-Intensity Running and Small-Sided Games in Young Soccer Players. International Journal of Sports Science & Coaching, 2013. 8(3): 455-465.

48. Rampinini, E., et al., Factors influencing physiological responses to small-sided soccer games. J Sports Sci, 2007. 25(6): 659-666.

49. Randers, M.B., et al., Physiological response and activity profile in recreational small-sided football: no effect of the number of players. Scand J Med Sci Sports, 2014. 24 Suppl 1: 130-7.

50. Sampson, J.A., H.H. Fullagar, and T. Gabbett, Knowledge of bout duration influences pacing strategies during small-sided games. J Sports Sci, 2014: 1-14.

51. Sanchez-Sanchez, J., et al., Effect of coach motivation in training load and physical performance of small sided games. Cuadernos de Psicologia del Deporte, 2014. 14(3): 169-175.

52. Torres-Ronda, L., et al., Heart rate, time-motion and body impacts when changing the number of teammates and opponents in soccer small-sided games. Journal of Strength and Conditioning Research, 2015.

53. Vilar, L., et al., The influence of pitch dimensions on performance during small-sided and conditioned soccer games. J Sports Sci, 2014. 32(19): 1751-9.