Objective  The difference of players(4v4+GK, 6v6+GK and 8v8+GK)was examined on running performance and energy cost(EC)of small-sided games(SSGs)in collegiate male soccer players, and the proportion of high-intensity activities was compared under the two categories(running speed and EC).

  Methods  Running data were collected from 20 collegiate male soccer players in SSGs using global positioning system (GPS); EC were estimated with the method based on players'acceleration with GPS.

  Results  ① The total running distance increased significantly with the increase of the number of players.The middle speed running distance of 8v8+GK was significantly higher than 6v6+GK and 4v4+GK(P < 0.01), while the middle and high speed running distance and high speed running distance of 4v4+GK were significantly lower than 6v6+GK and 8v8+GK(P < 0.01). ② The total speed change and low deceleration numbers decreased significantly with the increase of the number of players; and the low acceleration, middle acceleration and middle deceleration of 4v4+GK were significantly higher than those of 6v6+GK and 8v8+GK(P < 0.01). ③EC and metabolic power increased significantly with the number of players(P < 0.01). ④ The proportion of high-intensity activities (11.35%~13.34%)categorized by running speed was significantly lower than that by EC(17.00%~18.07%).

  Conclusions  In a certain range, SSGs with more players is more suitable for the development of collegiate male soccer players'running ability, SSGs with fewer players is more suitable for the development of their agility.EC per minute in 6v6+GK and 8v8+GK is close to that in an official competition.The proportion of high-intensity activities is underestimated according to the category of running speed, which is especially obvious in SSGs with fewer players.