Background: Small-sided games are frequently used as a training method in today´s football. The importance of the ability to perform high-intensity running is increasing and small-sided games may not lead to the required improvement of this ability. It might be necessary to add speed-endurance training to obtain the high-intensity running. Objective: The aim of this study was to investigate which of the training methods; small-sided games or speed-endurance training, leads to the highest performance improvements in three football-specific tests. Measures and Methods: The study was an intervention study where 31 male football players participated. They were randomized in to two groups which performed either speed-endurance training (SEP) (n=16) or small-sided games (SSG) 6 vs 6 (n=15). The study lasted four weeks and eleven sessions in total. Baseline tests and posttraining test were conducted in Yo-Yo IR2, Arrowhead agility test and Repeated sprint 30 meters. Result: SEP demonstrated an 17 % higher increase in testresults than SSG in Yo-Yo IR2. No significant difference between the groups were observed in the other tests. Conclusion: Small-sided games is a training method which entails football-specific training load. It might be necessary to add speed-endurance training which can lead to higher performance improvments in Yo-Yo IR2.