Effects of speed-agility-quickness training and sprint interval training on physiological and physical performance, and sports enjoyment in young soccer players

Sports enjoyment is crucial for young athletes as it influences both their immediate willingness to engage in sports and their long-term commitment and development. Therefore, understanding the effects of different training methods on sports enjoyment is essential. This study aimed to compare the effects of speed-agility-quickness training (SAQT) and sprint interval training (SIT) on young soccer players preparing to return after rehabilitation, investigating their impact on physiological and physical performance, as well as on sports enjoyment. A total of 56 adolescent soccer players (age, 15-17 years) were randomly assigned to either the SAQT (n = 28) and SIT (n = 28) groups and underwent training according to the group allocation twice weekly for 8 weeks. A graded exercise test for peak oxygen uptake (VO2 peak), isokinetic knee strength tests (peak torque, average power), and agility tests (Illinois agility test, Agility T-test) were used to assess physical factors. The Sports Commitment Questionnaire-2 (SCQ-2) was used to evaluated sports enjoyment. VO2 peak, isokinetic knee strength, and agility significantly improved in both groups after the 8 weeks of intervention. In between-group comparisons, it was found that SIT was more effective in enhancing VO2 peak (p < 0.05), anaerobic threshold (AT) (p < 0.05), and knee strength (p < 0.05), whereas SAQT was associated with greater enhancements in Illinois agility test (IAT) (p <0.05) and Agility T-test (ATT) (p <0.05) performance times, as well as in sport enjoyment scores (p < 0.05). In conclusion, it appears that SAQT may substantially enhance agility and quickness, which are crucial for optimal in-game performance, while SIT may improve other vital components such as cardiorespiratory fitness and muscle strength. Particularly for youth soccer players who are recovering from injuries, SAQT could be instrumental in fostering more positive affective responses and enhancing sport enjoyment.