High volume endurance training (ET) has traditionally been used to improve aerobic capacity but is extremely time-consuming in contrast to low-volume short-duration sprint interval training (SIT) that improves maximal oxygen uptake (V_ O2max) to a similar extent. Few studies have compared the effects of SIT vs. ET using running-based protocols, or in team sport athletes. Club level male Gaelic football players were randomly assigned to SIT (n = 7; 21.6 6 2.1 years) or ET (n = 8; 21.9 6 3.5 years) for 6 sessions over 2 weeks. V_ O2max, muscle mitochondrial enzyme activity, running economy (RE), and high-intensity endurance capacity (HEC) were measured before and after training. An increase in V_ O2max (p # 0.05) after 2 weeks of both SIT and ET was observed. Performance in HEC increased by 31.0 and 17.2% after SIT and ET, respectively (p # 0.05). Running economy assessed at 8, 9, 10, and 11 km$h 21 , lactate threshold and vV_ O2max were unchanged after both SIT and ET. Maximal activity of 3-b-hydroxylacyl coenzyme A dehydrogenase (b-HAD) was increased in response to both SIT and ET (p #0.05), whereas the maximal activity of citrate synthase remained unchanged after training (p = 0.07). A running-based protocol of SIT is a time-efficient training method for improving aerobic capacity and HEC, and maintaining indices of RE and lactate threshold in team sport athletes.