Sprint interval training (SIT), whether performed on a cycle ergometer or non-motorized treadmill, enhances exercise capacity and evokes favorable metabolic and cardiopulmonary adaptations. However, despite known differences between cycling and running, the influence of exercise modality on the adaptive response to SIT has not been directly addressed. Additionally, the effect of SIT on the angiogenic factors, pigment epithelial-derived factor (PEDF) and vascular endothelial growth factor (VEGF), has not been well characterized. PURPOSE: To examine the influence of exercise modality on the adaptive response to SIT, we compared the effects of SIT performed on one of three different exercise machines: non-motorized treadmill, cycle ergometer, or plyometrics platform. Additionally, we sought to characterize the changes in circulating and skeletal muscle PEDF and VEGF following three weeks of SIT. METHODS: Twenty-seven healthy, sedentary or recreationally active adults (age: 23 ± 5 years; body mass index: 25.7 ± 4.7 kg m-2; VO2peak: 36.7 ± 6.1 ml kg-1 min-1 (mean ± SE)) completed nine sessions of repeated (four to eight) 30-s bouts of maximal exercise on a non-motorized treadmill (RUN), cycle ergometer (CYC), or plyometrics platform (JMP) over 21 days. Prior to and following completion of SIT, peak oxygen uptake (VO2peak) and time to exhaustion at 80% VO2peak were measured. Additionally, blood and skeletal muscle was sampled prior to and following completion of SIT to measure PEDF and VEGF. RESULTS: Three weeks of SIT increased time to exhaustion (40.0 min ± 3.2 vs.51.3 ± 5.5 min, P = 0.006). The interaction with exercise modality did not achieve statistical significance (P = 0.08), however, it appears that time to exhaustion increased in the RUN (43.2 ± 5.2 vs. 57.4 ± 9.2 min) and CYC (41.7 ± 6.1 vs. 62.3 ± 11.6 min) groups, but not the JMP group (35.5 ± 5.6 vs. 35.0 ± 4.9 min). Circulating and skeletal muscle VEGF and PEDF were not altered by three weeks of SIT (P > 0.05). DISCUSSION: Independent of exercise modality, three weeks of SIT improves endurance exercise capacity and does not alter circulating or skeletal muscle PEDF or VEGF.