The aim of this study was to compare the effects of two high-intensity interval training (HIT) programmes on maximal oxygen uptake (over(V, ̇) O2 max), the lactate threshold (LT) and 3000 m running performance in moderately trained male runners. over(V, ̇) O2max, the running speed associated with over(V, ̇) O2max (vover(V, ̇) O2 max), the time for which vover(V, ̇) O2 max can be maintained (Tmax), the running speed at LT (vLT) and 3000 m running time (3000mTT) were determined before and following three different training programmes performed for 10 weeks. Following the pre-test, 17 moderately trained male runners (over(V, ̇) O2max = 51.6 ± 2.7 ml k g- 1 mi n- 1) were divided into training groups based on their 3000mTT (Group 1, G1, N = 6, 8× 60% of Tmax at vover(V,̇) O2 max, 1:1 work:recovery ratio; Group 2, G2, N = 6, 12× 30s at 130% vover(V, ̇) O2max, 4.5 min recovery; control group, GCON, N = 5, 60 min at 75% vover(V, ̇) O2 max). G1 and G2 performed two HIT sessions and two 60 min recovery run sessions (75% vover(V, ̇) O2max) each week. Control subjects performed four 60 min recovery run sessions (75% vover(V, ̇) O2 max) each week. In G1, significant improvements (p < 0.05) following HIT were found in over(V, ̇) O2 max (+9.1%), vover(V, ̇) O2 max (+6.4%), Tmax (5%), vLT (+11.7%) and 3000mTT (-7.3%). In G2, significant improvements (p < 0.05) following HIT were found in over(V, ̇) O2 max (+6.2%), vover(V, ̇) O2max (+7.8%), Tmax (+32%) and 3000mTT (-3.4%), but not in vLT (+4.7%; p = 0.07). No significant changes in these variables were found in GCON. The present study has shown that 3000 m running performance, over(V, ̇) O2 max, vover(V, ̇) O2 max, Tmax and vLT can be significantly enhanced using different HIT programmes in moderately trained runners, but that changes in performance and physiological variables may be more profound using prolonged HIT at intensities of vover(V, ̇) O2max with interval durations of 60% Tmax. © 2006 Sports Medicine Australia.
