Electronic Thesis and Dissertation Repository


Master of Science




Dr. Peter W.R. Lemon


Sprint interval training (SIT) improves maximal oxygen uptake (V̇O2max) and exercise performance but not maximal cardiac output (Q̇max). The brevity of typical SIT bouts (30-seconds) might hinder improvements in Q̇max. The purpose of this study was to determine whether extended duration SIT (up to 45 second bouts) improves Q̇max. Pre-/Post-SIT (or control) V̇O2max, Q̇max, maximum stroke volume (SVmax), maximum heart rate, arterial-mixed venous oxygen difference, and 5-minute run distance were measured. SIT progressed from 4x30s to 7x45s “all-out” efforts (4 min recovery) over 6 wk (3x/wk) on a manually driven treadmill. Following SIT, V̇O2max improved (pre-=3.6±0.8 vs post=3.8±0.8 L·min-1; p=0.012). Increases in Q̇max (pre-= 26.13±5.09 vs post=27.10±4.82 L·min-1; p=0.166) and SVmax (pre-= 138±27 vs post=144±28 mL·beat-1; p=0.095) were not significant. These data suggest 6 wk of extended SIT bouts (up to 45 s) does not increase Q̇max significantly and the observed increase in V̇O2max was due primarily to non-significant improvements in Q̇max and SVmax.