It has been suggested that the time spent at a high stroke volume (SV) is important for improving maximal cardiac function. The aim of this study was to examine the effect of recovery intensity on cardiovascular parameters during a typical high-intensity interval training (HIIT) session in fourteen well-trained cyclists. Oxygen consumption (VO₂), heart rate (HR), SV, cardiac output (Qc), and oxygenation of vastus lateralis (TSI) were measured during a HIIT (3×3-min work period, 2 min of recovery) session on two occasions. VO₂, HR and Qc were largely higher during moderate-intensity (60%) compared with low-intensity (30%) (VO₂, effect size; ES = +2.6; HR, ES = +2.8; Qc, ES = +2.2) and passive (HR, ES = +2.2; Qc, ES = +1.7) recovery. By contrast, there was no clear difference in SV between the three recovery conditions, with the SV during the two active recovery periods not being substantially different than during exercise (60%, ES = –0.1; 30%, ES = –0.2). To conclude, moderate-intensity recovery may not be required to maintain a high SV during HIIT.

• Moderate-intensity recovery periods may not be necessary to maintain high stroke volume during the exercise intervals of HIIT.

• Stroke volume did not surpass the levels attained during the exercise intervals during the recovery periods of HIIT.

• The practical implication of these finding is that reducing the intensity of the recovery period during a HIIT protocol may prolong the time to exhaustion, potentially allowing completion of additional high-intensity intervals increasing the time accumulated at maximal cardiac output.