The Effect Of High-intensity Interval Training On Cardiorespiratory Fitness For Non-ambulatory Stroke Survivors: A Randomized Controlled Trial

Objective:To explore the effects of high-intensity interval training（HIIT）as an aerobic training technique for improving cardiorespiratory fitness compared with low-intensity continuous training（LICT）in non-ambulatory stroke patients through a randomized controlled trial.The aim was to provide a new aerobic exercise protocol to improve the cardiorespiratory function of stroke patients.Methods:Non-ambulatory patients with ischemic or hemorrhagic stroke were selected as the study subjects,and were randomly assigned to either the experimental group or the control group using a random number table.Participants in the intervention group underwent HIIT,and those in the control group underwent LICT.The training protocol was repeated five times per week for four consecutive weeks（20 training sessions）.The patients were assessed before and after the intervention.The primary outcome measure was peak oxygen uptake(VO_2peak).The secondary outcomes were stroke volume（SV）,cardiac output（CO）,Barthel index（BI）,and Fugl-Meyer assessment lower limb（FMA-LL）.Results:A total of 65 patients were selected for the study,with 11 patients dropping out early and 7 patients having missing data during the study.The final statistical analysis included 54 participants.No differences were found between the two groups at baseline for clinical messages or functional levels（P>0.05）.VO_2peak significantly improved in the LICT group（P=0.025）,whereas there was no significant difference in the HIIT group（P=0.978）.The score of BI and FMA-LL of both groups significantly improved after 4 weeks of intervention,while the improvement in other secondary outcomes(SV,CO,VO_2AT)was not significant.In the HIIT group,the change scores in VO_2peak（P<0.001）and VO_2AT（P=0.003）were significantly greater in the good compliance subgroup than in the poor compliance subgroup.There was a significant difference in change score in VO_2peak between the good compliance subgroups in the LICT and HIIT groups（P=0.036）.Conclusion:HIIT can significantly improve the cardiorespiratory fitness of non-ambulatory stroke patients with good compliance.Compliance is an important factor affecting the cardiorespiratory rehabilitation effect after stroke.