KITE Research Institute, Toronto Rehabilitation Institute, University Health Network Toronto ON Canada.
Rehabilitation Sciences Institute, University of Toronto ON Canada.
J Am Heart Assoc. 2023 Nov 21;12(22):e031532. doi: 10.1161/JAHA.123.031532. Epub 2023 Nov 10.
The exercise strategy that yields the greatest improvement in both cardiorespiratory fitness () and walking capacity poststroke has not been determined. This study aimed to determine whether conventional moderate-intensity continuous training (MICT) or high-intensity interval training (HIIT) have different effects on and 6-minute walk distance (6MWD).
In this 24-week superiority trial, people with poststroke gait dysfunction were randomized to MICT (5 days/week) or HIIT (3 days/week with 2 days/week of MICT). MICT trained to target intensity at the ventilatory anaerobic threshold. HIIT trained at the maximal tolerable treadmill speed/grade using a novel program of 2 work-to-recovery protocols: 30:60 and 120:180 seconds. V̇O and heart rate was measured during performance of the exercise that was prescribed at 8 and 24 weeks for treatment fidelity. Main outcomes were change in and 6MWD. Assessors were blinded to the treatment group for but not 6MWD. Secondary outcomes were change in ventilatory anaerobic threshold, cognition, gait-economy, 10-meter gait-velocity, balance, stair-climb performance, strength, and quality-of-life. Among 47 participants randomized to either MICT (n=23) or HIIT (n=24) (mean age, 62±11 years; 81% men), 96% completed training. In intention-to-treat analysis, change in for MICT versus HIIT was 2.4±2.7 versus 5.7±3.1 mL·kg·min (mean difference, 3.2 [95% CI, 1.5-4.8]; <0.001), and change in 6MWD was 70.9±44.3 versus 83.4±53.6 m (mean difference, 12.5 [95% CI, -17 to 42]; =0.401). HIIT had greater improvement in ventilatory anaerobic threshold (mean difference, 2.07 mL·kg·min [95% CI, 0.59-3.6]; =0.008). No other between-group differences were observed. During V̇O monitoring at 8 and 24 weeks, MICT reached 84±14% to 87±18% of while HIIT reached 101±22% to 112±14% of (during peak bouts).
HIIT resulted in more than a 2-fold greater and clinically important change in than MICT. Training to target (ventilatory anaerobic threshold) during MICT resulted in ~3 times the minimal clinically important difference in 6MWD, which was similar to HIIT. These findings show proof of concept that HIIT yields greater improvements in cardiorespiratory fitness than conventional MICT in appropriately screened individuals.
URL: https://www.clinicaltrials.gov; Unique identifier: NCT03006731.
目前尚未确定能够最大程度提高心肺适应能力和脑卒中后步行能力的运动策略。本研究旨在比较常规中等强度持续训练（MICT）和高强度间歇训练（HIIT）对心肺适应能力和 6 分钟步行距离（6MWD）的影响。
在这项为期 24 周的优效性试验中，患有脑卒中后步态功能障碍的患者被随机分为 MICT（每周 5 天）或 HIIT（每周 3 天，其中 2 天进行 MICT）组。MICT 以目标强度训练至通气无氧阈。HIIT 以最大耐受跑步机速度/坡度进行训练，使用一种新的 2 种工作-恢复期方案：30:60 和 120:180 秒。在第 8 周和第 24 周对规定的运动进行 V̇O 和心率测量，以评估治疗的一致性。主要结局为心肺适应能力和 6MWD 的变化。评估人员对 MICT 组（n=23）和 HIIT 组（n=24）的治疗效果保持盲态，但对 6MWD 除外。次要结局为通气无氧阈、认知功能、步态经济性、10 米步行速度、平衡、爬楼梯能力、力量和生活质量的变化。在 47 名随机分为 MICT 组（n=23）或 HIIT 组（n=24）的参与者中（平均年龄 62±11 岁；81%为男性），96%的患者完成了训练。在意向治疗分析中，MICT 组与 HIIT 组心肺适应能力的变化分别为 2.4±2.7 和 5.7±3.1 mL·kg·min（平均差值 3.2[95%CI 1.5-4.8]；<0.001），6MWD 的变化分别为 70.9±44.3 和 83.4±53.6 m（平均差值 12.5[95%CI -17 至 42]；=0.401）。HIIT 组在通气无氧阈方面的改善更为显著（平均差值 2.07 mL·kg·min[95%CI 0.59-3.6]；=0.008）。未观察到其他组间差异。在第 8 周和第 24 周的 V̇O 监测期间，MICT 组达到了 84±14%至 87±18%的峰值，而 HIIT 组达到了 101±22%至 112±14%的峰值（在峰值时）。
HIIT 导致心肺适应能力的改善程度比 MICT 高 2 倍以上，且具有临床意义。在 MICT 期间以目标值（通气无氧阈）进行训练，可使 6MWD 的最小临床重要差异达到 3 倍以上，与 HIIT 相似。这些发现为 HIIT 在适当筛选的人群中比传统的 MICT 更能提高心肺适应能力提供了证据。
