Purpose: 

The objectives of this study were to compare the effects of two different high-intensity interval training (HIIT) programs (low-volume vs high-volume) on chronotropic responses during exercise and recovery, and to contrast the results of the HIIT groups together to only physical activity recommendations in post-myocardial infarction (MI) patients taking β-blockers.

Methods: 

Resting heart rate (HR_rest), peak HR (HR_peak), HR reserve (HR_reserve = HR_peak-HR_rest), HR recovery (HRR) as the difference between HR_peak and post-exercise HR, and chronotropic incompetence were assessed in 70 patients (58 ± 8 yr) following MI with a cardiopulmonary exercise test to peak exertion before and after a 16-wk exercise intervention period. All participants were randomized to either attention control (AC) (physical activity recommendations) or one of the two supervised HIIT groups (2 d/wk).

Results: 

After the intervention, no significant between-HIIT group differences were observed. The HR_peak increased (P < .05) in low- (Δ= 8 ± 18%) and high-volume HIIT (Δ= 6 ± 9%), with a small decrease in AC (Δ=− 2 ± 12%, P > .05) resulting in large differences (P < .05) between HIIT and AC. The HR_reserve increased (P < .05) in high-volume HIIT. The HRR slightly increased (P < .05) in low-volume (5th min, Δ= 19 ± 31%) and high-volume HIIT (2nd min, Δ= 15 ± 29%, and 5th min, Δ= 19 ± 28%).

Conclusion: 

These findings suggest that both low- and high-volume HIIT elicit similar improvements in chronotropic responses after MI, independent of β-blocker treatment. Supervised HIIT was more effective than giving physical activity recommendations alone. Low-volume HIIT is presented as a potent and time-efficient exercise strategy that could enhance the sympathovagal balance in this population.

中文翻译：

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有氧高强度间歇训练后服用 β 受体阻滞剂的心肌梗塞患者对运动和恢复的变时反应：一项 INTERFARCT 研究

目的： 

本研究的目的是比较两种不同的高强度间歇训练 (HIIT) 计划（低容量与高容量）对运动和恢复期间变时性反应的影响，并将 HIIT 组的结果对比仅对服用 β 受体阻滞剂的心肌梗塞(MI) 患者的身体活动建议。

方法： 

_评估静息心率（HR _rest）、峰值 HR（HR _peak）、HR 储备（HR _Reserve = HR _peak - HR rest ）、HR 恢复（HRR）作为 HR_峰值和运动后 HR之间的差异，以及变时性无能在 70 名患者 (58 ± 8 年) 中，在 16 周运动干预期之前和之后进行心肺运动测试以达到运动峰值。所有参与者被随机分配到注意力控制 (AC) (体育活动建议) 或两个受监督的 HIIT 组之一 (2 d/wk)。

结果： 

干预后，HIIT组间未观察到显着差异。HR_峰值在低容量 (Δ= 8 ± 18%) 和高容量 HIIT (Δ= 6 ± 9%) 中增加 ( P < .05)，AC 有小幅下降 (Δ=− 2 ± 12%, P > .05) 导致HIIT 和 AC 之间存在很大差异 ( P < .05)。高容量 HIIT的 HR_储备增加 ( P < .05)。低容量（第 5 分钟，Δ= 19 ± 31%）和高容量 HIIT（第 2 分钟，Δ= 15 ± 29% 和第 5 分钟，Δ= 19 ± 28）的 HRR 略有增加（P < .05） %）。

结论： 

这些发现表明，低容量和高容量 HIIT 在 MI 后引起类似的变时反应改善，与 β 受体阻滞剂治疗无关。有监督的 HIIT 比单独提供体育活动建议更有效。低容量 HIIT 被认为是一种有效且省时的锻炼策略，可以增强该人群的交感迷走神经平衡。