Cardiorespiratory fitness (CRF) mitigates age-related decline in cognition and brain volume. Little is known, however, about the effects of high-intensity interval training (HIIT) on cognitive aging and the relationship between HIIT, cognition, hippocampal subfield volumes, and cerebral oxygen extraction fraction (OEF). Older sedentary women participated in an 8-week HIIT intervention. We conducted cognitive assessments, fitness assessments (VO₂max), MRI scans: asymmetric spin echo oxygen extraction fraction (ASE-OEF), high-resolution multiple image co-registration and averaging (HR-MICRA) imaging, and transcranial Doppler ultrasonography before and after the intervention. VO₂max increased from baseline (M = 19.36, SD = 2.84) to follow-up (M = 23.25, SD = 3.61), Z = − 2.93, p < .001, r = 0.63. Composite cognitive (Z = − 2.05, p = 0.041), language (Z = − 2.19, p = 0.028), and visuospatial memory (Z = − 2.22, p = 0.026), z-scores increased significantly. Hippocampal subfield volumes CA1 and CA3 dentate gyrus and subiculum decreased non-significantly (all p > 0.05); whereas a significant decrease in CA2 (Z = − 2.045, p = 0.041, r = 0.436) from baseline (M = 29.51; SD = 24.50) to follow-up (M = 24.50; SD = 13.38) was observed. Right hemisphere gray matter was correlated with language z-scores (p = 0.025; r = 0.679). The subiculum was correlated with attention (p = 0.047; r = 0.618) and verbal memory (p = 0.020; r = 0.700). The OEF and CBF were unchanged at follow-up (all p > .05). Although we observed cognitive improvements following 8 weeks of our HIIT intervention, they were not explained by hippocampal, OEF, or CBF changes.

心肺健康 （CRF） 可缓解与年龄相关的认知和脑容量下降。然而，关于高强度间歇训练 （HIIT） 对认知衰老的影响以及 HIIT、认知、海马子场体积和脑氧提取分数 （OEF） 之间的关系知之甚少。久坐不动的老年女性参加了为期 8 周的 HIIT 干预。我们在干预前后进行了认知评估、体能评估 （VO₂max）、MRI 扫描：不对称自旋回波氧提取分数 （ASE-OEF） 、高分辨率多图像共同配准和平均 （HR-MICRA） 成像以及经颅多普勒超声检查。VO₂max 从基线 （M = 19.36，SD = 2.84） 到随访 （M = 23.25，SD = 3.61） 增加，Z = − 2.93，p < .001，r = 0.63。 复合认知 （Z = − 2.05， p = 0.041）、语言 （Z = − 2.19， p = 0.028） 和视觉空间记忆 （Z = − 2.22， p = 0.026），z 分数显着增加。海马子区体积 CA1 和 CA3 齿状回和下眼减少不显著 （均 p > 0.05）;而 CA2 （Z = − 2.045，p = 0.041，r = 0.436） 较基线 （M = 29.51; SD = 24.50） 进行随访 （M = 24.50;SD = 13.38）。右半球灰质与语言 z 分数相关 （p = 0.025;r = 0.679）。子眼与注意力相关 （p = 0.047;r = 0.618） 和语言记忆 （p = 0.020;r = 0.700）。 随访时 OEF 和 CBF 保持不变 （均 p > .05）。尽管我们在 HIIT 干预 8 周后观察到认知改善，但这些改善并不能用海马、 OIF 或 CBF 变化来解释。