Abstract
BACKGROUND: The aim was to determine the effects of 8 weeks of concurrent training of abbreviated high-intensity interval-training and low–load resistance training (CT(HIIT+RT)) on functional and structural vascular outcomes of breast cancer survivors with a history of high or low exposure to chemotherapy sessions. METHODS: Breast cancer survivor women (n = 21, 58.7 ± 8.7 years) were divided into high– (HV(chemo), n = 11) or low–volume chemotherapy groups (LV(chemo), n = 10). Pulse wave velocity (PWV) and carotid intima–media maximum (cIMT(max)) were the primary outcomes, while flow-mediated dilation (FMD), carotid intima–media average (cIMT(av)), baseline brachial artery diameter (D(base)), peak diameter (D(peak)), and one-repetition maximum tests for the biceps (1RM(bc)), shoulder (1RM(sp)), back (1RM(back)), and leg extension (1RM(Leg)) served as secondary outcomes. RESULTS: PWV decreased in the LV(chemo) group (∆˗1.64 m⋅s(− 1), p < 0.001) but not in the HV(chemo) group. cIMT(max) was reduced only in the HV(chemo) group (∆˗0.23 mm, p = 0.024). FMD was significantly increased in the HV(chemo) (∆+5.06%, p = 0.023) but not in the LV(chemo) group. HV(chemo) and LV(chemo) groups increased D(base) (∆+0.38 mm, p = 0.005; and ∆+0.16 mm, p < 0.0001) and D(peak) (∆+0.32 mm, p = 0.008; and ∆+0.12 mm, p < 0.0001). HV(chemo) and LV(chemo) groups increase 1RM(bc) (∆+2.3 kg; and ∆+2.09 kg), 1RM(sp) (∆+2.15 kg; and ∆+2.36 kg), 1RM(back) (∆+4.4 kg; and ∆+4.58 kg), and 1RM(Leg) (∆+6.15 kg; and ∆+5.27 kg), all p < 0.01. CONCLUSIONS: Eight weeks of CT(HIIT+RT) in women breast cancer survivors who received higher chemotherapy volume reduces cIMT(max), but increases FMD, D(base), D(peak), cardiorespiratory fitness, and muscle strength. Vascular improvements were partially observed in subjects with lower chemotherapy volumes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40659-026-00677-y.