# Supervised high-intensity interval training reduces the negative effect of chemotherapy on cardiorespiratory fitness in young breast cancer women: a randomised controlled study PMID: 40471270 Journal: European Journal of Applied Physiology Published: 2025-11-01 Authors: Dudek M, Górecki M, Marszałek S, Kufel-Grabowska J, Litwiniuk M, Nowak A, Bartczak-Rutkowska A, Doś J, Marszałek A, Nowaczyk P, Lembryk M, Piotrowski I, Rosochowicz MA, Suchorska W, Lesiak M, Straburzyńska-Migaj E ## Question Whether supervised HIIT performed concurrently with chemotherapy affects cardiorespiratory fitness and cardiovascular measures in young breast cancer patients during the preoperative period. ## Summary In young women with breast cancer receiving neoadjuvant chemotherapy, a 6-month supervised HIIT program delivered during chemotherapy reduced the chemotherapy-associated decline in cardiorespiratory fitness compared with usual activity guidance. Relative peak VO2 and exercise time still declined, but the decline was smaller in the HIIT group, and no exercise-related adverse events were observed. ## Population - Young women aged 18-40 with histopathologically confirmed breast cancer scheduled for neoadjuvant chemotherapy. - Sample size: 26 - Age: 18-40 years; mean 34.33 years among completers - Sex: Female - Fitness level: ECOG 0-1; baseline relative peak VO2 33.630 mL/kg/min in HIIT and 29.679 mL/kg/min in control. - Health status: Breast cancer patients qualified for neoadjuvant chemotherapy with preserved LVEF > 50% and required normal marrow, liver, and kidney labs. ## Methodology - Open-label, parallel, randomized controlled study. - 6 months during neoadjuvant chemotherapy, with baseline and end-of-treatment assessments - Greater Poland Cancer Centre, Poznan; supervised group training with a trained physiotherapist plus CPET and impedance cardiography assessment - Randomized and controlled study design. ## Protocol - Supervised HIIT during chemotherapy. - Modality: Circuit using treadmill, elliptical bike, cycloergometer, rowing machine, and endurance stepper. - Work intervals: Month 1: 1 min 15 s; month 2: 1 min 30 s; months 3-4: 1 min 45 s; months 5-6: 2 min. - Recovery: 4 min active walking recovery to lower HR to about 120 bpm. - Sets or repetitions: 4 sets in month 1; 5 sets in months 2-6. - Intensity: 75% HRmax in month 1; 80%-90% HRmax in months 2-6. - Session duration: About 40 min. - Frequency: 2 supervised sessions/week plus one 45-min individual aerobic session/week. - Program length: 6 months. - Progression: Increased training load, number of stations, intensity, and work-bout duration across mesocycles. - Control physical activity guidance. - Modality: Patient-selected aerobic activity. - Intensity: WHO guidance: 150-300 min/week moderate aerobic activity or 75-150 min/week vigorous aerobic activity. - Frequency: Weekly activity guidance, no supervised training. - Program length: Throughout chemotherapy for 6 months. ## Outcomes ### Relative peak VO2 Status: mixed Peak VO2 declined in both groups after chemotherapy, but the decrease was significantly smaller in the HIIT group than in control. HIIT 33.630 to 29.540 mL/kg/min; control 29.679 to 22.571 mL/kg/min; ANCOVA p = 0.018, ES = 0.469. ### Exercise time Status: improved Control group exercise time decreased substantially, while HIIT group exercise time was largely maintained. HIIT 685.600 to 666.500 s; control 703.357 to 555.500 s; ANCOVA p = 0.008, ES = 0.815. ### Ventilatory anaerobic threshold Status: no clear change Only the HIIT group showed a significant within-group decrease, but there was no significant between-group difference. No significant difference between CTR and HIIT groups. ### Resting cardiac output/hemodynamic parameters Status: mixed HIIT group showed decreased SV and SVi after chemotherapy; control showed increased SVR and SVRi; between-group differences were not significant. No between-group difference noted for SV/SVi; no statistically significant between-group differences for CPET parameters measured at rest. ### Exercise-related adverse events Status: no clear change No adverse events related to exercise intervention were observed in the HIIT group. ## Practical Insights - For medically cleared young breast cancer patients, supervised HIIT during chemotherapy may attenuate loss of cardiorespiratory fitness. - Clinical HIIT programming should use supervision, heart-rate monitoring, gradual progression, and recovery criteria. - For consumer HIIT content, this paper should be used as condition-specific background rather than direct workout prescription. ## Limitations - Single-centre study. - Small sample size. - No dietary habit data. - No extended follow-up period. - Open-label design and clinical special population. ## Safety And Adherence - No adverse events related to exercise intervention were observed in the HIIT group. - Eligibility was determined by an oncologist and cardiologist before group allocation. - Heart rate was monitored during every supervised training session. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/40471270/) (pubmed) - [DOI](https://doi.org/10.1007/s00421-025-05822-1) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12528350/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.