Comparison of the effects of high-intensity interval and moderate-intensity continuous training on inflammatory markers, cardiorespiratory fitness, and quality of life in breast cancer patients
Question
Do supervised HIIT and MICT differ in their effects on inflammatory indices, adipokines, metabolic markers, body composition, cardiorespiratory fitness, and quality of life in breast cancer patients during adjuvant endocrine therapy?
Summary
This three-arm randomized controlled trial compared 12 weeks of supervised, volume-matched HIIT, MICT, and usual care in inactive women with non-metastatic breast cancer receiving adjuvant endocrine therapy after chemotherapy and/or radiotherapy. HIIT improved VO2peak more than MICT or control and both exercise groups improved several quality-of-life domains, but most inflammatory, adipokine, metabolic, body-composition, and sex-hormone outcomes did not differ meaningfully between groups. Adherence was high and no serious adverse events were reported, but the study was small and clinically specific.
Methodology
- Thirty inactive women with non-metastatic stage I-III breast cancer receiving adjuvant endocrine therapy after chemotherapy and/or radiotherapy.
- 30 participants.
- Treadmill walking or running.
- Work intervals: 4 minutes.
- Recovery: 3 minutes active walking recovery.
- Intensity: 90% VO2peak, corresponding to about 95% HRpeak.
- 33 minutes including 5-minute warm-up and 3-minute cool-down.
- 3 sessions/week.
- 12 weeks.
- Single randomized controlled trial with three parallel groups: HIIT, MICT, and usual-care control.
- Inflammatory cytokines and adipokines, Cardiorespiratory fitness, Quality of life, and Body composition and anthropometry were tracked.
Outcomes
VO2peak
HIIT increased VO2peak by 16.8% from baseline and improved VO2peak versus both control and MICT.
HIIT baseline-to-post mean difference 3.61 mL/kg/min, p=0.023; HIIT vs control mean difference 3.609 mL/kg/min, p=0.001; HIIT vs MICT mean difference 2.974 mL/kg/min, p=0.005.
HDL-C
Both HIIT and MICT increased HDL-C compared with control, with no HIIT-MICT difference.
Between-group p=0.005; HIIT vs control mean difference 9.172 mg/dL, p=0.003; MICT vs control mean difference 7.879 mg/dL, p=0.014.
Inflammatory markers and adipokines
Most inflammatory and adipokine markers did not significantly change; SOCS3 increased in the HIIT group from baseline.
No significant changes in IL-6, TNF-alpha, IL-10, leptin, or adiponectin; HIIT SOCS3 mean difference 0.09 pg/mL, p=0.032.
Quality of life
HIIT improved social, emotional, functional, and total FACT-G outcomes compared with control; both exercise groups improved total FACT-G versus control.
Total FACT-G between-group p=0.001; HIIT vs control mean difference 14.204, p=0.001; MICT vs control mean difference 10.036, p=0.001.
Body composition
Neither HIIT nor MICT produced substantial changes in body weight, BMI, fat mass, body fat percentage, waist circumference, or hip circumference.
Between-group p values included body weight p=0.613, BMI p=0.497, fat mass p=0.255, waist circumference p=0.397.
Safety
Muscle soreness and joint pain were reported, but no serious adverse events occurred.
Insights
- A supervised 4 x 4-minute HIIT format can improve VO2peak in medically screened breast cancer patients over 12 weeks.
- Clinical HIIT claims should focus on fitness and quality of life rather than inflammation, metabolic markers, or body composition.
- The protocol is reproducible but requires clinical screening, HR/RPE monitoring, and conservative safety rules.
- High adherence in this study occurred under close supervision and should not be assumed for unsupervised consumer workouts.
Limitations
- Small sample size with only 10 participants per group.
- Body composition was measured by skinfold thickness rather than DXA or hydrostatic weighing.
- No diet recommendations were provided.
- No long-term follow-up or clinical oncology endpoints.
- Clinical population and supervised treadmill setting limit generalization to ordinary app users.
Safety
- Muscle soreness and joint pain were reported as possibly related to participation.
- No serious adverse events were reported.
- The study used medical screening and day-of-session exclusion criteria for abnormal vital signs, infection, bleeding signs, thrombocyte count, and leucocyte count.