# The Effects of High-Intensity Interval Training vs. Moderate-Intensity Continuous Training on Inflammatory Markers, Body Composition, and Physical Fitness in Overweight/Obese Survivors of Breast Cancer: A Randomized Controlled Clinical Trial PMID: 34503198 Journal: Cancers Published: 2021-08-30 Authors: Hooshmand Moghadam B, Golestani F, Bagheri R, Cheraghloo N, Eskandari M, Wong A, Nordvall M, Suzuki K, Pournemati P ## Question Does supervised 12-week cycling HIIT improve inflammatory markers, body composition, and physical fitness in overweight or obese breast cancer survivors more than moderate-intensity continuous training or usual lifestyle control? ## Summary This randomized trial tested whether 12 weeks of supervised cycling HIIT or moderate continuous cycling could improve inflammation, body composition, and fitness in sedentary overweight or obese postmenopausal breast cancer survivors. Both exercise groups improved several inflammatory markers, body weight, fat mass, VO2peak, and strength compared with baseline and control. HIIT produced larger improvements than MICT for body mass, fat mass, TNF-alpha, leptin, and lower-body strength, with no adverse side effects reported and 86.6% training adherence. ## Population - Sedentary overweight/obese postmenopausal female breast cancer survivors at least six months after treatment. - Sample size: 40 - Age: Mean about 57 years; inclusion 50-75 years. - Sex: Female - Fitness level: Sedentary, low VO2peak. - Health status: Breast cancer survivors, stage I-III at diagnosis, BMI at least 25 kg/m2 and body fat percentage greater than 30%. ## Methodology - Three-arm randomized controlled trial comparing HIIT, MICT, and lifestyle control. - 12 weeks - Supervised laboratory cycle-ergometer exercise in Iran with medical clearance and pre/post laboratory assessments. - Randomized and controlled study design. ## Protocol - HIIT. - Modality: Cycle ergometer. - Work intervals: 30 seconds. - Recovery: 2 minutes active recovery. - Sets or repetitions: 4 progressing to 7 intervals. - Intensity: 95-115 rpm and at least 90% maximum target HR by the fourth interval. - Session duration: 20-30 minutes including warm-up and cool-down. - Frequency: 3 days/week. - Program length: 12 weeks. - Progression: Add one interval per week until seven intervals by week 4, then maintain. - MICT and control. - Modality: Cycle ergometer for MICT; usual lifestyle for control. - Work intervals: 20-minute continuous conditioning period for MICT. - Sets or repetitions: One continuous bout. - Intensity: 55-65% peak power or Borg 9-13. - Session duration: 30 minutes including 5-minute warm-up and 5-minute cool-down. - Frequency: 3 days/week for MICT. - Program length: 12 weeks. - Progression: Intensity adjusted to maintain prescribed range. ## Outcomes ### Inflammatory markers Status: improved HIIT and MICT reduced IL-6, TNF-alpha, and leptin and increased IL-10 and adiponectin; HIIT was superior to MICT/control for TNF-alpha and leptin. HIIT TNF-alpha -1.84 pg/mL, MICT -0.99 pg/mL; HIIT leptin -0.35 ng/mL, MICT -0.16 ng/mL; HIIT post values significantly favored versus MICT and control for TNF-alpha and leptin. ### Body composition Status: improved HIIT and MICT reduced body mass and fat mass; HIIT produced greater reductions than MICT and control. HIIT body mass -1.8 kg and fat mass -0.81 kg; MICT body mass -0.91 kg and fat mass -0.18 kg; ANCOVA favored HIIT for body mass and fat mass. ### VO2peak Status: improved Both exercise groups improved VO2peak versus control, with no significant difference between HIIT and MICT. HIIT +0.95 mL/kg/min, MICT +0.67 mL/kg/min; both differed from control, not from each other. ### Safety/adherence Status: improved Training adherence was high and no adverse side effects were reported. Adherence across HIIT and MICT was 86.6%; no adverse side effects reported. ## Practical Insights - A low hard-work dose, progressed from 2 to 3.5 minutes of hard cycling per session, can still produce measurable benefits in a supervised clinical population. - Long active recovery after short 30-second efforts may be a useful tolerance strategy for lower-fitness or clinical users. - Cancer survivor HIIT content should emphasize screening, clearance, and supervision rather than presenting the protocol as universally self-directed. ## Limitations - Small sample size. - Bioelectrical impedance body-composition measurement. - No long-term follow-up. - Specific postmenopausal breast cancer survivor population limits generalization. ## Safety And Adherence - No adverse side effects were reported. - Participants were medically screened and supervised. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/34503198/) (pubmed) - [DOI](https://doi.org/10.3390/cancers13174386) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8430701/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.