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

SIMPLE SUMMARY: We conducted this study to see whether HIIT and MICT can significantly decrease inflammatory markers through improving body composition in BCS. As such, these practical studies have a high degree of utility for the readership of this journal since most cancer survivors are afraid to perform physical activities. Although HIIT and MICT are effective strategies for improving inflammation, body composition, and physical fitness in BCS, our findings suggest that HIIT is superior to MICT in attenuating TNF-α and leptin as well as improving BM, FM, and LBS. ABSTRACT: Background: Chronic inflammation associated with breast cancer (BC) poses a major challenge in care management and may be ameliorated by physical activity. This randomized controlled trial assessed the effects of a 12-week high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on inflammatory markers, body composition, and physical fitness in BC survivors (BCS). Methods: Forty BCS (age = 57 ± 1 years; body mass [BM] = 74.8 ± 1.5 kg; VO(2peak) = 20.8 ± 2.1 mL·kg(−1)·min(−1)) were randomly assigned to three groups: HIIT (n = 15), MICT (n = 15), or control (CON; n = 15). The intervention groups (HIIT and MICT) performed their respective exercise protocols on a cycle ergometer 3 days/week for 12 weeks while the CON group maintained their current lifestyle. Baseline and post-intervention assessments included body composition (BM, fat mass (FM), lean mass (LM)), physical fitness (VO(2peak), lower body strength (LBS), upper body strength (UBS)), and serum concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), leptin, and adiponectin. Results: Both intervention groups significantly (p < 0.05) decreased BM (HIIT = −1.8 kg, MICT = −0.91 kg), FM (HIIT = −0.81 kg, MICT = −0.18 kg), TNF-α (HIIT = −1.84 pg/mL, MICT = −0.99 pg/mL), IL-6 (HIIT = −0.71 pg/mL, MICT = −0.36 pg/mL), leptin (HIIT = −0.35 pg/mL, MICT = −0.16 pg/mL) and increased VO(2peak) (HIIT = 0.95 mL·kg(−1)·min(−1), MICT = 0.67 mL·kg(−1)·min(−1)), LBS (HIIT = 2.84 kg, MICT = 1.53 kg), UBS (HIIT = 0.53 kg, MICT = 0.53 kg), IL-10 (HIIT = 0.63 pg/mL, MICT = 0.38 pg/mL), and adiponectin (HIIT = 0.23 ng/mL, MICT = 0.1 ng/mL) compared to baseline. The changes in BM, FM, TNF-α, leptin, and LBS were significantly greater in HIIT compared to all other groups. Conclusions: Our findings indicate that compared to the often-recommended MICT, HIIT may be a more beneficial exercise therapy for the improvement of inflammation, body composition and LBS in BCS; and consequently, merits long-term study