HIITING CANCER BACK: THE EFFECTS OF ONE MONTH OF HIGH INTENSITY INTERVAL TRAINING ON INFLAMMATION, BODY COMPOSITION, AND CARDIORESPIRATORY FITNESS IN CANCER SURVIVORS

Abstract

Chronic inflammation, low fitness, and unfavourable body composition are often side effects of anti-cancer therapies and are associated with an increased risk of cancer recurrence. However, the response of these variables to high intensity interval training (HIIT), and the relationship among these predictors of cancer recurrence, is yet to be explored in cancer survivors. The aim of this study was to investigate the effect of one month of HIIT on inflammation, body composition, and cardiorespiratory fitness and explore the relationships among these variables in breast, prostate, and colorectal cancer survivors. Survivors (n=131) of breast, prostate, and colorectal cancer (60.1±10.3 years, 26.9±4.9 kg/m2, 67% female) completed one month of HIIT (12 sessions: 4x4min at 85-95% peak heart rate (HRpeak), interspersed with 3-minutes at 50-75% HRpeak). Body composition via dual-energy X-ray absorptiometry, cardiorespiratory fitness via V̇O2peak, and fasted blood were measured at baseline and at one month. Blood was analysed for inflammatory factors (interleukin (IL)-6, IL-10), and tumour necrosis factor alpha (TNF-α)). HIIT resulted in significant reductions in IL-6, IL-10, TNF-α (-37-39%, p<0.001) and significant increases in leg lean mass (+400g, p=0.008) and absolute V̇O2peak (+0.2 L/min, p<0.001). Despite this, the only significant association among the changes in these variables was a weak correlation between IL-10 and absolute V̇O2peak (rs=0.256, p=0.013). One month of HIIT elicited significant improvement in markers of systemic inflammation, body composition, and cardiorespiratory fitness. However, improvements in these variables were not strongly related and occur independent of each other. The findings of this study demonstrate 4x4 HIIT is an effective prescriptive tool to elicit rapid improvements in physiological markers, through apparent independent pathways. Therefore, exercise physiologists working with cancer survivors should consider utilising 4x4 HIIT to their exercise prescriptions as a time efficient means to reduce the risk of cancer recurrence and improve survivorship.