Does low volume high-intensity interval training elicit superior benefits to continuous low to moderate-intensity training in cancer survivors?

AIM To determine the impact of low volume high-intensity interval training (LVHIIT) and continuous low to moderate-intensity exercise training (CLMIT) on cardiovascular disease (CVD) risk and health outcomes in cancer survivors. METHODS Sedentary cancer survivors (n = 75, aged 51 ± 12 year) within 24 months of diagnosis, were randomised into three groups for 12 wk of LVHIIT (n = 25), CLMIT (n = 25) or control group (n = 25). The exercise intervention involved 36 sessions (three sessions per week). The LVHIIT group performed 7 x 30 s intervals (≥ 85% predicted maximal heart rate) with a 60 s rest between intervals, and the CLMIT group performed continuous aerobic training for 20 min (≤ 55% predicted maximal heart rate) on a stationary bike. Outcome variables were measured at baseline and at 12 weeks and analysed using a 3 x 2 (group x time) repeated measures ANCOVA to evaluate main and interaction effects. RESULTS Significant improvements (time) were observed for seven of the 22 variables (ES 0.35-0.97, P ≤ 0.05). There was an interaction effect (P < 0.01) after 12 wk in the LVHIIT group for six-minute walk test (P < 0.01; d = 0.97; 95%CI: 0.36, 1.56; large), sit to stand test (P < 0.01; d = -0.83; 95%CI: -1.40, -0.22; large ) and waist circumference reduction (P = 0.01; d = -0.48; 95%CI: -1.10, 0.10; medium). An interaction effect (P < 0.01) was also observed for quality of life in both the LVHIIT (d = 1.11; 95%CI: 0.50, 1.72; large) and CLMIT (d = 0.57; 95%CI: -0.00, 1.20; moderate) compared with the control group (d = -0.15; 95%CI: -0.95, 0.65; trivial). CONCLUSION Low-volume high-intensity training shows promise as an effective exercise prescription within the cancer population, showing greater improvements in cardio-respiratory fitness, lower body strength and waist circumference compared with traditional CLMIT and control groups. Both LVHIIT and CLMIT improved quality of life. A proposed benefit of LVHIIT is the short duration (3 min) of exercise required, which may entice more cancer survivors to participate in exercise, improving health outcomes and lowing the risk of CVD.