Published online Feb 10, 2018. doi: 10.5306/wjco.v9.i1.1
Peer-review started: November 23, 2017
First decision: December 27, 2017
Revised: December 31, 2017
Accepted: January 23, 2018
Article in press: January 23, 2018
Published online: February 10, 2018
Processing time: 77 Days and 3.9 Hours
Research into the optimum exercise guidelines for cancer survivors are not conclusive. Little evidence exists for the use of low-volume high-intensity interval training (LVHIIT) within the cancer population, even though it shows promise in other chronic populations. LVHIIT has been used in populations such as stroke, diabetes, cardiovascular disease (CVD), cardiac rehabilitation showing more pronounced health benefits than the more commonly prescribed continuous low-moderate intensity training (CLMIT). Therefore, it should be further investigated for use with cancer survivors as it is a time efficient exercise modality, with greater health benefits.
Using LVHIIT in the cancer population shows promise as a more efficient exercise prescription. The encouraging results of this study has opens the possibility of introducing LVHIIT into rehabilitation programs. LVHIIT is a time efficient exercise modality, which could be used to increase the fitness levels in cancer survivors. The LVHIIT protocol in this study improved fitness and functional capacity and decreased waist circumference compared with CLMIT and the control group. Both LVHIIT and CLMIT improved QoL. LVHIIT may be an effective alternative to traditional exercise prescription within this population. The benefit of LVHIIT is that for selected variables it produces more pronounced results compared with CMIT and it is short, which could entice more cancer survivors to participate in exercise as time is a barrier.
To determine the effectiveness of LVHIIT compared to CLMIT and a control group and to determine if LVHIIT and CLMIT improved CVD risk and health outcomes in cancer survivors. The significance of these objectives is that this form of exercise can be used to achieve more pronounced improvements in health outcomes than the commonly prescribed CLMIT.
The experiments and data analysis used in this study were a mix of validated methods used before within this population (6MWT, STS, DXA, hip/waist circumference) and unique protocols which have been used with other populations, but not commonly with cancer survivors (Sphygmocor). The use of the ANCOVA analysis and effect size analysis was chosen due to the robustness that this analysis provides for the data collected.
There were significant improvements in functional capacity, specifically cardiorespiratory fitness, lower-limb strength, and waist circumference in participants who completed the LVHIIT compared with the CLMIT and control groups. QoL improved in both the LVHIIT group and the CLMIT group when compared with the control group, however a greater effect was observed in the LVHIIT group. Additional research is required to fully understand the mechanisms involved in the changes identified in this study in relation to different doses of exercise. This research would be highly beneficial to assist clinicians in the optimisation of clinical exercise recommendations for cancer survivors.
Present exercise guidelines for cancer survivors lack detail on the type, mode, duration and intensity of exercise necessary to achieve best outcomes. This current research was required to fill the gaps in current knowledge to further improve exercise recommendations. LVHIIT is the use of small doses of high-intensity exercise to elicit physiological responses such as improved VO2 max and positive metabolic changes in skeletal muscle which seem greater than the commonly prescribed CLMIT. The LVHIIT physiological changes show potential for use in clinical practice in the rehabilitation of cancer survivors. At present there is limited research examining the effects of LVHIIT in improving health outcomes for cancer survivors. This study shows promise for the use of LVHIIT in the cancer population. The encouraging results opens up the possibility of introducing LVHIIT in therapy programs, as a shorter and more efficacious exercise to increase the fitness levels in cancer survivors. The benefit of LVHIIT is that for selected variables it produces more pronounced results compared with CMIT and it is short in duration which could entice more cancer survivors to participate in exercise. This study highlights that the most commonly prescribed CLMIT may not be enough to induce clinically relevant changes in cancer survivors.
The use of VO2 max testing would be beneficial if it can be tolerated well by cancer survivors post treatment. Future research should analyse ways to measure the mechanisms involved in the changes seen in the study results and clarify how and why these changes occur.