Interval Walking Improves Glycemic Control and Body Composition After Cancer Treatment: A Randomized Controlled Trial.

CONTEXT: Patients with colorectal cancer have increased risk of metabolic diseases including diabetes. Exercise training may counteract metabolic dysregulation, but the impact of exercise training on glycemic control, including postprandial glycemia, has never been explored in patients with colorectal cancer. OBJECTIVE: To examine the effects of home-based interval walking on aerobic and metabolic fitness and quality of life in patients with colorectal cancer. DESIGN: Randomized controlled trial. SETTING: Clinical research center. PARTICIPANTS: Thirty-nine sedentary (<150 minutes moderate-intensity exercise per week) patients with stage I to III colorectal cancer who had completed primary treatment. INTERVENTION: Home-based interval walking 150 min/wk or usual care for 12 weeks. MAIN OUTCOME MEASURES: Changes from baseline to week 12 in maximum oxygen uptake (VO2peak) by cardiopulmonary exercise test, glycemic control by oral glucose tolerance test (OGTT), body composition by dual-energy x-ray absorptiometry scan, blood biochemistry, and quality of life. RESULTS: Compared with control, interval walking had no effect on VO2peak [mean between-group difference: -0.32 mL O2 · kg-1 · min-1 (-2.09 to 1.45); P = 0.721] but significantly improved postprandial glycemic control with lower glucose OGTT area under the curve [-126 mM · min (-219 to -33); P = 0.009], 2-hour glucose concentration [-1.1 mM (-2.2 to 0.0); P = 0.056], and improved Matsuda index [1.94 (0.34; 3.54); P = 0.01]. Also, interval walking counteracted an increase in fat mass in the control group [-1.47 kg (-2.74 to -0.19); P = 0.025]. CONCLUSION: A home-based interval-walking program led to substantial improvements in postprandial glycemic control and counteracted fat gain in posttreatment patients with colorectal cancer, possibly providing an effective strategy for prevention of secondary metabolic diseases.

The "Interval Walking in Colorectal Cancer" (I-WALK-CRC) study: Design, methods and recruitment results of a randomized controlled feasibility trial.

BACKGROUND: Low physical activity level is associated with poor prognosis in patients with colorectal cancer (CRC). To increase physical activity, technology-based platforms are emerging and provide intriguing opportunities to prescribe and monitor active lifestyle interventions. The "Interval Walking in Colorectal Cancer"(I-WALK-CRC) study explores the feasibility and efficacy a home-based interval-walking intervention delivered by a smart-phone application in order to improve cardio-metabolic health profile among CRC survivors. The aim of the present report is to describe the design, methods and recruitment results of the I-WALK-CRC study.Methods/Results: The I-WALK-CRC study is a randomized controlled trial designed to evaluate the feasibility and efficacy of a home-based interval walking intervention compared to a waiting-list control group for physiological and patient-reported outcomes. Patients who had completed surgery for local stage disease and patients who had completed surgery and any adjuvant chemotherapy for locally advanced stage disease were eligible for inclusion. Between October 1st, 2015, and February 1st, 2017, 136 inquiries were recorded; 83 patients were eligible for enrollment, and 42 patients accepted participation. Age and employment status were associated with participation, as participants were significantly younger (60.5 vs 70.8 years, P < 0.001) and more likely to be working (OR 5.04; 95%CI 1.96-12.98, P < 0.001) than non-participants. CONCLUSION: In the present study, recruitment of CRC survivors was feasible but we aim to better the recruitment rate in future studies. Further, the study clearly favored younger participants. The I-WALK-CRC study will provide important information regarding feasibility and efficacy of a home-based walking exercise program in CRC survivors.