# Feasibility and acceptability of an mHealth, home-based exercise intervention in colorectal cancer survivors: A pilot randomized controlled trial PMID: 37347792 Journal: PloS one Published: 2023-06-22 Authors: Moraitis AM, Rose NB, Johnson AF, Dunston ER, Garrido-Laguna I, Hobson P, Barber K, Basen-Engquist K, Coletta AM ## Question Is a remotely monitored, home-based mHealth exercise intervention that includes a HIIT prescription feasible and acceptable for stage II-III colorectal cancer survivors within five years after resection and adjuvant therapy? ## Summary This small pilot randomized controlled trial tested a 12-week home-based mHealth exercise intervention in stage II-III colorectal cancer survivors after surgery and adjuvant therapy. Participants were randomized to HIIT or moderate-intensity continuous exercise, remotely monitored with Polar devices. Retention was 100%, workout completion averaged 88.6%, and no adverse events were reported, but only two participants were assigned to HIIT and adherence to the prescribed HIIT heart-rate zones was low because participants often exceeded the target zones. ## Population - Stage II-III colorectal cancer survivors less than five years post-resection and adjuvant chemotherapy, recruited from Huntsman Cancer Institute clinics. - Sample size: 7 - Age: Median 39 years; first quartile 36, third quartile 50. - Sex: 4 male, 3 female overall; HIIT group 2 male, MICE group 3 female and 2 male. - Fitness level: Currently engaging in less than 90 minutes of structured moderate- or vigorous-intensity aerobic exercise. - Health status: Stage II-III colorectal cancer survivors post-resection and adjuvant therapy; excluded recurrent disease, uncontrolled resting BP, functional limitations requiring walker/scooter/wheelchair, and known or symptomatic cardiovascular/metabolic/renal disease. ## Methodology - Pilot parallel randomized controlled trial. - 12 weeks. - Home-based intervention with remote monitoring; baseline and end-of-study assessments at a University of Utah research center. - Randomized and controlled study design. ## Protocol - Home-based mHealth HIIT. - Modality: Self-selected weight-bearing aerobic exercise, including walking, jogging, elliptical, or calisthenic exercise. - Work intervals: Five 4-minute intervals at 85-90% peak HR. - Recovery: Four-minute active recovery at 50-75% peak HR after each high-intensity interval. - Sets or repetitions: 5 high-intensity intervals per goal workout. - Intensity: 85-90% peak HR for intervals; 50-75% peak HR warmup and recovery. - Session duration: 50 minutes. - Frequency: 4 workouts per week. - Program length: 12 weeks. - Progression: 4-week progression in time and intensity to goal prescription. - Home-based mHealth moderate-intensity continuous exercise. - Modality: Self-selected weight-bearing aerobic exercise. - Work intervals: Continuous aerobic exercise. - Intensity: 50-70% peak HR. - Session duration: 60 minutes. - Frequency: 5 workouts per week. - Program length: 12 weeks. - Progression: 4-week progression in time and intensity to goal prescription. ## Outcomes ### Workout completion Status: improved Participants completed a high proportion of prescribed workouts across both intervention groups. Mean completion 88.6%; 95% CI 79.4-97.8; range 63-100%. ### Retention and safety Status: improved Retention was complete and no adverse events were reported. 100% retention; no adverse events. ### HIIT HR-zone adherence Status: worse/safety concern HIIT participants did not meet the prespecified HR-zone adherence benchmark; adherence was low for high-intensity and active recovery intervals because HR often exceeded prescribed zones. HIIT adherence: 28.8% for high-intensity intervals and 51% for active recovery intervals; feasibility benchmark was >=75% of participants adhering to prescription. ### Acceptability Status: improved Qualitative responses supported acceptability, including accountability, motivation, autonomy, improved quality of life, and plans to continue exercising. Qualitative thematic analysis; all participants noted plans to continue exercise. ### Health outcomes Status: mixed Descriptive health outcomes were mixed and underpowered; the study was not designed to establish efficacy. HIIT n=2 and MICE n=5; peak aerobic capacity not analyzed due to limited paired testing under COVID-19 restrictions. ## Practical Insights - For clinical or post-treatment users, HIIT should be framed around medical screening, HR monitoring, conservative zone targets, and supervision/escalation rules. - Remote monitoring plus weekly follow-up can support completion, but HR-zone adherence may require better real-time coaching. - User autonomy and self-selected modality may improve acceptability in home-based exercise programs. ## Limitations - Very small pilot sample, especially HIIT group with n=2. - Trial ended early because of COVID-19 recruitment and assessment disruptions. - Homogeneous sample: all non-Hispanic White and married. - Peak aerobic capacity change was not analyzed due to limited paired cardiopulmonary tests. - Remote HR measurement had possible lag when changing intensity, potentially affecting adherence estimates. - Clinical population limits direct translation to unscreened general consumers. ## Safety And Adherence - No adverse events were reported. - Eligibility excluded recurrent disease, uncontrolled resting blood pressure, mobility limitations requiring assistive devices, and known or symptomatic cardiometabolic/renal disease. - Baseline cardiopulmonary testing used 12-lead ECG and blood-pressure monitoring. ## Original Sources - [PubMed](https://pubmed.ncbi.nlm.nih.gov/37347792/) (pubmed) - [DOI](https://doi.org/10.1371/journal.pone.0287152) (doi) - [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10286977/) (full text) ## Agent Guidance Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.