Cycling-Based Aerobic Exercise Intervention for Individuals With Chemotherapy-Induced Peripheral Neuropathy (CIPN)

CIPN is a common and dose-limiting side effect of neurotoxic chemotherapeutic agents used in cancer treatments, with symptoms affecting up to 100% of patients depending on the drug class. These symptoms-classified as positive (e.g., tingling, pain, allodynia) or negative (e.g., numbness, decrease in fine motor skills) -primarily occur in the hands and feet. CIPN persists in approximately 30% of patients six months post-treatment, significantly impacting quality of life. As there are no pharmacological treatments established for CIPN, there is a critical need to explore lifestyle interventions to improve survivorship care.

Exercise is a promising lifestyle intervention for managing CIPN, with research suggesting improvements in CIPN symptoms such as pain and numbness. Most existing studies have utilized multimodal exercise interventions (typically aerobic, resistance, and balance training) and often rely exclusively on patient-reported outcome measures (PROMs), limiting generalizability. There is significant variability in CIPN outcome measures used across studies, as a standardized core outcome set has not yet been established. Aerobic exercise may reduce CIPN symptoms through neurotrophins that affect neurons, peripheral nerves, and inflammation; however, the exact mechanisms remain unclear. While aerobic exercise shows considerable potential for CIPN symptom reduction, its isolated effects on CIPN-associated symptoms and function observed through the use of both PROMs and objective clinical measures remain unexplored. The FITT principle (Frequency, Intensity, Time, Type) provides a standardized framework for exercise prescription, yet few studies have examined its application in dosing CIPN-specific aerobic exercise interventions. Stationary cycling offers a safe, non-weight-bearing aerobic exercise mode that is accessible for individuals with CIPN. To address current research gaps, further investigation is warranted to examine the feasibility, acceptability, and outcomes of cycling-based aerobic exercise intervention using both patient-reported and objective outcome measures.

The primary objective of this study is to determine the feasibility and acceptability of a stationary cycling-based aerobic exercise program for individuals with CIPN using both objective and patient-reported outcome measures, as defined by:

Recruitment rate: 30 participants recruited within one year

Completion rate: >70% of participants consenting to the study complete the 12-week assessment

Adherence rate: average completion of >70% of the FITT prescription variables

Program satisfaction: >70% reporting high to very high program satisfaction

Safety: no serious adverse events related to exercise

The study will involve 30 participants (aged 18+) with CIPN, either undergoing or post-chemotherapy. Participants will be recruited from the Cross Cancer Institute and the University of Alberta's Cancer Rehabilitation Clinic. Subjects will be screened for eligibility, and if all eligibility criteria are met, they will be provided with a study brochure. Participants will be asked to contact the investigators if they are interested. All participants are required to provide written informed consent as per the Health Research Ethics Board of Alberta: Cancer Committee (HREBA-CC).

The intervention consists of a 12-week aerobic exercise stationary cycling program to determine the acceptability and appropriateness of the intervention for CIPN. The program will be administered through the Cancer Rehabilitation Clinic and Exercise Oncology Research Laboratory at the University of Alberta. Based on the results of the participants' baseline assessments (i.e. % heart rate maximum from cardiopulmonary exercise testing), participants will receive individualized exercise programs. Twice weekly, participants will attend in-person small group exercise sessions, supervised by certified exercise physiologists and qualified exercise professionals (supervisor-to-participant ratio of 1:3). Exercise prescriptions were adapted from the most recent exercise guidelines for cancer survivors and previous aerobic-exercise-including trials in individuals with cancer. Each week, participants will undergo two different exercise sessions: (1) continuous cycling-based aerobic exercise, and (2) high-intensity interval training (HIIT) on a cycle ergometer.

Analyses: All participants who provide informed consent and complete the baseline assessment will be considered for analysis. A per-protocol (PP) analysis will be implemented as there is no randomization or multi-group designation in this study. Participants included in the PP analysis will be those who provide informed consent, complete both pre- and post-intervention assessments, and attend at least 70% of exercise sessions. Participants who do not meet the PP analysis criteria will be excluded from the PP analysis, but will be included in proof-of-concept outcomes (i.e. completion rate, adherence, adverse events). Descriptive statistics will be used to summarize demographic characteristics. Completion, recruitment, and adherence rates will be calculated using numbers and percentages, and the mean rates will be reported. All statistical analyses in the PP analysis will use a two-tailed, repeated measures t-test with a significance level set at α=0.05. Effect size (i.e. Cohen's d) will be reported to describe the magnitude of change between pre- and post-intervention assessments.