High-intensity aerobic interval training and resistance training are feasible in rectal cancer patients undergoing chemoradiotherapy: a feasibility randomized controlled study
Question
Can HIIT and resistance training be delivered feasibly and safely during neoadjuvant chemoradiotherapy in rectal cancer patients, and are either superior to usual care for physical or psychological impairments related to treatment?
Summary
This single-center randomized feasibility study tested whether supervised high-intensity aerobic interval training or resistance training could be delivered during five weeks of neoadjuvant chemoradiotherapy for localized rectal cancer. Eighteen patients were randomized equally to HIIT, resistance training, or usual care. Recruitment, retention, and attendance were high, all HIIT participants reached the prescribed heart-rate target during high-intensity bouts, and no exercise-related adverse events occurred. The study was too small to determine efficacy, and measured physical and psychological outcomes mostly did not differ between groups.
Methodology
- Eighteen adults with localized rectal cancer scheduled for long-course neoadjuvant chemoradiotherapy; patients doing regular exercise or with contraindicating uncontrolled disease were excluded.
- 18 participants.
- Cycle ergometer.
- Work intervals: 60 s at cadence 90-100 rpm and >=85% theoretical maximal heart rate.
- Recovery: 60 s unloaded active rest at cadence 50-60 rpm.
- Intensity: >=85% theoretical maximal heart rate during high-intensity bouts; warm-up/cool-down 65-70% theoretical maximal heart rate.
- 26-40 min including 5 min warm-up and 5 min cool-down.
- 3 sessions/week.
- 5 weeks.
- Single-center, three-arm randomized controlled feasibility study
- Recruitment, Retention, Attendance, and Exercise-related adverse events were tracked.
Outcomes
Recruitment
Eighteen of 20 eligible patients enrolled, yielding a 90% recruitment rate.
Retention
All randomized patients completed the study, yielding 100% retention.
Attendance
Attendance was 92% in HIIT (77/84 sessions) and 88% in resistance training (74/84 sessions).
HIIT intensity adherence
All HIIT participants reached the target heart rate during high-intensity bouts.
Exercise-related adverse events
No exercise-related adverse events occurred in either exercise group.
Physical and psychological outcomes
No measured outcome significantly differed between groups except social/family well-being, which changed more favorably in resistance training than HIIT.
FACT-G social/family well-being change differed between RES and HIIT (p = 0.017; table p = 0.022).
Functional exercise capacity
6-minute walk test percentage change did not significantly differ between groups.
p = 0.236 for between-group percentage change.
Insights
- In carefully screened, supervised rectal cancer patients, 60 s cycle-ergometer HIIT intervals at >=85% theoretical maximal heart rate were feasible during chemoradiotherapy.
- A 1:1 work-recovery ratio and progression from 8 to 15 intervals provide a concrete clinical interval structure.
- Embedding sessions immediately after radiotherapy and near the radiotherapy department may improve attendance.
- For consumer translation, this is safety-boundary evidence requiring medical screening and supervision rather than a direct home-workout template.
Limitations
- Small feasibility sample with six participants per group.
- Underpowered to evaluate effects on physical and psychological outcomes.
- Participants and evaluator were not blinded.
- Single-center clinical setting.
- No longer-term follow-up was reported.
Safety
- No exercise-related adverse events occurred.
- No HIIT participant was excluded because of abnormal cardiac stress test.
- Intense diarrhea and fatigue were common reasons for missed sessions.
- Authors reported gastrointestinal symptoms did not worsen directly after radiotherapy and HIIT did not appear to influence bowel activation more than resistance training.