# Affective and enjoyment responses to 12 weeks of high intensity interval training and moderate continuous training in adults with Crohn's disease

PMID: 31539378
Journal: PLoS ONE
Published: 2019-09-20
Authors: Bottoms L, Leighton D, Carpenter R, Anderson S, Langmead L, Ramage J, Faulkner J, Coleman E, Fairhurst C, Seed M, Tew G

## Question

How do affective responses, perceived exertion, and enjoyment compare between supervised HIIT and MICT in adults with quiescent or mildly active Crohn's disease?

## Summary

This secondary analysis of a randomized feasibility trial compared affect and enjoyment during 12 weeks of supervised cycling HIIT and MICT in adults with quiescent or mildly active Crohn's disease. HIIT produced higher HR and RPE than MICT, but end-exercise affect and post-program enjoyment were similarly positive. Attendance was moderate and two HIIT participants attended no sessions, showing feasibility constraints in this clinical population.

## Population

- 25 adults with Crohn's disease assigned to exercise groups in the parent feasibility trial; HIIT n=13 and MICT n=12.
- Sample size: 25
- Age: HIIT 37.0 +/- 11.1 years; MICT 38.5 +/- 13.0 years
- Sex: HIIT 7 men (54%); MICT 3 men (25%)
- Fitness level: Excluded >90 min/week purposeful exercise; baseline VO2peak about 27-29 mL/kg/min
- Health status: Quiescent or mildly active Crohn's disease with stool calprotectin <250 micrograms/g and stable medication

## Methodology

- Secondary analysis of a three-arm randomized feasibility trial focused on exercise-group affect/enjoyment
- 12 weeks
- Supervised cycle ergometer training at university exercise sites in England
- Randomized and controlled study design.

## Protocol

- Cycling HIIT for Crohn's disease feasibility trial.
- Modality: Cycle ergometer.
- Work intervals: 1 min at 90% Wpeak.
- Recovery: 1 min at 15% Wpeak.
- Sets or repetitions: 10 intervals.
- Intensity: 90% Wpeak work intervals.
- Session duration: 28 min including 5-min warm-up at 15% Wpeak and 3-min cool-down at 15% Wpeak.
- Frequency: 3 sessions/week.
- Program length: 12 weeks.
- Progression: Wpeak recalibrated at weeks 4 and 8 from incremental tests.
- Cycling MICT.
- Modality: Cycle ergometer.
- Work intervals: 30 min continuous cycling.
- Sets or repetitions: One continuous bout.
- Intensity: 35% Wpeak.
- Session duration: 38 min including 5-min warm-up and 3-min cool-down.
- Frequency: 3 sessions/week.
- Program length: 12 weeks.
- Progression: Wpeak recalibrated at weeks 4 and 8 from incremental tests; selected for similar energy expenditure to HIIT.

## Outcomes

### Heart rate and perceived exertion
Status: mixed
HIIT elicited higher HR and RPE than MICT, while exertion decreased over time.

HR HIIT 173 +/- 8 vs MICT 128 +/- 6 bpm, p<0.001; RPE-L 5.5 +/- 1.6 vs 3.3 +/- 1.5 and RPE-C 5.1 +/- 1.7 vs 2.9 +/- 1.5, p=0.03 for both

### Affective response
Status: no clear change
End-exercise affect was similarly positive for HIIT and MICT.

No group effect p=0.25; no time effect p=0.94; HIIT 2.2 +/- 1.9 and MICT 2.1 +/- 1.4

### Enjoyment
Status: no clear change
PACES enjoyment scores were high and did not differ between groups.

HIIT 99.4 +/- 12.9 vs MICT 101.3 +/- 17.4, p=0.78

### Attendance and peak power
Status: mixed
Attendance was moderate. HIIT improved peak power over time while MICT did not show a significant peak-power effect.

Attendance HIIT 62% vs MICT 75%; peak power group x time interaction reported with HIIT increases and p=0.05

## Practical Insights

- In carefully screened Crohn's disease patients, supervised cycling HIIT can be enjoyable despite higher RPE.
- Attendance barriers such as work, illness, and holidays may dominate feasibility in clinical populations.
- Do not generalize findings to active Crohn's disease or unsupervised HIIT.

## Limitations

- Small feasibility sample and secondary analysis.
- Clinical population limited to quiescent or mildly active Crohn's disease.
- Not powered for definitive effectiveness.
- Enjoyment measured at one main post-intervention timepoint.
- No crossover design; possible group imbalance.

## Safety And Adherence

- The article states the parent trial had very few exercise-related adverse events but does not detail them. Screening excluded exercise contraindications and several higher-risk conditions.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/31539378/) (pubmed)
- [DOI](https://doi.org/10.1371/journal.pone.0222060) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6754139/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.