# High-Intensity Interval Training Elicits Higher Enjoyment than Moderate Intensity Continuous Exercise

PMID: 28076352
Journal: PLoS ONE
Published: 2017 Jan 11
Authors: Thum JS, Parsons G, Whittle T, Astorino TA

## Question

Does an acute cycling HIIT bout differ from moderate-intensity continuous cycling in enjoyment, affect, perceived exertion, heart rate, and blood lactate in recreationally active adults?

## Summary

In 12 healthy recreationally active adults, a single low-volume cycling HIIT session was more enjoyable than a 20-minute moderate continuous cycling session, even though HIIT felt harder, produced higher heart rate and lactate, and less positive in-task affect. Eleven of 12 participants preferred HIIT. This was an acute laboratory preference study, not a training trial.

## Population

- Twelve healthy, non-obese recreationally active adults.
- Sample size: 12
- Age: 18-49 years; mean 25.5 +/- 10.7 years.
- Sex: 8 men and 4 women.
- Fitness level: Recreationally active; VO2max 41.3 +/- 4.9 mL/kg/min.
- Health status: Healthy, non-obese, non-smokers.

## Methodology

- Randomized crossover repeated-measures laboratory study with VO2max testing followed by one HIIT and one MICT trial.
- Acute exercise comparison; trials separated by 2-7 days after baseline testing.
- Climate-controlled university exercise laboratory at CSU San Marcos.
- Randomized and controlled study design.

## Protocol

- Cycling HIIT.
- Modality: Cycle ergometer.
- Work intervals: 60 s at 85% Wmax.
- Recovery: 60 s at 25% Wmax.
- Sets or repetitions: 8 intervals.
- Intensity: 85% Wmax work; peak HR about 89% HRmax.
- Session duration: 16 min main set plus 5 min warm-up.
- Frequency: Single acute trial.
- Program length: Acute crossover study.
- MICT.
- Modality: Cycle ergometer.
- Work intervals: 20 min continuous cycling.
- Sets or repetitions: One continuous bout.
- Intensity: 45% Wmax; peak intensity about 77% HRmax.
- Session duration: 20 min main set plus 5 min warm-up.
- Frequency: Single acute trial.
- Program length: Acute crossover study.

## Outcomes

### Enjoyment
Status: improved
PACES enjoyment was higher after HIIT than MICT; 92% preferred HIIT.

HIIT 103.8 +/- 9.4 vs MICT 84.2 +/- 19.1; p=0.013; d=1.54.

### Exercise intensity markers
Status: mixed
HIIT produced higher heart rate and blood lactate than MICT.

HR regime x time F(4,40)=10.0, p<0.001; lactate F(3,30)=14.6, p<0.001.

### Perceived exertion and affect
Status: mixed
HIIT produced higher RPE and less positive affect during exercise than MICT.

RPE F(4,40)=9.6, p=0.003; affect F(4,40)=7.1, p=0.004.

## Practical Insights

- A short 1:1 interval structure can be more enjoyable than continuous moderate cycling for active adults.
- Separate post-session enjoyment from in-session affect because hard intervals may feel unpleasant during work yet still be preferred afterward.
- Use caution applying this to sedentary or clinical users.

## Limitations

- Very small sample.
- Healthy recreationally active participants only.
- Acute preference study, not a longitudinal adherence trial.
- HIIT and MICT were not equal in duration or physiological strain.

## Safety And Adherence

- All participants completed all bouts without incident.
- Participants were screened for health status and knee ailments.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/28076352/) (pubmed)
- [DOI](https://doi.org/10.1371/journal.pone.0166299) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5226715/) (full text)

## Agent Guidance

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