# Physiological, perceptual and affective responses to high-intensity interval training using two work-matched programs with different bout duration in obese males

PMID: 35510254
Journal: Journal of Exercise Science and Fitness
Published: 2022 Apr 11
Authors: Tsirigkakis S, Koutedakis Y, Mastorakos G, Stavrinou PS, Mougios V, Bogdanis GC

## Question

Do work-matched cycling HIIT programs using 10-second or 60-second bouts differ in physiological, perceptual, and affective responses during 8 weeks of training in obese males?

## Summary

In 16 low-to-moderately active obese men, two work-matched 8-week cycling HIIT programs both improved peak power output, but the short-bout 10-second protocol produced lower lactate and RPE and more favorable affective responses than the 60-second protocol. Enjoyment stayed high in both groups and no injuries or adverse events were reported. The study is small and limited to supervised cycling in men with obesity.

## Population

- Sixteen low-to-moderately active obese men completed two different supervised cycling HIIT protocols.
- Sample size: 16
- Age: Eligible age 18-50 years; group means about 37-40 years.
- Sex: Men only.
- Fitness level: Low-to-moderately active; no structured exercise in previous 12 months.
- Health status: BMI 28-35 kg/m2 and body fat >=25%; medically cleared.

## Methodology

- Randomized two-arm supervised exercise training study comparing work-matched short-bout and long-bout cycling HIIT.
- 8 weeks.
- Supervised laboratory exercise setting in Greece.
- Randomized and controlled study design.

## Protocol

- HIIT10 short-bout cycling HIIT.
- Modality: Cycle ergometer.
- Work intervals: 48 x 10 s at 100% PPO.
- Recovery: 15 s at 15% PPO.
- Sets or repetitions: 48 intervals.
- Intensity: 100% PPO work; 15% PPO recovery.
- Session duration: 20 min interval block plus 5 min warm-up and 3 min cool-down.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: +10% PPO after 6 sessions; readjusted after 12 sessions; +5% PPO after 18 sessions.
- HIIT60 long-bout cycling HIIT.
- Modality: Cycle ergometer.
- Work intervals: 8 x 60 s at 100% PPO.
- Recovery: 90 s at 15% PPO.
- Sets or repetitions: 8 intervals.
- Intensity: 100% PPO work; 15% PPO recovery.
- Session duration: 20 min interval block plus 5 min warm-up and 3 min cool-down.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: +10% PPO after 6 sessions; readjusted after 12 sessions; +5% PPO after 18 sessions.

## Outcomes

### Peak power output
Status: improved
Both HIIT10 and HIIT60 improved peak power output after 12 and 24 sessions.

After 12 sessions: HIIT10 +13.2 +/- 2.8%, HIIT60 +12.9 +/- 3.4%; end training: +19.5 +/- 2.8% and +16.7 +/- 3.4%; p<0.001.

### Blood lactate
Status: improved
HIIT10 produced lower lactate than HIIT60 and lactate fell over training only in HIIT10.

Between-group p=0.003 in first session and p=0.001 in final session; HIIT10 lactate reduced from 10 min onward by 28 +/- 19%, p<0.001.

### RPE
Status: improved
HIIT10 had lower perceived exertion than HIIT60, and RPE decreased over training only in HIIT10.

Group effect p=0.027; HIIT10 RPE decreased by about 1.0 +/- 1.1 units in later training blocks.

### Affective valence
Status: mixed
Feeling Scale improved in HIIT10 but declined in HIIT60.

HIIT60 declined from 3.0 +/- 1.1 to 2.2 +/- 0.8 (p=0.026) and 2.1 +/- 0.9 (p<0.001).

### Enjoyment
Status: no clear change
PACES enjoyment remained high and did not significantly differ by group or training block.

No significant group or training effects reported.

### Safety
Status: improved
No musculoskeletal injuries or adverse events were reported.

## Practical Insights

- For users who find HIIT unpleasant, shortening bouts while matching work may reduce lactate, RPE, and negative affect.
- Post-session enjoyment and in-session affect can diverge, so both are useful product signals.
- Short-bout evidence here is cycling-specific; bodyweight translation should be conservative.

## Limitations

- Very small sample.
- Men with obesity only.
- No non-exercise or moderate-intensity control group.
- Supervised cycling protocol with PPO-based workload.
- Short 8-week duration and no follow-up.
- Industry funding creates possible perceived conflict despite no reported study role.

## Safety And Adherence

- No musculoskeletal injuries were reported.
- No adverse events were reported.
- Participants were medically cleared by a cardiologist.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/35510254/) (pubmed)
- [DOI](https://doi.org/10.1016/j.jesf.2022.04.002) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9035702/) (full text)

## Agent Guidance

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