# High-intensity resistance exercise is not as effective as traditional high-intensity interval exercise for increasing the cardiorespiratory response and energy expenditure in recreationally active subjects

PMID: 34799752
Journal: European Journal of Applied Physiology
Published: 2021-11-19
Authors: Järvinen L, Lundin Petersdotter S, Chaillou T

## Question

Do high-intensity resistance exercise circuits match traditional cycling HIIT for acute cardiorespiratory response and energy expenditure?

## Summary

In 15 recreationally active adults, an acute cycling HIIT session produced a much stronger cardiorespiratory and aerobic energy-expenditure response than two high-intensity resistance-exercise circuits, even though the resistance sessions produced high lactate and felt demanding.

## Population

- Healthy recreationally active young adults with resistance-training experience.
- Sample size: 15
- Age: 25.5 +/- 3.3 years
- Sex: 10 men and 5 women
- Fitness level: Recreationally active and resistance trained
- Health status: Apparently healthy

## Methodology

- Randomized crossover acute exercise comparison
- Three acute exercise sessions separated by at least 2 days
- Exercise physiology laboratory
- Randomized and controlled study design.

## Protocol

- High-intensity resistance exercise.
- Modality: Free-weight/bodyweight resistance circuit.
- Work intervals: 30 s.
- Recovery: 30 s transition/recovery.
- Sets or repetitions: 2 sets of 10 exercises.
- Intensity: 40% or 60% 1RM; maximum sustainable repetitions.
- Session duration: About 46 min including monitoring.
- Frequency: Acute sessions.
- Program length: Single session per condition.
- Progression: None.
- Cycling HIIE.
- Modality: Cycle ergometer.
- Work intervals: 30 s.
- Recovery: 30 s at 50% Pmax.
- Sets or repetitions: 2 sets of 10 intervals.
- Intensity: 100% Pmax, reduced to 95% Pmax for 4 participants.
- Session duration: About 46 min including monitoring.
- Frequency: Acute session.
- Program length: Single session.
- Progression: None.

## Outcomes

### VO2 exposure
Status: worse/safety concern
Resistance HIIT produced much less time above 90% VO2max than cycling HIIT.

T90%VO2max total: HIIE 785 +/- 191.6 s, HIRE40 47.3 +/- 63.4 s, HIRE60 60.0 +/- 76.0 s; p<0.05.

### Heart-rate exposure
Status: worse/safety concern
Resistance HIIT produced lower mean HR and less high-HR exposure than cycling HIIT.

HRmean about 92.1% HRmax in HIIE versus 86.5% and 88.0% in HIRE.

### Aerobic expenditure
Status: worse/safety concern
Resistance HIIT had lower aerobic energy expenditure than cycling HIIT.

Reported significant between-condition differences, p<0.05.

### EPOC
Status: no clear change
Post-exercise oxygen-consumption energy expenditure was similar across sessions.

## Practical Insights

- Use cyclic HIIT when the target is cardiorespiratory load or time near VO2max.
- Resistance HIIT may be better framed as strength-conditioning with a moderate cardio component.

## Limitations

- Small sample
- Acute-only outcomes
- Young active sample
- Resistance exercise results depend on exercise selection and technique

## Safety And Adherence

- No adverse events were reported.
- Four participants could not complete cycling HIIT at 100% Pmax and repeated it at 95% Pmax because of severe exhaustion.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/34799752/) (pubmed)
- [DOI](https://doi.org/10.1007/s00421-021-04849-4) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8783843/) (full text)

## Agent Guidance

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