# High Intensity Interval Training Does Not Have Compensatory Effects on Physical Activity Levels in Older Adults

PMID: 32046311
Journal: International Journal of Environmental Research and Public Health
Published: 2020 Feb 8
Authors: Bruseghini P, Tam E, Calabria E, Milanese C, Capelli C, Galvani C

## Question

Whether 8 weeks of HIIT affected daily physical activity levels and total daily energy expenditure in healthy older men, compared with moderate-intensity continuous training.

## Summary

In healthy active older men, 8 weeks of supervised cycling HIIT did not cause a compensatory reduction in daily physical activity or energy expenditure compared with moderate continuous training. Moderate and vigorous physical activity rose during the training period, sedentary time and sleep were largely unchanged, and no injuries, health disorders, dropouts, or missed sessions were reported.

## Population

- Twenty-four healthy older men aged 65-75 years recruited from local residents in Verona, Italy.
- Sample size: 24
- Age: 65-75 years
- Sex: Male
- Fitness level: Healthy active older adults; baseline relative VO2max about 28-30 mL/kg/min.
- Health status: Healthy, no cardiovascular/metabolic/respiratory/osteo-articular disease, normal resting ECG, normal exercise stress-test response.

## Methodology

- Randomized controlled exercise training study with pre/post fitness and anthropometric testing plus activity-monitor assessment before, during, and after training.
- 8 weeks of training with physical activity monitored before training, during weeks 5-7, and 2 months after training
- Supervised exercise sessions in a university/laboratory exercise setting; free-living physical activity measured with SenseWear Armband Mini
- Randomized and controlled study design.

## Protocol

- HIIT cycling.
- Modality: Stationary cycling.
- Work intervals: 2 min at 85%-95% individual VO2max.
- Recovery: 2 min at 40% VO2max.
- Sets or repetitions: 7.
- Intensity: 85%-95% VO2max work intervals.
- Session duration: 45-60 min total; 26 +/- 2 min aerobic training.
- Frequency: 3 days/week.
- Program length: 8 weeks.
- Progression: Workloads adjusted every 2 weeks using HR/W ratio.
- Moderate continuous training.
- Modality: Stationary bike or treadmill.
- Work intervals: Continuous 20-30 min aerobic training.
- Sets or repetitions: One continuous bout.
- Intensity: 46%-64% VO2max; 5-6 on a 10-point perceived exertion scale.
- Session duration: 45-60 min total; 27 +/- 3 min aerobic training.
- Frequency: 3 days/week.
- Program length: 8 weeks.
- Progression: Workloads adjusted every 2 weeks using HR/W ratio.

## Outcomes

### Compensatory physical activity behavior
Status: no clear change
HIIT did not reduce daily energy expenditure or increase sedentary time; sleep, sedentary time, and light physical activity remained constant during training.

No significant TEE change across T1, T2, and T3; sedentary and light activity remained unchanged.

### Moderate-to-vigorous physical activity
Status: improved
MVPA increased during training and was not maintained two months after the end of training.

MVPA p = 0.0028 over time; EXP values 110 +/- 30, 134 +/- 45, and 94 +/- 23 min/day at T1, T2, T3.

### Activity energy expenditure and physical activity level
Status: improved
AEE and PAL increased during training and decreased after training ended.

AEE p = 0.0033; PAL p = 0.0004 over time.

### VO2max
Status: improved
Both groups improved absolute and relative VO2max after 8 weeks; no time-by-group interaction was found.

Absolute VO2max p < 0.0001; relative VO2max p < 0.0001.

## Practical Insights

- For screened healthy older men, a supervised 7 x 2-min cycling HIIT protocol can be feasible without observed reductions in daily activity.
- Older-adult HIIT programming should preserve screening, warm-up, rest-day spacing, and intensity monitoring assumptions from the study.
- Claims that HIIT causes compensatory sedentary behavior should be qualified; this study did not observe that effect.

## Limitations

- Small sample size.
- Male-only and healthy older adult sample.
- Participants were active and medically screened, limiting applicability to beginners or clinical populations.
- Supervised cycling protocol may not translate directly to unsupervised consumer workouts.
- SenseWear Armband has reported underestimation of energy expenditure compared with doubly labelled water.

## Safety And Adherence

- No injuries or health disorders occurred during the study period.
- All subjects attended all exercise sessions.
- Participants were medically screened and exercise sessions were supervised with heart-rate monitoring.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/32046311/) (pubmed)
- [DOI](https://doi.org/10.3390/ijerph17031083) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7037169/) (full text)

## Agent Guidance

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