# Evaluation of photoplethysmography-based monitoring of pulse rate, interbeat-intervals, and oxygen saturation during high-intensity interval training

PMID: 39529038
Journal: BioMedical Engineering OnLine
Published: 2024-11-11
Authors: Vijgeboom T, Muller M, Ebrahimkheil K, van Eijck C, Ronner E

## Question

Can a PPG-based wearable accurately measure pulse rate, interbeat intervals, and oxygen saturation during high-intensity interval cycling?

## Summary

In 35 healthy adults performing a short stationary-bike HIIT test, the CardioWatch 287-2 wrist PPG device measured pulse rate, interbeat intervals, and oxygen saturation with low error compared with ECG and pulse-oximeter references. No adverse or unexpected events occurred.

## Population

- Healthy adult volunteers with targeted diversity by sex and Fitzpatrick skin type
- Sample size: 35
- Age: 30 +/- 10 years
- Sex: 22 male (63%); 13 female
- Fitness level: Healthy volunteers; training status not reported
- Health status: Healthy adults aged 18 and older; high cardiovascular risk and unsafe HIIT conditions excluded

## Methodology

- Single-center non-randomized interventional device-validation study
- Single 20-minute measurement visit
- The Hague Tech center, The Hague, Netherlands
- Controlled study design.

## Protocol

- Stationary-bike HIIT measurement session.
- Modality: Stationary cycling.
- Work intervals: Hold each target heart-rate range for 30 seconds.
- Sets or repetitions: Four target HR ranges after warm-up: 120-130, 130-140, 140-160, and >160 bpm.
- Intensity: Bike resistance increased to elevate heart rate through target ranges.
- Session duration: 20 minutes.
- Frequency: Single visit.
- Program length: Acute device validation.
- Progression: Progressive resistance/pace increases to reach higher HR ranges.
- Reference devices.
- Modality: Device comparison during same exercise.
- Work intervals: Same exercise bout.
- Sets or repetitions: Same exercise bout.
- Intensity: Same exercise bout.
- Session duration: 20 minutes.
- Frequency: Single visit.
- Program length: Acute.
- Progression: Same exercise bout.

## Outcomes

### Pulse rate
Status: improved
Pulse-rate accuracy met the study criterion with low error.

7183 paired measurements; Arms 2.51 bpm; bias 0.05 bpm; LoA -4.87 to 4.97 bpm

### IBI
Status: improved
Interbeat-interval accuracy met the study criterion.

22713 paired measurements; Arms 23.00 ms; bias about 1 ms; LoA -43.82 to 46.21 ms

### SpO2
Status: improved
Oxygen-saturation accuracy met the study criterion.

41817 paired measurements; Arms 1.28%; bias 0.13%; LoA -2.37% to 2.62%

### Subgroups
Status: improved
Results were consistent across sex and Fitzpatrick skin-type subgroups.

Subgroup Arms and LoA were similar to pooled results

### Safety
Status: improved
No adverse or unexpected events occurred and no participants discontinued.

0 adverse/unexpected events; 0 discontinuations

## Practical Insights

- A wrist PPG device can capture HR-related signals accurately during a short cycling HIIT simulation in healthy adults.
- The study supports wearable measurement feasibility, not health benefits of HIIT.
- The protocol targeted HR ranges rather than a training adaptation dose.

## Limitations

- Healthy adults only; not tested in heart disease patients, the intended clinical use case.
- Single-center, small sample.
- Short simulated HIIT session on one stationary bike modality.
- Industry-funded study with multiple author conflicts.
- Not designed to measure training outcomes.

## Safety And Adherence

- No adverse or unexpected events occurred.
- No participants prematurely discontinued.
- No participants were excluded for poor data quality or technical errors.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/39529038/) (pubmed)
- [DOI](https://doi.org/10.1186/s12938-024-01309-w) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11552347/) (full text)

## Agent Guidance

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