# Brief Exercise at Work (BE@Work): A Mixed-Methods Pilot Trial of a Workplace High-Intensity Interval Training Intervention

PMID: 34278300
Journal: Frontiers in Sports and Active Living
Published: 2021-07-02
Authors: Burn NL, Weston M, Atkinson G, Graham M, Weston KL

## Question

Is a flexible, multi-activity workplace HIIT program feasible, acceptable, and promising enough to justify a definitive randomized trial?

## Summary

This non-randomized pilot tested an 8-week workplace HIIT program using boxing, stair climbing, and stepping. Attendance and intensity fidelity were fairly good, and estimated VO2max improved more than control with a moderate pilot effect, but the study was exploratory and not powered for formal effectiveness claims. Two intervention-related injuries occurred, including a fractured elbow from tripping during a shuttle run.

## Population

- Healthy office-based employees.
- Sample size: 54
- Age: Mean 46 +/- 10 years overall.
- Sex: 20 men and 34 women total.
- Fitness level: Working adult sample with varied baseline activity.
- Health status: Healthy enough for exercise; major cardiometabolic and injury risks excluded.

## Methodology

- Mixed-methods pilot non-randomized controlled trial.
- 8 weeks.
- Two office-based workplaces in Northeast England.
- Controlled study design.

## Protocol

- BE@Work HIIT.
- Modality: Boxing, stair climbing, stepping, shuttle runs, skipping/jumping.
- Work intervals: 60 s high-intensity bout.
- Recovery: 75 s rest.
- Sets or repetitions: 4-7 bouts.
- Intensity: Target >=85% HRmax; mean achieved peak HR 87% HRmax.
- Session duration: About 15 to <=22 min.
- Frequency: 3 sessions/week.
- Program length: 8 weeks.
- Progression: One additional 60-s bout every fortnight.
- No-intervention control.
- Modality: No workplace HIIT intervention.
- Program length: 8 weeks.

## Outcomes

### Feasibility/fidelity
Status: improved
Attendance and intensity fidelity were adequate for a pilot workplace program.

Attendance 82 +/- 15%; mean peak HR 87% HRmax; median 70% of bouts reached >=85% HRmax.

### Predicted VO2max
Status: improved
Pilot control-adjusted effect favored BE@Work.

+3.9 mL/kg/min, 95% CI -0.2 to 8.1, d = 0.47.

### Well-being and quality of life
Status: mixed
Vitality, perceived stress, general health perceptions, and WEMWS favored intervention with small-to-moderate effects; pain favored control.

Vitality d = 0.51; PSS d = -0.40; WEMWS d = 0.34; pain d = -0.67.

### Safety
Status: worse/safety concern
Two intervention-related injuries occurred.

One fractured elbow with withdrawal; one minor calf strain with one missed session.

## Practical Insights

- Flexible scheduling and exercise choice supported workplace HIIT attendance.
- Session length under 22 min helped fit workday constraints.
- Movement selection needs safety review; shuttle runs created injuries.
- Pilot results justify future trials but not definitive claims.

## Limitations

- Non-randomized allocation by workplace.
- Pilot sample and not powered for effectiveness.
- Predicted rather than directly measured VO2max.
- Self-reported physical activity instead of accelerometry.
- Scalability concerns from offering 19 sessions per week.
- Study-related injuries.

## Safety And Adherence

- One participant tripped during a shuttle run, fractured an elbow, withdrew, and later fully recovered.
- One participant had a minor calf strain during a shuttle run and missed one session.
- Participants reported breathlessness, local muscular fatigue, heat, sweating, stitches, and tiredness during HIIT.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/34278300/) (pubmed)
- [DOI](https://doi.org/10.3389/fspor.2021.699608) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8282817/) (full text)

## Agent Guidance

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