Design: Randomised controlled trial
Population: 131 people with fibrotic interstitial lung disease in an 8-week rehabilitation programme
Primary outcome: Cycle endurance time
Effect: Mean difference -63 s (95% CI -195 to 68); 6MWD difference 4 m (-20 to 28)

This randomised trial assigned 131 people with fibrotic interstitial lung disease to high-intensity interval training or the standard moderate-intensity continuous training within an eight-week, twice-weekly pulmonary rehabilitation programme, stratified by exertional desaturation.

Both groups made clinically important gains in cycle endurance, with no difference between them (mean difference -63 seconds, 95% CI -195 to 68). Six-minute walk distance (difference 4 m) and all secondary outcomes were similar. There were no adverse events, and completion rates were similar.

The practical message is that rehabilitation works in fibrotic lung disease and that intervals are a safe alternative for patients who find continuous exercise hard.

Refer patients with fibrotic interstitial lung disease to pulmonary rehabilitation.
Offer interval training as an alternative when continuous exercise is limited by breathlessness or desaturation.
Use supplemental oxygen during training for patients who desaturate on exertion.
Reassess six-minute walk distance before and after the programme.

Why it matters

It removes a reason to delay rehabilitation while debating the best exercise format.

The statistics, in plain English

The confidence interval for endurance runs from about three minutes worse to one minute better with intervals, so the trial cannot exclude a modest difference either way, but finds none.