Feasibility and physiological responses of supramaximal high-intensity interval training in people with COPD
Question
Can people with COPD feasibly complete very short supramaximal cycling HIIT, and how do acute intensity, symptoms, and exerkine responses compare with MICT?
Summary
In older adults with COPD and matched healthy controls, very short supramaximal cycling intervals were feasible, preferred over moderate continuous cycling, and produced higher external power with lower total work and lower ventilatory demand. Both supramaximal HIIT and MICT increased plasma BDNF acutely.
Methodology
- Older adults with COPD and age/sex-matched healthy controls
- 32 participants.
- Cycle ergometer.
- Work intervals: 6 seconds at 80-90 rpm.
- Recovery: 54 seconds total: 24 seconds passive plus 30 seconds active at 30% MAP.
- Intensity: HIIT60 at 60% MPO6 (~150% MAP); HIIT80 at 80% MPO6 (~200% MAP).
- 20 minutes including 5-minute warm-up and 5-minute cool-down.
- Acute crossover visits.
- Single acute sessions.
- Randomized controlled crossover single-center trial
- Exercise intensity, Plasma BDNF, Feasibility, and Symptoms were tracked.
Outcomes
Intensity
SupraHIIT achieved much higher external power than MICT.
COPD HIIT60 184 +/- 66 W and HIIT80 245 +/- 88 W versus MICT 71 +/- 22 W; P < 0.001
Feasibility
All participants completed SupraHIIT, while 5 of 16 COPD participants could not complete 20 minutes of MICT.
SupraHIIT 100% completion; COPD MICT non-completion 5/16, P = 0.008
Preference
Most participants preferred SupraHIIT over MICT.
COPD 13/16 preferred SupraHIIT, P = 0.009; healthy controls 14/16, P = 0.002
BDNF
Plasma BDNF increased after both SupraHIIT and MICT, with no modality or group difference; normalized per minute at target power, SupraHIIT showed a larger response.
Average relative increase 59% (range 30-87%); per-minute-at-target-power increase 5-10-fold greater for SupraHIIT, not consistently statistically significant
Ventilation
SupraHIIT had lower ventilatory demand and lower symptoms than MICT despite higher external power.
Minute ventilation, VE/MVV, breathing frequency, RPE, dyspnoea and leg fatigue generally lower in SupraHIIT than MICT
Insights
- Very short 6-second cycling intervals may be more tolerable than continuous moderate work for some older adults with COPD.
- High external power does not necessarily mean high ventilatory burden when intervals are extremely brief with long recovery.
- This was acute and supervised; it does not prove long-term training safety or adaptation.
Limitations
- Small sample.
- Acute crossover design; no long-term training outcomes.
- Few participants with severe COPD and none with very severe airflow obstruction.
- Exercise protocols were not work-matched.
- Assessors were not blinded and allocation was not concealed.
- Some results rely on supplementary data not fully extracted here.
Safety
- All participants completed SupraHIIT.
- Five of 16 COPD participants interrupted MICT because of intolerable dyspnoea/exhaustion.
- No other adverse events described in the paper.