PMID 32992871

Research
All papers

High-Intensity Interval Training Is Effective at Increasing Exercise Endurance Capacity and Is Well Tolerated by Adults with Cystic Fibrosis

Sawyer A, Cavalheri V, Jenkins S, Wood J, Cecins N, Bear N, Singh B, Gucciardi D, Hill K

Question

Is an 8-week supervised low-volume cycling HIIT program effective and tolerable for improving exercise capacity in people with cystic fibrosis?

Summary

In a small randomized study of adults and adolescents with cystic fibrosis, 8 weeks of brief supervised cycle HIIT improved constant-work-rate exercise endurance and peak work capacity compared with usual care contact. Attendance was high, all attended sessions were completed, soreness was mild, and no adverse events were reported.

Methodology

  • Adults and adolescents with cystic fibrosis, clinically stable enough for maximal cycle testing.
  • 14 participants.
  • Stationary cycling.
  • Work intervals: 30 s.
  • Recovery: 30 s rest.
  • Intensity: 60% Wmax initially, progressing to 80% Wmax by week 2 and higher as symptoms allowed.
  • 10 min.
  • 2/week for 2 weeks, then 3/week for 6 weeks.
  • 8 weeks.
  • Pilot randomized controlled trial
  • Time to limitation, Wmax, VO2peak, and Tolerability were tracked.

Outcomes

Endurance time

Time to limitation improved more with HIIT than control.

Experimental median 276 to 555 s; control 248 to 230 s; p=0.017.

Improved

Wmax

Peak work capacity improved more with HIIT than control.

p=0.017 for Wmax and Wmax percent predicted.

Improved

VO2peak

VO2peak did not differ significantly between groups.

Reported p values included p=0.20 and p=0.27.

No clear change

Safety

The protocol was well tolerated with high attendance, mild soreness only, and no reported adverse events.

Attendance 93% (IQR 83, 95); 100% completion of attended sessions.

Improved

Insights

  • A 10 min, 6 x 30 s cycle-HIIT format may be feasible in stable CF when supervised clinically.
  • SpO2 and pulse monitoring were part of the safety model.

Limitations

  • Recruitment was low
  • Target sample size was not met
  • Very small randomized groups
  • Clinical supervision limits direct consumer-app translation

Safety

  • No minor or major adverse events were reported.
  • Four participants reported one episode each of mild quadriceps soreness.