PMID 40132852

Research
All papers

Effects of aquatic high-intensity interval training on aerobic capacity in adults with rheumatic and musculoskeletal diseases: the AquaHigh randomised controlled trial

Bunæs-Næss H, Heywood SE, Kvæl LAH, Heiberg KE, Nilsson BB

Question

Does 12 weeks of aquatic high-intensity interval training improve aerobic capacity more than aquatic moderate-intensity continuous training in adults with rheumatic and musculoskeletal diseases?

Summary

In adults with rheumatic and musculoskeletal diseases, 12 weeks of peer-led aquatic HIIT improved estimated VO2peak more than moderate aquatic exercise at 3 months, but the advantage was not maintained at 6 months. Lower-limb sit-to-stand performance improved similarly in both groups, and no exercise adverse events were reported.

Methodology

  • Adults with rheumatic and musculoskeletal diseases
  • 89 participants.
  • Aquatic exercise.
  • Work intervals: 4 min at Borg RPE 14-18.
  • Recovery: 2-3 min light aquatic recovery exercises.
  • Intensity: Borg 14-18; mean achieved RPE 15.
  • 45-60 min.
  • 2 sessions/week.
  • 12 weeks.
  • Assessor-blinded pragmatic multisite randomized controlled trial
  • Estimated VO2peak, Lower-limb functional strength, and Adverse events were tracked.

Outcomes

VO2peak

AHIIT improved estimated VO2peak more than AMICT after 12 weeks.

Mean difference 1.91 mL/kg/min, 95% CI 0.05 to 3.77, p=0.045.

Improved

VO2peak follow-up

The between-group VO2peak advantage was not maintained at 6 months.

Mean difference 1.06 mL/kg/min, 95% CI -1.05 to 3.17, p=0.322.

No clear change

Sit-to-stand

Lower-limb functional strength improved in both groups without between-group differences.

30sSTS mean difference 0.55 at 3 months, p=0.528; 0.55 at 6 months, p=0.543.

No clear change

Safety

No exercise adverse events were reported.

No clear change

Insights

  • Aquatic HIIT can use a 4 x 4-min RPE-based structure for screened clinical adults.
  • Intensity adherence may need repeated RPE training and instructor feedback.
  • Ongoing participation may be needed to sustain aerobic gains.

Limitations

  • High dropout
  • Small sample
  • Participants and instructors not blinded
  • No healthcare professional supervision at every session
  • Pool-based protocol limits direct app translation

Safety

  • No adverse events were reported during the intervention.
  • Medical contraindications to high-intensity exercise were excluded.