High-Intensity Interval Training in Polycystic Ovary Syndrome: A Two-Center, Three-Armed Randomized Controlled Trial.
Level 2 - randomized trial
Two-center, three-armed randomized controlled trial
PubMed 35019901 · doi:10.1249/MSS.0000000000002849
What was done
In a two-center randomized controlled trial in Norway and Australia (IMPROV-IT), 64 women with polycystic ovary syndrome (PCOS) were stratified by body mass index (<27 or ≥27 kg·m⁻²) and study center, then randomly allocated 1:1:1 to high-volume high-intensity interval training (HV-HIT, n = 20), low-volume HIT (LV-HIT, n = 21), or a control group (n = 23). The exercise intervention was semisupervised and lasted 16 weeks, with follow-up at 12 months. The primary outcome was menstrual frequency at 12 months. Secondary outcomes included cardiometabolic and reproductive health markers, quality of life, adherence, and enjoyment.
What was found
Menstrual frequency at 12 months did not differ significantly between LV-HIT and control (frequency ratio 1.02, 95% CI 0.73–1.42), HV-HIT and control (frequency ratio 0.93, 95% CI 0.67–1.29), or LV-HIT and HV-HIT (frequency ratio 1.09, 95% CI 0.77–1.56). Menstrual frequency increased across all groups from baseline to 12 months. Significantly more participants became pregnant in the LV-HIT group (n = 5) than in the control group (n = 0, P = 0.02). The abstract reports no numerical values for cardiometabolic markers, quality of life, adherence, or enjoyment.
Why it matters
Structured HIT did not improve 12-month menstrual frequency over control in women with PCOS, questioning whether interval exercise specifically enhances this reproductive marker.
Limits
The sample size was small (n = 64 across three arms). The exercise intervention was semisupervised and lasted 16 weeks, while the primary outcome was measured at 12 months. Specific data for other secondary cardiometabolic and reproductive outcomes were omitted from the abstract.
Cited by
- supports Research from Norway shows that high-intensity interval training provides specific health benefits for individuals with polycystic ovary syndrome (PCOS).