Categories of research evidence used for this report, adapted from the American College of Sports Medicine criteria62 (applied in box 1)
| Category | Descriptor |
|---|---|
| (A) Randomised, controlled trials (overwhelming data) | Provides a consistent pattern of findings with substantial studies |
| (B) Randomised, controlled trials (limited data) and high-quality observational data | Few randomised trials exist which are small in size, and results are inconsistent or observation studies supported by evidence of causality from acute or experimental studies |
| (C) Non-randomised trials, observational studies | Outcomes are from uncontrolled, non-randomised, and/or observational studies |
| (D) Panel consensus judgement | Panel’s expert opinion when the evidence is insufficient to place it in categories A–C |