The Parallel Index
Independent verdicts in sport.
We score running products, supplements, wearables and popular claims against a single published rubric, and we show the working. Every entry gives an evidence score, the effect size, who the evidence covers and who it doesn't, the cost, and a one-line verdict. It's free and public, and the rubric is open to audit.
No Parallel Score for yet.
We only score something once we've read the literature and can stand behind the verdict. We've logged your question, and you can ask us to prioritise it.
Nothing matches that yet.
Try a different search or clear the filters.
How a verdict is made.
Every entry runs through the same five-step rubric, in the same order, whoever writes it. We publish the method so you can check our reasoning and challenge it. If you think we've missed a study, email contact@parallelperformance.co.uk and we'll review it against the entry.
Weighted by study design, sample size, population relevance and independence of funding. Randomised, adequately powered trials in trained runners count for more than a single small study or a brand-funded white paper.
Reported in plain units, such as a percentage, seconds or watts, rather than only as "significant". Where studies disagree, we give the full range rather than the most flattering number.
The population the evidence covers. A gain measured in elite marathoners is not a promise to a 28-minute 5K runner, and we say so.
The effect set against what it costs in money, time or trade-offs. A 1% gain for £5 and a 1% gain for £250 are not the same verdict.
One sentence you can act on, plus what the evidence still cannot tell us. The limits are part of the score, and we state them on the card.
The rubric is versioned. When we change how we score, the version number changes and older entries are re-reviewed against it, so the standard stays auditable over time.
If a product we'd love to be sponsored by doesn't hold up, the score says so. If a score can be bought, it isn't worth publishing.
When new research overturns something we wrote, we update the entry and log the change. The version history is public.
Every entry states the sample, the population and what the evidence can't yet tell you. We don't claim certainty we don't have.
Sport Science Simplified
A new verdict lands in the newsletter every week.
Get the Index in your inbox: 60 seconds of what the research says, every Tuesday.
Free. One email per week. Unsubscribe any time.