The Study
Early warning system for player recovery? A series of case studies illustrating the application of individualised adaptive reference ranges in the longitudinal blood monitoring of English Premier League soccer players
This study watched a few soccer players over time and saw that tracking their own blood numbers helped spot when something might be off. But it didn't test if this actually made them feel better or play better—it just noticed patterns.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Instead of using the same normal range for everyone, this study tried making a custom normal range for each soccer player based on their own past CRP levels.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 526 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — if a player's body is consistently stable, small changes in CRP might signal they need rest or medical help before they feel sick or injured.
- 2Custom ranges found more true problems than the one-size-fits-all range, especially when a player's own numbers didn't change much from game to game.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Biomarkers
Year
2025
Authors
Diarmuid Daniels, Davood Roshan, Nathan A Lewis, John Newell, G. Bruinvels, Paul Catterson, J. Harley, Micheál Newell, A. Barr, Charles R. Pedlar
Related Content
Claims (4)
Doctors use average blood test numbers to decide what's 'normal,' but those averages include sick people, so healthy people might be told they're unhealthy—and real health problems might be missed.
Doctors can use a quick blood test at the sideline to see if soccer players are under stress or have inflammation, just by checking a protein called CRP.
Instead of using the same CRP blood test numbers for everyone, doctors could tailor the normal range for each soccer player based on their own body patterns — this might help catch when they're stressed or injured earlier.
Scientists think that adjusting what counts as a 'normal' CRP level for each soccer player might help coaches spot when a player needs rest or medical care — but it won't tell you for sure if they're sick.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.