The Journal

HbA1c, ApoB, hs-CRP, ferritin and vitamin D: what each one tells you over the years, and why a trend is worth more than any single result.

Why most people in the UK run low between October and March, what the NHS advises, and why a test is better than guessing.

Baseline, mid-block and pre-race: how to time a blood test so hard sessions do not muddy the results.

Reference ranges, flags, what "optimal" means, why trends beat snapshots, and when to take a result to your GP.

What iron stores do, why endurance athletes run low, the thresholds sports medicine uses, and what to ask your GP.