Helvy
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Haematology
In the UK, the standard clinical (NHS) reference range for Full Blood Count (FBC) is Hb: 130–170 g/L (men), with Hb: 145–165 g/L (men) considered the performance-optimised range. A result within these ranges suggests typical status; only a qualified clinician can interpret an individual reading.
A full blood count — often called an FBC or CBC — is the most commonly requested blood test in UK medicine. It measures haemoglobin (the oxygen-carrying protein in red blood cells), white blood cell count and differential (your immune army), platelets (clotting function), haematocrit (the proportion of your blood that is red cells), and red cell indices like MCV and MCH that reveal the size and haemoglobin content of individual red cells. Together, these markers paint a comprehensive picture of oxygen delivery, immune readiness, and nutritional status.
Optimal range · UK
Hb: 145–165 g/L (men)
Performance-optimised band · clinical (NHS) range Hb: 130–170 g/L (men)
Reference ranges for FBC, not a personal result. Any individual reading should be interpreted by a qualified clinician.
Optimal ranges
| Range | Value |
|---|---|
| Clinical (NHS) reference range | Hb: 130–170 g/L (men) |
| Performance-optimised range | Hb: 145–165 g/L (men) |
The clinical range defines what is considered medically “normal” — broad enough to cover 95% of the population. The performance range reflects where research and clinical experience suggest most people feel and function at their best. A result in either range suggests typical status and is not a diagnosis; any individual reading should be interpreted by a qualified clinician.
Why it matters
For active men, the FBC is the single most informative baseline test. Haemoglobin directly determines your VO₂ max ceiling — research shows total haemoglobin mass is roughly 15% higher in endurance-trained athletes than untrained individuals, and even a small drop from iron-deficiency anaemia can slash exercise capacity before you notice symptoms. Your white cell differential flags overtraining: a persistently low lymphocyte count or inverted neutrophil-to-lymphocyte ratio can signal immune suppression from excessive training load. MCV and MCH catch early B12 or folate deficiency (macrocytic anaemia) or iron deficiency (microcytic anaemia) months before you feel fatigued — the red cell indices shift before haemoglobin drops. Platelet count matters for recovery: low platelets impair wound healing and bruising, while a reactive high count can follow intense inflammation.
Symptoms
Low / Deficiency
High / Excess
Dietary sources
Supplementation
FBC abnormalities are treated by addressing the root cause, not by supplementing blindly. Low haemoglobin with low MCV suggests iron deficiency — ferrous bisglycinate (25–50mg elemental iron daily) is better tolerated than ferrous sulphate, taken with vitamin C on an empty stomach. Low haemoglobin with high MCV points to B12 or folate deficiency — methylcobalamin (1,000mcg daily) and/or methylfolate (400–800mcg daily). Low WBC in the context of heavy training may respond to zinc (15–30mg daily), vitamin D optimisation, and reducing training volume. Persistently abnormal FBC results warrant investigation by your GP — do not self-treat without understanding the cause. Retest after 8–12 weeks of targeted supplementation to confirm improvement.
Testing
FBC is measured from a blood sample. With Helvy, that means a finger-prick kit taken at home and posted to a UKAS-accredited UK laboratory, with results in around 5 days, reviewed by a qualified clinician. Your result is reported against both the clinical range (Hb: 130–170 g/L (men)) and the performance-optimal range (Hb: 145–165 g/L (men)), so you can see not just whether you are “normal” but whether you are optimal. If you make a change, retest after 8-12 weeks to confirm it worked.
Research
Blood Biomarker Profiling and Monitoring for High-Performance Physiology and Nutrition: Current Perspectives, Limitations and Recommendations
Pedlar CR, Newell J, Lewis NA
Sports Medicine (2019)
DOI: 10.1007/s40279-019-01158-xRelated biomarkers
Inflammation
Optimal: 80-150 ng/mL
Vitamins & Minerals
Optimal: 15-25 µmol/L (serum iron), 20-45% transferrin sat.
Vitamins & Minerals
Optimal: 500-800 pg/mL
Vitamins & Minerals
Optimal: 20-45 nmol/L
Related guides
This content is for educational purposes only and does not constitute medical advice. Your data suggests areas for optimisation, but any concerns should be discussed with a qualified healthcare professional. If your results flag values outside safe ranges, we recommend consulting your GP.
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