PERFORMANCE INTELLIGENCE / BLOG POST / BIOMARKERS

Which Health Markers Should Men Over 40 Pay Attention To?

A practical introduction to the blood markers that matter most for high-performing men over 40 and why most of them are not on a standard GP panel.

GP blood panel

A standard GP blood panel is designed to identify clinical illness.

It does this job reasonably well.

But clinical illness and optimal performance are not the same thing. And the gap between these two standards the gap between markers that are not alarming enough to treat and markers that are genuinely optimal for a man operating under sustained professional demand is where most high-performing men over 40 are living without knowing it.

Here is a practical introduction to the markers that actually matter.

Hormonal markers

Free testosterone and SHBG, not just total testosterone. Total testosterone is what appears on a standard panel. Free testosterone, the fraction that is actually biologically available, and SHBG (sex hormone-binding globulin), the protein that binds testosterone and reduces its availability, are rarely included. A man can have total testosterone in the normal range with SHBG so elevated that the free fraction is significantly suboptimal. Without testing both, you have an incomplete picture.

Morning cortisol is the most important performance marker for a man under sustained professional pressure and is almost never included in a standard screen. Chronically elevated cortisol is the upstream driver of visceral fat accumulation, testosterone suppression, sleep disruption, and the performance decline most men attribute to age. Knowing where yours sits changes the entire intervention.

Metabolic markers

Fasting insulin is the single most informative metabolic marker available and almost never included in a standard panel. Insulin resistance develops silently across years before it appears as elevated blood glucose. Fasting insulin elevated above optimal indicates developing insulin resistance years before it would be flagged clinically, allowing intervention at a point where it is still highly responsive.

HbA1c measures average blood glucose across the preceding three months. More informative than a single fasting glucose reading because it reflects the pattern rather than the point in time. Sitting below diabetic threshold but above optimal is extremely common and clinically invisible on most standard screens.

Inflammatory markers

High sensitivity CRP is a measure of systemic inflammatory burden. Chronic low-grade inflammation is now understood to be the upstream driver of cardiovascular disease, metabolic syndrome, cognitive decline, and biological ageing. hs-CRP provides a sensitive measure of this burden at levels that standard CRP testing misses.

Homocysteine is an amino acid that at elevated levels is strongly associated with cardiovascular risk and cognitive decline. Responsive to B vitamin status and measurable through a routine blood test. Rarely included in standard screening.

Cardiovascular markers

ApoB is the most precise cardiovascular risk marker available. Standard cholesterol testing measures the amount of cholesterol. ApoB measures the number of atherogenic particles, the actual driver of arterial plaque formation. Two men with identical LDL cholesterol readings can have significantly different ApoB levels and correspondingly different cardiovascular risk. ApoB is the marker that tells the story standard cholesterol cannot.

Nutrient status

Vitamin D at 25-OH is not whether you are deficient but whether you are optimal. Governing testosterone synthesis, immune function, mood regulation, and neural performance. Present at inadequate levels in over 40% of UK adults.

Ferritin: iron storage. Low ferritin is one of the most commonly missed drivers of fatigue in men, particularly those who train consistently. Sitting below optimal without triggering a clinical flag. Directly affecting oxygen-carrying capacity and physical output.

Magnesium is chronically depleted in men under sustained professional stress. Involved in over three hundred enzymatic processes including energy production, cortisol regulation, and sleep quality. Almost never tested on a standard panel.

How to use this information

These markers do not need to be tracked obsessively.

They need to be established as a baseline, ideally before symptoms appear and reviewed at meaningful intervals. Quarterly for the key performance markers. Annually for the broader picture.

What a baseline establishes is the specific starting point for the specific man. Not the reference range. Not the average. Where this particular biology is and what direction it is moving.