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The Bodybuilder's Guide to Bloodwork: What to Test, When to Test, and What to Do With the Results

14 May 202612 min read

If you take your training seriously, your bloodwork should be as structured as your programming. Here's a comprehensive guide to building a blood testing protocol that gives you real, actionable data.

The minimum testing panel

At bare minimum, test the following twice per year: full blood count (FBC), comprehensive metabolic panel (CMP), lipid panel, testosterone (total and free), SHBG, vitamin D, ferritin, CRP. This gives you a baseline picture of organ function, hormonal status, inflammation, and key micronutrients.

The performance panel

For those who want more complete data, add: thyroid panel (TSH, free T3, free T4), IGF-1, cortisol (morning draw), insulin (fasting), HbA1c, ApoB, homocysteine, magnesium (RBC), zinc, B12, folate. This panel catches most of the issues that drive suboptimal performance and recovery.

When to test

The most useful time to test is after a period of normal training — not immediately after a hard competition or deload. Test fasted (10–12 hours), with no training in the preceding 24–48 hours for markers like ALT and creatine kinase that training elevates. Morning is best for cortisol. Consistent conditions across tests make trend data much more reliable.

Reading your results

The order of interpretation matters. First: is anything critically out of range — flagged with H* or L* on your report? These require medical attention. Second: what is borderline — within range but at the edges? These are your optimisation targets. Third: what is sub-optimal against athlete-adjusted or optimal ranges? These are your performance edges.

Tracking over time

A single blood test is a snapshot. Trends across 3–4 tests are where the real signal is. Is your haemoglobin trending down over 12 months? Is your testosterone declining year on year? Is your LDL rising? Single results can be explained away. Trends require action.

Acting on results

For most markers, the first interventions are dietary and lifestyle. Vitamin D: supplement. Ferritin: dietary iron and supplementation. Testosterone: sleep, zinc, training load, body fat. High LDL: diet composition, fibre intake, ApoB testing. Elevated inflammatory markers: recovery, stress, sleep, dietary anti-inflammatories. Only after consistent lifestyle intervention fails should medication conversations begin.

What to do with the data

Upload to MarkerX after each test. Over time you'll build a trend database of your own biology — seeing correlations between training blocks, dietary changes, sleep quality, and your markers. That's when blood testing becomes genuinely powerful.

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