Standard lab reference ranges are calibrated on the general population — sedentary individuals, elderly patients, people with chronic disease. They do not apply to strength athletes, and they certainly do not apply to AAS users.
Here is the problem: your lab report prints ranges based on a statistical average of everyone who has ever walked into that lab. That includes people who do not train, do not track their health, and do not use performance-enhancing substances. If you are reading this, you are none of those things.
The table below shows how dramatically different the "normal" range is depending on who you are. We use three columns: the standard lab range printed on your blood work, the athletic range calibrated for healthy training individuals, and the AAS user range for those on or recently off exogenous androgens.
| Marker | Standard Range | Athletic Range | AAS User Range |
|---|---|---|---|
| 🩺 Kidney Function | |||
| eGFR | > 90 mL/min | > 75 mL/min | > 60 mL/min (with normal Cystatin C) |
| Creatinine | 0.7—1.2 mg/dL | 0.9—1.4 mg/dL | 1.0—1.5 mg/dL |
| Cystatin C | 0.5—1.0 mg/L | 0.5—1.0 mg/L | 0.5—1.0 mg/L (gold standard) |
| 🫀 Liver & Muscle | |||
| AST | 10—40 U/L | 20—60 U/L | 20—80 U/L |
| ALT | 7—56 U/L | 10—60 U/L | 10—70 U/L |
| GGT | 8—61 U/L | 8—55 U/L | 8—55 U/L (must be normal) |
| CK | 30—200 U/L | 100—1,000 U/L | 100—1,500 U/L |
| ❤️ Lipids & Cardiovascular | |||
| HDL | > 40 mg/dL(M), > 50 mg/dL(F) | > 35 mg/dL | > 25 mg/dL (on blast) |
| LDL | < 100 mg/dL | < 130 mg/dL | < 160 mg/dL (on blast) |
| ApoB | < 100 mg/dL | < 110 mg/dL | < 130 mg/dL |
| Triglycerides | < 150 mg/dL | < 150 mg/dL | < 200 mg/dL |
| 🩸 Hematology | |||
| Hematocrit | 38—50%(M), 34—44%(F) | 40—52% | 45—54% |
| Hemoglobin | 13.5—17.5 g/dL(M) | 14—18 g/dL | 15—19 g/dL |
| RBC | 4.5—5.9 M/uL(M) | 4.8—6.2 M/uL | 5.0—6.5 M/uL |
| 🧪 Hormones | |||
| Total Testosterone | 300—1,000 ng/dL | 350—1,100 ng/dL | 100—3,000+ ng/dL |
| Estradiol (sensitive) | 10—40 pg/mL(M) | 15—35 pg/mL(M) | 20—60 pg/mL (on cycle) |
| SHBG | 10—50 nmol/L | 15—45 nmol/L | 5—25 nmol/L (suppressed) |
| TSH | 0.4—4.0 mIU/L | 0.5—3.0 mIU/L | 0.5—3.5 mIU/L |
Every difference in that table has a specific physiological explanation. None of it is random. Let us walk through each category so you understand the reasoning behind the numbers.
Kidney Markers: eGFR, Creatinine & Cystatin C
eGFR is not actually measured — it is calculated from your serum creatinine level. Creatinine is a waste product of muscle metabolism. The more muscle you carry, the more creatinine your body produces, and the lower your calculated eGFR drops.
For a strength athlete, an eGFR of 75 mL/min is typically normal physiology, not kidney disease. On AAS, muscle mass increases further, pushing creatinine even higher and eGFR even lower. This is why Cystatin C is so important: it is a kidney function marker that is completely independent of muscle mass. If your Cystatin C is normal, your kidneys are fine regardless of what the creatinine-based eGFR says.
Practical tip: Always request Cystatin C alongside creatinine if you are a strength athlete or AAS user. It prevents unnecessary nephrology referrals.
Liver Markers: AST, ALT, GGT & CK
AST and ALT are present in both liver cells and skeletal muscle cells. When you train hard — especially with heavy compound lifts — you create microtrauma in your muscle fibers. Those damaged muscle cells release AST and ALT into your bloodstream, exactly as liver cells would if you had liver damage.
The key insight is GGT: this enzyme is found in the liver but not in muscle. If your AST and ALT are elevated but your GGT is normal, the source is almost certainly muscle, not liver. CK (creatine kinase) confirms this: a high CK alongside elevated AST/ALT with normal GGT is the classic muscle-leak pattern.
Oral AAS add a genuine hepatic burden that GGT captures well. If you are on oral compounds and your GGT starts rising, that is a real signal — not training noise.
Lipids: HDL, LDL, ApoB & Triglycerides
AAS suppress HDL and raise LDL through multiple mechanisms: increased hepatic lipase activity, altered reverse cholesterol transport, and direct effects on lipid metabolism. The standard "HDL above 40" threshold is almost never met on blast.
The athletic-adjusted threshold of above 25 mg/dL reflects on-cycle reality while still flagging truly dangerous values. The more important marker is ApoB: it measures the number of atherogenic particles and is a stronger predictor of cardiovascular risk than LDL or HDL in isolation.
Hematology: Hematocrit, Hemoglobin & RBC
AAS stimulate erythropoiesis — your bone marrow produces more red blood cells. A hematocrit of 50—52% is expected on cycle. Above 54% requires intervention such as dose reduction or therapeutic phlebotomy.
The standard range upper limit of 50% would flag almost every AAS user as abnormal, creating unnecessary alarm. However, once hematocrit exceeds 54%, the increased blood viscosity becomes a genuine stroke and cardiovascular risk regardless of the cause.
Hormones: TT, E2 & SHBG
Total testosterone on cycle ranges from supraphysiological to suprapharmacological. Standard ranges simply have no concept for this — they are designed for natural production. SHBG is pharmacologically suppressed by AAS in a dose-dependent manner. E2 rises proportionally to T via aromatase. These are expected pharmacological effects, not pathological findings.
Fewer False Positives
Standard ranges flagging athletes as abnormal is not harmless. It leads to unnecessary medical workups, patient anxiety, and sometimes harmful interventions.
Example: statins for benign LDL elevations on cycle.
Fewer False Negatives
If we use only athletic ranges for AAS users, we miss drug-specific toxicity. The AAS column catches what training alone does not explain.
Example: rising GGT on oral AAS = real liver stress.
Better Clinical Decisions
Your doctor sees the same lab values. When you bring adjusted ranges, you help them interpret correctly. Many GPs have no training in sports medicine or AAS pharmacology.
Accurate Trend Tracking
When you track markers over time using the correct baseline, you see real changes — not artifacts of comparing yourself to the wrong population.
The Cost of False Positives
📏One number can mean health or disease depending entirely on context. A creatinine of 1.4 in a 65-year-old sedentary woman is kidney concern. The same number in a 100 kg strength athlete is Tuesday.
— GearCheck Reference System
How do you use this information in practice? Here is a simple workflow:
- Know your category. Are you a non-training individual, a strength athlete, or an AAS user? Your reference ranges change based on this answer.
- Compare within your column. When reviewing your lab results, use the Athletic or AAS column — not the Standard column printed on the report.
- Watch the cross-check markers. Cystatin C for kidneys, GGT for liver, ApoB for cardiovascular risk. These are the specificity markers that separate real problems from expected physiology.
- Track trends, not snapshots. A single out-of-range value is less meaningful than the direction it is moving over consecutive tests.