Blood tests for strength training and bodybuilding

The tests that matter most

Most important first. Each one links to its full page, where the note for this group sits near the top.

• Creatinine

  Creatinine comes from muscle, so more muscle, creatine supplements and high-protein diets can raise it without any change in how well the kidneys filter. In healthy people, a creatine-related rise is unlikely to mean kidney damage.

  Sources: KDIGO (2024) and Journal of the International Society of Sports Nutrition (2021)

  Men, 15+

  0.74–1.35 mg/dL

  Women, 16+

  0.59–1.04 mg/dL

• eGFR (Creatinine-based)

  Most eGFR results are worked out from creatinine, so a very muscular person can get an eGFR that looks lower than their true kidney function. Kidney guidelines list bodybuilding among the reasons a creatinine-based estimate can be off.

  Source: KDIGO (2024)

  Usual adult range

  60 and above mL/min/1.73 m²

• Cystatin C

  Cystatin C is a second kidney marker that doesn't depend on muscle. Kidney guidelines say an eGFR from cystatin C may suit people whose only reason to doubt their creatinine is extra muscle. The same guidelines note that steroids, including anabolic steroids, can affect cystatin C as well as creatinine.

  Source: KDIGO (2024)

  18–49

  0.63–1.03 mg/L

  50+

  0.67–1.21 mg/L

• Creatine Kinase (CK), Total

  CK leaks from muscle after training, and resistance work, especially the lowering (eccentric) part of a lift, tends to raise it the most. A high CK after lifting is common, and some people rise far more than others after the same session.

  Source: Journal of Nutrition and Metabolism (2012)

  Men, 19–49

  26–366 U/L

  Women, 19–49

  20–239 U/L

• Aspartate Aminotransferase (AST)

  AST is found in muscle as well as liver. In one study, a single hour of weightlifting raised AST in men new to lifting, while GGT and bilirubin stayed normal.

  Source: British Journal of Clinical Pharmacology (2008)

  Men, 14+

  8–48 U/L

  Women, 14+

  8–43 U/L

• Alanine Aminotransferase (ALT)

  ALT is usually read as a liver test, but heavy workouts can raise it too. An Endocrine Society statement notes that liver enzymes raised by heavy workouts can be misread as a sign of liver problems.

  Sources: British Journal of Clinical Pharmacology (2008) and Endocrine Reviews (2014)

  Men, 18+

  0–44 U/L

  Women, 18+

  0–32 U/L

• Hematocrit

  Hematocrit is the share of blood made of red cells. Testosterone and anabolic steroids raise hemoglobin and hematocrit in a dose-related way, and a high count is a common side effect.

  Source: Endocrine Reviews (2014)

  Men, 13+

  37.5–51 %

  Women, 13+

  34–46.6 %

• HDL Cholesterol

  Anabolic steroids lower HDL cholesterol, especially steroids taken by mouth. A low HDL is one of the lab signs the Endocrine Society says might suggest steroid use.

  Source: Endocrine Reviews (2014)

  Usual adult range

  40 and above mg/dL

• LDL Cholesterol

  Anabolic steroids tend to raise LDL cholesterol while lowering HDL. That pattern is linked to artery disease over time.

  Source: Endocrine Reviews (2014)

  Usual adult range

  up to 99 mg/dL

• Testosterone, Total

  Taking testosterone or other steroids switches off the body's own testosterone signal. After stopping, natural testosterone can stay low for months or longer.

  Source: Endocrine Reviews (2014)

  Men, 20+

  264–916 ng/dL

  Men, 18–19

  150–785 ng/dL

• Luteinizing Hormone (LH)

  LH is the brain's signal to the testes to make testosterone. A high testosterone with a suppressed LH and FSH is the pattern seen when testosterone comes from outside the body.

  Source: Endocrine Reviews (2014)

  Usual adult range

  1.7–8.6 mIU/mL

Ranges shown are the usual adult ranges labs print. The range on your own report is the one your result is judged against.

Also written for

• Endurance athlete
• On testosterone therapy
• Kidney disease or at risk