Lactate Dehydrogenase

Understanding LDH:

• LDH is found in all tissues — elevation alone does not indicate the source
• Pair with ALT/AST (liver), CK (muscle), haptoglobin/reticulocytes (haemolysis) to identify origin
• Post-intense training elevation is expected and benign if transient

If Elevated:

• If ALT/AST also elevated → hepatic source, assess oral AAS use and liver support
• If CK also elevated → skeletal muscle damage from training (expected, benign if <5x normal)
• If haptoglobin low → haemolysis (foot-strike haemolysis in cardio, or intravascular from EPO-driven polycythaemia)
• Persistent elevation (>2 weeks rest) warrants investigation

Supplements:

• NAC -- 600-1200mg/day (hepatoprotective, antioxidant)
• TUDCA -- 250-500mg/day (if on oral AAS)
• CoQ10 -- 100-200mg/day (supports cellular energy, reduces oxidative damage)

Lifestyle:

• Allow 48-72 hours rest before blood draw for baseline reading
• Avoid intense training 72h before testing
• If on oral AAS and LDH persistently elevated with liver markers, consider discontinuing orals

References:

• Brancaccio, P., Maffulli, N., & Limongelli, F. M. (2007). Creatine kinase monitoring in sport medicine. British Medical Bulletin, 81-82(1), 209-230. DOI: 10.1093/bmb/ldm014
• Banfi, G., Colombini, A., Lombardi, G., & Lubkowska, A. (2012). Metabolic markers in sports medicine. Advances in Clinical Chemistry, 56, 1-54. DOI: 10.1016/B978-0-12-394317-0.00015-7
• Lippi, G., Schena, F., & Ceriotti, F. (2012). Diagnostic biomarkers of muscle injury and exertional rhabdomyolysis. Clinical Chemistry and Laboratory Medicine, 50(3), 403-405. DOI: 10.1515/cclm.2011.814