Avoid strenuous or unusually intense exercise for at least 24 hours before testing, particularly where CRP, Full Blood Count or liver-related markers are being assessed.
For an accurate baseline or treatment-monitoring sample, 48 hours without strenuous exercise may be preferable, especially after an exceptionally hard or prolonged session. Follow any longer instruction specific to the tests you are having.
Normal light activity, including routine walking, is generally acceptable. The aim is to avoid taking a baseline sample immediately after an unusually demanding effort.
Hard exercise can alter inflammatory and blood-cell measurements and raise muscle-derived enzymes, particularly CK and AST. These effects can make a sample less representative of your usual resting state.
ALT and other biochemical measurements may also change.