Cell biology and proposed mechanisms
Antioxidant
In biochemistry an antioxidant is any molecule that slows or prevents the oxidation of another molecule, usually by being oxidised itself. In everyday use the word has come to mean a supplement or food assumed to be healthy. The two meanings have drifted far apart.
Also called antioxidants, free radical scavenger, ORAC
The biochemical meaning
The body’s antioxidant system has two arms. Enzymes — superoxide dismutase, catalase, glutathione peroxidase — destroy reactive species catalytically and are regenerated. Small molecules such as glutathione, vitamin C and vitamin E are consumed as they act. The enzymatic arm does most of the work, regulated by Nrf2.
Why “more is better” is not what the biology says
Reactive oxygen species are not only damage. They are signalling molecules the body uses deliberately, and suppressing them indiscriminately suppresses the signal.
- Antioxidants prevent health-promoting effects of physical exercise in humans, PNAS (2009): vitamin C and E supplements abolished the insulin-sensitivity gain from four weeks of training, and blocked the exercise-induced rise in superoxide dismutase.
- Antioxidant supplements for prevention of mortality, Cochrane (2012): 78 trials, 296,707 participants. No mortality benefit, and in low-bias trials beta-carotene and vitamin E increased it.
The popular meaning is loosely grounded too: the ORAC score that food marketing was built on was reportedly withdrawn by the US Department of Agriculture in 2012, its values having no demonstrated relevance to human health.
Why this shapes our timing guidance
On the oxidative preconditioning hypothesis the oxidant is the active agent and the antioxidant rise is the body’s own response, so a large antioxidant dose around a session may work against the proposed mechanism. That is a question rather than settled science, but it is one reason we ask clients to leave one to two hours either side of a session before taking vitamin C or supplements.
If you take any medication, ask your doctor or pharmacist whether to time your session around it. Never skip, delay or move a prescribed dose to fit a session.
Why it matters here
Many people already take antioxidant supplements. This is the background to the guidance about leaving an hour or two either side of a session before vitamin C or supplements. If you take any medication, ask your doctor or pharmacist whether to time your session around it. Never skip, delay or move a prescribed dose to fit a session.