So what are pathogens, something to do with the Ancient Greeks?

Nope, pathogens are just viral and bacterial infections, the things that make us sick and keep us off our bikes.

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Sounds like we want to avoid those then?

Not really, no. Frequent contact with those nasties comes from being outside in the wilds — getting sprayed with mud, hugging trees, drinking from your muddy waterbottle and so on — actually boosts your body’s ability to fight them off. That makes mountain biking the perfect antidote to the increasingly sterile lives most people live.

So we need to rub as much dirt into our orifices as possible then?

No, there are limits, and doing that would be disgusting and also potentially overwhelm your immune system. There are two ways your body fights off infections, the first is called the Innate Immune Response (IIR) and it starts with your skin – it keeps out pathogens and it’s backed up by chemical barriers like mucus and tears, which keep those pathogens out of and gaps in the skin. Don’t try and force dirt through then by rubbing your eyes or touching your face, you’ll absorb enough just by riding your bike in it all.

I’m full of holes though, surely loads of dirt will get through?

Definitely, and that’s where the IIR has another trick up its sleeve — natural killer cells, neutrophils, macrophages and dendritic cells to take over, destroying infected cells that are compromised by pathogens.

I like the sound of natural killer cells

Well they’re not as cool as they sound, they don’t learn anything.

No one said I was going to have to learn!

Shut up and listen. The IIR doesn’t change, it’s innate. But the second way we fight off infections is really smart. Called the Adaptive Immune Response, it can learn how to fight off pathogens and uses immune cells called lymphocytes, cyctokines and antibodies to beat infections. It’s not quick, it takes something like 4-7 days to get fired up, but once you have those antibodies in your body it takes less time to react the next time you come into contact with it.

How does that help me when I’m riding?

Studies have shown (bit.ly/immunesuppression) that moderate exercise strengthens your entire immune system – riding increases your white blood cell count and with it your ability to fight off infections. More than that though, it boots ‘immunosurveillance’ and helps your body find infections faster. Good cardio also helps the pathogen-fighting cells move more easily through the body. When your body heats up it might even prevent infections from multiplying, much the same way a fever slows it all down when you’re sick.

So you’re telling me never to wash my hands?

Certainly not, wash those hands, especially in the Covid era as doing so kills off the virus before you get a chance to rub it into your eyes, pick your nose or do any other disgusting thing. What is really interesting though is the idea of old and new dirt put forward by Dr. Michael Ruscio (drruscio.com), a gut health expert in the US.

I know old dirt – loam, right?

Well yes, but he’s talking about something else. Dr Ruscio says that old dirt is all that stuff found outside we were talking about before, mud and leaves and the like. It’s good for us because it improves gut health and builds the immune system and reduces inflammation.

What about the bad and the ugly?

Well that’s new dirt – go into a public toilet and that’s very new dirt and you definitely need to wash your hands plenty after touching anything in there.

Gotcha, so wash after picking up a flat white, don’t worry when you faceplant into the mud then?

Oh you should worry, but more for your teeth. You raise an interesting point though, and that’s the use of carbohydrate to prevent illness. Research (bit.ly/carboimmunity) has shown that refuelling with the stuff — milk from your coffee or a recovery drink for example, boost your immune system

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Right, so head straight to the coffee shop post ride

Not if it’s been a really hard ride and you’re totally wasted, in that case it’s best to stay away from anyone not your immediate family for a period of four hours. That’s because you’re actually more susceptible to infection in that period. So although the overall effect of exercise is beneficial, don’t expose yourself more than is necessary post ride. While we’re on the topic too, research shows (bit.ly/cardioandhealth) that aerobic exercise – so steady riding, not hammering yourself – produces enzymes that protect against respiratory infections.

Anything else?

For more information on boosting your immune system head to torqfitness.co.uk.

Why yes, you need your vitamins. Keep those vitamin C and D levels up, we can’t produce them naturally in the body, so if there isn’t enough sunlight in your life or your diet’s not up to scratch you could become deficient in both. That’s bad news because your body needs both to fight off any infection.