Runners get more mosquito bites than sedentary individuals – learn how to avoid the pesky little blood-suckers.

The name Mosquito is considered to have it’s origin in the Spanish language, being a combination of the words “mosca” = fly and “ito” = miniscule.

Mosquitos are remarkable little critters. There are more than 3500 known species of mosquito and they’ve survived on our beautiful planet in one form or another for approximately 80 million years. Longevity as a species aside, they possess some amazing characteristics and they are food for an incredible array of other life forms -spiders, birds, fish, frogs etc – heck I’m sure I’ve even swallowed a few.

But I can’t bring myself to like them. In fact I loathe them. Perhaps it’s the irritating sound they make or because they carry disease. Or maybe it’s my inability to square their paradoxical position in the order of things – they’re at the bottom of the food chain – yet they feed on us – at the top of the food chain. But most likely it’s because they like to bite me and those bites are so annoyingly itchy for days afterwards…

I’ve recently returned from a family holiday in Croatia (Chiovo island). As I adore running, I always pack my running shoes and kit for my holidays and love to get up early and have a run. It’s a great way to start the day and elude the oppressive heat, plus I get to explore where we’re staying and get a feel for what’s available within walking distance. I’m normally back and showered before my family have woken up.

As is the norm whenever we holiday in warmer climes, I get bitten by mosquitos considerably more than any other member of my family. Like 3 to 4 times as much!! I often end up looking like I have the measles, whilst you’d be hard pressed to notice more than a handful of bites on either of my kids or wife. I’ve often wondered why and have for some time suspected that my being a runner has something to do with it. So, this year, after suffering with some particularly-itchy-mozzie-bites I did some research and it turns out that my hunch was right.

Runners are much more likely to be bitten by mosquitos than sedentary individuals…

Mosquitos are attracted to their human chow by:

  • Odorants or scent markers – namely:
    • Carbon Dioxide (CO2). We all produce CO2 , but the rate of production rises with increased metabolism. Running will temporarily increase your metabolic rate. This effect will roll-over and continue even when you’re resting. In fact this metabolic boost can result in a runner producing up to 4 times as much CO2 as a sedentary person.
    • Lactic Acid. This is a natural by-product of prolonged aerobic exercise and something that runners are good at producing and processing. Unfortunately, those little insect vampires also love the stuff and having oodles of it sloshing around in your veins is like strapping on an illuminated neon sign saying “FREE all you can eat buffet here – no reservations necessary” in Mosquito.
    • Ammonia. This is quite a common constituent part of our sweat when we exercise/run, especially if our diet is lacking in carbohydrates. Unfortunately, it also attracts the gnat-pack in droves.
    • Blood Type. They really like Type O for some reason. There are several theories about exactly why that should be. But the Type O scent marker does prove to be more attractive to the irksome flying leeches. I Don’t know what my blood type is, but there’s a very good chance that it’s O, as according to the National Blood Service 36% of the UK population is O +ve and 12% are O -ve. It’s a very similar picture for the US and Canada too. So I suppose if you’re of Caucasian origin you have close to a 50-50 chance of being a mosquito’s favourite source of sustenance.
    • Alcohol. There is some debate about whether Mosquitos are attracted to the scent-markers of alcohol or whether it’s the effect that consuming alcohol has on the human body (it increases metabolism and body temp) that result in more bites. But the consensus is that drinking alcohol is a factor in attracting mosquitos to us. I think they just like the buzz and there are probably some alcohol dependant mozzies flitting about and hanging around outside bars just waiting for their next boozed-up-human to drink from to get their own alcohol fix.
    • Perfumed Products. Some scented hair gels, shampoos and antiperspirants/deodorants, especially those with floral scents can be very attractive to mosquitos. I get showered soon after my morning run and slap some shower gel on, then add antiperspirant once towelled off. So, from the get-go I’m smelling as fresh as a daisy and also wafting an irresistible smell of a nutritious-foodstuff in the directions of every mozzie within a mile radius for the rest of the day. Also as I get slathered up with sun-cream throughout the day I generally have another shower before dinner. Depending on your own personal hygiene standards and what products you use, you may also be doing a fine job of advertising your deliciousness to every mozzie in the neighbourhood.
  • Skin temperature – Yep, you guessed it, those tiny-winged-parasites are like little heat-seeking-missiles and can use body heat as a guidance system to their next meal. The higher your skin temperature, the easier it is for them to find you. Running will increase skin temperature in two main ways: firstly because of the heat generated by the exercising muscles and secondly by the increased metabolic rate. So, it’s a double whammy, with a quick, more pronounced increase when you run and a prolonged effect for the rest of the day thereafter. Plus if you drink alcohol (hey if you’re on holiday it would seem rude not to) – that’s another potential source for raising your skin temperature too. Pregnancy will also raise your body temperature, metabolism and CO2 production. But I don’t think that’s ever been a factor for me…

So now you know what it is about running that can set you up as a veritable mosquito banquet.

Here are some things that you can do to reduce your chances of being bitten constantly

  • Stay inside at Dusk and Dawn. Mozzies are far more active at dusk and dawn than throughout the rest of the day. As noted above, this is when I have a tendency to exercise, smear myself in lovely smelling products and drink alcohol (to clarify, I drink the alcohol at dusk not dawn – I’m not the vodka-for-breakfast type of holidaymaker). On reflection, pretty much all of my holiday habits seem almost purposefully designed to bring the airborne-plasma-thieves thronging in my direction…
  • There is a problem with staying indoors at these times of day of course. It’s not always practical, especially if like me you run early in the morning, because that’s when it’s coolest and most comfortable to do so, from a heat and humidity perspective. Plus I really love a good sunrise or sunset – especially when I’m near the coast or high in the mountains. But, I could warm-up and cool-down/stretch in doors in my air-conditioned room, with the doors and windows closed.

  • Wear light coloured loose fitting clothes and cover up as much flesh as is practical. Most of the contents of my holiday suitcase are running gear. I find my running clothes to be the perfect travelling garb.
    • It doesn’t crease or need ironing.
    • It’s lightweight and breathable
    • It dries quickly.

All great qualities for warmer climes. However, I tend to opt for darker colours, as they don’t show the sweat marks as readily (especially shorts).

A potential downside to stuffing your luggage to the brim with running gear – is that it won’t get you into any swanky restaurants, where formal attire is a must. But then again – I don’t tend to frequent such establishments either – So no biggie.

  • Apply an insect repellent with a min 20% DEET content. DEET’s technical name being N,N-Diethyl-meta-toluamide, or diethyltoluamide. Apparently mosquitos find DEET totally repulsive, though there is some research that suggests some can get used to it.

Although rare, DEET can cause skin irritation and you should not apply it to damaged skin and avoid spaying in the eyes. There are some claims of other more serious side-effects too, like memory loss, nausea and tremors. Which may well be enough to put you off using it. There are other potentially less harmful repellents available, but according to my research – none are as effective as DEET. Some of the more ‘natural’ alternates – include citronella, catnip oil, lemon and eucalyptus.

Runners tend to sweat a lot. So apply insect repellent to your clothes rather than skin, when you go for a run, as otherwise your sweat could wash it away.

  • Avoid stagnant water sources as well as heavily wooded or long-grassed areas. These are the breeding grounds of Mosquitos and where they’re likely to congregate in large numbers.
  • Avoid perfumes and smelly hair products, shower gels and deodorants – especially the ‘floral’ variety. Instead opt for citrus notes as the miniature-nibbling-vermin detest it – especially lemon.
  • Avoid or reduce your alcohol consumption – especially at dusk. Maybe opt for a few cocktails in the middle of the day (but not if you’re driving obviously) and drink a glass of water with your evening meal – with a slice of lemon perhaps.
  • Eat Garlic: This will result in the release of allicin through the skin, which will help to mask your natural scent markers. Making it more difficult for those horrid-little-blood-guzzlers to locate you. If you don’t like eating garlic, you could consider taking it in capsule form.
  • Vitamin B1 also known as Thiamine. There is some evidence that consuming this supplement will make you less palatable to the minute-blood-swallowing-freeloaders. Though some research suggests that it is only the females that dislike it. There doesn’t appear to be any real consensus as to how much B1 to take either. But as a vitamin supplement in tablet form, it is readily available and it’s not considered toxic. So, it may be worth a punt or perhaps increase your consumption of foods that contain it like: pork, fish, nuts, seeds, beans, peas, brown rice, asparagus and tofu.
  • Hang out where there are natural predators, like bats, swallows, house-martins and swifts. Maybe even put up a suitable bird or bat box to encourage their nesting above or near your outside eating area. Just a thought. I love swifts myself.

Following some or all of the above advice should drastically reduce the number of mosquito bites you get. Or at least that is the collective wisdom gleaned from my research. However, I think it only fair to say that I’ve yet to test any of these theories in the field. That will have to wait until my next holiday in some sun-soaked-mozzie-infested destination.

Finally, I have a couple of tips for dealing with any bites you do get:

  • Don’t scratch. I know that’s a big ask, but please try, as scratching can increase the risk of infection and that would just be adding insult to injury.
  • Anti-histamine. Take some with you, tablets or liquid will do. Taking some can help to relieve itchiness, soreness and inflammation.
  • Rubbing a cooled tea-bag or slice of cucumber on a bite can also provide some relief

So there you have it – good luck & happy mozzie-bite-free running

Coach D

About the author 

Coach D

Hi, I'm Dave. I'm a UK Athletics qualified and licensed Coach in Running Fitness (CiRF), Endurance Event Group Coach and Certified Running Technique Coach. I coach groups and individuals of all abilities both online and in person.

I particularly enjoy coaching beginner and improver runners in the 40+ age range.

I'm also a regular recreational runner and I've been competing in races from 5k to marathon distance for over 30 years.

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