So the BBC news story is about what you can potentially catch from dirty gym equipment and gym mats due to the unhygienic practices of some gym members. And I have to agree, some people are particularly revolting in that they sweat and drip all over equipment then just wander off leaving someone else to either clean up after them or lie in the wet patches!
This got me thinking, what can you catch from a yoga mat? What it comes down to is almost any bacteria, virus, fungi or parasite which can be part of the human microbial flora is potentially transferable between people, if the microorganism can survive on the surface acting as the vector e.g. the mat or equipment. These transferred microorganisms colonise the equipment and then “hop onto” and colonise the next person to use that equipment. Actually…do I really want to know all of this as I’m about to go to the gym?!
- Bacteria e.g. staphylococci, streptococci
- Fungi e.g. athletes foot
- Viruses e.g. Herpes Simplex Viruses (HSV), Human Papilloma Virus (HPV) which causes genital warts
Worryingly I think this is only the tip of the iceberg! The list becomes even more unpleasant when you consider the number of people (apparently boys are worse than girls) who do not even wash their hands after going to the toilet!
Almost all bacteria can survive in the environment for hours if not days. This includes the vast majority of human bacterial flora with the exception of a few of the more fastidious anaerobes which will die within an hour or so if exposed to a normal oxygen containing atmosphere… unless they can produce spores …then these spores will survive (e.g. Clostridium difficile).
The most important bacteria in the context of gym equipment are those that have the ability to cause skin and soft tissue infections. The most common causes of skin and soft tissue infections are Staphylococcus aureus and the Beta-haemolytic streptococci groups A, C and G (BHS).
It is well known that in hospitals these types of bacteria can cause outbreaks relating to equipment (known as fomites) so there is no reason to expect gym equipment to be any different. In addition certain aspects of the bacteria themselves make skin and soft tissue infections more likely e.g. S. aureus which produces the Panton-Valentine Leukocidin (PVL) toxin (the PVL makes it more likely to cause soft tissue infections such as boils and abscesses). PVL is known to cause outbreaks in the military, sports teams and other close knit communities who share equipment and cleaning facilities.
Okay, so S. aureus and BHS are the most concerning as they can lead to infection but it is worth remembering that bowel flora can also be transferred between people on equipment, surfaces and hands. Most people know of the infamous study that cultured bar snacks (you know peanuts, crisps, pretzels, etc.) and found them to be riddled with faecal organisms… the study found it was possible to transfer someone else’s bowel microorganisms via an innocent bar snack to your hands or guts! Yep we’re back to that not washing your hands after going to the toilet business again! In the same way someone who comes in to contact with bacteria on a piece of gym equipment can become colonised.
So why do so many people use gyms but not get infections with these bacteria we are all sharing around? Well, the main reason is our own normal flora. The 100 trillion (100,000,000,000,000) bacteria that make up our own normal flora usually out-compete these “alien” bacteria trying to force their way in and stop them becoming a problem. So whilst we may temporarily become colonised the bacteria soon disappear again as they are “defeated”. Therefore the risk of getting an infection with bacteria that you have acquired at the gym is actually very low.
The environment is full of different fungi, some of which can cause infection but most of which are harmless to people with normal immune systems. The main exception to this are the dermatophytes which cause fungal nail and skin infections; including tinea pedis or “athlete’s foot”. This really isn’t a great term as you don’t need to be an athlete to catch it but as the fungus is often found around swimming pools, public showers, and locker rooms, the term stuck. It likes warm and moist skin… so what better than a pair of smelly, sweaty, gym shoes?! Athlete’s foot is more common in men than women… it may be that men are also not so good at changing their socks!
I’ll talk about dermatophytes in a future blog but needless to say that these fungi could definitely be acquired if standing bare foot on a contaminated yoga mat, especially if you have small abrasions on your feet.
Viruses are potentially more of a problem than bacteria and fungi. Not only are they equally good at surviving in the environment, but they are:
- Highly infectious (usually having a much lower infectious dose)
- Not usually part of our normal flora
- Not usually out competed by our normal flora
Whilst the article talks about the potentially more “sensational” viruses that in any other context would be considered sexually transmitted (e.g. HSV, HPV) I would be more concerned about the less “glamorous” viruses spread by droplets or faeces. These include the respiratory viruses such as Influenza Virus and Adenovirus, upper respiratory tract viruses such as Varicella Zoster Virus (VZV) and Measles Virus as well as the causes of gastroenteritis such as Norovirus and Rotavirus.
Even small amounts of virally contaminated fluid in the environment can cause infection to spread. For infections like Norovirus there are 1 billion (1,000,000,000) infectious particles per gram of infected stool and the infectious dose is only 10-100 particles… that’s 100 million infectious doses per gram of stool!! If Norovirus gets on your yoga mat you’re almost guaranteed to catch it… and downward facing dog would become a risky procedure… ooh yuck!!
Other viruses which could be caught doing bare foot yoga include other wart viruses other than the genital types, which cause verrucae on the hands or feet. And yes, it might theoretically be possible to catch HSV and genital HPV but as the BBC article implies, you would have to be cycling in the nude to really be at risk… but it makes for a good story.
So what should be done?
Simple, wash your hands and clean the mat before and after use.
Washing your hands will protect you and the mat from anything your hands have come in to contact with. Cleaning the mat with an appropriate disinfectant before you use it will allow for the grubby so-and-so who didn’t clean it after they used it and cleaning it afterwards means you won’t be that grubby so-and-so for someone else.
Whilst we’re at it, how about wiping down any gym equipment you’ve used, whether you’ve sweated over it or not? At least it’s courteous to the person who follows you afterwards.
Another solution, take your own yoga mat. That way you don’t have to worry about what you are being exposed to, it’s just your own normal flora. You can then clean it or not as you want, you’re the one who has to put their face and body down on to it…so it’s up to you.
At the wonderful yoga shalla I’ve just been to (It’s Yoga Fuerteventura) all mats are wiped down and left to dry after every class. It’s a great place to go and Salla runs a fantastic ROCKET® yoga class based on ashtanga yoga.
NB A while ago I read an editorial in the New England Journal of Medicine which said that healthcare staff not cleaning their hands was negligence. The argument was that healthcare staff are told to wash their hands and they are provided with sinks, soap, water and alcohol scrubs to clean their hands. There is therefore no excuse for not cleaning their hands and so it becomes a conscious decision not to do so… this is negligence. Okay, it might seem a bit extreme, (but this level of litigiousness is unusual in the UK but this was being reported in a USA journal) but unless there is a medical emergency where taking the time to clean your hands might result in patients harm (e.g. they’re about to fall out of bed, pull out a catheter or tug on their endotracheal tube) then the editorial had a point.