You love your smartwatch – but chances are, so do bacteria 

Study finds E coli and staphylococcus are commonly present on wristbands

While a smartwatch or fitness tracker may be a great asset for boosting your fitness, a recent study has found that the watch straps themselves may be a haven for undesirable companions.

The study, by researchers at Florida Atlantic University (as reported in the New York Post), found that straps made from materials commonly used on devices such as Apple Watches and Fitbits are a breeding ground for potentially harmful bacteria. 

The study tested straps for the Apple Watch and other devices that were made from rubber, cloth, plastic, leather and metal. The intention behind the study was to “examine the hygienic state of various types of wristbands worn by active individuals”. In other words, testing to see how clean were the wristbands worn by people who are active in their daily lives. 

An older woman checking activity on fitness tracker in gymCredit: Shutterstock / LightField Studios

What the researchers found

The research used a small sample of 20 randomly selected individuals (eight female and 12 male). Swabs were taken from their wristbands before being processed. And the results are striking. 

While it was a small sample size, the researchers identified that 95% of the wristbands (19 out of 20) were contaminated by some form of dangerous bacteria. Some 30% of the wristbands had pseudomonas, 60% of the wristbands were found to have E coli, while 85% of them were found to have staphylococcus bacteria present.


The bacteria found by the researchers

Pseudomonas – can cause infections of the blood, lungs and other parts of the body. It’s also associated with urinary tract infections and pneumonia. According to the CDC (Centers for Disease Control and Prevention in the US), the bacteria is developing drug-resistance. 

E coli – can cause gastrointestinal infections, and in severe cases, kidney failure. 

Staphylococcus – most commonly associated with staph infections which usually affect the skin, but staph bacteria can also cause blood poisoning and toxic shock syndrome. 

According to the research published in the journal Advances in Infectious Diseases, bacteria – particularly staphylococcus – was most prevalent on wristbands worn by users while working out. There also appeared to be some correlation between the material of the watch strap, and the levels of bacteria found on it.  

According to the researchers: “viable bacteria varied widely between subjects and even wristbands made of the same materials.” They went on to say that on average, cloth had the highest bacteria load, followed by plastic, followed by rubber, then leather, then metal. 

What isn’t entirely clear is whether the material also reflected how likely the wearer was to be active, and whether this could be a factor in the results. Would someone wearing a gold watch strap be likely to wear it while exercising, or more likely to remove it? 

The researchers went on to say: “The highest total counts were found on rubber and plastic wristbands, while the lowest was from metal and rubber wristbands. Plastic and rubber wristbands may provide a more appropriate environment for bacterial growth.” 

Another significant conclusion from the study was that “the most important predictor of wristband bacteria load was the texture of wristband material and activity (hygiene) of the subject at sampling time”. Users who had just worked out, or, in one example, a vet who was working closely with animals, were found to have higher levels of bacteria on their watch straps. The researchers wrote: “These results emphasize the necessity of wristband sanitation after working with animals or engaging in rigorous activity at the gym or at home.” 

It may seem obvious, but keeping your watch strap clean matters. The authors of the study noted that: “Wristbands, often worn daily, without routine cleaning, may accumulate potentially pathogenic bacteria…this experiment shows that there is a need for regular and popular sanitation of these surfaces.” 

What happened when they cleaned the watch straps

The researchers also tested some common household cleaning products to see how effective these were at cleaning the straps and killing the bacteria. Specifically, they tested Lysol disinfectant spray, a 70% ethanol solution, and apple cider vinegar. 

The Lysol and ethanol were both found to kill 99.9% of the bacteria within 30 seconds, while the apple cider vinegar was less effective, taking a full two minutes before having the same effect.   

The takeaways

While this research only used a small sample size of 20 people, it does remind us of the importance of cleaning your smartwatch or fitness tracker. This is especially the case for anyone who uses one when they’re exercising, or working with animals, or potentially after engaging in activities such as gardening, where you might be getting your hands dirty. 

And, as the researchers noted, if you spend time in hospital environments, or encounter anyone immunocompromised (who are potentially more vulnerable to these types of bacteria), then it’s particularly important that you remember to keep your device clean. 

The good news is that common household disinfectants, alcohol wipes, and even vinegar seem to be highly effective at killing anything nasty that may be lurking on your watch strap. 

Steven Shaw

Written by Steven Shaw he/him


Steven Shaw has been a freelance writer for a variety of outlets, most notably TechRadar. His degree in Medieval History prepared him less adequately for his career than you might expect, but the years spent working in technology focused retail were much more helpful.

Outside of work, Steven is passionate about health and fitness, and particularly enjoys high-intensity interval training, weight training, and increasingly, spending time recovering. Steven loves reading, films and a wide variety of sports. A particular highlight was watching Viv Richards and Sachin Tendulkar batting together in an exhibition match.

He wishes he could travel more. He can also tell you a lot about the Anglo-Saxons, Vikings, and Carolingians. Most of his non-work time is spent with his young children, who are the living embodiment of high-intensity training.