What lives on gym equipment: a swab study of public cardio machines

This is a planned study, and nothing has been swabbed yet. We’ll swab the handrails, consoles and emergency-stop keys of gym treadmills and ellipticals, have an accredited lab count what grows, and compare those counts with our own home machines and with a phone, a sponge and a door handle. The three targets at the top of the page are what we expect to be able to report, not findings.

Why we’re doing this

Everyone who’s used a gym treadmill has wondered what’s on the handrails. The internet is full of answers, usually some number of times dirtier than a toilet seat, and almost none of them say how the number was measured or whether the comparison surface was tested the same way. We want to do it properly, publish the method next to the results, and be straight about what a colony count can and can’t tell you.

There’s a practical question under the squeamish one. Home cardio buyers often tell us the thing that pushed them to buy a treadmill or an elliptical wasn’t price or convenience but the shared machine at the gym. We’d like to know whether that instinct holds up, and if it does, which surfaces matter. If a wiped console at home and a wiped console at the gym look the same to the lab, we’ll say that too.

The sample

We plan to work with gyms in at least three metro areas, mixing big chains, small independents and hotel fitness rooms, because they clean at different times with different products. Every gym takes part with written permission from its management. No gym is named in the write-up, no member is photographed or identified, and results are reported in aggregate by type of setting, never by location.

Within each gym we’ll swab treadmills and ellipticals, the two machines with the most hand contact. We’ll pick them by position in the room rather than by brand, so we aren’t only sampling the newest machines.

What we’ll swab

Three touch points on each machine:

1. The handrails, both sides. That’s where a sweaty hand rests for 30 minutes.
2. The console around the speed and incline buttons. It’s touched with fingertips and rarely wiped as carefully as the rails.
3. The emergency-stop key and its clip. It’s the small plastic part everyone handles and nobody thinks about.

We’ll swab a fixed area using a sterile template, with pre-moistened swabs in a neutralizing buffer, so any sanitizer left on the surface stops working the moment the swab goes into the tube. Without a neutralizer, a freshly wiped rail can look cleaner in the lab than it really was.

We’ll swab at two times of day, before the gym opens and at the evening peak, and log when staff last wiped each machine, using the gym’s cleaning log or asking the staff on duty. That gives us a before-and-after on the cleaning routine without staging anything.

The comparisons

A count with nothing to compare it to is just a scary number. So on the same days, with the same swabs and the same lab, we’ll swab the same three surfaces on our own home test machines: the Sole F80, the Horizon T101 and the Sole E25, which two or three people will be using daily and wiping when someone remembers. We’ll also swab a few everyday things from a house: a phone screen, a kitchen sponge and a front-door handle. Those are the honest yardstick.

The lab

Swabs go cold to an accredited microbiology lab within 24 hours. We’re asking for two things. The first is an aerobic colony count per surface area, the standard measure of how much is growing on a surface. The second is identification of the common organisms, as far as the lab can do it routinely, so we can say whether what grows is the ordinary skin and environmental bacteria you’d expect from hands, or something else. We’ll publish the lab’s method and detection limits alongside the numbers.

What the numbers will and won’t mean

A colony count isn’t a measure of your risk of getting sick. Most of what grows on a handrail is what grows on hands, and healthy skin deals with it. We won’t make medical claims, and if you have a condition that affects your immune system, ask your doctor about shared equipment rather than reading a swab table. What the numbers can show is whether cleaning routines work, which surfaces get missed, and whether the gap between home and gym that people assume is really there.

What we’ll publish

Ranges rather than single scary figures: the spread of counts for each touch point across all the gyms, split into before-opening and peak, with the home machines and household surfaces on the same chart. The organisms the lab identifies, with plain explanations. A short, practical note on what to wipe and when, on a shared machine and on your own. We’ll also add a pointer from our running treadmill picks and ellipticals for seniors pages for readers who asked. If the results are boring, we’ll publish boring results. There’s no date yet; everything goes up on this page when the lab reports are back.

How to request the data

Once the study is published, journalists and researchers can have the full count table, the lab reports with gym identifiers removed, and our sampling log. Ask through the link in the sidebar and tell us what the data is for. We won’t release anything that could identify a participating gym.