Shocks on Treadmills
June 30, 2010
Steve Fowler Fowler
"I've recently purchased a
Brand new treadmill and I've used it in the last 4-5 days with no
problems. But today when I went on to start my workout and started
the machine, as soon as I touched the heart rate control (metal)
handle in front of the treadmill, an electric shock caught my hand.
I tried several times and the same happened!! The shock only happens
once I'm on the rubber platform of the treadmill."
"One thing I hate about treadmills at our club is the amount
static charge you can build up when running on the treadmill!
When I touch the heart rate monitor it discharges like lightning!
When I use my ear buds on the TV monitor selection gadget. The charge
releases itself about every 10 to 5 min. While running right in
These are but a couple of comments
from treadmill users that have been posted about static electric
shocks. Look over the links on the bottom of this page for more
information on the problem.
Sadly the "help" that comes
from responses on the blogs are not very useful or accurate.
The problem is simple:
1. The problem is Triboelectric
2. This static generation is from the
insulative shoes walking on an insulative moving belt.
3. This electrostatic charge is accumulated
on the shoes of the person inducing a high electric potential on
the person. This means the person rises in potential (Volts) sympathetically
to the accumulated charges on the shoes.
4. This potential causes a painful
or annoying spark discharge when the person touches the grounded
treadmill frame, heart monitor or an IPODs being used. It is like
walking across a carpet and touching a metal door knob. ZAP! Except
in this case the person is walking constantly and generating a constant
charge ready to discharge each time the person touches metal.
Lack of grounding of the treadmill
is not the problem. In fact it is the grounding of the treadmill
that makes the energy of the discharge higher. It has a very low
resistive path to ground of the discharge from the person. However,
ungrounding the treadmill (don't do that) would not change the discharge
much at all.
This problem can be reduced by the treadmill manufacturer by making
the moving belt conductive with carbon loading or conductive fibers.
Many manufacturers either do not know this or do not want to add
The problem can also be solved by connecting the person to the treadmill
by an electrical wire (don't do this). However, this would make
an electrical hazard and a physical hazard problem.
solution which has had some very good success is the use of conductive
threads in a bracelet form much like a "Friendship Bracelet".
This bracelet's fine conductive threads perform what is called Corona
ionization causes ions to flow from the charged person to ground
(treadmill) and discharge the person so gently that they do not
know it is happening.
These threads have very small points
which allow ions to flow freely as soon as the person reaches a
high potential from the triboelectric charging from the treadmill.
This animation shows how the bracelets
are worn. As the person walks and reaches for the grounded treadmill
metal parts or an IPOD, she is discharged gently by the passive
Click on the following video for a
more detailed view. Bracelet
The following video shows how the bracelet
works by Passive Corona Ionization. Notice the Van De Graff generator
charges and arcs repeatedly until the bracelet is held close to
it. The arcs cease during the time the bracelet is near the dome.
This is because it is drawing ions from the Van de Graff by corona
ionization unfelt by the wearer. It seems like magic but in fact
it is real physics.
Van de Graff and Static Friendship
The bracelet can be fabricated using Static String* or any highly
Anyone can make such a bracelet if
they have highly conductive string such as from Static
To place an order for a bracelet,
please contact Anit Static Bracelets & Accessories @
Additional Links on the Topic:
* Static String is a trademark of Stop
**"Static Friendship Bracelet"
is a trademark of the ESD Journal and Fowler Associates, Inc. Patent