Polar FT4 and swimming

Can I swim with my heart rate monitor?

Most Heart Rate Monitors are water resistant to 20, 30, 50 or 100 metres depending on the model. This is a theoretical static pressure measurement and does NOT relate to a practical depth. Most 20-50 metre water resistant HRMs are fine for surface swimming only. Please check with us before making any assumptions on water resistancy.

Generally, HRMs do NOT work (read the heart rate) in the water due to inability to transmit the radio (FM) waves under water. They are designed to transmit in the air. It is possible to get a good reading in the pool only when your chest area, and the transmitter, is clear of the water. This is the same for all chest strap type HRMs.

For Triathletes, this means that the HRM becomes a stopwatch only for the swim section. The unit will not be damaged in the pool, but it will not record heart rate (unless you are lucky, we cannot guarantee it, nor is it a fault if it fails to read HR while swimming).

For SWIMMING, there are currently three main options:

1) Forget about your heart rate while swimming - get a POOLMATE swimmers watch and dramatically improve your swim efficiency. The Poolmate is the best innovation for swimmers since... googles !! Highly recommended. A swimmer never reaches the same levels of cardio intensity that a RUNNER or CYCLIST does - the chances of cardio OVER training in the pool are VERY slim. It is our considered opnion that a heart rate monitor for swimming is just not necessary - better to improve stroke technique etc. We recommend the POOLMATE swim watch.

2) OK - you're still reading so you really do want heart rate feedback from your swims.. then it has to be the Polar RCX5 - this heart rate monitor has been specially developed with a DUAL frequency transmitter - one for OUT of WATER that uses Polar WIND digital signal to prevent intereference... another for IN THE WATER which uses a more traditional analogue signal that works perfectly in the water. You still have to wear a chest strap, but you should be able to download a clean heart rate curve after your pool session.

3) LIVE heart rate reading at the END of a set of lengths. We have had a lot of success selling the modern strapless heart rate monitors that have sensors on the front. The swimmer places their fingers on the sensors with the watch OUT of the WATER... within 3 - 8 seconds you are presented with an ECG accurate heart rate reading. A popular unit for this is the Oregon Scientific SE138 strapless heart rate monitor.

4) Polar Health Check .... Polar brand this product as an EQUINE product (used to be called a VET CHECK) - hold it against the chest of the horse, and get a live heart rate. It has been used by hundreds of swimming coaches for SWIMMING with GREAT SUCCESS. Just hold it against the swimmers chest, and have a live heart rate reading within 4 or 5 seconds. The COACH wears the watch - the swimmer just presents their chest to the coach to push the handle against. This unit WILL work through a swimsuit or a Tri-vest. We sell this item from our sister site - HORSEBEAT.co.uk - SWIMMERS heart monitor.

We recommend in most models that you should not press any buttons under water. See user's manual for details. Heart rate measurement in a water environment is technically demanding for the following reasons:

Pool water with a high chlorine (or bromine) content, as well as seawater, may be very conductive and the electrodes of a transmitter may get short circuited and ECG signals cannot be detected by the transmitter unit.

Jumping into the water or strenuous muscle movement during competitive swimming may cause water resistance that shifts the transmitter on the body to a location where it is not possible to pick up the ECG signal.

The ECG signal strength varies depending on the individual's tissue composition. The percentage of people who have problems in heart rate measuring is considerably higher in a water environment than in other uses.

In the watch industry the water resistance is generally indicated as metres of water pressure, meaning a static pressure of water at the level in question. Most manufacturers' apply the same indication system, as it is well known and water resistance is an essential feature of the heart rate monitor.

However, it should be noted that when performing any underwater activity, the dynamic pressure generated by movement through the water is greater than the static pressure. Generally, all the HRM's we sell are fine for use while bathing, swimming and showering, BUT, not under water activity like scuba diving.