The technology most traditional chest-strap heart rate monitors use—sensors that detect changes that happen in the skin because of the electrical activity of the heart—means that a good fit is essential for getting accurate and reliable readings. Fortunately, it’s pretty easy to make sure that you’ve got the exercise monitor on just the way it’s meant to be, provided you understand a few basic guidelines.
Front and Center
The basic rule of thumb for positioning a exercise monitor chest strap and transmitter is that the strap should sit just below the pectoral muscles, with the transmitter centered on the torso. (This placement is very familiar and comfortable for the majority of ladies, as it’s the same place the bottom band of a bra usually goes.) Most manufacturers use this positioning because it gets the sensors extremely close to the heart, which is actually centered and to the anterior within the rib cage. HRM companies also recommend this placement because it usually is more comfortable, with the thicker transmitter not getting in the way during supine exercises like the bench press or crunches. In a small number of people, however, the sensors get the best contact and provide the best results if the strap and transmitter are off to one side or, rarely, worn on the back. People who find that the alternate positioning options work better usually suffer from a slightly more concave chest shape, which can happen due to extreme body building, very poor posture or certain medical/genetic conditions.
Once you’ve got your exercise monitor strap in the right position, it still needs to be pretty tight around your torso—Polar, one of the leading HRM manufacturers, claims that failing to get good tension on straps is the most common error people make. A snug strap means that the sensors will be in constant contact with your skin, which is necessary for them to detect what’s going on with your ticker. A tighter strap is also a matter of comfort, convenience and safety, as it doesn’t rub as easily against the skin, fall down at inopportune times or get caught on equipment.
To make sure your strap stays put and works properly, adjust it so that the compression is right on the edge of being uncomfortable. As you move through your workout, the feeling of pressure should melt away until it’s not even noticeable. You should be able to take a deep breath even though the strap is pulling hard. Another sign that you’ve got the strap properly tightened is that it doesn’t slip downward if you raise your hands above your head and fully exhale.
Avoiding fit and positioning issues with your HRM strap relates to the ordering or purchase process. Before you buy your monitor, measure your chest to find out the circumference you have where the device will sit. From there, check the website of the manufacturer for your product, or contact the company’s customer support. The website should provide a chart or drop down menu that shows which size strap is appropriate for the number of inches/centimeters you need. Representatives can tell you whether a specific size will fit you through email, chat or phone.
When Your Band Is Well Loved
Bands for exercise monitors are like any other fabric item in that, over time, they stretch out. For many people, this isn’t an issue, as they can keep on tightening the strap enough to maintain good sensor-skin contact. Sometimes, though, individuals already have pulled the strap as small as it will go and still have a problematic gap. Closing the extra distance with a safety pin or sewing it to the needed length often can get some more mileage out of the fabric. If this doesn’t work, or if the band is becoming so worn or frayed that it’s starting to chafe, it’s time to upgrade to a newer version.
Changing Body, Changing Fit
As you get closer to your fitness goals through your workouts, one of two things might happen with the fit of your band due to changes in your body. If you pack on a bunch of muscle, the strap might start to feel too tight at your old length—simply let it out a bit as you develop. If you drop a significant amount of weight, you’ll likely find that the band starts to feel too loose over time as you lose inches—tighten the band until you have a snug fit again. In either case, changes in how the band feels can signal that it’s a good time to take some new chest measurements and update your progress, even if you don’t feel like there’s a big difference when you look in the mirror. If your clothes are fitting differently, too, then you can be even more certain that you’re moving in the right direction.