Is Your Heart Rate Monitor Outdated?

If you have a heart rate monitor you probably feel pretty cutting edge, glancing down to see where your heart rate is or just using your strap in the gym for the cardio equipment. But did you know you might be using 1970s technology?

As a professional in the fitness industry, I was a little surprised to find out that manufacturers haven't really improved heart rate monitors all that much since they were first invented in 1977 for the Finnish National Cross Country Ski Team. Other than making them wireless in 1983, the concept has remained pretty stable: use a radio frequency (analog) to transmit information from a chest strap to a receiver, which is usually a watch on your wrist or part of the cardio equipment you huff away on in the gym.

I spoke with Sally Edwards, a former pro triathlete who literally wrote the book on cardio training zones and owns HeartZones, a cardiovascular training and education company.

"Analog [frequencies] can get interrupted by power pulls, and treadmills have generators that have the same wave pull as the heart rate monitors," said Edwards. What this means is your readings can get disrupted making your information inaccurate. "[Monitors are also] very sensitive to cross talk, too." Cross talk is when you're heart rate monitor picks up the analog signal from the guy working out next to you.

So when you're on a treadmill or you're in a spin class and your monitor goes wonky it's probably the guy or the machine next to you that is interfering with the signal.

"Digital heart rate monitors have been around since 2005," said Edwards. "What's being sent are packets of data that are unique to the receiver unit. Digital transmission is a pure clean signal."

Edwards uses Suunto for her heart rate monitors. The company has both analog and digital watches so you can still use the receivers in the cardio equipment in your gym, but you'll get more accurate results with the receiver/watch on your wrist.

If you're a runner, don't only rely on technology to keep you going in the heat, here are some tips for summer running.