There are two ways to measure if you’re exercising moderately: 1. By your breathing – heavy but you can still speak. 2. By wearing a heart rate monitor. For exercise beginners, those not sure they can gauge their intensity properly, and those who want to make certain they’re exercising in their target zone; a heart rate monitor is the best option. But choosing a heart rate monitor can be tricky.

The most accurate and popular monitors have two components: a chest strap that contains the sensor and transmitter, and a wrist watch-like display. The ability to measure your heart rate is the most fundamental feature. Some also sport bells and whistles like calories burned, workout logs, computer synching capabilities and more.

 “You should let the person in the store show you the heart rate monitor. Try it on, make sure you can see the numbers on the wrist watch, make sure the band is comfortable, and get a good feel if you like it,” says Nieca Goldberg, MD, clinical associate professor of medicine and medical director of New York University’s Women’s Heart Program and an American Heart Association representative.

For those who may have difficulty pushing tiny buttons or reading small displays, we’ve narrowed down the top trouble-free choices:

Polar FS1

The FS1 is perfect for those who want simplicity and an extra large display. One-button operation makes it a cinch to use. Basic features: your heart rate, a visual and audible alarm that lets you know if you’re in your exercising target zone, a stop watch and clock.  $50 to $60.

Oregon Scientific SE300

Do you have difficulty reading small displays? The monitor announces heart rate readings, workout time and calories burned through headphones. Wireless chest strap is a snap to attach. Includes a Smart Training Program to track your progress, clock and alarm, water resistant to 100 feet. $70.

Brookstone Heart Rate Ring

The ring may be the simplest to use heart rate monitor of all. Just slip it on your finger and go – no wires or straps to adjust and only one big button to push. The continuous readout lets you check your heart rate without interrupting your workout. Includes a stopwatch, a clock and a minimum/maximum target heart rate alert. $40.