Exercise is an important part of maintaining a healthy lifestyle, and there are many gadgets out there to help track progress. However, none seems more effective than a heart monitor, at least when it comes to high-intensity interval training. Tara Pope Parker, a writer for the NYTimes recently attended a fitness seminar that focused on the use of heart rate monitors, specifically watches that include chest strap sensors, during a H.I.I.T session. The seminar was headed by Alex Chriest, a fitness coach with a doctorate in education.

Before starting her workout, Tara noted her resting heart rate, which she determined was 80 beats per minute; a normal range is between 60 and 100. Then, she chose to workout on a stationary bike, her other options being a rowing machine, treadmill and stair-climber. First, Tara and the group warmed up for three minutes, which she mentioned was no problem. Then, they were instructed to “push hard” for three minutes; Dr. Chriest wanted Tara and the group to enter a zone of discomfort, but not a zone of pain. Physically exerting yourself and feeling pain are two distinguishable sensations–you just have to know what they feel like.

After the three minute sprint, the group took a three minute break though Dr. Chriest encouraged them to keep moving at a moderate pace. Then, it was back to another three minute sprint, but this time, he wanted more exertion without them entering a zone of pain. Tara noticed that this exercise began to feel like a competition because she had a heart rate of 145 after the first sprint and was keen on raising it, which she did during the second bout, to about 160 bpm. The cycle of work and rest repeated for thirty minutes. With a heart rate monitor, you don’t have to guess if you’re exerting yourself enough because the stats are right there on your for you to monitor.