This heart rate profile is typical of a group cycling class. The first 20 minutes or so is a nice steady warm up reaching into the cardiovascular range (blue). Over the next few songs, I settled down at about 70% exertion.
At about the halfway point in the class, I started to turn things up. First, I did some interval work pushing just above and just below the anaerobic threshold (orange). To bring my heart rate back down between the intervals, I focused on breathing and took some of the tension off the bike.
The next couple of songs were more consistent effort. Note that for the second of the three I was a little lower than for the other two. After the first song, I noticed that I was consistently nearing 90% exertion (red) and decided that I should take just a little bit off. After all, I was teaching this class and I needed to make absolutely sure I can last to the end of the class and be able to talk the whole time, too! I felt pretty good after the second song and decided that I could push a little harder again for the third. This is the type of small adjustment that is nearly impossible to make without using a heart rate monitor, even for the experienced exerciser.
The last song was an intense push to the finish. After a brief break to get below my anaerobic threshold again, I used three progressive sprints to push as hard as I possibly could. I am able to estimate that my maximum heart rate is at about 190 based on watching how I respond to these workouts over the course of the last few years. I knew not to approach that number until the very end of the workout.
After that last push was done, it was time for a cool down. For this cool down, I made sure to keep my legs moving while doing some upper body stretching. It may look like I came down quickly, but I didn’t fall below the light aerobic zone for about 10 minutes.