On the cardio machines at my gym, there’s a series of colored lights that represent what ‘zone’ your heart rate is in - it detects your heart rate through your palms on the handles. Since it asks for your age and weight before you start, I assume it’s adjusted for that.
The lower third or so of the acceptable range (bounded by too high and too low) is labelled “weight loss” and the higher two thirds is labelled “cardiovascular”. I’ve read at some point that there’s a certain heart rate where you stop burning predominantly fat for energy.
What is it that you’re using for fuel at the higher heart rates?
I tend to keep my heart rate at about 155 (or higher), or I don’t feel like I’m working hard enough, which is well into the “cardiovascular” zone. Would I lose less weight per time spent than if I slowed it down? Not that it’s my primary goal, but I’m curious to understand the merits of working at different heart rates.
What’re the benefits and downsides to various levels of heart rates during cardiovascular excercise?