The way you feel while exercising is just as important as the number on your heart rate monitor. And the way you feel may be very different from the way someone else feels, even if you're doing the same workout. So, if your body's telling you it needs to chill, you should absolutely feel free to dial it back or take a break — regardless of where your heart rate's at. Some other clues to pay attention to : how quickly and deeply you're breathing, how quickly you start sweating and how much you sweat, and whether or not you can carry on a conversation. If you feel like you're overdoing it — if you can't keep up your end of the RHONY convo, for instance — definitely take a second to slow it down.