|Heart rate chart for a weight lifting workout
This is a fairly typical heart rate profile for a weight bearing workout. I started with a 10-minute warm up on an elliptical machine then cleaned off the elliptical and walked back to the weight room. I noticed that this took enough time that my heart rate dropped a bit too much so I did a few warm up sets to get it back up into the light aerobic zone (green). Here is an example of the value of a heart rate monitor.
Then, I did my first “real” sets of the workout. Unfortunately, I pushed it a little too hard the first two sets and went over my anaerobic threshold. “Going anaerobic” is not necessarily a bad thing, but it should be done towards the end of the workout so you absolutely know that the body is ready to support it. Pushing past that limit can be very tiring on days when you thought you were ready for a great workout but weren’t. Here's another good example of the value of heart rate training. There is little chance that I would have "felt" that my heart rate was a bit too high.
Once I adjusted the weight and recovery time after the first set, I continued with the workout as I had planned. I did decide ‘on the fly’ that I should limit any time spent above my anaerobic threshold (orange) because I didn't feel as energetic as I should have at the higher heart rates, so I slowed down whenever I hit the cardiovascular range (yellow). There are a number of possible reasons for my lack of energy. Maybe I was still a bit tired from a recent workout or hadn't slept as well as I thought I had. Whatever the problem was, I decided to ease off that day and used the feedback from my heart rate to keep within those limits.