The last time I went to the gym, I couldn't even finish thirty minutes of cardio on the easiest StairMaster setting without getting really nauseated. I decided this was a sign that I needed to give the iron supplements more time to do their work.

Lo and behold, when I went back today I had a pleasant (if mild) workout at the same setting that was overwhelming me last time. I think I'll take a day or two more at this setting, then start edging it up a bit. Such a relief to find out that the lack of energy and poor cardio performance wasn't just a lack of motivation!