How goes it?

Well it was my first gym workout in almost a year. I pulled a women's intermediate circuit training plan from fitclick to get going. I was thinking to myself that the weights seemed so light, and that surely this workout would need to be beefed up (I formerly had lifted more heavy weights with less reps). However, I kept sweating, and thinking, "well, it must be doing something..." Before I was even out of the shower, I could feel the ache setting in- my thighs were really feeling it! I felt like some old woman walking down stairs in heels for my dinner date. And when I woke up the next day, my arms and shoulders were feeling the burn too...even my upper abs felt achy when I started in with my allergy-related sneezing. I can see I will need to shift my mindset on this new workout rather than the weight. Since I have mostly been running and doing cardio for the last year, I hope the added days of circuit work help improve the running and make the rest of my body feel more able to endure when I want to run longer.