I have been working out by lifting weights for about 3 weeks, following a program designed for me by someone at my gym. After the first couple of workouts, I was really sore the next day, but now I barely feel any soreness the next day. I have increased reps and/or weight each week based on the program that was suggested to me. Does this mean I am not working hard enough? Should I increase the weight even more?
You shouldn’t expect to feel sore after exercise like you did when you started working out. Sore muscles happen when you do something new and by now your body has adapted. But that doesn’t mean you aren't working hard enough. You are simply not sore. In addition, you probably prevented soreness by proper warm up and cool down, stretching, and frequent repetition. Now, keep your reps at 16 or less while you focus on your form. After 6 weeks (or more) of consistent training, you can change your routine to 'shock' the body. That's when you'll start to hurt again. Read up on the basics of lifting weights at About.com.