[ImpalaHoarder]

I do a weight lifting class at my gym with a bar that does many reps for each exercise. I am finding more and more that the weights I can put on the bar are not what the instructor recommends. I can't squat almost anything, presumably because squats require lifting my substantial extra fat weight. But my chest and triceps weights are also disproportionately high compared to my shoulder, back, and biceps weights,which I haven't been able to increase much at all over time and I don't have to lift my whole body to do biceps curls.

So am I doing exercises wrong somehow? Am I just being a wuss about these muscle groups? Is there something I can do to get my back, shoulders, and legs stronger faster?

Thanks!