I'm clueless when it comes to weight/circuit training. All the strength training I do is using my own body weight (push-ups, leg lifts, lunges, body squats, etc..)
The last time I saw my doctor she suggested I do some leg strengthening specifically for my hamstrings. Apparently, my quads have gotten very strong and my hamstrings are much weaker. When there is a disparity between the two, you are more likely to injure the hamstring (and I have strained it a few times)
My question is this...do I need to do a warmup before I use the weight machine? Is it OK to do the leg curls cold?