Hit The Bikes!
First off, get on the bike and peddle for 5-10 minutes, just enough to break a sweat. This will get blood flowing to your muscles, which will warm and loosen them, making them less susceptible to injury. I always get on the bikes for about five minutes before I do anything else. Then I go over to the ab mats and lightly stretch my entire body, giving a little extra attention to the body part that I am training that day. A lot of people skip this whole part. I know it's not as fun as lifting, but its very important.
Ok, so you're off the bike, and you found a place to stretch, now what? Start with your major muscle groups like back, legs, and chest, and work your way down to smaller groups such as shoulders, triceps, and biceps. Hold each stretch for at least 15 seconds. Over time you will become more limber and you should be able to hold a stretch for longer. It should feel like a stretch, not a tear!
Don't stretch to the point that you have tears in your eyes. There should just be a little tension there. Speaking of tears, never bounce. Bouncing can cause muscle tears and strains. As always, you should breathe while you stretch. Holding your breath will not impress anyone and will not improve your athletic performance in anything, except for depth diving.
Warm Up Set
Your first set of any exercise should be light, with high reps. If I'm going to be doing bench press, the first thing I do is one set with just the bar, for about 15 reps. I do these reps nice and slow. I do this to remind myself of correct form, and to make sure I'm completely warmed up before I slap on the metal. Once again, if you have the patience to prepare yourself, you will see greater results. I see too many guys that go in there and immediately start off with a ton of weights that they shouldn't be using.
Lift With Control
I'm sure you've seen guys in the gym doing bench press, or any other exercise while arching their back, squirming around, and screaming. No, you don't need to start off with these bad habits. If the weight is so incredibly heavy that you have to scream, you should reduce the weight, its that simple. By the way, there is scientific evidence to prove that screaming wont make you stronger. And don't hold your breath, you need oxygen when lifting.
You control the weight on the way down and up, you are its owner. The weight should NEVER control you. You won't build muscle that way. The weight is a tool that you use and control. You wouldn't cut the lawn with an unstable rocket powered mower would you? Then don't ever let weight take over you.
Respect The Plates
Guess what part of working out causes the most injuries? Squatting 405, Benching 225? Nope, how about putting a 25-pound plate on a bar. That's right, most injuries occur when you're not paying attention because "its just 25 pounds" or when you're adding weight to a bar, or weight tree. You have to pay attention at all times. I've smashed my fingers while putting a weight back before. It's embarrassing to say, but I've done it, and so have many others.
Anytime you pick a weight off the ground, or the bottom of a weight tree you have to be careful. Hold the weight with both hands close to the body. Once it's on the bar, use a clip to secure it in place. When you're putting back a dumbbell, LOOK at where you're putting it so you don't miss the dumbbell rack and break your foot.
All it takes is a little more focus, and respect for what could happen if you make a mistake. It might mean a little less talking and staring at girls, but then again are you here to socialize or get big?
I suggest you end your workout with a light 5 minutes back on everyone's friend, the bike. This will help return some of your bodily functions like breathing, blood pressure, and heart rate to a normal level. You will find that you are less sore the next day if you do this also.
Give your muscle groups at least 48 hours before trying to train them again. I work out each muscle groups once every 7 days. You have to remember that your muscle will need time to recover from the workout, adapt to the stresses you put on it and the fun part GROW from all the food your eating. Just give them time to grow that's all, you don't need to be in a rush to get back in there.
Sometimes less is more, and if you're a beginner, you are going to need to allow your body to recover from the stresses of training. When I started training, I went in the gym every day for about an hour and a half each day. I did this for about two weeks, then I got a cold.
Now if I was a betting man Id put my money on over training as the culprit for my cold. So resist the urge to live in the squat rack. Take a day off, and enjoy the other aspects of life! So now that you know a little more on how to stay safe in the gym, go in there and train smart, and hard.