As a rule of thumb, let’s keep this very simple. The basics of weight lifting revolve around three basic principles and they are: Push & Pull, Breathing and Proper Form.
When it comes to weight-lifting or resistance training it involves only two movements, and that is pushing and pulling. For example, when you do a chest press you are pushing the weight and this involves the chest muscles, triceps, and the shoulders. There are other muscles that innervate or come into play when doing this certain movement, but for this article, we are going to stick with the major muscles groups. If you want to get more in detail I would suggest hiring a personal trainer to learning the action, insertion, and origins of the muscles in an anatomy or anatomical kinesiology text book (excellent reference tool). Another example would be doing a back exercise. For example, when doing a seated row you are pulling with your back muscles, biceps muscles, forearm muscles (flexors/extensors), core muscles (transverse abdominal) and your lower leg muscles.
The second most important component of resistance training would be breathing. A lot of individuals from advanced to novice still do not know how to breath correctly, and it highly recommended that you seek advice form a fitness professional to learn this correctly. For example, when you are performing a leg press you initially need to get the weight moving. When you push the weight up/out you want to exhale your air. When you are bringing the weight down, pretend the air is going down into your lungs and when the weight is going up/out you want to exhale the air out. Also, you want to count to yourself underneath your breath. When you bring the weight down and then up, that is one repetition. When you count you automatically breath because that is the way sound travels (through air particles). If you feel like you are getting dizzy or are seeing stars, stop what you are doing because you are getting your breathing reversed or you are holding your breath.
Also, if you vomit when doing resistance training, a lot of this is caused by intra-abdominal pressure or valsalva maneuver. You do not want to do this because this can be dangerous with individuals who have high blood pressure. To get this technique down perfect, hire a professional personal trainer. The basic rule of thumb is, if you don’t feel good, stop and rest. You can always go back and finish your set or choose another exercise/machine that will work those same muscles groups.
The last principle is form or proper biomechanics. I am going to make this as easy as possible – the key is 90 degrees. If you can remember a right triangle, then you will always maintain proper form. For example, when you are doing shoulder press, as you push the weight up and are bring it down, you want to stop when your elbow looks like a right triangle (90 degrees) and then push it back up. This rule applies to 95% of all the exercises you are going to be doing. Another example would be when you are doing a squat or leg press. When you bring the weight down, stop when your legs look like a right triangle, and the push it back up. Remember, when you push the weight up, you do not want to lock your elbows or knees because this can cause future injury to these areas by stretching out certain tendons and ligaments.
These are the three basic rules for resistance training and/or weight lifting. One last fitness trainer tip, when doing your major muscles groups, you always want to do your larger muscles, like chest, back, shoulders first before exercising your triceps, biceps & forearms muscles. This rule also applies to lower leg muscles. You do not want to do leg extensions and leg flexion when you are going to be doing leg press and/or squats that day. I would suggest doing a warm-up by riding the stationary bike to get some blood flow to those lower extremities. If you are a novice, just take your time when embarking on this type of training. By doing so you will be more knowledgeable and avoid future injury and improper form.