A good question, one that often enters my thoughts after either a hard workout or a bad lazy workout. I often wonder about myself and the handful of other guys who always seem to be at the gym when I'm there, what make me put myself through this pain, stress and soreness? Why don't I succumb to laziness and just stay home?
Why is it that those of us who are out of school, and on our own to train can sometimes motivate ourselves to find the time to train and maintain a training schedule, and other times not? Sometimes we can get into the exercise habit and other times not? How can we make training part of our schedule?
By now most of us have probably hit the "summer training dilemma". You've been working hard all winter and now it's time to go to the beach, spend time with your girlfriend, party at the cottage and go to clubs and concerts. Who needs to train anymore? Right?
To be motivated to do something means to be persuaded that there is some gain in it for you. Presumably, you should convince yourself that there some gain for you in training even though it may be too hot or you may have a million other more enjoyable things to do. Think over what you have to sacrifice to have the time to train. A movie, dinner with friends, sex with your partner, late night TV, time with your family? It seems impossible to keep up right?
This is an example of the body controlling the mind. The body wants to take the easy road. How can we avoid this?
The first step is losing Performance Anxiety. Performance anxiety - wobbly muscles, stomach butterflies, racing pulse, short-circuited thought processes and narrowed peripheral vision; it effects both the voluntary and involuntary nervous system, and cognitive and perceptual process. There are days when we'll feel like not lifting because we feel too mentally exhausted to train, or we're afraid of not reaching our normal training levels. When I'm feeling performance anxiety I force negative thoughts into my head. Positive thinking only makes me complacent and sluggish. Before and during my workout I use negative mental imagery to force myself to work harder. I usually picture my ex girlfriend watching me workout. In my imagination she's making critical comments. Questioning why I'm training; my lack of talent; imperfect physique for the sport, and the drain on my time and energy. I also always picture her having a perfect body even though I know she doesn't. This makes me want to go to the gym and really gets me motivated to break through and barriers set up in front of me.
This type of motivation is called Visual/kinesthetic synesthesia. This is the process by which the brain transforms a visual image into a feeling. In the case of lifting weights, the feeling is in the musculature. There, a pattern of neuromuscular firing that ultimately coordinates the movement of the body is developing. This type of motivation usually involves watching a videotape or looking at pictures of either you or others and then mentally picturing yourself performing that exact task.
Visualization and imagery are strong psychological tools. Imagery is based on two theories. The psychomuscular theory suggests that vivid imaginations of muscular movements or events can result in nervous responses similar to those produced by the actual movements. Thus through imagery, one can strengthen the neural pathways and raise or lower heart rate response. The symbolic theory states that imagery can increase an athlete's performance by coding his movements, creating mental blueprints that produce familiar, fluid and autonomic movements.
Another way to keep motivated to train is to warm up slowly - increasing your weight in a natural progression. Your body gradually prepares for the energy production that is required for strenuous exercise. Give it time to give you the energy you will need to feel strong and concentrated as you develop strength. Set your own pace. Be sensitive to how you are feeling. You might already know that one day of training will be invigorating, and another day it will just make you tired. You body needs rest to realize gains from your efforts. If training becomes a period of suffering that you endure in order to increase your one rep max, you may find it difficult to motivate yourself. Or, if on the other hand, training becomes an escape from problems or responsibilities, soon it will become associated with guilt. In this case too, it becomes difficult to motivate yourself to go to the gym.
Have you ever had a sinking sick feeling as you approach the gym? Do images of half-written papers, deadlines, and exams make you wish you were back at your desk making progress toward lightening your load instead of wearing yourself out under a tonne of metal? Sometimes even though you've shifted your concentration from your normal life to your task at hand it can sometimes be hard to keep focused as the workout progresses. A way to control this is self hypnosis. No I'm not referring to some quack waving a shiny object on a chain back and forth in front of your eyes saying, "You are getting sleepy". I'm referring to putting yourself in a "trance" during training, thus delaying and sometimes avoiding the mental fatigue that comes with each session in the gym. Use this state of mind to forget the last 10 reps of an exercise, thus making each rep the first. Focusing your mind on each rep allows you to forget your last set, your last hour and any other unfinished task you have a home that could force into quitting your training session early and going home. Hypnotherapy, trance, or self-hypnosis is designed purely to allow a person to gain greater access to the resources of his or her unconscious mind. The unconscious mind is assumed to be creative and to contain your potentials.
A question to ask yourself. What do you like about weight training? Most people will say "I want to be better than other people" or "I like to push myself; and see each step in improvement and reach my goal". But what would happen if you achieve your goal? Would you stop training? Keeping yourself constantly motivated involves giving yourself a new goal to reach each time you enter the gym. If you have no goals you'll have no reason to train and eventually you'll stop training. Goals are what give our entire lives meaning. Goals highlight what is important to you, provide direction and act as a standard for evaluating progress. Because goals reflect improvement, they can be used to increase motivation and confidence while simultaneously decreasing anxiety and frustration.
There are two motivational feelings to use in the gym; Anger and Frustration.
Anger will give you a sense of power. The anger should be directed at someone or something other than yourself.
Frustration will give you the drive to succeed. Past failures and moments of shyness and weakness can be remembered and conquered in the gym.
This article is intended only to touch on the subject of mind over body.
The subject goes much deeper than I care to go, yet this should give you something
to reflect upon the next time you feel like skipping a workout or if you just
feel too drained and unmotivated to workout. 
References
Yukelson D. Concentration - A key to performing effectively. Sports Med Digest, 4, 1989. Yukelson D. Imagery in sports. Sports Med Digest, 6, 1989.
Yukelson D. Improving motivation through goal setting. Sports Med Digest, 4, 1989.
Vealy R. Imagery training for performance. Appl Sports Psych, 209:34, 1986.