Most Americans think of two things when they think of shape: a muscular build, and loosing the flab. Large muscles take a while to build, but weight loss can be achieved FAST, if you have the will to do it. Best of all, when you loose the weight, not only will you appear and feel younger, but all that fat will no longer be hiding your natural physique. You will appear more muscular, and over time you will acheive real bulk.
Although everybody loves FAST, the most important thing to keep in mind is proper pacing. Trying to kill your muscles in one day will not build muscle mass, and you will be too worn out to exercise frequently enough to enjoy weight loss. In fact, exercise strictly for weight gain (muscle) and weight loss (fat) are considered separate disciplines by body builders, requiring different strategies and methods.
Especially if you are new to weights, or have been inactive for a while, it is best to stick to the medium-light category. There is nothing wrong with finishing your day at the gym with a heavy repetition, but to maximize calorie burning, it is better to begin with lighter weights, and try to do several sets over a period of an hour. It is necessary to take this amount of time; the objective is to stay hot and sweaty for as long as possible, something you do better when training intensively with moderate weights.
Since the objective is to lose weight, try to focus on your upper leg muscles and various back muscles. These are the largest muscle groups and tend to burn the most calories. Better yet, make the leg press or similar exercise the first thing you do, since this will stimulate your metabolism. Even better, run several laps around the track before hitting the weights. It will warm your body up, and you will find that lifting weights are easier with your metabolism already thrumming full throttle.
Of course, if you are training vigorously for the sake of weight loss and fitness, then diet plays a critical role. You, of course, do not want to ruin your training with a bag of junk food, but just as important is rewarding your body for its effort. If you are pushing it, then muscle is breaking down and trying to rebuild itself stronger. If it does not have the proper building materials--protein and vitamins and minerals, then it will be forced to borrow from other muscle cells. This is not a good picture.
Give your body what it needs by eating nutritious fruits and vegetables, and well as a vitamin supplement for good measure. If you are active, then you will need more nutrients than usual. Surprisingly, an excellent source or cheap, lean protein is poultry products. Grilled chicken and egg whites are preferable. The yolk contains healthy cholesterol, but if you are going to eat half a dozen eggs or more, boil them and throw out the yolk. Another good source of protein is fish; it is lean, and the oils in fish like salmon contain essential acids, and are well worth their calorie content.
To review on how to get in shape quickly:
1) Perform moderate exercises on a daily basis, instead of heavy lifting
2) Eat a proper diet with all the vitamins and protein needed to build muscle
3) Avoid fats and sugary snacks
4) Perform a varied and full-bodied workout, exercising different muscle groups on different days.
The most important thing to remember is proper rest to stay on track. You accomplish less when you are worn out. After only after a week of a proper regime, there should be a noticeable difference on the scale. If you keep it up, the pounds will glide off, one week after the other. Make sure you do not over-stress yourself. It is your body, and you want it to be healthy for a lifetime.