Below, are the methods I suggest if you are trying to maximize fat loss or increase your muscle definition.

Usually, I prefer to keep strength training separate from the fat loss part of the workout. Muscle definition is best achieved using heavy weights and brief strength training at a low volume. Your muscles will firm up and you will begin to see an increase in definition this way. Strength training is usually the easiest part of any workout. With any workout, the calorie burning, fat loss portion is the most intense and difficult. It is best to include an intense fat loss routine into your workout at least three times each week. You can use any method of circuit workout or strategic interval that you want, including HIIT and body weight circuits.

You can't get an "after effect" using low intensity during a workout.

Most often, when I am at the gym, I see people doing a fat loss workout with no intensity in it. If you aren't resting or cooling down for the next part of your workout, walking on a treadmill is useless. When you do a cardio workout that is low intensity, you are not maximizing the amount of calories you could be burning.

Watch closely, to avoid a workout that is too high in intensity also.

You will more than likely find yourself resting for longer periods of time when you are finished with your routine, if it is too intense or difficult. For the most effective fat loss workout, you should be able to go on without extra breaks as if you never worked out at all. If you become overly tired and spend hours sitting down or resting after a workout, your fat loss workout is ineffective.

How do you know if you are working out with the right intensity for your fat loss routine?

Pay attention to what is called the "HGH Flush" I am not sure where this term originated from, but it does serve as a great tool for rating your fat loss workout. You will know you have reached the HGH flush if you are out of breath, with hot slightly red skin after each workout. Try to remember how hot and out of breath you felt, after the gym teacher had you run lines in junior high. HGH is a hormone released by your body to burn fat when your metabolism is suddenly increased by heavy activity, like a high energy workout.

Your comfort zone can also guide you if you keep your workouts just inside its limit.

I see personal trainers push their clients too hard early in a routine, which is a major mistake. I once hired a personal trainer who wanted to "destroy me" with each workout. That wasn't for me. The ideal workout intensity will help you reach an HGH flush, without leaving you so exhausted that you want a nap. In regards to workout intensity, I refer to this as the "sweet spot". You can start increasing your intensity as your body adjusts. However, pay close attention and back off a bit if you find yourself overly tired after a workout.