Let’s dissolve the term of "toning" right now!

The firming-up or toning is due to an increase in muscle tissue as well as a low enough bodyfat percentage to see the definition and shape of the muscles and get rid of the "jiggle"

The more muscle tissue that you add through strength training the greater your basal metabolic rate (resting metabolism) will be and therefore you will be burning more total calories and fat at rest. This is more of a permanent solution to weight loss.

What about spot reduction?

Spot reduction doesn’t work either because it usually targets muscles that are relatively small through exercises that are relatively insignificant in terms of enhancing overall fitness, strength and energy expenditure—regardless of how much you “feel the burn” when training them. Overall fitness, not small muscle fatigue, is a stronger determining factor of your body’s fat-burning effectiveness. People who are very fit burn fat more efficiently during workouts and while at rest than people who are less fit.

Here is the reality—fat doesn’t melt. Technically, it doesn’t actually “burn” either. But “burning fat” is a more accurate depiction of the process (although it is completely unrelated to the “burning” sensation felt through some forms of exercise). Fat does get released from fat cells for energy. Unfortunately, the systems responsible for this process do not take into consideration the parts of the body you would most like the fat to be drawn from.

So, how do you get the “toned” look?

Here's where things get frustrating. The body doesn't only draw energy from the cells in the area you're working. It gets energy from the body as a whole, which means that lower body lifts alone won't do much for removing fat from the thighs. However, exercising your legs can increase strength and endurance in your lower body.

So, while targeting specific body areas during exercise can be effective to build muscle and shape those areas, it won't necessarily help you lose fat in that specific area. Instead, you'll need to address your overall diet to reduce the amount of fat that is stored, and increase your activity level to try to burn the fat that has already been stored throughout the body.

Ultimately, the key to abs isn't doing a zillion crunches. It's working the entire body and eating correctly. Strength training will increase the calories you burn 24/7. Aerobic workwill let you also burn big chunks of calories. 

Lastly, a healthy diet will ensure that you're taking in the proper number of quality calories. You might not lose three pants sizes in a week like the people in the ads, but you will eventually reach your goal. And as a bonus, the rest of your body will look and feel better as well!