The "fat zone training" myth debunked
Popular wisdom (straight from the 70's) has it that low intensity exercise is the best exercise for fat loss (and consequently cellulite reduction) because fat is utilised more than carbohydrates when performing slow, low intensity exercise. This is represented as the "fat zone" training intensity range in most cardiovascular equipment found in gyms. Unfortunately, although "fat calories" comprise a larger percentage of the total calories burned when performing low intensity exercise, the total amount of those calories is very low, in comparison to high intensity exercise.
In contrast, high intensity exercise "burns" much more calories per amount of time, even though carbohydrates are utilised at a higher rate than fat. Given that excessive carbohydrates are turned into fat and stored in fat cells (including cellulite fat cells), it doesn't really make sense to burn a small amount of "fat calories" with low intensity exercise, when you can burn a large amount of "carb calories" with high intensity exercise.
How does walking compare to running in terms of calorie burning and cellulite reduction
Practically this means that instead of spending two hours walking moderately at (3 mph) in order to burn a total of 390 calories, you are better off if you run moderately (at 6 mph) for one hour and burn 590 calories (data for an adult woman weighing 130lbs). Or, if you are fit enough, you can burn 885 calories in one hour of running at 9 mph - this is more than twice the fat burned when walking for two hours!
Or, to put it the other way round, you only need to run moderately (at 6 mph) for 39' minutes in order to achieve the same fat burned when moderately walking of 2 hours. Even better, you can run fast (at 9 mph) for only 26' minutes and still burn the same amount of calories that you would normally burn if you walked moderately (at 3 mph) for two hours. Given that nobody has enough time for exercise these days, the fast running solution seems to make much more sense than the moderate walking one.
In addition to immediate fat loss during the running session, fast running will boost overall metabolism after exercise to a much higher extent than walking, so you will lose fat when you sleep, in addition to losing fat when you run. So much for the fat burning zone and those outdated tables on the cardiovascular gym equipment! The truth is that, just like cars, the human body burns more fuel at higher speeds.
Pilates, Yoga, slow walking and leisurely swimming are a waste of time when it comes to cellulite reduction
Examples of low intensity exercise that does nothing or very little to reduce fat and cellulite include Pilates, Yoga, slow swimming, slow walking and similar activities. Some more intensive forms of Yoga and Pilates, such as Ashtanga Yoga and "Power Pilates" or "Hard Core Pilates" can help you burn calories faster than the plain varieties, but still they cannot compare to high intensity exercise for fat and cellulite reduction. Examples of high intensity exercise that works wonders for cellulite are fast running, fast swimming, fast cycling, spinning classes, circuits, interval training or sports such as basketball, netball, football, water polo etc.
The effect of exercise intensity on fat cells
Although it sounds counterintuitive, research has shown time and again that low intensity exercise stimulates the release of fat from the fat cells during exercise for only 20 minutes. After that time, whatever fat is to be burned during exercise originates from the liver or from fat stored in the muscles - not from fat cells. This may be of significance if you are trying to focus the effect of exercise on a specific body part by combining exercise with a suitable anti-cellulite treatment or cream (spot cellulite reduction).
In other words, if you are trying to burn local fat with the combination of low intensity exercise and an anti-cellulite treatment/cream applied immediately before or after exercise, then the fact is that low intensity exercise will not boost the effectiveness of the treatment or cream. All in all, low intensity exercise is better than nothing, but if you really want to reduce cellulite fast you should better opt for high intensity exercise or sports.
[Safety note: always check with your doctor if you are unsure about your ability to safely perform vigorous exercise]