Let's just get straight to the point...
Spot fat reduction is not real, and it is therefore an ineffective way to train.
What IS spot fat reduction??
It's the idea that if you train a certain set of muscles then the fat around those muscles will be lost in a higher priority than the fat elsewhere on your body. For example: doing sit ups and crunches to lose belly fat, doing tricep exercises to lose upper arm flab, or side bends to lose love-handles, etc.
As a fitness professional who spends hours upon hours in a gym setting I very often get the question, "what can I do to lose [insert problem area here]?" And the answer always comes back to some version of eat right and exercise! Which is not usually what the person doing the asking wants to hear. Instead they're looking for one or two magical exercises they can do to "target" the fat in their aforementioned problem area. But, in order to lose fat in one place on your body you must lose fat everywhere on your body. Unfortunately we don't get to pick and choose where it comes off. (Wouldn't that be nice, though??)
I like Nick Nilsson's pool analogy from the following article: fat loss is similar to draining a pool. Let's say we've got a shallow end of 3 feet and a deep end of 7 feet. When draining the pool we can't selectively take water out of just the 7 foot deep end. The water drains from the ENTIRE pool. The ground begins to show in the shallow end first, but as we continue draining, eventually the ground will also show in the deep end.
Fat loss in our bodies works similarly. I'll give a very crude explanation. Our body needs fuel to support physical exercise. This fuel comes in the form of what's called ATP (adenosine tri-phosphate). Our bodies make ATP from the nutrients we consume (proteins, carbs, fats). How does it do this? It takes those nutrients and breaks them down into their smaller components -- a process called metabolism -- and then uses those components create the needed ATP. In the instance of triglycerides (aka: fat), which is made up of glycerol and fatty acids, the body must first break the fat molecule down into those glycerol and free fatty acid components and then release them into the blood stream before they can be used to create the necessary energy.
As mentioned, our body can create ATP from proteins, carbs, and fats, and it can get this energy from anywhere in our body. Just because we're working our abs does NOT mean that the energy we need to do those sit ups is being supplied just by the fatty deposits around our ab muscles. Instead, it's coming from all over, and there is no way to target one single area for fat loss.
Though the concept of spot fat reduction does make sense at a surface level, and it certainly appeals to our more vain desires, that's just not how it actually works. Sorry to burst your bubble. (I'm actually not even done bursting it... there's more bad news...)
As mentioned, energy comes from what we consume whether it's carbs, fats, or proteins. All three of these macronutrients can be (1) used to create the energy needed for exercise, as we've thoroughly established, or (2) stored in the body as either lean mass or fat mass. Most simply: when we are eating our bodies are storing, and when we are exercising our bodies are "burning" (aka: creating energy). But the building blocks for storage and the building blocks for creating energy are all the same -- CARBS, FATS, and PROTEINS.
Okay, okay, I'm sure you get it by now...
Food is fuel. Yep, move on...
Well, because our bodies are pretty damn smart and pretty damn bent on survival, they prefer to reap energy from our lean muscle mass first, because muscle is metabolically expensive!! In other words, it requires more energy from the body to maintain lean mass versus fatty mass. This means that, as our muscle mass increases, so does our metabolism. (That should sound familiar as a commonly sited benefit of strength training; more muscle = higher metabolism!) Well, our body doesn't WANT to spend that extra energy if it doesn't have to, so it will preferentially burn off its lean mass to avoid the expenditure.
It gets rid of what it thinks it doesn't need.
This is why strength training is absolutely essential to fitness and weight loss...
We must make our bodies think that our lean mass is necessary to its survival.
What better way to do this than with regular, progressive weight training?! (Hint: there isn't one.) When you lift weights on a regular basis your body will preserve the muscle it needs to support this activity. And, to build muscle you must progressively overload your training (aka: do MORE every time). This is still my all time favorite article on muscle building. Give it a read if you're interested!
But, let's get back to the topic at hand: fat loss.
As we've established, in order to lose fat from one particular spot on your body you must resign to losing it all over your body. (Not such a bad thing!) And how do you accomplish this?
Diet control + exercise.
You must SPEND more calories than you CONSUME in order to lose weight. And, as discussed, in order to lose fat mass instead of your hard-earned muscle mass, you must incorporate strength training.
My suggestion for burning calories efficiently while also incorporating strength training would be HIIT (high intensity interval training) workouts. This allows you to elevate your heart rate to varying levels for an efficient calorie burn. It allows you to use weighted exercises to build muscle and get stronger. And it only takes 30-45 minutes when done correctly. AND, you don't have to run!! HIIT really hits all the nails on the head when it comes to burning calories and gaining strength, which is really what fat loss comes down to.
Or, you can separate your more cardiovascular exercise from your strength training entirely. This would be like running/biking/swimming/etc. some days while lifting weights on others. This method allows for a little more variety and exploration with the activities you do, but the calorie burn is a little less efficient than HIIT. (Just think about how long you'd have to run for in order to burn 400-500 calories. With HIIT you can do that in 30 minutes or less.)
If you've made it to this point in the blog, good for you and thank you for reading! I hope you'll take this information to heart and use it to more effectively reach your goals. Otherwise you'll keep doing hundreds and hundreds of crunches, get no closer to that 6 pack, find yourself feeling frustrated, and probably throw in the towel. Well, maybe not this EXACT scenario, but you get my point. Targeted exercises are not the answer for fat loss.
SPOT FAT REDUCTION IS NOT REAL.
In order to lose fat in one place you must lose it everywhere.
THE WAY TO LOSE FAT IS TO BURN MORE CALORIES THAN YOU CONSUME.
This is accomplished by (1) controlling your diet, and (2) exercise!
STRENGTH TRAINING IS ESSENTIAL TO FAT LOSS.
Your exercise regimen should allow you to both burn calories AND build muscle in order to most efficiently lose fat (and keep it off!).