Defined abdominal muscles or "abs" have become a symbol of fitness and health.
For this reason, the internet is full of information about how you can achieve a six pack.
Many of these recommendations involve exercises and devices that target the ab muscles.
These methods supposedly stimulate your abs to burn belly fat.
However, they're not as effective as some of us may think.
This article explains everything you need to know about ab exercises and belly fat.
Abdominal muscles help stabilize your core.
They also assist your breathing, allow movement, protect your internal organs and are in charge of postural support and balance.
There are four main abdominal muscles:
- Rectus abdominis.
- Transverse abdominis.
- External oblique.
- Internal oblique.
It is important to maintain strength in all these muscles.
Strong abdominal muscles can help improve posture and balance. They can also help reduce back pain and increase flexibility (1, , , ).
Bottom Line:Abdominal muscles allow movement and provide stability, support and balance. Strong abs can prevent back pain and other problems.
Excess abdominal fat, or belly fat, is associated with a higher risk of insulin resistance, type 2 diabetes and heart disease ().
Abdominal obesity is also one of the main causes of metabolic syndrome (, ).
However, not all abdominal fat is created equal. There are two types — subcutaneous fat and visceral fat.
This is the type of fat you can pinch. It's located under the skin, between your skin and muscles.
Subcutaneous fat is not directly related to metabolic risk. In moderate amounts, it will not dramatically increase your risk of disease (, 9).
This type of fat is located in the abdominal cavity around your internal organs.
It's linked to metabolic syndrome and health conditions such as type 2 diabetes and heart disease (, 9, ).
Visceral fat is hormonally active. It releases compounds that influence several disease-related processes in the human body ().
Bottom Line: There are two types of abdominal fat — subcutaneous and visceral. Visceral fat releases hormones that have been linked to disease.
Exercising your abdominal muscles will strengthen them.
However, twisting, crunching and side bending will not make your abdominal muscles visible if they are covered by a thick layer of fat.
When present in large amounts, subcutaneous (under the skin) fat will prevent you from seeing your abdominal muscles.
In order to have defined abs or a six pack, you need to get rid of subcutaneous fat from your abdominal area.
Bottom Line:Exercising your abs will help them become strong and muscular. However, you won’t be able to see them if they’re covered by subcutaneous fat.
Many people do ab exercises because they want to lose belly fat.
However, the evidence suggests targeted ab exercises are not very effective.
Spot Reduction May Not Be Effective
The term "spot reduction" refers to the misconception that you can lose fat in one spot by exercising that part of your body. It's true that spot-training exercises will make you "feel the burn" while muscles grow and strengthen. However, studies show they won't help you get rid of belly fat.
One study followed 24 people who did ab exercises 5 days a week for 6 weeks. This training alone did not reduce subcutaneous belly fat ().
Another study tested the effects of a 27-day sit-up program. It found that neither fat cell size nor subcutaneous belly fat thickness decreased (13).
This is not only true for the abdominal area. It applies to all areas of the body.
For instance, one study asked participants to complete 12 weeks of resistance training, exercising only their non-dominant arm.
They measured subcutaneous fat before and after the program and found that participants lost fat throughout their bodies, not just in their trained arms ().
Several other studies have shown similar results (, , , ).
However, Some Studies Disagree
Some studies seem to contradict the above results.
One study tested whether spot reduction decreased subcutaneous arm fat. It found that exercise in a specific area of the arm reduced the fat in that area ().
Another study examined whether the location of the subcutaneous fat mattered. It compared subcutaneous fat beside working muscles to fat next to resting muscles.
Interestingly, no matter how intense the exercise, blood flow and fat breakdown were higher in subcutaneous fat that was close to active muscles ().
Nevertheless, the methods or measurement techniques used in these studies could be the reason for the conflicted results.
Bottom Line: The evidence is mixed, but many studies have shown that training one area of your body will not help you burn fat in that area. Studies also show that ab exercises alone have no effect on subcutaneous belly fat.
One reason why targeted fat loss does not work is because muscle cells cannot use the fat contained in fat cells directly.
Fat mass needs to be broken down before it can enter the bloodstream. This fat can come from anywhere in the body, and not just from the body part being exercised.
Additionally, doing sit-ups and crunches isn't particularly effective for burning calories.
What Exercises Should You Do?
Regular, whole-body exercises will speed up your metabolism and burn calories and fat. Aerobic exercise (cardio) may also be effective at targeting visceral belly fat ().
Intensity plays a role as well. Moderate or high-intensity exercise can reduce belly fat mass, compared to low-intensity aerobic exercise or strength training (, ).
Additionally, you need to exercise often if you want to achieve significant results ().
For example, do moderate-intensity cardio for 30 minutes, five days a week, or high-intensity cardio for 20 minutes, three days a week ().
The muscle changes that take place in response to exercise also promote fat loss. In other words, the more muscle mass you build, the more fat you will burn ().
Combining Multiple Types of Exercise May Be Effective
High-intensity intermittent exercise (HIIE) is another approach that has been shown to reduce body fat more efficiently than standard aerobic exercise (, , , ).
HIIE is a type of interval training that combines short bouts of high-intensity exercise followed by slightly longer but less intense recovery periods ().
Aspects of HIIE that make it effective include appetite suppression and greater fat burning during and after exercise ().
Furthermore, combining resistance training and aerobic exercise been shown to be more effective than aerobic exercise alone (, ).
Even if you don't want to do HIIE or resistance training, studies have shown that just regular brisk walks can also effectively reduce belly fat and total body fat (, ).
Bottom Line:Aerobic training and HIIE burn calories and speed up your metabolism. Combining aerobic exercise and resistance training seems to be particularly effective.
You may have heard the saying, "Abs are made in the kitchen, not the gym." There is truth to this, as good nutrition is essential if you want to lose body fat.
Eating too much sugar can cause weight gain and increase your risk of metabolic diseases (, ).
Instead, focus on consuming higher amounts of protein. High-protein diets have been linked to greater feelings of fullness that may translate to lower calorie intake.
A study of overweight and obese men showed that when protein made up 25% of their calorie intake, appetite control and feelings of fullness increased by 60% ().
Moreover, a protein intake of around 25–30% of your daily calories may increase your metabolism by up to 100 calories per day (, , ).
Increasing your fiber intake is another good strategy for weight loss. Vegetables high in soluble fiber have been shown to help with weight loss. They may increase feelings of fullness and decrease calorie intake over time (39, , ).
Portion control is another effective tool, as moderating your food intake has been shown to help cause weight loss (, ).
When you consume whole foods, more fiber, more protein and control your portions, you are more likely to cut back on calories.
Achieving a long-term calorie deficit is crucial for losing weight and belly fat.
Studies show that people can lose belly fat through either moderate or vigorous-intensity aerobic exercise, as long as they maintain a caloric deficit (, ).
Bottom Line: Good nutrition is important for losing belly fat. Eat fewer processed foods, watch your portions and eat more protein and fiber.
Evidence shows that you can't lose belly fat by exercising your abs alone.
For total-body fat loss, use a combination of aerobic exercise and resistance training, such as lifting weights.
In addition, eat a healthy diet with plenty of protein, fiber and portion control — all of which are proven to help reduce body fat.
These methods will help you burn calories, speed up your metabolism and make you lose fat. This will ultimately cause belly fat loss and give you a flatter stomach.