It’s unlikely that core exercises alone will cause your waist size to increase. However, if you take in more calories than you burn, core exercises won’t prevent the excess calories from converting to stomach fat, which can cause your waist to grow no matter how many crunches you do.
The Core Muscles
The core muscles include muscle groups that are used for both stabilization and movement. Stabilization muscles include the internal obliques, pelvic floor muscles, diaphragm and transversus abdominis, among others. Movement muscles include the rectus abdominis, external obliques, erector spinae and both hip abductors and adductors. Core exercises that target the “abs” usually focus on strengthening and toning the rectus abdominis, transversus abdominis and both internal and external obliques. Sit-ups, crunches and other core exercises can strengthen your core and give you well-defined, “six pack” abs. But for those defined muscles to be visible beneath the skin, you also have to get rid of belly fat, something core exercises alone can’t accomplish.
Stubborn Belly Fat
Although fat accumulates all over the body, things like stress and overeating can cause it to collect disproportionately around the belly, according to the Rush University Medical Center. This is often the first area to gain fat and the last to lose it. While a normal amount of abdominal fat is healthy, excess fat in this region will make your waistline appear thick and your stomach appear fat or flabby, no matter how rock-solid your core muscles may be. Getting rid of belly fat and reducing the waistline requires a whole-body approach that includes a healthy diet, cardio and fat-burning exercises, according to Dr. Martica Heaner at MSN Healthy Living.
The Spot Reduction Myth
While it was previously believed that individual parts of the body could be targeted for fat reduction, the truth, according to American Council on Exercise fitness expert Jessica Mathews, is that it is impossible to target fat reduction to a specific body part. Toning and strengthening exercises do help to burn both fat and calories, but the fat burning is distributed throughout the body, not just in the spot that’s getting worked. Although sit-ups, crunches and other core exercises will strengthen the abdominal muscles, which will help burn fat in the entire body, they won’t specifically target the abdominal fat.
Waist Expansion Culprits
If you’re eating healthy and combining core training with body conditioning, yet you’re still seeing your waistline growing, there could be a few other culprits, according to the Medical News Today website. Premenstrual syndrome can cause fluid retention and constipation, both of which can lead to a bloated stomach. Gas and other digestive issues can also cause bloating. Other causes of water retention may include too much salt, birth control pills, anti-inflammatory medications such as aspirin or ibuprofen, and thyroid disease.
- CDC.gov: Physical Activity: Frequently Asked Questions: Is it true that muscle weighs more than fat? If so, will I gain weight when I start strength training if I don't go on a diet?
- Human Kinetics: Improve the Overall Look of Your Body by Sculpting Your Abdominal Muscles
- Rush University Medical Center: An Expert Opinion: Is There Really "One Trick" to Losing Belly Fat?
- MSN Healthy Living: I Feel the Burn, but My Belly Is Still Fat
- ACE Fitness: Fit Life: Why is the concept of spot reduction considered a myth?
- University of Maryland Medical Center: Pre-Menstrual Syndrome
- Medical News Today: What Is Water Retention (Fluid Retention)? What Causes Water Retention?
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