Having your legs elevated allows crunches to better isolate your abdominals.
Crunches offer numerous health benefits, including that they tone and strengthen your abdominals, which helps you maintain proper alignment of your spine and lower your risk of back pain. They don't have the capability, however, to reduce the size of your stomach or make an impact on any excess fat you have at your tummy. To flatten your stomach, you've got to create a caloric deficit with regular bouts of calorie-burning exercise and by eating healthy.
Looking at Crunches
Although there are variations, the traditional crunch is performed while lying on your back on an exercise mat with your knees bent and feet elevated, either held up on their own or resting atop a bench. With your fingers interlocked and hands behind your head, lift your upper torso from the floor by flexing your spine. Your lower back should remain on the floor. Lower your shoulders back to the mat to complete the rep and then repeat. According to ExRx.net, crunches primarily target your rectus abdominis, which is the largest muscle in your abs, and require assistance from your obliques.
Myth of Spot Reducing
If performed correctly and at an appropriate frequency and intensity, crunches effectively develop strength and tone in your rectus abdominis. However, the abdominal muscle tissue is completely independent of your fat tissue. Most fat is located outside the level of muscle tissue, so if you were to build abdominal definition with crunches, those developments would remain unseen because they'd be covered by fat. According to exercise science professor Jessica Matthews, spot reducing, which refers to the capability of losing fat in a selected, specific area, isn't possible.
Flattening Your Stomach
To lose body fat, instead of a workout based on crunches, incorporate regular cardio and strength training exercises into your regimen. You lose fat by creating a caloric deficit, which means you burn a greater number of calories than you consume. Cardio exercises, such as jogging or swimming, burn a high number of calories in a short duration. Strength training builds lean muscle, which burns calories but also increases your metabolic rate, further increasing total calories burned. Following a healthy eating plan that focuses on consuming fruits, vegetables, whole grains, lean proteins and low-fat dairy products, is also essential for creating the caloric deficit needed for fat loss. As you lower your body fat percentage, you'll see improvements throughout your entire body, including your stomach.
Arguing for Crunches
Although crunches won't help you flatten your stomach, they're still beneficial and worthy of finding their way into your workouts. Perform them two to three days per week and you'll see strength improvements in your abs and obliques, two of the major muscles in your core. According to Harvard Health, strengthening your core positively impacts your ability to physically perform an array of movements, such as bending, lifting, twisting and standing. In addition, a stronger core allows you to maintain proper posture and protects you from lower back issues.