When you work your core muscles a bit too hard, you might end up with delayed-onset muscle soreness. Relieve the pain with stretches and heat therapy.

Leg lifts are great for lower abs because they engage the hip flexors, and the hip flexors engage the lower belly.

Belly dancing is fun and makes your exercise time fly by. But, like any exercise -- it requires consistency to lead to weight loss and reveal a flat stomach.

While you could perform ab exercises daily, it may not be the most effective strategy to achieve your goals.

Ab exercises can cause muscle strain or back pain if performed incorrectly. Avoid negative side effects by using safer exercises and plenty of rest.

Get a strong, toned lower back and waist by doing bicycle crunches and plank variations, including weighted planks and stability ball planks.

Spotting and nausea after working your abs could be a warning sign that something's wrong, or it could be a natural result of your menstrual cycle.

Being a teen girl is hard enough without the pressures to have the perfect body. Eat healthy and move more to achieve your right weight and flat stomach.

Hanging leg raises are a staple of advanced ab training. Alternatives to this move are available if you just can't hang from a bar.

Quick tightening of the abs is unlikely to be a permanent fix. Combine short-term strategies with long-term work on your diet and at the gym.

A flabby stomach can be a stubborn place to tone up, but with time, the right diet and committed exercise, it can be done.

The hanging leg sit-up, or leg raise, looks like a powerful ab exercise. But, it can actually overwork your hip flexors and fail to give you the abs you desire.