Crunches and sit-ups are both common abdominal exercises. A sit-up is a strength training exercise which strengths the hip flexors and abdominal muscles, in addition to chest, neck, lower-back and lower-leg...

The main difference is that ophthalmology is a medical field, whereas optometry is not. This means that an ophthalmologist is a Medical Doctor with an M.D. degree. An optometrist is a trained professional;...

Calorie is a pre-SI metric unit of energy. Fats are the fatty acid esters of glycerol and are the primary energy depots of animals.

HIV is a virus that causes a body’s immune system to weaken. Sexually Transmitted Diseases (STD), also known as Sexually Transmitted Infections (STI) or venereal diseases (VD) are diseases that are contracted...

Anxiety is a feeling of fear, unease, and worry. It can be rooted in any event that makes one feel frustrated, angry, or nervous. Depression is defined as a state of low mood and aversion to activity.