Commonly thought to be a very important mineral to get in before exercise, potassium has many roles in the body. Potassium acts as an electrolyte in the fluids of the body that is essential for maintaining proper nerve to muscle signals. When the potassium-sodium electrolyte balance gets thrown off, athletic performance will start to suffer greatly. Furthermore, potassium also plays a role in bringing oxygen to the brain so you can think clearly.

When a deficiency is seen, it is usually due to an increased loss in the urine that can sometimes happen when an individual is put on certain heart disease medications. To overcome this issue, anyone taking such medications will likely be told by their doctor to consume more foods rich in this mineral. Low levels in the blood are termed 'hypokalemia' and can also result from vomiting as well. The symptoms that will occur when this happens include an alteration in the membrane potential and cellular metabolism leading to fatigue, muscle weakness, cramps, intestinal paralysis, bloating, constipation and abdominal pain. If this problem becomes severe enough, abnormal heart rhythms can also result.

Foods that contain the highest amounts include bananas, cantaloupe, grapefruit, oranges, tomatoes, honeydew melons, prunes and potatoes.

The recommended daily intake for adults, both male and female, is 4700 mg's per day. By ensuring you get enough you can prevent conditions such as stroke, osteoporosis, kidney stones and high blood pressure.