What is cortisol? Cortisol is the hormone that your body releases when it is under stress or danger. When the body is under threat, afraid, or suddenly stressed, a "fight or flight" response is the first coping mechanism of the human body. This is when cortisol, also called the stress hormone, is produced to give the body a burst of energy in order to fight or flee. Two tiny adrenal glands that sit on top of your kidneys secrete the hormone, along with adrenaline, to respond to stressful situations. Why does the body need a stress hormone? Cavemen used to release cortisol to cope with dangerous conditions, such as fighting a lion or surviving under famine. This is why the stress response is also known as the fight or flight response. Your brain sends adrenal glands a message to put the body on high alert. In modern times, we have fewer lions and famine to fight, but our stressful lives are replaced by worries regarding money, deadlines, relationships, rush hour traffic, health conditions, and the future of our kids. To deal with these stressful situations, adrenalin along with the hormone cortisol changes the way your body functions. Here's how: Adrenaline accelerates heart rate and increases your energy. Cortisol releases glucose into the blood so muscles can fuel a run or fight. It increases blood flow to the skeletal muscles. It raises your blood pressure and blood sugar levels. It suppresses your digestive and immune systems. Why is this evolutionary stress response a problem? When your brain or body is stressed out or in danger, the survival mechanisms take top priority. This makes regular body functions like absorbing nutrients, fighting infection and even sex hormones secondary. Elevated cortisol levels can, over time, increase the chances of skin disorders, poor digestion, insomnia, depression, and even heart disease. All that unused sugar that is not used up is stored as fat (usually as belly fat). This is why high cortisol levels are linked to digestion and obesity too. What are the symptoms of high cortisol levels? Weight gain, especially around the stomach or abdomen. Puffy and flushed face. Mood swings and lower serotonin levels. Digestive disorders and obesity. High blood pressure. Higher risk of heart disease. Anxiety, depression or insomnia. Acne or other skin problems. Higher risk of getting infections. Are cortisol and exercise reduction linked? Doctors will tell you that regular exercise will reduce stress hormone levels in your blood. Studies have revealed that aerobic exercise is the most effective in reducing the stress hormone levels. Your body releases more cortisol during exercise, but it soon returns to normal levels. Exercise not only builds muscle mass, heart and bone health but also releases serotonin and dopamine These "happy hormones" both offset stress and anxiety. When you get into the habit of exercising regularly, the overall amount of the stress hormone in your bloodstream decreases, leading to reduced symptoms of stress. Can aerobics reduce cortisol? Yes, aerobics and just about any cardio workout will lower your cortisol levels. Experts believe only 20 to 30 minutes of an aerobic activity will lower stress hormone levels. Aerobic exercises increase your heart rate, making your lungs and heart pump more oxygen and blood through your body. Examples of sports and outdoor activities, such as jogging, cycling, swimming, racquet sports, brisk walking, skating and stair climbing all provide you with an aerobic workout. Consider other options Try meditating, yoga and other remedies. Drink plenty of fluids and omit sugary foods and simple carbs from your diet. Consider taking an anti-stress supplement or herbal remedies. Try deep sleep and relaxation techniques before bedtime. Always ask a qualified healthcare expert, or see your doctor before taking up a new fitness routine, especially if you already have a health condition. Some conditions are made worse by exercising. If you are feeling stressed after a workout or exercising, seek medical attention.