If the lure of firmer abs and a trimmer waistline aren't enough to get you to the gym, the rush of a exercise-induced endorphin release may be more your style. Endorphins are types of neurotransmitters that stimulate reactions in your central nervous system. Endorphins are activated by a range of activities and sensations from the painful to the pleasurable, and exercise is one of the ways to get those endorphins moving. Men and women trigger an endorphin release with the right kind of exercise, but the implications of endorphins for women are not exactly the same as the implications for men.
Endorphins act primarily as inhibitors of your body's physical and emotional reaction to stress, pain and fear. Receptor cells inside your brain and spinal cord are responsible for translating nerve messages into physical and emotional experiences: the pain you feel when you touch a hot stove or the anxiety you experience when you're about to parachute from a plane are the result of these receptors translating nerve messages. While your body is processing these stress reactions, the chemical shift triggers other parts of your body, like your pituitary gland, to release endorphins. Endorphins travel through your bloodstream to the receptor cells in your brain and attach to them, inhibiting their ability to transmit pain, fear, stress or anxiety signals instead. They act like a natural opioid in your body, and high levels translate to feelings of euphoria or relaxation, even in the face of stressful experiences.
Endorphins and Exercise
Exercise releases a cocktail of natural chemicals inside your body. Exercise increases levels of stress hormones in your body because your body interprets exercise as a form of mild trauma. When the messages from those hormones reach your brain, your body sends endorphins to block the receptors in an attempt to keep you calm and reduce pain. Though both men and women experience a rise in endorphin levels during intense exercise, according to a research study in "Medicine and Science in Sports and Exercise," a 1996 study found that female athletes had higher concentrations of endorphins prior to exercise, so their increase in endorphins was less pronounced compared to male athletes.
The Exercise Pay-off
Men and women benefit from the endorphin surge of exercise. Higher levels of endorphins block the pain of exercise and can help you power through to a longer workout. Endorphins are responsible for a range of pleasant feelings during and after exercise, ranging from simple happiness to the euphoria known as runners' high. Women may also experience an increase in their libido thanks to an exercise-induced endorphin kick. Another benefit reserved especially for women is the role of endorphins in childbirth. Endorphins kick into overdrive to block pain receptors during childbirth and contribute to a sense of post-labor euphoria. Even if babies aren't on your immediate radar, women who exercise regularly and are in shape report shorter, easier labors. Athletic women tend to have higher levels of endorphins during childbirth, thanks to their regular exercise regime.
How Hard, How Long
Not just any activity will kick your endorphins into overdrive. The rate of endorphin release, and the subsequent feel-good sensations, are directly related to exercise intensity and duration. A study in "Medicine and Science in Sports and Exercise" found that submaximal running, or moderate-paced running, had little to no impact on endorphin release, and that athletes had to run at a high intensity in order to trigger an endorphin response. A subsequent study found that athletes had to operate at 70 percent of their VO2max, a measurement of their maximum aerobic capacity, in order to trigger an endorphin release. Most women have a lower VO2max than men, so it will take less resistance or time for them to achieve 70 percent, though the perception of the intensity is likely the same between men and women.
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