Stress is a slippery word to define, but most people would agree that Sally felt it that evening. And scientists would concur. In their eyes, all stress, great or small, arises from our struggle to survive and reproduce. We experience it when we sense a threat to ourselves or our children. That's why Sally's reaction reached a crescendo when she stood defending Sara. A situation doesn't have to threaten imminent death to cause stress. As social creatures, we all instinctively know that we, and our children, depend on others for our long-term well-being. That's why Sally was so disturbed by social threats like job hassles, problems in her marriage, and the angry scowls of other drivers. One key thing to remember about stress is that a threat doesn't have to be real to cause it; we just have to believe it's real. Sally didn't need an actual burglar to get her blood pumpingan imagined one did the job well enough. Scientists differentiate between short-term (acute) stress and long-term (chronic) stress. Acute stress evokes physical and emotional responses that activate the body and mind to deal with an immediate threat. When the threat passes, the reactions subside. Long-term stress evokes similar responses, usually at a lower intensity, but keeps repeating them day after day without respite. When they repeat too often for too long, the life-saving responses that are so helpful in the short run can actually become life-threatening. The short-term stress reaction is often called the fight-or-flight response. That's what Sally experienced when Sam opened the door. She perceived danger, so her brain and body automatically readied themselves for intense action, either combat or escape. To do either of these well, our bodies need maximum alertness, powerful muscle action, and the ability to keep going even if injured. Sally's brain activated a bogglingly complex set of physiological processes to support these needs. Many of these processes had already started, at a lower intensity, in response to the minor stressors she had endured before Sam came home. Sally's stress response began with her perceptions. When her car stalled, the reasoning part of her brain (the cerebral cortex) perceived a problem that required quick action but was not a life-or-death emergency. Then the emotional part of her brain (the limbic system, especially an almond-shaped structure called the amygdala) increased her sense of urgency by responding with fear and anger to the honking horns and hostile faces of passing drivers. Her cortex and her limbic system triggered some responses more or less directly, including increased heart rate and muscle tension, but they delegated most of the responsibility for activating the rest of her responses to a sort of 911 control center located in the rear part of the hypothalamus (a brain area that coordinates basic drives like hunger, sleep, and self-defense). The threat situation was only moderate, so the stimulus to the hypothalamus wasn't that strong. But when Sally thought an intruder was entering her kitchen, her cortex and limbic system screamed "Danger!" at the top of their neural lungs. The posterior hypothalamus got the message loud and clear. In a flash, this little complex of brain cells turned on all the physiological systems she needed to get her muscles and mind going at full power, and turned off everything that might interfere. It told her pituitary gland to send out a chemical messenger to her adrenal cortex, the outer layer of her adrenal glands, stimulating it to release the stress hormone cortisol into the bloodstream. It told her brain's sleep centers to shut off and its wakefulness centers to kick into their highest gear. It activated brain centers that control muscle tone, increasing tension everywhere in her body. It told breathing centers at the base of Sally's brain to increase respiration to provide oxygen for all the extra muscle and brain activity about to occur. And, most important of all, it cranked her entire sympathetic nervous system up to full throttle.

All Revved Up, No Place to Go The sympathetic nervous system is a network of nerve cells that extends throughout the body. It helps support our normal activities; for example, it makes our heart beat faster when we climb stairs. In an emergency, though, it goes into overdriveand Sally felt the results. To get more blood to her heart, skeletal muscles, and brain, the sympathetic nervous system widened arteries in those places, narrowed them in others, and started her heart racing and pounding. That's why she felt a throbbing in her temples. In her digestive tract, Sally's sympathetic system narrowed arteries and inhibited other functions. That's why she felt a dry mouth and a knot in her stomach. To help her get more oxygen, sympathetic nerves opened up her air passages. That's why her nostrils flared, her nose cleared, and her voice faltered when she first saw Sam. Other sympathetic nerves worked to make sure Sally could see everything going on around her. They dilated her pupils and opened her eyelids so wide that Sam could see the whites all the way around. To keep her from overheating, still other sympathetic nerves activated sweat glands. The sympathetic nervous system triggered most of these responses by releasing a major chemical messenger called norepinephrine (or noradrenaline) at nerve endings on target tissues like blood vessels and sweat glands. It also stimulated the adrenal medulla (the core of the adrenal glands) to flood the bloodstream with more norepinephrine plus a second essential chemical, epinephrine (also called adrenaline). These chemicals not only intensified the stimulation of organs directly targeted by sympathetic nerves, they also acted on parts of the body that don't have these nerve connections. For example, they made Sally's blood clot faster (so her cut did not bleed much), made her muscle fibers contract more strongly (so she could easily lift an iron table), and made her brain activity speed up (so the world around her seemed to slow down). The hormone cortisol, acting alone and in combination with epinephrine and norepinephrine, supported Sally's fight-or-flight response in other ways. It stimulated her liver, muscles, and other organs to release extra fuel (glucose and glycogen) into her bloodstream, contributing to her strength and mental activity. It increased her pain tolerance so she didn't notice her cut, and it suppressed inflammation and swelling, a response that would have enabled her to keep going even if she had a more serious injury, like a sprained ankle. Effects from a fight-or-flight response take a long time to wear off. Muscles that have tensed are left shortened and do not automatically go back to their former length. On the contrary, spinal reflexes make them contract if they begin to lengthen: After the danger has passed and the brain lets the muscles relax a little, the spinal cord immediately tells them to tense up again. At first, they go through a very rapid cycle of relaxing a little and then contracting, again and again. That's why Sally trembled after her scare was over. Eventually, the stretch reflex abates enough for the trembling to subside, but the muscles still don't settle back to their former resting length. They remain relatively short and tense until the reflex is reset by a relaxing experience, like the gentle, conscious stretching that occurs during a massage or a yoga session. Muscles aren't the only part of the body slow to recover from a fight-or-flight reaction. Stress hormones remain in the bloodstream for quite a long time, and more may be released in response to memories of the danger. That's why Sally was not hungry for dinner after her fright (her digestive tract was still shut down) and why she had trouble falling asleep that evening (her brain was still highly activated).

Sally's story shows what can happen when we face acute, major stress. But what happens when we experience moderate stress repeatedly, day after day? Our bodies activate the same emergency systems, although to a lesser degree. Unfortunately, when invoked chronically, physiological responses that help us cope with danger can become dangerous themselves. Suppression of digestion can contribute to gastrointestinal problems, and promotion of high glucose levels in the blood may contribute to diabetes. Constricted blood vessels, a pounding heart, and rapid clotting can eventually lead to high blood pressure, heart disease, or stroke. Suppression of inflammation can also suppress the immune system, making us more susceptible to infection and possibly even cancer. Chronic stress can also lead to infertility, poor healing capability, and exhaustion. Stress BustersLuckily, there are lots of ways to reduce stress or even to head it off in the first place. They fall into three main categories: changing your situation, changing your attitude, and taking good care of yourself. Changing your situationgetting a new job, moving to a new neighborhood, or leaving an unhealthy relationshipcan be very effective, but it's often not practical or even desirable. Changing your attitudedeciding you don't have to knock yourself out working overtime to prove your self-worth, for example, or deciding it's not your responsibility to make your partner changecan be very powerful, even life-transforming, because it puts you in control. When you realize you can choose how you react, many events you formerly found stressful may lose their power to push your buttons. Taking care of yourselfeating right, avoiding harmful drugs, exercising, making rest a priority, and scheduling time in pleasant environments with nice peoplehelps you recover from stress and keeps it from building up again. One of the best stress busters around is yoga. It directly counteracts both the physiological and psychological components of stress, simultaneously helping you take better care of yourself and change your attitude. The stretching you do in yoga relieves muscle tension. Upside-down poses and reclining poses slow the heart, relax the blood vessels, inhibit production of norepinephrine, and calm the brain. Pranayama (yoga's classic breathwork) slows respiration. As you practice being more aware and mindful, you gain a sense of self-control, equanimity, and peace. Perhaps most important of all, meditation and the teachings of yoga philosophy can help you realize that most of the things that upset you just aren't worth getting stressed about.Breathing Room Yoga allows you to pay attention to the breathand brings greater awareness to the parts of the body that allow us to exhale and inhale fully. By Julie Gudmestad Until you start doing yoga, you may never pay much attention to your breath. But with the coaching of yoga teachers--or perhaps just because of your new awareness of your body--you start to see all the ways your breath can vary. Is it quiet or noisy, heavy or soft? Where does it originate and how does it move through you? Is it relaxing, energizing, or making you tense? Helping or hindering your asana practice?

Yoga teaches that the breath exerts a powerful influence on the body and mind--and vice versa. When you're tense or guarded, for example, you may first hold the breath and then take fast, shallow breaths. Relaxed breathing is slower and softer, and has a steady, even pattern. This deep, slow, relaxed breathing, used in Savasana (Corpse Pose) and other restorative poses, is most commonly associated with yoga. But to supply oxygen to the hardworking muscles in an active series of poses like Sun Salutations, we also need a faster deep breathing pattern. And most subtle of all is the finely controlled deep breathing of pranayama. For best results, all three patterns require openness of the breathing space (the rib cage and abdomen) and fine coordination of several muscle groupsBreath Mechanics The diaphragm muscle in the middle of the torso is a key player in establishing the pattern of the breath. Stretching like a drumhead across the bottom of the chest, the diaphragm separates the heart and lungs above it from the abdominal cavity and digestive organs below. The muscle fibers then extend inward toward the middle of the body and gather into a central tendon that doesn't attach to the skeleton. When relaxed, the diaphragm curves upward like a dome. When it contracts, it shortens and flattens, pushing on the digestive organs below and lengthening the chest cavity above. This expansion of the chest cavity draws air into the lungs. The lungs have no capacity to expand or contract on their own. They simply respond to the size and shape of their container, the chest cavity. When it expands, the lungs inflate and air rushes in to fill the vacuum. When the container shrinks, the lungs are compressed and air is pushed out. To feel the action of the diaphragm, lie on your back. The belly needs to be completely soft and relaxed, so it may be helpful to put some support under your knees. Now place your hands on your belly and feel the movement of your breath. In relaxed diaphragmatic breathing, your hands should softly lift on the inhalation. As the diaphragm relaxes, it returns to its dome shape and the belly softly drops. In order to take a full breath, the diaphragm and several accessory muscles must work in concert to expand the rib cage in all directions. The accessory muscles include the sternocleidomastoids, which form a V-shape on the front of your neck, extending from the top of the sternum and collarbones up to the base of the skull just behind your ears. It's easy to see them work. Stand in front of a mirror with your neck uncovered. Near the end of a deep inhalation you'll see the sternocleidomastoids contract. They lift up on the rib cage as the diaphragm lengthens the chest cavity from below. This chest cavity expansion is also assisted by the intercostals, three layers of small muscles that span adjacent ribs. As they contract, they lift each rib up and away from the center of the body, providing both vertical and lateral expansion of the chest cavity. To feel this for yourself, stand and wrap a long, soft belt or tie around your lower ribs, about three to four inches above where you normally belt your pants. Cross the belt ends in front and hold one end in each hand. As you exhale and the rib cage compresses, pull the belt tight; as you inhale, feel the belt expand as the rib cage opens up and out. This expansion is created by the combined action of the diaphragm and intercostals. You can use this exercise with the belt to increase lung capacity and help expand the rib cage in preparation for pranayama. You also need strong back muscles to help you take a deep breath. Your spine forms a strong column that supports the expansion of the ribs up and out, with the erector spinae muscles running up each side of the spine, acting like guy wires to support the spine and rib cage. When you are curved over in a slump, with a forward head and a collapsed chest, your posture significantly limits your ability to breathe deeply. The collapsed chest puts pressure on the diaphragm, limiting its ability to function, and also hampers the expansion of the ribs. Breath movements can also be limited by short and tight abdominal muscles. Chronic pain in the lower back, pelvis, or abdomen can also affect breathing patterns by causing guarding and holding in the diaphragm and abdominal muscle layers. In fact, most pain, chronic or acute, is accompanied by abnormal breathing patterns. When I work with a client in pain, I often begin with breath awareness.

Freedom of Motion Yoga can help improve your breathing patterns, and good breathing patterns can immeasurably improve the quality of your yoga practice. Whether you are practicing quiet, relaxing poses like forward bends, energizing poses such as Sun Salutations, or the subtle techniques of pranayama, one of the most important steps to improve your breathing is to free the movement of the diaphragm by opening the chest and upper abdomen.

Since it's much more challenging to open the chest while standing or sitting, you'll do best to begin lying down. Lie on your back lengthwise on a bolster. Your hips should be on the floor, with the end of the bolster supporting your lowest back ribs, just above your waist. The bolster's support will open space for the diaphragm to contract and relax without constriction.

Put a folded blanket or small firm pillow under your head so that your chin is a little lower than your forehead. This head position will help direct your focus inward, so that your attention can center on your breath. As you relax and settle down onto the bolster, notice that your breathing becomes slower and smoother. Your belly should softly rise and fall with each breath. This quality of relaxed, slow, and smooth breathing indicates relaxation of the nervous system; you can use it to facilitate the release of muscle tightness in stretching poses like forward bends and supported backbends.

You may be able to feel your rib cage expanding softly up and out as the diaphragm and intercostals work together to expand the chest cavity with each inhalation. This chest expansion is the primary action needed in pranayama; the abdomen should remain quiet, with most of the increase in volume occurring in the rib cage. Most of us need many months or years of practice to make this breath pattern smooth and nearly effortless.

Now bring your attention to the exhalation. During demanding physical activity, the breathing rate increases. Air must be pushed out of the lungs quickly to make room for more incoming air. The abdominals and some intercostals contract to help compress the chest cavity and squeeze air out.

During quiet, relaxed breathing, however, no squeezing is necessary. As always, we use muscular energy to expand the lungs, but during relaxed exhalation the air is simply pushed out of the lungs by the elastic recoil of the rib cage. The abdominals, along with all the muscles of respiration, can release completely during a relaxed exhalation.

As you become more deeply relaxed and your breathing becomes quieter, see how little effort you can use on each inhalation. Let exhalations become virtually effortless, so that each one provides an opportunity to completely relax. Relaxed, open, and centered, you are now perfectly prepared to begin Savasana, pranayama, or meditationgives me the mental and physical energy to be more productive and feel youngerIt makes the body more flexible and helps you relax even in the midst of a stress stricken environment. This is one of the foremost reasons why people want to start Practicing Yoga - to feel fitter, be more energetic, be happier and peaceful.Hatha yoga involves a series of postures, or asanas, intended to align your muscles, skin and bones. Its physical benefits can be the most immediate and obvious, but it's the mental and spiritual benefits that can transform your lifePracticing poses helps align your body, breath and mind, a connection that takes your attention away from the chaos of the outside world and into your inner being. With your attention focused inward, you can become more aware of the way you habitually think or react to situations, without judging if such thinking or reactions are necessarily good or bad -- they just are. Hatha yoga can help you recognize your behaviors and respond more effectively to your experiencesHatha yoga's overall goal is to enhance your spiritual development, which it does by releasing the energy that flows throughout your body and balancing the opposite aspects of your being. According to yoga theory, everyone has masculine and feminine aspects to his being, referred to as the hot, active energy of the sun -- or "ha" -- and the cooling, receptive energy of the moon, or "tha." Hatha, which literally translates to sun-moon, balances these two opposites while opening your body's energy channels. The main channel is the spine, which holds the divine energy, or kundalini sakti, at its base. The object is to achieve balance so that energy streams freely through your body, ultimately facilitating a spiritual awakeningOne of the most immediate health benefits of practicing Hatha yoga poses is a feeling of calm; when you focus on your yoga practice, you may focus less on your worries or woes. Yoga can increase your flexibility, range of motion and strength as well as enhance your balance, leaving you with a higher fitness level and reduced risk of injuries.

The breathing practices, or pranayama, are one component of hatha yoga, which is intended to give one a healthy body and mind