When one thinks of ways mental health can be improved they often do not consider physical aspects. “The importance of exercise is not adequately understood or appreciated by patients and mental health professionals alike. Evidence has suggested that exercise may be an often-neglected intervention in mental health care” (Sharma). Doctors once thought depressed people experienced physical sickness in addition to mental illness because they did not practice healthy habits. It is now known that there are biological reasons which explain how physical and mental diseases are connected. Many people are diagnosed with a physical disease in addition to a mental disease (MacMillan). There are exciting advances regarding exercise and its contribution to mental health therapy. According to Psychologist Mary de Groot, research regarding the most effective type of exercise, the amount of exercise necessary and if exercise works best when combined with other therapies is in the preliminary stages (Weir). The idea of exercise as therapy is fairly new. In order to find out which type and how much exercise is necessary, more studies will need to be created.There are five different hypotheses in regards to physical activity’s positive effect on mental health problems. The first is known as the thermogenic hypothesis. The hypothesis suggests that the increase in body temperature from exercise decreases the symptoms of depression. This increase in body temperature affects the brain, causing feelings of relaxation and decreased muscle tension (Craft). The relief in muscle tension is interpreted by the brain as relaxation and reduced anxieties.The next hypothesis, and most popular, is the endorphin hypothesis. “Endorphins are related to a positive mood and an overall enhanced sense of well-being.” The endorphin hypothesis states that the increased release of endorphins following exercise has a positive effect on depression (Craft). In addition, “meditation, acupuncture, massage therapy, even breathing deeply can cause your body to produce endorphins” (“Physical Activity”). Since meditation and deep breathing also produce endorphins, it can be inferred that yoga can help reduce stress and in turn, reduce depressive symptoms. Any physical activity which produces endorphins could be used as a successful treatment for depression.The third hypothesis is the monoamine hypothesis. A monoamine is “a compound having a single amine group in its molecule, especially one that is a neurotransmitter” (Dictionary.com). “This hypothesis states that exercise leads to an increase in the availability of brain neurotransmitters (e.g., serotonin, dopamine, and norepinephrine) that are diminished with depression” (Craft). Increased vulnerability to depression can come from a genetic “deficiency” of depleted neurotransmitters. (Beach). By increasing available neurotransmitters, depression can be improved or possibly prevented. Stephen Beach says antidepressants are used to stimulate neurotransmitters, as well and help reduce symptoms of depression even if the neurotransmitter’s activities are affected by something other than genetics (Beach). Since exercise has proven to improve depressive symptoms by increasing neurotransmitters, scientists have begun researching the use of exercise in place of antidepressants. Psychologist James Blumenthal studied the “connection” between mood and exercise with a controlled experiment. “A group of adults with major depressive disorder were given one of four assignments: supervised exercise, exercise at home, antidepressants or a placebo.” He concluded that patients exercising or on antidepressants showed more improvement than those on the placebo (Weir). This study leads to the conclusion that exercise can reduce the use of antidepressants. One of the more easily understood hypotheses is the distraction hypothesis. This hypothesis implies that exercise can distract a person from depressive thoughts and worries. Generally, distracting activities have a more positive influence on the management of depression than self focused activities such as journaling or identifying things that describe one’s mood (Craft). In multiple studies, exercise has been compared with other types of distractions. Exercise is either more effective than some activities in reducing depression or similar in aiding the reduction of depression (Craft). Therefore, exercise is a good choice of a distracting activity. In correlation with the distraction hypothesis, sports psychologist Darcy Wallace suggests that exercise can be used for getting people out of their depressive cycle. If someone gets into a routine of walking daily, it gives them a goal. Once the patient gets moving and experiences even a short burst of feeling good, “they can document that things got lighter for them” (Wallace). This happy memory will make the person more inclined to exercise again.The last major hypothesis is the self efficacy hypothesis. Self-efficacy is “the belief that one possesses the necessary skills to complete a task as well as the confidence that the task can actually be completed with the desired outcome obtained” (Craft). Psychologist Albert Bandura explains that depressed people often feel they cannot bring about positive outcomes in their life and have low confidence that they can deal with their symptoms of depression. Exercise causes self efficacy to be enhanced because it provides the individual with a feeling that they have mastered something (Craft). Self efficacy is difficult to measure, and its effects on depression continue to be studied. Wallace was asked whether the positive effect from exercise is due to feeling confident or being fit. She said the positive effect is due to confidence; a person can look physically fit, but not feel good. She added that confidence is internal so that is why it is more beneficial than fitness to someone who is depressed (Wallace). This idea supports the self efficacy hypothesis. All five of these hypotheses continue to be studied. “More research is needed to determine which, if any, of the mechanisms described herein are important moderators of the exercise effect. It is highly likely that a combination of biological, psychological, and sociological factors influence the relationship between exercise and depression” (Craft). The exact mechanism, type and duration of exercise that will produce these effects on depression have not been determined; however, it is known that exercise exerts positive effect on depression itself.Exercise has also been tested as therapy for anxiety. When a person experiences anxiety, their nervous system fires signals and a series of chain of reactions occurs, causing an increase in heart rate and sweating. Workouts also produce increased heart rate and sweating, the same sensations people with anxiety associate with fear. When working out, people associate these sensations with safety instead of danger:”Exercise is exposure treatment.” Doctor Jasper Smits created a study where he stimulated triggers for a panic attack by having volunteers breathe in carbon dioxide enriched air. People with high anxiety were more likely to panic during the test. Those with anxiety who also self reported frequently exercising were less likely to panic than people who did not exercise (Weir). Their previous experience with exercise exposure minimizes the likelihood of panicking. Depressive illness has been linked to many physical diseases including diabetes. There is a mind and body link associated with diabetes. Diabetes is a condition where glucose is not utilized properly because the body lacks insulin. This leads to high levels of glucose in the blood. Glucose is utilized by the body for energy. In type one diabetes, not enough insulin is made by the pancreas, and in type two diabetes the body cannot respond normally to insulin. Insulin is needed to transport glucose into body cells. “Mental illness is often associated with specific physical conditions–depleted neurotransmitters, or excessive spiking of blood sugar” (“Blood Sugar”). Someone with diabetes would be at a greater risk for depression because they have high blood sugar due to a lack of insulin. Overweight adults have a higher risk of developing type 2 diabetes. Exercise can help mitigate this risk. Mercedes Carnethon, from Northwestern School of Medicine, “suspects that stress hormones–which tend to be elevated in depression–link the two conditions. Too much cortisol, in particular, can build abdominal fat and an apple-shaped body, which are strong risk factors for diabetes” (Vastag). New research shows that in older adults, depression precedes diabetes. A ten year study monitored over 4,000 adults who filled out surveys on “mood, lifestyle, and other health-related factors.” Patients who showed depressive symptoms or whose depressive symptoms increased, faced 50-60 percent increased risk for developing diabetes (Vastag). If the depression can be treated early, this risk of developing diabetes can be lessened. Groot is researching “the role” of exercise in people with depression and diabetes. She says that depression is higher in adults with diabetes compared to the “general population.” She also states, “People with diabetes are more likely to develop depression, and people with depression are also more likely to develop diabetes.” In addition, many studies show that having both disorders puts people at a higher risk of mortality than either disorder alone (Weir). Since obesity and diabetes are related, de Groot predicted that exercise could treat the two conditions. She created a study with adults who had been diagnosed with both diabetes and depression using a 12 week exercise program. Participants who exercised showed less depressive symptoms and higher levels of A1C, “a blood marker that reflects blood- sugar control and therefore improved symptoms of diabetes” (Weir). Specific types of exercise and their benefits vary based on type of diabetes and the individual (Colberg). The important part is that exercise is a beneficial treatment component for both diabetes and depression. “Exercise improves blood glucose control in type 2 diabetes, reduces cardiovascular risk factors, contributes to weight loss, and improves well-being” (Colberg). Exercise can be used not only to treat mental disorders, but also physical diseases. This discovery could change how different health problems are treated in the future and will further open up the field of physical therapy. The positive correlation between exercise and improved health allows physicians to encourage physical exercise as an easily accessible treatment option. The duration and types of exercise as therapy can vary from person to person. Early research suggests that aerobic exercise is best for reducing tension, improving mood, sleep and self esteem (“Physical Activity”). Generally, patients should start slowly, exercising a few times weekly at a comfortable pace for a small amount of time. Once the patient feels they can exercise for ten minutes per session, the duration can be increased (Craft). Craft has found that moderate intensity exercise (60-80% max heart rate) will “enhance mood” just as much as intense exercise. It also is more enjoyable than intense activity (Craft). “Doctors should advise patients to choose an enjoyable type of exercise; most people choose walking. Patients should choose a place to exercise where they feel safe” (Craft). Choosing a safe place is important because if the patient feels anxious when they exercise they will associate that feeling with exercise and this will discourage them from the activity. Wallace also emphasized this point. She says people who are less inclined to exercise often find letting go of the fear of being ridiculed to be difficult. She suggests patients find a safe environment, which she calls a safety container; this is someplace such as a park where you feel safe and comfortable (Wallace). Just as different types of exercise benefit different people, the same goes for therapy. Wallace explained that when she worked in a mental health facility, she would go on walks with her patients for therapy sessions instead of sitting face to face. Often times face to face therapy makes the patient feel trapped. Walking therapy gives the patient freedom and they would be more willing to talk with her. She added that after the walk the patient would usually feel better because they elevated their heart rate and they were exposed to fresh air (Wallace). Conducting therapy sessions as walks could be more productive because the patient would simultaneously feel the benefits of exercise as well as the freedom of being outdoors.