A great many interventions for posttraumatic stress disorder (PTSD) in adults have been described in the literature. These include, but are not limited to, cognitive-behavioral therapy, psychodynamic therapy, psychopharmacology, exposure therapy, anxiety management training, stress management techniques, eye movement desensitization and reprocessing, and physical exercise (Foa & Meadows, 1997) . In contrast, there is limited research and empirical support for evaluating treatment interventions for children diagnosed with PTSD. The material below will focus specifically on the role of exercise in reducing not only PTSD but also the major components that are associated with PTSD (i.e., anxiety and depression). Exercise fits in naturally with the ecological framework of children and with their educational curricula.
EFFECTS OF EXERCISE ON ANXIETY
Following a review of numerous cross-sectional and longitudinal studies, Salmon (2001) found consistent reductions in anxiety in adult samples following exercise. There are a variety of psychologically based explanations as to why exercise reduces anxiety. The distraction hypothesis implies that diversion from unpleasant stimuli or painful somatic complaints leads to improved affect following physical activity (Paluska & Schwenk, 2000). Bandura's (1977) self-efficacy theory suggests that individuals' perceptions of their capability to engage in exercise are increased following actual exercise participation. This might then lead to increases in self-confidence and enhancement of mood. The mastery hypothesis proposes that individuals gain afeeling of independence and control and therefore experience less anxiety (Paluska & Schwenk, 2000). Finally, the social interaction hypothesis indicates that those individuals who participate in physical activity gain social support from others, thus improving their mental health (Paluska & Schwenk, 2000).
Physiological explanations of the effect of exercise on anxiety include the monoamine hypothesis, which suggests that exercise enhances brain aminergic synaptic transmission (Paluska & Schwenk, 2000), and that this leads to increased levels of arousal and attention. This neurophysiological enhancement might then result in increased perceptions of self-efficacy and lowered anxiety. The endorphin hypothesis suggests that beta-endorphins are produced throughout the body during exercise and that beta-endorphins decrease pain and create a euphoric state that might be counter to the uncomfortable state associated with anxiety. Lastly, the thermogenic hypothesis proposes that after one engages in physical activity, body temperature rises and this rise is associated with enhancement of mood.
The majority of studies that show anxiety reductions with exercise have been done with adult samples. According to Berk (2007) , the few exercise interventions that have been implemented with anxious children and adolescents have resulted in lower levels of anxiety. Berk suggests that the lower levels of anxiety may stem from an increase in the release of endorphins. The improvements in mood that are said to be connected with endorphin release lead to improvements in social skills, increases in self-confidence, and a disregard of negative thoughts.
A lower risk of heart disease, hypertension, type II diabetes, negative mood states, and enhancement of self-esteem are all associated with adult participation in physical activity, according to Parfitt and Eston (2005). However, adolescents and children tend to provide less accurate estimates of their exercise levels than do adults, thereby complicating research efforts. Parfitt and Eston (2005) note that children and adolescents 11-13 years old recalled less than 50% of their daily activities throughout their school day and remembered 5596-65% of their daily activities from the previous day. Thus, the self-report measures that are typically used with adults to assess levels of physical activity would appear to be less desirable when used with children and adolescents. …