After completing this article, readers should be able to:The word yoga is derived from the Sanskrit word yuj meaning “union.” An ancient Indian practice, yoga has been classified by the National Center for Complementary and Alternative Medicine as a mind-body medicine modality. (1) Mind-body skills, often called self-regulation skills, can help a child reframe a painful or difficult experience into one that reinforces their sense of resiliency, self-control, and confidence. (2)According to the 2007 National Health Interview Survey (NHIS), which included a comprehensive survey on the use of complementary health approaches by Americans, mind-body therapies were the preferred complementary and alternative medicine practice among children with emotional, mental, or behavioral health conditions. (3) Per the 2012 NHIS, children using yoga as a therapeutic modality increased by more than 400,000 from the 2007 survey from 2.5% to 3.2%. (4) In a survey of children and adolescents with chronic pain, yoga was indicated by 32% as their first choice of complementary medicine therapy. (5)Therapeutic yoga is the practice of uniting the mind, body, and spirit through mindfulness of breathing and body postures to improve stress coping, lessen pain, and improve specific health conditions. Although not completely understood, yoga causes changes in the parasympathetic nervous system, positively affecting heart rate variability. (6) There have been no recent systematic reviews of pediatric therapeutic yoga, and this article reviews the literature to help clinicians make evidence-based recommendations regarding yoga for their patients.Yoga is a complex mind-body practice incorporating eight components, according to Pantjali’s Yoga Sutras, considered the “guidebook” for yoga as it is currently widely practiced. (7) Four of these eight essentially define the yoga methods used in the research trials cited in this review.For this systematic review of yoga as a pediatric therapeutic intervention, we searched PubMed for relevant English language articles published from January 1994 through December 2013. We identified 15 controlled studies and four systematic reviews, eliminating from consideration all uncontrolled trials and those in which yoga was not the sole treatment intervention. The previously published systematic reviews (8)(9)(10)(11) can be summarized as follows: yoga appears to be a promising complementary therapy for children and adolescents, especially for those with pain and emotional, mental, and behavioral conditions, with very few reported adverse effects. However, a lack of methodologic and statistical rigor, including results based on small sample sizes, absence of systematic randomization, and a high degree of variability between intervention methods, limits the ability to recommend yoga as a primary intervention for any particular population.For this review, 15 studies met criteria for inclusion, all evaluating yoga as an intervention compared with a control group (Table). We included all English language studies published since 1994 that examined patients younger than age 20 years, used yoga as the primary intervention, and compared outcomes with a control group. For clinical relevance, we grouped publications based on category of patient condition, with the majority primarily addressing emotional, mental, and behavioral concerns. One study evaluated adolescents with irritable bowel syndrome (IBS) and included measures of anxiety. Four trials investigated various metabolic parameters in adolescents. We summarize the included studies to help pediatric health practitioners counsel patients about the value of therapeutic yoga for specific conditions.One study of 14 Australian boys with attention-deficit/hyperactivity disorder (ADHD) tracked measures of attention before and after the boys participated in a controlled yoga intervention. (12) The boys, ages 8 to 13 years, were diagnosed by specialists and 12 of 14 were receiving stimulant medication. The study used a randomized crossover design in which boys who were initially assigned to the control group had the opportunity to cross over into the yoga group after completion of the first intervention program. Six boys were randomized to begin in the intervention group, with five crossing over after the first sessions; eight boys served as controls. The intervention consisted of 20 weekly 1-hour group yoga sessions with encouraged daily home practice. The control group met for 1 hour monthly, participating in “cooperative games and activities that involved the skills of talking and listening, turn-taking, sharing equipment, and talk time.” Outcome measures included Conners’ Parent and Teacher Rating Scales and the Test of Variables of Attention. Significant improvement on eight measures on the Conners’ Parent Ratings Scales (Oppositional, Global Index Emotional Lability, Global Index Total, Global Index Restless/Impulsive, ADHD Index, Perfectionism, Diagnostic and Statistical Manual of Mental Disorders [DSM]–IV Hyperactive/Impulsive, DSM-IV Total) was noted in the intervention group, while six scales (Hyperactivity, Anxious/Shy, Social Problems, Perfectionism, DSM–IV Hyperactive/Impulsive, DSM-IV Total) significantly improved in the control group. No significant improvement was noted in either group for any of the Conners’ Teacher Ratings Scales.Several trials examined the benefits of yoga for psychosocial well-being in school populations. In one study, fourth- and fifth-grade students in two after-school programs in the South Bronx, NY, participated in a community-based trial in which children either did 1 hour of yoga weekly for 12 weeks (n = 39) or physical activities other than yoga (n = 32). (13) Participation in the yoga intervention was determined by attendance in an after-school program that historically included yoga instead of typical physical activities. Yoga classes were taught by qualified yoga instructors and included traditional yoga practice with physical postures (asanas), breathwork, meditation, and relaxation. Pre- and postintervention assessments of emotional and physical well-being were administered by the investigator as well as trained after-school program staff members. It is not clear if evaluators were blinded to intervention assignment. The assessments designed for this study were based on previously validated scales. The intervention group showed significant reductions in the use of negative behaviors in response to stressors on the Emotional Well Being Assessment and significant improvements in one-leg standing balance on the Physical Well Being Assessment compared with the control group.Another trial evaluated fourth- and fifth-grade students (n = 97) at four public elementary schools in Baltimore, MD. (14) Students at two schools served as wait-list controls (n = 46) while those at the other two schools (n = 51) participated in 45-minute yoga sessions 4 days per week for 12 weeks. Of note, the yoga intervention included a “savasana” component at the end of each session, a mindfulness meditation resting pose commonly included at the end of yoga classes. Pre- and postintervention measures of responses to social stress, the Responses to Stress Questionnaire Involuntary Engagement Scale and its component subscales for rumination, intrusive thoughts, and emotional arousal were significantly improved in the yoga versus control group.Two studies evaluated 11th- and 12th-grade students at a public high school in rural Massachusetts. In one investigation, students who registered for physical education (PE) were cluster-randomized by class in a 2-to-1 ratio of yoga and PE-as-usual. (15) Participants in the yoga group (n = 36) attended two to three yoga sessions per week (alternating weekly due to the school schedule) over 10 weeks (28 yoga sessions total). The intervention consisted of a Kripalu-based yoga program of physical postures, breathing exercises, relaxation, and meditation. Participants in the PE-as-usual class (n = 15) met for 30 to 40 minutes two to three times per week over the course of the 10-week yoga program. Pre- and postparticipation self-report questionnaires included measures of psychosocial well-being related to mood and anxiety changes. Mood and anxiety markers, as well as negative affect ratings, improved in yoga students and worsened in controls.In the other study, students were randomized to either an 11-week yoga program (n = 74) or PE program (n = 47). (16) The yoga intervention, also led by Kripalu-style-certified instructors, involved two to three classes per week (each 30–40 minutes) consisting of “simple yoga postures, breathing exercises, visualization, and games with an emphasis on fun and relaxation” as well as “development and training in the cognitive skills of mindfulness and self-awareness and a yoga-based psychological and philosophical attitude.” Students in both groups completed pre- and postintervention self-report questionnaires evaluating mood, anxiety, perceived stress, and resilience. Statistically significant improvements were noted among yoga participants versus controls in measures of anger, resilience, and fatigue/inertia.Fourth- and fifth-grade girls in two public schools near Boston, MA, were randomized to a yoga group (n = 70) or a wait-list control group (n = 85) to investigate the impact of a structured yoga intervention on stress reduction in school-age girls. (17) The yoga group met for 60 minutes after school 1 day per week for 8 weeks and completed 10 minutes of yoga homework 6 days a week. The intervention (“Mindful Awareness for Girls through Yoga”) was adapted from the principles of Mindfulness-Based Stress Reduction, focusing on age-appropriate yoga portions of the program. The control group met one time at the beginning of the study and one time at the end. Self-esteem and self-regulation increased in both groups, while the intervention group reported greater appraisal of stress and greater frequency of coping. The author hypothesized that greater awareness of stressors in children may lead to greater perceived stress while simultaneously leading to improved coping when provided with yoga and mindfulness instruction.A prospective randomized, controlled trial in India evaluated the effect of a yoga program on reducing anxiety symptoms in adolescent girls with polycystic ovarian syndrome (PCOS). (18) A total of 72 girls (15–18 years old) from a residential college in Anantapur, Andhra Pradesh, India, who met the Rotterdam criteria for PCOS, were randomly assigned to one of two groups. The intervention group (n = 37) participated in 1 hour of yoga per day, 7 days per week for 12 weeks (90 sessions total), with a focus on “asanas (yoga postures), pranayama, relaxation techniques, meditation, and lectures on yogic lifestyle and stress management through yogic counseling.” The control group (n = 35) did 1 hour of physical exercise per day, 7 days per week for 12 weeks. Both groups also received 1 hour of individualized counseling. Pre- and postintervention state-trait anxiety inventory questionnaires were completed. Although changes in state anxiety (“a transitory emotional state that varies in intensity, fluctuates over time and is characterized by feelings of tension and apprehension and by heightened activity of the autonomic nervous system”) did not differ significantly between the two groups, trait anxiety (“a relatively stable individual predisposition to respond to situations perceived as threatening”) showed a statistically significant improvement in the yoga group compared with the control group.Another Indian study evaluated 98 primary school students (ages 9–12 years), with the intervention group (n = 49) participating in 45 minutes of yoga 5 days per week for 3 months and the control group (n = 49) participating in 45 minutes of PE 5 days per week for 3 months. (19) The yoga program included pranayamas, asanas, and yoga relaxation techniques. Pre- and postintervention assessments included measures of physical fitness, cognition, and self-esteem. Both groups showed improvement in all measures, although social self-esteem statistically improved more significantly in the PE group versus the yoga group.Adolescent students (mean age 16 years) in a residential summer music program in the Berkshires, MA, were assigned to a yoga group (n = 84) or control group (no yoga, n = 51). (20) The intervention group participated in 60 minutes of yoga three times weekly for 6 weeks. Yoga was led by a Kripalu-certified instructor and consisted of asanas, breathwork, and meditation. Pre- and postintervention measures included scales of anxiety and performance-related musculoskeletal disorders. Of note, music performance anxiety scores were significantly reduced in the yoga group compared with the control group.Thirty sixth-graders in a busy New York City public school were randomized to either a yoga (n = 15) or PE program (n = 15) for 50 minutes three times per week for 15 weeks. (21) The yoga program included asanas, breathwork, and relaxation led by certified yoga instructors, while the PE classes included common games and walking exercises. Physiologic responses to behavioral stressors were measured pre- and postintervention, with no significant differences found between the two groups.Twenty-five adolescents (11 to 18 years old) with IBS diagnosed by Rome I criteria were randomly assigned to either a yoga (n = 14) or wait-list control group (n = 11). (22) There were no significant differences in demographic variables between the two groups. Teens were recruited from either the local gastroenterology clinic or through the community. The yoga intervention consisted of a 1-hour instructional session, demonstration, and practice, followed by 4 weeks of daily home practice guided by a video containing “specific poses and breathing instructions selected for the purported easing and self-regulation on the abdomen and bowel.” Pre- and postintervention questionnaires in both groups measured gastrointestinal symptoms, pain, functional disability, coping, anxiety, and depression. Following the comparison trial, the wait-list control group was offered the opportunity to participate in the yoga program. Adolescents in the yoga group reported lower levels of functional disability, less use of emotion-focused avoidance, and lower anxiety following the intervention than those in the control group. In addition, when the data for the two groups were combined after the control group finished the yoga component, adolescents had significantly lower scores for gastrointestinal symptoms. Importantly, all but one of the teens reported that they planned to continue to use yoga to manage their IBS in the future.One randomized, controlled study based at Seattle Children’s Hospital, Seattle, WA, evaluated the impact of yoga in the treatment of eating disorders, both from metabolic and emotional perspectives. (23) A total of 50 girls and 4 boys ages 11 to 21 years receiving outpatient care for diagnosed eating disorders (anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified) were randomly assigned to an 8-week trial. After attrition, 24 patients participated in the yoga intervention group and 26 in the standard care (no yoga) control group. There were no significant differences in demographic variables between the two groups. One-on-one yoga instruction was led by a certified instructor, with children participating in 1 hour of yoga semiweekly for 8 consecutive weeks. Pre- and postintervention measures as well as a 1-month follow-up assessment included Eating Disorder Examination (EDE) scores; body mass index (BMI); and measures of anxiety, depression, and food preoccupation. Significantly, EDE scores decreased over time in the yoga group, while the control group showed some initial decline but then returned to baseline levels at the 1-month follow-up assessment. Food preoccupation dropped significantly after all sessions, with both groups maintaining BMI and improving in anxiety and depression measures.A total of 34 obese Korean children were randomized to yoga or control groups to compare changes in metabolic parameters. (24) After attrition, 20 children ages 13 to 15 years with BMIs greater than the 95th percentile completed 8 weeks (three times a week) of yoga (n = 10) or control programs (health education and exercise) (n = 10). The yoga program included a warm-up period, asanas, and meditation in each session. Pre- and postintervention measures of body weight and BMI significantly decreased in the yoga group but not the control group, while fat mass decreased in both groups but significantly more in the yoga intervention group.Two prospective randomized, controlled trials in the same Indian PCOS population cited previously (15) examined metabolic and hormonal parameters before and after yoga versus exercise control programs. (25)(26) In these studies, the yoga and control interventions were identical to those used in the PCOS anxiety study. One trial (yoga n = 35, control n = 36) measured pre- and postintervention fasting lipids, fasting blood glucose, insulin resistance, BMI, and other body measurements, while the other (yoga n = 37, control n = 35) evaluated endocrine parameters, including anti-müllerian hormone (AMH), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, prolactin, BMI, hirsutism, and menstrual frequency. In the metabolism study, investigators found statistically significant improvements in fasting insulin, fasting blood glucose, and insulin resistance in the yoga versus control group. In the endocrine study, those participating in yoga demonstrated significant changes in AMH, LH, LH/FSH ratio, and testosterone; improved scores for hirsutism; and improved menstrual frequency compared with controls. Overall, yoga was more effective than conventional exercises in improving important metabolic and endocrine parameters in adolescent girls with PCOS.Yoga is a promising complementary therapy and stress management tool for children and adolescents, with very low reports of adverse effects. In fact, the lack of harm in all the studies reviewed, especially when compared to other therapeutic modalities for children with chronic health-care needs, should help pediatricians feel comfortable recommending yoga as a therapeutic intervention. Yoga has positive effects on psychological functioning, especially in children coping with emotional, mental, and behavioral health problems. Specifically, research has shown that educational curricula incorporating stress management programs improve academic performance, self-esteem, classroom behaviors, concentration, and emotional balance, (27) suggesting that schools may be an ideal setting to bring yoga to a heterogeneous, socioeconomically diverse sample of children. In addition, yoga has been demonstrated to positively influence metabolic and hormonal parameters. Given the increasing prevalence of obesity and metabolic dysfunction in children, coupled with the relative safety and cost-effectiveness of yoga as an intervention, more research in this population is needed. Limitations of reviewed studies include small sample sizes, high attrition rates, lack of evaluator blinding, reliance on self-report measures, and heterogeneity of intervention and control designs. Well-designed controlled trials of yoga for conditions with strong stress-modulated components are warranted. Excellent candidate conditions include asthma, IBS, inflammatory bowel diseases, juvenile idiopathic arthritis, and fibromyalgia.Yoga is an increasingly used complementary therapy for children with chronic pain and stress-related conditions. Given the biologic plausibility for response, limited potential for adverse effects, and promising pilot efficacy data, pediatricians can recommend yoga as safe and potentially effective therapy for children coping with emotional, mental, and behavioral health conditions. Further, yoga is a promising intervention for children with metabolic dysfunction and chronic pain conditions. Larger well-designed trials are warranted to evaluate further the efficacy of yoga in these populations.