The Effects of Emotional Exposure on State Anxiety
The Effects of Emotional Exposure on State Anxiety
A randomized repeated-measures crossover clinical trial was performed. Forty healthy, female
 college students completed a 30 min session of YogaFit and a time-matched seated rest
 condition on separate days. After each condition, participants viewed 30 min of emotional
 picture stimuli. State anxiety, heart rate and time-domain and frequency-domain measures of
 HRV were assessed baseline, post- condition, and post-exposure to emotional stimuli. Data
 were analysed using a condition x time (2 × 3) repeated-measures ANOVA.
The design was a repeated-measures randomized crossover trial. Each study participant
 completed 4 different sessions on 4 different days: (day 1) participant screening; (day 2 or
 3) study condition A (seated, quiet rest); (alternate day 2 or 3) study condition B
 (moderate-intensity YogaFit); and (day 4) a session to rate IAPS pictures (14) and undergo a
 single DEXA scan [Prodigy/301776R. G.E. Medical Systems-Lunar DEXA Scanner, Fairfield, CT,
 USA]. Utilizing a simple randomization process, participants were randomized in a 1:1 ratio
 to participate in either the YogaFit condition or the quiet rest condition. The study
 conditions were counterbalanced and alternated using odd and even numbers to begin the
 sequence. Participants were not informed if the first condition was A or B. Self-reported
 anxiety levels and 10 min of continuous physiological data were collected: (a) baseline; (b)
 post-condition; and (c) post-exposure for both condition A and B. All participants completed
 both the psychological and physiological assessments. Both experimental conditions A and B
 were completed in 90 min. To ensure compliance, participants were observed through a glass
 window every 10 min during study conditions. Testing time and procedures were identical with
 the exception of the experimental condition on days two and three.

 All participants were familiarized with the videotaped YogaFit session before participating
 in the study. Participants were instructed to arrive for all visits dressed in loose fitting
 athletic wear and were asked to refrain from all food, alcohol, caffeine, gum chewing or the
 use of tobacco products 3 h before their scheduled meeting in the laboratory.

 During pre-screening, participants completed: (a) a standard health history questionnaire;
 (b) the STAI-Y2; (c) the BDI and (d) a custom DEXA safety questionnaire. Qualified
 participants were then asked to track their menstrual cycle using a menstrual log and e-mail
 the primary investigator on day 1 of the follicular phase of their menstrual cycle, thus
 using the first day of the women's menstrual cycle to generate an unpredictable random
 sequence and to eliminate any sequence bias. The participant was then scheduled for condition
 A first or condition B first. The conditions were counterbalanced to control for order
 effects, with odd numbers beginning condition A first and even numbers beginning condition B
 first. To control for the effects of the menstrual cycle on anxiety, participants completed
 condition A and condition B within a 7-day period during the follicular phase of their
 menstrual cycle (specifically days 1-10). Participants were also asked to maintain pre-study
 physical activity levels during the 7-day period. All testing was completed by day 10 of
 their menstrual cycle. State anxiety was psychologically quantified using a reliable and
 validated assessment of anxiety, Spielberger's State-Trait Anxiety Inventory (STAI-YI).

 Instruments for testing all physiological variables were calibrated and used by the same
 investigator in order to control possible inter-tester variation. During both condition A and
 B, a ProComp Infiniti System with Biograph software version 6.0 was used to measure HR and
 indices of HRV at a sampling rate of 2048 cycles per sec at the 3 different time points.
 Three electrodes were placed on the participants to monitor HR as specified by the ProComp
 Infiniti System. The negative electrode was placed in the right shoulder fossa below the
 clavicle, the positive electrode was placed medially on the thorax below the sternum, and the
 ground electrode was placed in the left shoulder fossa below the clavicle. Indices of HRV
 included the time-domain variable, root mean square of successive differences (RMSSD) and two
 frequency-domains: the low frequency power bands and the high frequency power bands in
 normalized units (LFNU and HFNU, respectively).

 Measures of HR and HRV were analysed using CardioPro Infinity-HRV Analysis Software
 Module-SA7J90 [ProComp Infiniti System, Montreal, Quebec, Canada: Cimetra LLC]. An
 accelerometer using the ActiLife 6 Software and a Polar Heart Rate Sensor were strapped to
 the participant and used to monitor the intensity level of both study conditions A and B. The
 accelerometer was used only to record HR data and no other accelerometer data were analysed.
 Participants were then informed of the experimental condition. For study condition A (quiet,
 seated rest), participants sat on a yoga mat in a cross-legged position for 30 min in a quiet
 laboratory setting. For study condition B [YogaFit Vinyasa Flow (referred to as YogaFit in
 this manuscript)], participants followed, via digital versatile disc, a standardized YogaFit
 format choreographed by a certified American Council of Exercise Instructor and Registered
 Yoga Alliance Teacher. Yoga- Fit was performed in the same laboratory setting and lasted 30
 min. There are 7 principles of alignment that are applied in every YogaFit session: (1)
 establish a base and dynamic tension; (2) create core stability; (3) align the spine; (4)
 soften and align the knees; (5) relax shoulders back and down; (6) hinge at the hips; and (7)
 shorten the lever. The YogaFit essence is based on: Breathing, Feeling, Listening to the
 Body, Letting Go of Competition, Judgement, Expectations, and Staying in the Present Moment.
 The movements included in each specific phase were chosen from Beth Shaw's YogaFit Vinyasa
 Flow Series. To measure intensity of theYogaFit routine, ratings of perceived exertion (RPE)
 [24] were recorded following both condition A and B. The accelerometer and heart rate sensor
 were removed after the study condition. After both study conditions, participants again
 completed STAI-Y1 and 10 min of post-condition data were collected. Participants then viewed
 90 emotionally arousing pictures from the IAPS after both study conditions A and B. Pictures
 were viewed on a 70" × 70"portable projection screen. The 90 pictures were arranged in 3
 blocks of 30; each block contained 10 pictures from each valence category. Among the 90
 pictures used, 30 were pleasant (15 erotica and 15 babies, families, and cute animals); 30
 were neutral (15 neutral people and 15 neutral objects and scenes); and 30 were unpleasant
 (15 threat and 15 mutilation) based on normative ratings of valence [5]. No more than two
 pictures from the same category appeared consecutively. Two different picture orders were
 constructed and counterbalanced across testing day and experimental condition. Each picture
 was shown for 4-s, followed by a 12-, 14-, or 16-s inter-picture interval, which consisted of
 a centrally located fixation cross. The total picture-viewing time, including brief breaks
 between each picture block, was approximately 30 min. Participants were instructed to look at
 each picture the entire time it was on the monitor and to subjectively categorize each
 picture as pleasant, neutral, or unpleasant using a response pad [E-Prime 2.0, Psychology
 Software Tools, Inc., Pittsburgh, PA, USA] resting on their lap. These ratings were not used
 to compare to the normative ratings, but rather, the purpose of categorizing the pictures was
 to ensure that participants concentrated on the pictures. Immediately after viewing the
 pictures, participants again completed STAI-Y1 and 10 min post-exposure data were collected.
 In accordance with the Center for the Study of Emotion and Attention, participants were also
 asked to rate the IAPS images in order to further image standardization. Participants rated
 each of the 90 pictures (hard copy, one picture per page in a standard, self-paced order)
 using the Self-Assessment Manikin (SAM) during visit 4 to the laboratory. Additionally,
 participants underwent a single DEXA scan for body composition assessment.
Inclusion Criteria:

 The inclusion criteria included women who:

 -  were between 18 and 25 years of age;

 -  were not suffering from any medical conditions that would influence the results or
 compromise safety during training-such as disorders effecting balance, or pregnancy;

 -  who were not taking antidepressant or anti-anxiety medication;

 -  were not clinically diagnosed with generalized anxiety disorder in the previous six
 months;

 -  were within the normal range (± 1 SD from the M) for female college students for trait
 anxiety according to Spielberger's Trait Anxiety Inventory [(STAI-Y2); range: 40.40 ±
 10.15] (Spielberger 1983);

 -  were within normal (minimal to mild) levels of depression according to the Beck
 Depression Inventory [(BDI); range: 0-18] (Oliver and Simmons 1984);

 -  had a normal menstrual cycle (cycles occurring less than every 26 to 35 days and
 lasting less than 2 or more than 7 days);

 -  were not considered high-risk for dual energy x-ray absorptiometry (DEXA) based on a
 standardized questionnaire approved by the University Radiation Safety Committee; and

 -  were familiar with yoga or had not participated in at least 3 yoga practice sessions.

 Exclusion Criteria:

 -  The exclusion criteria included women who:

 -  were less than 18 or more than 25 years of age;

 -  were suffering from any medical conditions that would influence the results or
 compromise safety during training-such as disorders effecting balance, or
 pregnancy;

 -  who were taking antidepressant or anti-anxiety medication;

 -  were clinically diagnosed with generalized anxiety disorder in the previous six
 months;

 -  were not within the normal range (± 1 SD from the M) for female college students
 for trait anxiety according to Spielberger's Trait Anxiety Inventory [(STAI-Y2);
 range: 40.40 ± 10.15];

 -  were not within normal (minimal to mild) levels of depression according to the
 Beck Depression Inventory [(BDI); range: 0-18];

 -  had an abnormal menstrual cycle (cycles occurring less than every 26 to 35 days
 and lasting less than 2 or more than 7 days);

 -  were considered high-risk for dual energy x-ray absorptiometry (DEXA) based on a
 standardized questionnaire approved by the University Radiation Safety Committee;
 and

 -  were not familiar with yoga or had not participated in at least 3 yoga practice
 sessions.