The effects of yoga and quiet rest on subjective levels of anxiety and physiological correlates: a 2-way crossover randomized trial.

BACKGROUND: Rest or acute exercise can decrease state anxiety, with some evidence showing exercise to prevent laboratory-induced elevations in anxiety. No study has examined whether yoga provides short-term protection against laboratory-induced anxiety. The aim of this study was to examine the effectiveness of an acute YogaFit session on state anxiety and measures of heart rate variability (HRV) to determine whether yoga provides short-term protection against emotional picture stimuli. METHODS: 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. RESULTS: Post-hoc comparisons indicate the following: (1) state anxiety significantly decreased from baseline to post-condition for both yoga and rest (p = 0.001) but returned to baseline values following exposure to emotional stimuli (p < 0.001) for both conditions; (2) heart rate decreased post-condition to post-exposure (p = 0.020) and baseline to post-exposure (p = 0.033) for both conditions; (3) time-domain measure of HRV showed a significant increase in HRV between baseline and post-condition (p = 0 .019), post-condition and post-exposure (p = 0 .007), and between baseline and post-exposure (p < 0.001). CONCLUSIONS: Both YogaFit and seated rest were effective at acutely reducing state anxiety post-condition, but not at preventing an induced anxiety response post-exposure. Following exposure to the emotionally stimulating pictures, there was a shift from the high frequency-domain to the low frequency-domain and an increase in the time-domain measure of HRV for both the YogaFit and the quiet rest condition. TRIAL REGISTRATION: Retrospectively registered 2/16/2018, clinicaltrials.gov, Identifier: NCT03458702 .

Omega-3 fatty acids in obesity and metabolic syndrome: a mechanistic update.

Strategies to reduce obesity have become public health priorities as the prevalence of obesity has risen in the United States and around the world. While the anti-inflammatory and hypotriglyceridemic properties of long-chain omega-3 polyunsaturated fatty acids (n-3 PUFAs) are well known, their antiobesity effects and efficacy against metabolic syndrome, especially in humans, are still under debate. In animal models, evidence consistently suggests a role for n-3 PUFAs in reducing fat mass, particularly in the retroperitoneal and epididymal regions. In humans, however, published research suggests that though n-3 PUFAs may not aid weight loss, they may attenuate further weight gain and could be useful in the diet or as a supplement to help maintain weight loss. Proposed mechanisms by which n-3 PUFAs may work to improve body composition and counteract obesity-related metabolic changes include modulating lipid metabolism; regulating adipokines, such as adiponectin and leptin; alleviating adipose tissue inflammation; promoting adipogenesis and altering epigenetic mechanisms.

Investigating the influence of shame, depression, and distress tolerance on the relationship between internalized homophobia and binge eating in lesbian and bisexual women.

There is limited research evidence about the specific factors influencing disordered eating for lesbian and bisexual women. Therefore, this study investigated relationships among binge eating, internalized homophobia, shame, depression, and distress tolerance in a sample of lesbian (n=72) and bisexual women (n=66). Two hypotheses were tested. First, it was hypothesized that shame and depression would mediate the relationship between internalized homophobia and binge eating. Second, it was hypothesized that distress tolerance would moderate the relationship between shame and binge eating and the relationship between depression and binge eating in the mediation relationships proposed in the first hypothesis. Results indicated that shame was a significant mediator for the relationship between internalized homophobia and binge eating, that depression was not a significant mediator, and that distress tolerance did not moderate the significant mediation relationship between shame and binge eating. The data in this study also indicated that the proportions of lesbian and bisexual participants who reported binge eating and compensatory behavior did not differ significantly, but that bisexual participants reported significantly more depression and shame than lesbian participants.

The Effects of Mindfulness-Based Movement on Parameters of Stress.

The Mindfulness-Based Stress Reduction program (MBSR) of Kabat-Zinn includes a combination of sitting meditation, yoga, and walking; thus, movement is not emphasized primarily to induce a state of awareness. The purpose of this study was to investigate the effects of a Mindfulness-Based Movement Program (MBM) in women on parameters of stress and coping; that is, in contrast to MBSR, MBM primarily emphasized yoga to cultivate awareness. This study investigated: (a) an objective measure of stress (the cortisol response to a laboratory stressor) following an 8-week MBM in year 1 participants only (n = 17; MBM group = 9; Control group = 8); (b) subjective measures of stress following an 8-week MBM in years 1 and 2 (n = 32; MBM = 16; C = 16); and (c) changes in coping style following an 8- week MBM in years 1 and 2 (n = 32; MBM = 16; C = 16). A mixed plot 2 (Group: TC or MBM) by 5 (Trial: Baseline, Stressor, Recovery 1, Recovery 2, and Recovery 3) repeated measures ANOVA was run for cortisol. Preliminary results indicated a strong trend towards a lowered cortisol response for the MBM group compared to the control group. A mixed plot 2 (Group: TC or MBM) by 2 (Time: Pretest, Post-test) repeated measures ANOVA was run for Spielberg's State Anxiety, the Perceived Stress Scale, and the Problem Focused Style of Coping Scale for the Suppressive, Reflective, and the Reactive Coping Style. There were significant main effects for time, group, and an interaction of time and group for Spielberg's State Anxiety and the Perceived Stress Scale. Significant differences were also found for time and the interaction of time and group for the Problem Focused Style of Coping for the Reflective Coping Style (p < 0.05). In conclusion, results indicate positive effects of the MBM program on perceived measures of stress and coping style in women.

Effect of sex hormones on neuromuscular control patterns during landing.

The purpose of the study was to investigate the effects of sex hormones across menstrual cycle phases on lower extremity neuromuscular control patterns during the landing phase of a drop jump. A repeated-measures design was utilized to examine sex hormone effects in 26 recreationally active eumenorrheic women. Varus/valgus knee angle and EMG activity from six lower extremity muscles were recorded during three drop jumps from a 50 cm platform in each phase of the menstrual cycle. Blood assays verified sex hormone levels and cycle phase. The semitendinosus muscle exhibited onset delays (p0.006) relative to ground contact during the luteal phase, and demonstrated a significant (p0.05) difference between early and late follicular phases. Muscle timing differences between the gluteus maximus and semitendinosus were decreased (p0.05) in the luteal compared to early follicular phases. These results suggest a different co-contractive behavior between the gluteus maximus and semitendinosus, signifying a shift in neuromuscular control patterns. It appears that female recreational athletes utilize a different neuromuscular control pattern for performing a drop jump sequence when estrogen levels are high (luteal phase) compared to when they are low (early follicular phase).

Explanatory variance in maximal oxygen uptake.

The purpose of this study was to develop a prediction equation that could be used to estimate maximal oxygen uptake (VO2max) from a submaximal water running protocol. Thirty-two volunteers (n =19 males, n = 13 females), ages 18 - 24 years, underwent the following testing procedures: (a) a 7-site skin fold assessment; (b) a land VO2max running treadmill test; and (c) a 6 min water running test. For the water running submaximal protocol, the participants were fitted with an Aqua Jogger Classic Uni-Sex Belt and a Polar Heart Rate Monitor; the participants' head, shoulders, hips and feet were vertically aligned, using a modified running/bicycle motion. A regression model was used to predict VO2max. The criterion variable, VO2max, was measured using open-circuit calorimetry utilizing the Bruce Treadmill Protocol. Predictor variables included in the model were percent body fat (% BF), height, weight, gender, and heart rate following a 6 min water running protocol. Percent body fat accounted for 76% (r = -0.87, SEE = 3.27) of the variance in VO2max. No other variables significantly contributed to the explained variance in VO2max. The equation for the estimation of VO2max is as follows: VO2max ml.kg(-1)·min(-1) = 56.14 - 0.92 (% BF). Key PointsBody Fat is an important predictor of VO2 max.Individuals with low skill level in water running may shorten their stride length to avoid the onset of fatigue at higher work-loads, therefore, the net oxygen cost of the exercise cannot be controlled in inexperienced individuals in water running at fatiguing workloads.Experiments using water running protocols to predict VO2max should use individuals trained in the mechanics of water running.A submaximal water running protocol is needed in the research literature for individuals trained in the mechanics of water running, given the popularity of water running rehabilitative exercise programs and training programs.

A pilot study to examine the effects of a mindfulness-based stress-reduction and relaxation program on levels of stress hormones, physical functioning, and submaximal exercise responses.

OBJECTIVE: Stress has been cited as a causal factor in heart disease. The objective of this study was to examine the effects of an 8-week mindfulness-based stress-reduction program on the resting levels of stress hormones, physical functioning, and submaximal exercise responses in women with heart disease. SUBJECTS: Random selection with the numbers 1 and 2 were used to assign 18 women (60 +/-6.3 years old) with documented histories of heart disease to a treatment group (n = 9) or a control group (n = 9). Speilberger's state anxiety scores for the treatment (M = 37.88; standard deviation (SD) = 10.91) and control group (M = 43.22; SD = 12.26) were not significantly different prior to the start of the study. However, their scores fell in the upper percentile rank for normal adults in their age category. INTERVENTION: The intervention was provided one night each week for 2 hours over a period of 8 weeks. The intervention included didactic, inductive, and experiential modes of learning regarding stress responses and mindfulness skill-development training. DESIGN: Pre-post test hormonal measurements and physical function were analyzed using a 2 (group) by 2 (time) analysis of variance (ANOVA) with repeated measures following the 8-week program. Submaximal exercise responses were also compared between the treatment group and the control group following the 8-week program. A 2 (group) by 3 (time) ANOVA with repeated measures was used to analyze the data. SETTINGS/LOCATION: Weekly meetings were held on a university medical school campus. Submaximal exercise responses were recorded while participants cycled on a stationary bike in an applied physiology laboratory following the 8-week program. RESULTS: There were no significant main effects or interaction for the resting levels of stress hormones or physical functioning. There were no significant interactions for the submaximal exercise responses, however, there were significant main effects between groups for ventilation [F(2,32) = 7.65, p < .01, f = 0.8], and between group [F(1,16) = 8.84, p < .01, f = 0.8] and time [F(2,32) = 10.42, p < .01, f = 0.9], for breathing frequency. CONCLUSION: While the 8-week stress reduction program for women with heart disease did not show significant interactions between groups for resting levels of stress hormones, physical functioning, or submaximal exercise responses, there was a significant difference in breathing patterns between the 2 groups during exercise following the mindfulness-based stress-reduction program. There was also a trend for change in the intervention group in the resting levels of cortisol and physical function scores that was not seen in the control group. Future studies could use the effect size generated from this pilot study to calculate the number of subjects needed for adequate power to detect significant differences between groups.