Background: Heart rate variability (HRV) as an accurate, noninvasive measure of the Autonomous Nervous System (ANS) can reflect mental health (e.g., stress, depression, or anxiety). Tai Chi and Yoga (Tai Chi/Yoga), as the most widely practiced mind–body exercises, have shown positive outcomes of mental health. To date, no systematic review regarding the long-lasting effects of Tai Chi/Yoga on HRV parameters and perceived stress has been conducted. Objective: To critically evaluate the existing literature on this topic. Methods: Five electronic databases (Web of Science, PubMed, Scopus, SportDiscus and Cochrane Library) were searched from the start of the research project to July 2018. Study selection, data extraction, and study quality assessment were independently carried out by two reviewers. The potentially identified randomized controlled trials (RCT) reported the useful quantitative data that were included only for meta-analysis. Results: meta-analysis of 17 medium-to-high quality RCTs showed significantly beneficial effects on HRV parameters (normalized low-frequency, Hedge’s g = −0.39, 95% CI −0.39 to −0.56, p < 0.001, I2 = 11.62%; normalized high-frequency, Hedge’s g = 0.37, 95% CI 0.22 to −0.52, p < 0.001, I2 = 0%; low-frequency to high-frequency ratio, Hedge’s g = −0.58, 95% CI −0.81 to −0.35, p < 0.001, I2 = 53.78%) and stress level (Hedge’s g = −0.80, 95% CI −1.17 to −0.44, p < 0.001, I2 = 68.54%). Conclusions: Stress reduction may be attributed to sympathetic-vagal balance modulated by mind–body exercises. Tai Chi/Yoga could be an alternative method for stress reduction for people who live under high stress or negative emotions.

BACKGROUND AND PURPOSEBones are widely innervated, suggesting an important role for the sympathetic regulation of bone metabolism, although there are controversial studies. We investigated the effects of propranolol in a model of experimental periodontal disease. EXPERIMENTAL APPROACHRats were assigned as follows: animals without ligature; ligated animals receiving vehicle and ligated animals receiving 0.1, 5 or 20 mg·kg -1 propranolol. After 30 days, haemodynamic parameters were measured by cardiac catheterization. Gingival tissues were removed and assessed for IL-1b, TNF-a and cross-linked carboxyterminal telopeptides of type I collagen (CTX) by ELISA, or intercellular adhesion molecule 1 (ICAM-1), receptor activator of NF-k B ligand (RANKL) and osteoprotegerin (OPG) by Western blot analysis. Sections from the mandibles were evaluated for bone resorption. Also, we analysed the ability of propranolol to inhibit osteoclastogenesis in vitro. RESULTSPropranolol at 0.1 and 5 mg·kg -1 reduced the bone resorption as well as ICAM-1 and RANKL expression. However, only 0.1 mg·kg -1 reduced IL-1b, TNF-a and CTX levels as well as increased the expression of OPG, but did not alter any of the haemodynamic parameters. Propranolol also suppressed in vitro osteoclast differentiation and resorptive activity by inhibiting the nuclear factor of activated T cells (NFATc)1 pathway and the expression of tartrate-resistant acid phosphatase (TRAP), cathepsin K and MMP-9. CONCLUSIONS AND IMPLICATIONSLow doses of propranolol suppress bone resorption by inhibiting RANKL-mediated osteoclastogenesis as well as inflammatory markers without affecting haemodynamic parameters. AbbreviationsAP, arterial pressure; BD, bone density; CTX, cross-linked carboxyterminal telopeptides of type I collagen; DMEM, Dulbecco's modified Eagle medium; DTT, dithiothreitol; FBS, fetal bovine serum; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; ICAM-1, intercellular adhesion molecule 1; LVEDP, left ventricular end-diastolic pressure; LVSP, left ventricular systolic pressure; NFAT, nuclear factor of activated T cells; OPG, osteoprotegerin; OVX, ovariectomized; RANKL, receptor activator of NF-k B ligand; SaM-1, human periosteum-derived osteoblastic cells; SaOS-2, human osteosarcoma-derived cells; SHR, spontaneous hypertensive rats; TBST, Tris-buffered saline-Tween; TRAP, tartrate-resistant acid phosphatase BJP British Journal of Pharmacology

This study evaluated the acute effect of ischemic preconditioning (IPC) on a high-intensity intermittent exercise performance and physiological indicators in amateur soccer players. Thirteen players (21.5 ± 2 yrs) attended three trials separated by 3–5 days in a counterbalanced randomized cross-over design: IPC (4 × 5-min occlusion 220 mmHg/reperfusion 0 mmHg) in each thigh; SHAM (similar to the IPC protocol but “occlusion” at 20 mmHg) and control (seated during the same time of IPC). After 6-min of each trial (IPC, SHAM or control), the players performed the YoYo Intermittent Endurance Test level 2 (YoYoIE2). The distance covered in the YoYoIE2 (IPC 867 ± 205 m; SHAM 873 ± 212 m; control 921 ± 206 m) was not different among trials (p = 0.10), furthermore, lactate concentration and rate of perceived exertion did not differ (P > 0.05) among protocols. There were also no significant differences in either mean heart rate (HR) or peak HR (p > 0.05) for both IPC and SHAM compared to control. Therefore, we conclude that acute IPC does not influence high-intensity intermittent exercise performance in amateur soccer players and that rate of perceived exertion, heart rate and lactate do not differ between the intervention IPC, SHAM and control.

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BackgroundAfter menopause, rapid bone mass loss occurs in response to hypoestrogenism. Several studies suggest that muscle mass and bone mineral density (BMD) are positively associated in postmenopausal women. Therefore, it may be assumed that postmenopausal low appendicular muscle mass (aMM) can increase BMD loss in a short period of time.ObjectiveThe purpose of this study was to assess relationship of aMM with femoral neck BMD in postmenopausal women.MethodsProspective, controlled clinical Trial including 64 women aged 45-70 years, who had not had their last menstruation for at least one year. Subjects were divided into two groups: low aMM (n = 32), and normal aMM (n-32). Femoral neck BMD and muscle mass were measured by DXA at baseline and after twelve months. Pairwise and independent t tests were used for data analysis.ResultsBaseline weight, BMI and muscle mass (total and appendicular) significantly differ between groups (p < 0.05). After twelve months, femoral neck BMD was significantly lower in the group with low aMM, whereas no significant difference was observed in the group with normal aMM (p < 0.05).ConclusionIn postmenopausal women, low appendicular muscle mass is associated negatively with femoral neck BMD in a short period of time.