Fifteen healthy elderly subjects participated in 10 weeks of Tai Chi Chuan practice. Inclusion criteria were:

• aged 60 years and older;
• sedentary behavior for at least 6 months;
• no previous experience of Tai Chi Chuan practice;
• good physical health determined by Physical Activity Readiness Questionnaire as - confirmed by medical history;
• no cognitive impairments determined by baseline Mini-Mental State Examination score of ≥ 45.

All participants were asked to not perform any sports activities while the research was ongoing.

In the control group, fifteen subjects also had to meet the same criteria and did not perform any exercises or make changes in their daily living life.

10 weeks of Tai Chi Chuan practice by 6-year experienced training teacher, 2 times per week, 60 min per session.

R-R intervals were recorded using a Polar H7 sensor with a chest strap (Kempele, Finland) in laying position, in rest.

Resting blood pressure was measured using digital electronic blood pressure monitor (Microlife BP A100, Widnau, Switzerland)

The purpose of this scale is to assess the degree of stress in subjects' lives. It consists of questions about the frequency of feeling and thoughts during the past time period. Potential answers: 0-never; 1-almost never; 2-sometimes; 3-fairly often and 4-very often. The scores are obtained by reversing the scores on the four positive items:for example, 0=4, 1=3, 2=2, etc. and then summing across all items. Scores for the 10-item form range from 0 to 40,with higher scores indicating greater perceived stress

To determine the level of anxiety and depression of subjects was used HADS scale. The scale consists of totally 14questions with the answers valued from 0 to 3. Half of questions addressed to estimate anxiety and rest - depression.The total scoring and conclusion for the both categories of questions: 0-7 = Normal; 8-10 = Borderline abnormal(borderline case); 11-21 = Abnormal (case)

Venous blood samples from the median antecubital vein were collected in 5 ml vacuum tubes with a gel separator and was separated by centrifugation (15 min at 1200g) to make blood serum. Samples were aliquoted and stored at -20°C until analysis. The serum concentration of Human Free BDNF was measured using an enzyme-linked immunoassay kit(R&D Systems, Minneapolis, USA).

Body weight was measured by Tanita Body Composition Analyzer TBF-300 (Japan).

The height was measured by a centimeter strip.