Inclusion Criteria:  Physical activity of minimum 30 min. duration, at least 3 times a week. No chest injuries. No contraindications for DTM/classic massage. No serious diseases of the respiratory and/or cardiovascular systems. No tobacco products smoking (incl.e-smoking). No posture defects that could affect the chest mobility.  Exclusion Criteria:  Contraindications to DTM/classic massage of the chest. Occurrence of serious diseases of the respiratory/cardiovascular system now or in the past. Lack of or low physical activity (< 30 min min. 3 times per week). Tobacco smoking (incl.e-smoking). Chest injuries. Posture defects that may affect the chest mobility.