Young footballers, assessed by deep breathing test, have a higher vagal response

Parasympathetic function can be assessed by the deep breathing test (DB) as a simple and reproducible cardiovascular reflex. The aim of this study is to use this test to compare the vagal response of a young footballers group to of age-matched untrained normal subjects. Deep breathing test was performed in 2 groups: one of 20 adult young footballers (average age of 19.3 ± 0.6 years), and a second age-matched group of 20 untrained subjects (average age of 19.6 ± 0.6 years). Subjects underwent the DB test after 30 min resting in supine position, and responses were expressed as a percentage of variation of heart rate during the stimulation. Student’s t-test was used to evaluate statistical differences among the two groups for all parameters (vagal response, heart rate, VO2max….) and considering p < 0.05 as a significant difference. The results showed that vagal response to deep breathing test was significantly higher in the young footballers when compared to the untrained controls (72.6% ± 16.2% vs 55.0% ± 12.8%, respectively, p = 0.03). The basal heart rate was significantly lower in footballers than in the controls group (52.1 ± 7.4 bat/min vs 69.8 ± 14.3 bat/min, p < 0.01). The use of the simple test of deep breathing allowed us to demonstrate that adult young footballers have a significantly lower basal HR and higher parasympathetic response in comparison to untrained subjects.