title: The influence of different modes of ventilation on standing balance of athletes.
abstract: BACKGROUND
  The respiratory movements are one of the factors influencing standing balance. Although well-trained athletes have better postural performance compared to untrained men, it's not quite clear, if the formers' upright posture would be more stable during different ventilation modes, maximal voluntary hyperventilation and inspiratory breath-holding. There are no studies on this subject in the available literature.
  
  
  OBJECTIVE
  The aim of this study was to investigate an influence of maximal inspiratory breath-holding and maximal voluntary hyperventilation on the standing balance of athletes.
  
  
  METHODS
  We assessed the amplitude and the velocity of postural sway in the athletes (n = 38) and untrained subjects (n = 28) by the force platform. The frequency characteristics of the center of pressure (CP) oscillations' were also analyzed. The amplitude and the frequency of respiratory movements were estimated by the strain gauge.
  
  
  RESULTS
  It was found that during quiet breath velocity and frequency of CP oscillations were lower in the athletes. Breath holding led to an increase of velocity and frequency of CP displacement in both groups, increase of these indices was more pronounced in the athletes. Maximal voluntary hyperventilation caused a significant increase of all stabilographic indices in both groups. Increase of frequency and amplitude of respiratory movements were mainly observed during hyperventilation in athletes and it caused an increase of the velocity of CP displacement. Changes of sway amplitude were the same in both groups.
  
  
  CONCLUSIONS
  Breath holding led to activation of the postural control, which was more pronounced in the athletes. Hyperventilation caused an impairment of the postural stability. The athletes' postural system compensated the impact of hyperventilation more efficiently versus controls, but it was achieved at the expense of greater effort.
authors.affiliation: Department of Normal Physiology With Biophysics, Yaroslavl State Medical Academy, Yaroslavl, Russia.
authors.forename: Maxim
authors.initials: M
authors.lastname: Malakhov
authors.affiliation: Department of Physical Education, Yaroslavl State Pedagogical University Named After K. D. Ushinsky, Yaroslavl, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Makarenkova
authors.affiliation: Department of Physical Education, Yaroslavl State Pedagogical University Named After K. D. Ushinsky, Yaroslavl, Russia.
authors.forename: Andrey
authors.initials: A
authors.lastname: Melnikov
keywords: Breath Holding; Hyperventilation; Sport