[Relationship between baroreflex function and training effects on altitude training].
OBJECTIVE
Altitude training is frequently used for athletes requiring competitive endurance in an attempt to improve their sea-level performance. However, there has been no study in which the mechanisms by which spontaneous arterial-cardiac baroreflex function changes was examined in responders or nonresponders of altitude training. The purpose of this study was to clarify the different effects of altitude training on baroreflex function between responders and nonresponders.


METHODS
Twelve university student cross-country skiers (6 men, 6 women; age, 19±1 years) participated in the altitude training in a camp for 3 weeks, which was carried out in accordance with the method of Living High-Training Low. Baroreflex function was estimated by transfer function analysis before and after the training.


RESULTS
The responders of the training were 3 men and 2 women, and the nonresponders were 3 men and 4 women. In the responders, the transfer function gain in the high-frequency range significantly increased after the training (28.9→46.5 ms/mmHg p=0.021). On the other hand, no significant change in this index was observed in the nonresponders (25.9→21.2 ms/mmHg p=0.405).


CONCLUSIONS
As indicated by the results of transfer function gain in the high-frequency range, the baroreflex function in the responders increased significantly after the altitude training, whereas no significant change was observed in the nonresponders.
Department of Social Medicine, Nihon University School of Medicine, Japan.
Ryo
R
Yanagida
Yojiro
Y
Ogawa
Fumio
F
Mizuochi
Tsukasa
T
Suzuki
Masanori
M
Takahashi
Kenichi
K
Iwasaki
D000531:Altitude; D017704:Baroreflex / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010806:Physical Education and Training; D012865:Skiing; D055815:Young Adult