ISSN:
1439-6327
Keywords:
Reduced frequency breathing
;
Hypoventilation
;
Lactate removal
;
Human
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The purpose of the present study was to investigate the blood lactate (LA−) responses to hypoventilation induced by reduced frequency breathing (RFB) during recovery from exercise. Five male subject performed 16 4 min cycling bouts alternating with 16 min rest periods. Exercise intensities were chosen at power outputs corresponding to 30% $$\dot V_{{\text{O}}_{{\text{2 max}}} } $$ at 2mMLA−, $$\dot V_{{\text{O}}_{\text{2}} } $$ at 4 mMLA−, and 90% $$\dot V_{{\text{O}}_{{\text{2 max}}} } $$ in each subject. Breathing frequency was voluntarily controlled starting 10 s before each 3rd min of exercise and maintained throughout the rest of the exercise period. Four different breathing patterns at each exercise intensity were used: normal breathing (NB), breathing every 4 s, breathing every 8 s, and maximal RFB. Except for the NB trials, subjects held their breath at functional residual capacity during each breathing interval. The concentration difference of LA− between the 3rd min sample and the 4th min sample was defined as the lactate change during exercise (Δ LA−ex), and that between the 4th min sample and the sample at the 3rd min after the end of the exercise as the lactate change during recovery (Δ LA−rec). An ANOVA showed significant (p〈0.05) differences in breathing procedures only in ΔLA−rec. ΔLA−rec seemed to increase as compared to NB only at $$\dot V_{{\text{O}}_{\text{2}} } $$ at 4 mMLA− and 90% $$\dot V_{{\text{O}}_{{\text{2 max}}} } $$ , while ΔLA−ex remained unchanged as compared to NB in spite of reduced ∵V A. These results might indicate that RFB inhibited lactate removal from working muscles during exercise.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00417994
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