東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

The effects of lactate accumulation ...

Wallace, Sina Gaylene.

Linked to FindBook

Google Book

Amazon

博客來

The effects of lactate accumulation and bicarbonate buffering on estimates of muscle metabolism in exercising humans.

Record Type:	Electronic resources : Monograph/item
Title/Author:	The effects of lactate accumulation and bicarbonate buffering on estimates of muscle metabolism in exercising humans./
Author:	Wallace, Sina Gaylene.
Description:	156 p.
Notes:	Source: Dissertation Abstracts International, Volume: 65-09, Section: B, page: 4514.
Contained By:	Dissertation Abstracts International65-09B.
Subject:	Health Sciences, Nutrition. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3148512
ISBN:	0496076256

The effects of lactate accumulation and bicarbonate buffering on estimates of muscle metabolism in exercising humans.
Wallace, Sina Gaylene.

The effects of lactate accumulation and bicarbonate buffering on estimates of muscle metabolism in exercising humans. - 156 p.

Source: Dissertation Abstracts International, Volume: 65-09, Section: B, page: 4514.

Thesis (Ph.D.)--University of California, Davis, 2004.

Indirect calorimetry is used to describe whole body substrate utilization. By analyzing expired breath, the rate of oxygen consumption (VO2) and carbon dioxide production (VCO2) can be determined and a respiratory exchange ratio (RER = VCO2/VO2) calculated. The RER is used as a measure of the respiratory quotient (RQ = VCO2/VO 2 measured at the cell), to determine what fuel the body metabolizes. Above the lactate threshold (LT), RER increases exponentially and is thought to represent an increase in total carbohydrate oxidation. However, bicarbonate (HCO3-) buffering of the hydrogen ion (H +) from lactic acid (LAH) occurs above the LT, resulting in the production of non-oxidative, excess VCO2. It is unclear how much of the rise in RER above the LT is due to a shift toward greater carbohydrate oxidation and/or the buffering of the dissociated H+.

ISBN: 0496076256Subjects--Topical Terms:

1017801
Health Sciences, Nutrition.

The effects of lactate accumulation and bicarbonate buffering on estimates of muscle metabolism in exercising humans.
LDR:03264nmm 2200301 4500 001 1843102
005 20051010101559.5
008 130614s2004 eng d
020 $a 0496076256
035 $a (UnM)AAI3148512
035 $a AAI3148512
040 $a UnM $c UnM
100 1 $a Wallace, Sina Gaylene. $3 1931345
245 1 4 $a The effects of lactate accumulation and bicarbonate buffering on estimates of muscle metabolism in exercising humans.
300 $a 156 p.
500 $a Source: Dissertation Abstracts International, Volume: 65-09, Section: B, page: 4514.
500 $a Chair: Nancy L. Keim.
502 $a Thesis (Ph.D.)--University of California, Davis, 2004.
520 $a Indirect calorimetry is used to describe whole body substrate utilization. By analyzing expired breath, the rate of oxygen consumption (VO2) and carbon dioxide production (VCO2) can be determined and a respiratory exchange ratio (RER = VCO2/VO2) calculated. The RER is used as a measure of the respiratory quotient (RQ = VCO2/VO 2 measured at the cell), to determine what fuel the body metabolizes. Above the lactate threshold (LT), RER increases exponentially and is thought to represent an increase in total carbohydrate oxidation. However, bicarbonate (HCO3-) buffering of the hydrogen ion (H +) from lactic acid (LAH) occurs above the LT, resulting in the production of non-oxidative, excess VCO2. It is unclear how much of the rise in RER above the LT is due to a shift toward greater carbohydrate oxidation and/or the buffering of the dissociated H+.
520 $a We tested two hypotheses in this study: (1) The increase in excess VCO2 would be directly proportional to the decrease in plasma [HCO 3-] and the increase in lactate ([LA- ]) regardless of training status. (2) The proportion of fat and carbohydrate intake had no effect on the above relationship. To test the first hypothesis, twelve endurance trained and twelve untrained subjects performed six, 18 minute bouts of cycling exercise, ranging from low to high intensity. Venous blood was analyzed for [LA-] and [HCO3 -] before and immediately after each bout. [LA- ] accumulation and [HCO3-] depletion were highly correlated (r2 = 0.9431, p < 0.0000, SEE = +/-0.5973). Excess VCO2 was directly proportional to Delta[LA- ] and inversely proportional to Delta[HCO3- ] (r2 = 0.9566, p < 0.001, SEE = +/-2.4003), regardless of training status.
520 $a To test the second hypothesis, the same exercise protocol was performed after 24 hours of consuming two different randomly assigned diets: fat-rich (45% fat, 40% carbohydrate) and carbohydrate-rich (10% fat, 75% carbohydrate). [LA-] and [HCO3-] were highly correlated (r2 = 0., p < 0.001, SEE = +/-0). The interrelationship between excess VCO2, [HCO3 -] and [LA-] was robust. (r2 = 0.8525, p < 0.001, SEE = +/-1.544). The confounding effect of [LA-] accumulation may render the usage of indirect calorimetry inaccurate as a means of assessing oxidative fuel mixture during exercise above the LT.
590 $a School code: 0029.
650 4 $a Health Sciences, Nutrition. $3 1017801
650 4 $a Health Sciences, Recreation. $3 1018003
690 $a 0570
690 $a 0575
710 2 0 $a University of California, Davis. $3 1018682
773 0 $t Dissertation Abstracts International $g 65-09B.
790 1 0 $a Keim, Nancy L., $e advisor
790 $a 0029
791 $a Ph.D.
792 $a 2004
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3148512