PMID- 10601155
OWN - NLM
STAT- MEDLINE
DCOM- 20000203
LR  - 20171213
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 87
IP  - 6
DP  - 1999 Dec
TI  - VO(2) kinetics of mild exercise are altered by RER.
PG  - 2097-106
AB  - We propose that variations in fat and carbohydrate (CHO) oxidation by working 
      muscle alter O(2) uptake (VO(2)) kinetics. This hypothesis provides two 
      predictions: 1) the kinetics should comprise two exponential components, one fast 
      and the other slow, and 2) their contribution should change with variations in 
      fat and CHO oxidation, as predicted by steady-state respiratory exchange ratio 
      (RER). The purpose of this study was to test these predictions by evaluating the 
      VO(2) kinetic model: VO(2)(t) = alpha(R) + alpha(F)(1 - exp[(t - TD)/-tau(F)]) + 
      alpha(C)(1 - exp[(t - TD)/-tau(C)]) for short-term, mild leg cycling in 38 women 
      and 44 men, where VO(2)(t) describes the time course, alpha(R) is resting VO(2), 
      t is time after onset of exercise, TD is time delay, alpha(F) and tau(F) are 
      asymptote and time constant, respectively, for the fast (fat) oxidative term, and 
      alpha(C) and tau(C) are the corresponding parameters for the slow (CHO) oxidative 
      term. We found that 1) this biexponential model accurately described the VO(2) 
      kinetics over a wide range of RERs, 2) the contribution of the fast (alpha(F), 
      fat) component was inversely related to RER, whereas the slow (alpha(C), CHO) 
      component was positively related to RER, and 3) this assignment of the fast and 
      slow terms accurately predicted steady-state respiratory quotient and CO(2) 
      output. Therefore, the kinetic model can quantify the dynamics of fat and CHO 
      oxidation over the first 5-10 min of mild exercise in young adult men and women.
FAU - Mole, P A
AU  - Mole PA
AD  - Human Performance Laboratory, Department of Exercise Science, University of 
      California, Davis, Davis, California 95616, USA. pamole@ucdavis.edu
FAU - Hoffmann, J J
AU  - Hoffmann JJ
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Fats)
SB  - IM
MH  - Adult
MH  - Carbohydrate Metabolism
MH  - Exercise/*physiology
MH  - Fats/metabolism
MH  - Female
MH  - Humans
MH  - Kinetics
MH  - Male
MH  - Models, Biological
MH  - Oxidation-Reduction
MH  - Oxygen Consumption/*physiology
MH  - Pulmonary Gas Exchange/*physiology
MH  - Respiratory Physiological Phenomena
MH  - Time Factors
EDAT- 1999/12/22 00:00
MHDA- 1999/12/22 00:01
CRDT- 1999/12/22 00:00
PHST- 1999/12/22 00:00 [pubmed]
PHST- 1999/12/22 00:01 [medline]
PHST- 1999/12/22 00:00 [entrez]
AID - 10.1152/jappl.1999.87.6.2097 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 1999 Dec;87(6):2097-106. doi: 
      10.1152/jappl.1999.87.6.2097.