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Methods Inf Med 1997; 36(04/05): 368-371
DOI: 10.1055/s-0038-1636856
Original Article
Schattauer GmbH

Continuous Estimation of CO2 Production during Exercise

R. Soma
1   Laboratory for Exercise Physiology and Biomechanics, Graduate School of Education, The University of Tokyo, Tokyo, Japan
,
Y. Yamamoto
1   Laboratory for Exercise Physiology and Biomechanics, Graduate School of Education, The University of Tokyo, Tokyo, Japan
› Author Affiliations
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Publication History

Publication Date:
19 February 2018 (online)

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Abstract.

A new method was developed for continuous isotopic estimation of human whole body CO2 rate of appearance (Ra) during non-steady state exercise. The technique consisted of a breath-by-breath measurement of 13CO2 enrichment (E) and a real-time fuzzy logic feedback system which controlled NaH13CO3 infusion rate to achieve an isotopic steady state. Ra was estimated from the isotope infusion rate and body 13CO2 enrichment which was equal to E at the isotopic steady state. During a non-steady state incremental cycle exercise (5 w/min or 10 w/min), NaH13CO3 infusion rate was successfully increased by the action of feedback controller so as to keep E constant.

Keywords:

NaH13CO3 - Fuzzy Logic Controller
 

  • REFERENCES

  • 1 Frayn KN. Calculation of substrate oxidation rates in vivo from gaseous exchange. J Appl Physiol 1983; 55: 628-34.
    CrossrefPubMedGoogle Scholar
  • 2 Barstow TJ, Cooper DM, Sobel EM, Landaw EM, Epstein S. Influence of increased metabolic rate on [13C] bicarbonate washout kinetics. Am J Physiol 1990; 259: R163-R71.
    PubMedGoogle Scholar
  • 3 Coggan AR, Habash DL, Menedenhall LA, Swanson SC, Kien CL. Isotopic estimation of CO2 production during exercise before and after endurance training. J Appl Physiol 1993; 75: 70-5.
    CrossrefPubMedGoogle Scholar
  • 4 Romijn JA, Coyle EF, Hibbert J, Wolfe RR. Comparison of indirect calorimetry and a new breath 13C/12C ratio method during strenuous exercise. Am J Physiol 1992; 263: E64-71.
    PubMedGoogle Scholar
  • 5 Wolfe RR. Radioactive and Stable Isotope Tracers In Biomedicine: Principles and Practice of Kinetic Analysis. NY: Wiley-Liss, Inc; 1992
    Google Scholar
  • 6 Beaver WL, Lamarra N, Wasserman K. Breath-by-breath measurement of true alveolar gas exchange. J Appl Physiol 1981; 51: 1662-75.
    CrossrefPubMedGoogle Scholar
  • 7 Mamdani EH. Advances in the linguistic synthesis of fuzzy controllers. Int J Man-Machine Studies 1976; 08: 669-78.
    PubMedGoogle Scholar
  • 8 Norwich KH. Measuring rates of appearance in systems which are not in steady state. Can 1 Physiol Pharmacol 1973; 51: 91-101.
    PubMedGoogle Scholar
  • 9 Issekutz BJ, Paul P, Miller HI, Bortz WM. Oxidation of plasma FFA in lean and obese humans. Metabolism 1968; 17: 62-73.
    CrossrefPubMedGoogle Scholar
  • 10 Wolfe RR, Wolfe MH, Nadel ER, Shaw JH. Isotopic determination of amino acid-urea interactions in exercise in humans. J Appl Physiol 1984; 56: 221-9.
    CrossrefPubMedGoogle Scholar
  • 11 Irving CS, Wong WW, Shulman RJ, O’Brien ESmith, Klein PD. [13C] bicarbonate kinetics in humans: intra- vs. interindividual variations. Am J Physiol 1983; 245: R190-R202.
    PubMedGoogle Scholar
  • 12 Pallikarakis N, Sphiris N, Lefevre P. Influence of bicarbonate pool and on the occurrence of 13CO2 in exhaled air. Eur J Appl Physiol 1991; 63: 179-83.
    CrossrefPubMedGoogle Scholar
  • 13 DeNiro M, Epstein S. Influence of diet on the distribution of carbon isotopes in animals. Geochim Cosmochim Acta 1978; 42: 495-506.
    CrossrefPubMedGoogle Scholar
  • 14 Barstow TJ, Cooper DM, Epstein S, Wasserman K. Changes in breath 13CO2/12CO2 consequent to exercise and hypoxia. J Appl Physiol 1989; 66: 936-42.
    CrossrefPubMedGoogle Scholar
  • 15 Gautier J-F, Pirnay F, Jandrain B. et al. Endogenous substrate oxidation during ex-A, ercise and variations in breath 13CO2/12CO2 . J Appl Physiol 1993; 74: 133-8.
    CrossrefPubMedGoogle Scholar
  • 16 Schoeller DA, Brown C, Nakamura K. et al. Influence of metabolic fuel on the 13C/12C ratio of breath CO. Biomed Mass Specromet 1984; 11: 557-61.
    PubMedGoogle Scholar
  • 17 Wagenmakers AJM, Rehrer NJ, Brouns F, Saris WHM, Halliday D. Breath 13CO2 background enrichment during exercise: diet-related differences between Europe and America. J Appl Physiol 1993; 74: 2353-7.
    CrossrefPubMedGoogle Scholar