Exogenous 13C glucose oxidation during exercise: North American vs Western European studies

Massicotte, Daniel; Péronnet, François; Pitre, C.; Adopo, E.; Brisson, Geneviève; Hillaire‐Marcel, Claude

doi:10.1007/bf00376455

Cited by 8 publications

(4 citation statements)

References 32 publications

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“…The values computed in normoxia which were remarkably similar at $54 and $77% _ V O 2 max (20.0 and 21.4 g over 40 min or $0.51 g min À1 ), are in good agreement with data reported for example by Pirnay et al (1982Pirnay et al ( , 1995 and Massicotte et al (1993) showing that the oxidation rate of exogenous glucose increases with workload up to $60% _ V O 2 max but tends to level off thereafter. Accordingly, the percent contribution of exogenous glucose oxidation to the energy yield in normoxia was significantly lower at $77 than at $54% _ V O 2 max (12.5 and 16.8%, respectively).…”

Section: Discussionsupporting

confidence: 88%

Substrate utilization during prolonged exercise with ingestion of 13C-glucose in acute hypobaric hypoxia (4,300 m)

et al. 2006

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Energy substrate oxidation was measured using indirect respiratory calorimetry combined with tracer technique in five healthy young male subjects, during a 80-min exercise period on ergocycle with ingestion of 140 g of (13)C-labelled glucose, in normoxia and acute hypobaric hypoxia (445 mmHg or 4,300 m), at the same relative [77% V(.-)((O)(2)(max))] and absolute workload (161+/-8 W, corresponding to 77 and 54% V(.-)((O)(2)(max)) in hypoxia and normoxia). The oxidation rate of exogenous glucose was not significantly different in the three experimental situations: 21.4+/-2.9, 20.2+/-1.2 and 17.2+/-0.6 g over the last 40 min of exercise at approximately 77 and approximately 54% V(.-)((O)(2)(max)) in normoxia and in hypoxia, respectively, providing 12.5+/-1.5, 16.8+/-1.1 and 14.9+/-1.1% of the energy yield, although ingestion of glucose during exercise resulted in a higher plasma glucose concentration in hypoxia than normoxia. The contribution of carbohydrate (CHO) oxidation to the energy yield was significantly higher in hypoxia (92.0+/-2.1%) than in normoxia for both a given absolute (75.3+/-5.2%) and relative workload (78.1+/-1.8%). This greater reliance on CHO oxidation in hypoxia was entirely due to the significantly larger contribution of endogenous glucose oxidation to the energy yield: 75.9+/-1.7% versus 66.6+/-3.3 and 55.2+/-3.7% in normoxia at the same relative and absolute workload.

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Section: Discussionsupporting

confidence: 88%

Substrate utilization during prolonged exercise with ingestion of 13C-glucose in acute hypobaric hypoxia (4,300 m)

et al. 2006

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“…These values were close to the mean value we have observed (see below). A previous study examining only six participants exercising at 50% Vo 2 max for two hours reported a 0.75‰ enrichment in the δ 13 C of the exhaled breath (Massicotte et al, 1993), but the researchers did not examine different exercise intensities. Gautier et al (1996) did measure the δ 13 C at different exercise intensities, but because they report the δ 13 C-values in terms of their own internal laboratory standard rather than an international standard (Slater et al, 2001;Werner and Brand, 2001), it is unclear whether the magnitudes of δ 13 C enrichment can be directly compared with those reported here.…”

Section: δ 13 C In the Exhaled Breathmentioning

confidence: 98%

“…North American diets are typically richer in C4 plants (e.g., maize and/or sugar cane) directly or the products of these plants (e.g., livestock raised on C4 plants) whereas European diets are typically richer in C3 plants (e.g., sugar beet and/or potato) directly or the products of these plants (Schoeller et al, 1980;Massicotte et al, 1993;Wagenmakers et al, 1993;Nardoto et al, 2006). Because of differing fractionation processes during photosynthesis, C3 plants exhibit measurably lower levels of 13 C in their bulk tissues (Hayes, 2001).…”

Section: δ 13 C In the Exhaled Breathmentioning

confidence: 99%

The magnitude of the naturally occurring isotopic enrichment of 13C in exhaled CO2 is directly proportional to exercise intensity in humans

McCue

Passement

Rodriguez

2015

Comparative Biochemistry and Physiology Part A: Molecular &

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“…Massicotte et al (1993a) ont par la suite confirmé cette hypothèse et montré que puisque les habitants d'Europe de l'ouest ont un apport plus faible en 13 C dans leur alimentation, la différence entre la composition isotopique des glucides et des lipides endogènes est inférieure à celle des Nord-Américains, et par conséquent les variations du bruit de fond sont faibles en réponse à l'exercice modéré.…”

Section: Méthode à Deux Niveaux D'enrichissement Des Substrats Exogènesunclassified

Sélection des substrats lors de l’exercice prolongé avec ingestion de glucides : études par traçage au ¹³C

Tremblay¹

2011

Appl. Physiol. Nutr. Metab.

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cides et davantage de lipides que les hommes. Les effets séparés d'une alimentation riche v en glucides ou de l'ingestion de glucose pendant l'exercice sur la sélection des substrats furent pourtant similaires chez les deux sexes. L'effet combiné des deux procédures de supplémentation est toutefois plus important chez la femme que chez l'homme, soutenant l'hypothèse qu'un léger déficit en glucides soit présent chez les femmes.Dans la troisième étude, l'oxydation des substrats et particulièrement celle d'amidon exogène au cours d'une marche prolongée à une faible puissance de travail a été décrite.Les individus qui pratiquent des activités physiques prolongées à des intensités faibles (< 40 %VO 2 max) sont encouragés à ingérer des glucides et de l'eau pendant l'effort, mais la contribution de leur oxydation à la fourniture d'énergie est relativement peu connue.Nous avons montré que, contrairement aux observations précédemment effectuées à jeun sans ingestion de glucides pendant l'effort, les glucides (incluant de source exogène) peuvent fournir une très grande partie de l'énergie lorsqu'ils sont ingérés à des intervalles réguliers au cours de l'exercice prolongé.Dans l'ensemble, les résultats des études expérimentales présentées dans cette thèse montrent que les glucides ingérés peuvent fournir une grande proportion de l'énergie pendant l'exercice prolongé. Toutefois, le mode d'exercice, le sexe et la puissance de travail mènent à des variations qui sont en grande partie liées à une dépense énergé-tique variable selon les conditions et les groupes d'individus ayant des caractéristiques différentes.Mots clés: calorimétrie indirecte respiratoire, sexe, mode d'exercice, marche. ABSTRACTThe main substrates oxidized during prolonged exercise, whether carbohydrates, fats or proteins, do not contribute equally to the energy supply. In addition, glucose can originate from different endogenous (muscle, liver) and exogenous sources. Many factors can affect their respective contribution including: active muscle mass, training, sex, nutritional state and environmental conditions. The use of stable isotopes, such as carbon 13 ( 13 C), combined with indirect respiratory calorimetry corrected for urea excretion in urine and sweat, allows the differentiation of endogenous and exogenous substrates and the estimation of their contribution to the energy yield.These methods, allowing the measurement of fuel selection during prolonged exercise with glucose ingestion, enabled the comparisons found in the three experimental studies part of this thesis. In the first study, fuel selection was compared during prolonged upper-and lower-body exercise with or without glucose ingestion. The difference in fuel selection between upper-and lower-body exercise when water was ingested was modest with a slightly higher reliance on carbohydrate oxidation during upper-body exercise. The amount of exogenous glucose oxidized was lower but its contribution to the energy yield was higher during upper-body exercise due to the lower energy expenditure.In t...

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Exogenous 13C glucose oxidation during exercise: North American vs Western European studies

Cited by 8 publications

References 32 publications

Substrate utilization during prolonged exercise with ingestion of 13C-glucose in acute hypobaric hypoxia (4,300 m)

Substrate utilization during prolonged exercise with ingestion of 13C-glucose in acute hypobaric hypoxia (4,300 m)

The magnitude of the naturally occurring isotopic enrichment of 13C in exhaled CO2 is directly proportional to exercise intensity in humans

Sélection des substrats lors de l’exercice prolongé avec ingestion de glucides : études par traçage au ¹³C

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Exogenous 13C glucose oxidation during exercise: North American vs Western European studies

Cited by 8 publications

References 32 publications

Substrate utilization during prolonged exercise with ingestion of 13C-glucose in acute hypobaric hypoxia (4,300 m)

Substrate utilization during prolonged exercise with ingestion of 13C-glucose in acute hypobaric hypoxia (4,300 m)

The magnitude of the naturally occurring isotopic enrichment of 13C in exhaled CO2 is directly proportional to exercise intensity in humans

Sélection des substrats lors de l’exercice prolongé avec ingestion de glucides : études par traçage au 13C

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Sélection des substrats lors de l’exercice prolongé avec ingestion de glucides : études par traçage au ¹³C