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Logo of jcinvestThe Journal of Clinical Investigation
J Clin Invest. 1971 December; 50(12): 2715–2725.
PMCID: PMC292221

Glucose metabolism during leg exercise in man


Arterial concentrations and net substrate exchange across the leg and splanchnic vascular bed were determined for glucose, lactate, pyruvate, and glycerol in healthy postabsorptive subjects at rest and during 40 min of exercise on a bicycle ergometer at work intensities of 400, 800, and 1200 kg-m/min.

Rising arterial glucose levels and small decreases in plasma insulin concentrations were found during heavy exercise. Significant arterial-femoral venous differences for glucose were demonstrated both at rest and during exercise, their magnitude increasing with work intensity as well as duration of the exercise performed. Estimated glucose uptake by the leg increased 7-fold after 40 min of light exercise and 10- to 20-fold at moderate to heavy exercise. Blood glucose uptake could at this time account for 28-37% of total substrate oxidation by leg muscle and 75-89% of the estimated carbohydrate oxidation.

Splanchnic glucose production increased progressively during exercise reaching levels 3 to 5-fold above resting values at the heavy work loads. Close agreement was observed between estimates of total glucose turnover during exercise based on leg glucose uptake and splanchnic glucose production. Hepatic gluconeogenesis—estimated from splanchnic removal of lactate, pyruvate, glycerol, and glycogenic amino acids—could supply a maximum of 25% of the resting hepatic glucose production but could account for only 6-11% of splanchnic glucose production after 40 min of moderate to heavy exercise.

It is concluded that: (a) blood glucose becomes an increasingly important substrate for muscle oxidation during prolonged exercise of this type: (b) peripheral glucose utilization increases in exercise despite a reduction in circulating insulin levels: (c) increased hepatic output of glucose, primarily by means of augmented glycogenolysis, contributes to blood glucose homeostasis in exercise and provides an important source of substrate for exercising muscle.

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Selected References

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  • ANDRES R, CADER G, ZIERLER KL. The quantitatively minor role of carbohydrate in oxidative metabolism by skeletal muscle in intact man in the basal state; measurements of oxygen and glucose uptake and carbon dioxide and lactate production in the forearm. J Clin Invest. 1956 Jun;35(6):671–682. [PMC free article] [PubMed]
  • RABINOWITZ D, ZIERLER KL. Role of free fatty acids in forearm metabolism in man, quantitated by use of insulin. J Clin Invest. 1962 Dec;41:2191–2197. [PMC free article] [PubMed]
  • REICHARD GA, ISSEKUTZ B, Jr, KIMBEL P, PUTNAM RC, HOCHELLA NJ, WEINHOUSE S. Blood glucose metabolism in man during muscular work. J Appl Physiol. 1961 Nov;16:1001–1005. [PubMed]
  • Havel RJ, Pernow B, Jones NL. Uptake and release of free fatty acids and other metabolites in the legs of exercising men. J Appl Physiol. 1967 Jul;23(1):90–99. [PubMed]
  • Keul J, Doll E, Keppler D. The substrate supply of the human skeletal muscle at rest, during and after work. Experientia. 1967 Nov 15;23(11):974–979. [PubMed]
  • Jorfeldt L, Wahren J. Human forearm muscle metabolism during exercise. V. Quantitative aspects of glucose uptake and lactate production during prolonged exercise. Scand J Clin Lab Invest. 1970 Aug;26(1):73–81. [PubMed]
  • Klassen GA, Andrew GM, Becklake MR. Effect of training on total and regional blood flow and metabolism in paddlers. J Appl Physiol. 1970 Apr;28(4):397–406. [PubMed]
  • Rowell LB, Masoro EJ, Spencer MJ. Splanchnic metabolism in exercising man. J Appl Physiol. 1965 Sep;20(5):1032–1037. [PubMed]
  • Bergström J, Hultman E. A study of the glycogen metabolism during exercise in man. Scand J Clin Lab Invest. 1967;19(3):218–228. [PubMed]
  • Felig P, Wahren J. Amino acid metabolism in exercising man. J Clin Invest. 1971 Dec;50(12):2703–2714. [PMC free article] [PubMed]
  • Rowell LB, Kraning KK, 2nd, Evans TO, Kennedy JW, Blackmon JR, Kusumi F. Splanchnic removal of lactate and pyruvate during prolonged exercise in man. J Appl Physiol. 1966 Nov;21(6):1773–1783. [PubMed]
  • HUGGETT AS, NIXON DA. Use of glucose oxidase, peroxidase, and O-dianisidine in determination of blood and urinary glucose. Lancet. 1957 Aug 24;273(6991):368–370. [PubMed]
  • SEGAL S, BLAIR AE, WYNGAARDEN JB. An enzymatic spectrophotometric method for the determination of pyruvic acid in blood. J Lab Clin Med. 1956 Jul;48(1):137–143. [PubMed]
  • Hagenfeldt L. A gas chromatographic method for the determination of individual free fatty acids in plasma. Clin Chim Acta. 1966 Feb;13(2):266–268. [PubMed]
  • Rosselin G, Assan R, Yalow RS, Berson SA. Separation of antibody-bound and unbound peptide hormones labelled with iodine-131 by talcum powder and precipitated silica. Nature. 1966 Oct 22;212(5060):355–357. [PubMed]
  • GARBY L, VUILLE JC. The amount of trapped plasma in a high speed micro-capillary hematocrit centrifuge. Scand J Clin Lab Invest. 1961;13:642–645. [PubMed]
  • MYERS JD. Net splanchnic glucose production in normal man and in various disease states. J Clin Invest. 1950 Nov;29(11):1421–1429. [PMC free article] [PubMed]
  • Chiandussi L, Greco F, Sardi G, Vaccarino A, Ferraris CM, Curti B. Estimation of hepatic arterial and portal venous blood flow by direct catheterization of the vena porta through the umbilical cord in man. Preliminary results. Acta Hepatosplenol. 1968 May-Jun;15(3):166–171. [PubMed]
  • Ekelund LG. Circulatory and respiratory adaptation during prolonged exercise. Acta Physiol Scand Suppl. 1967;292:1–38. [PubMed]
  • Pozefsky T, Felig P, Tobin JD, Soeldner JS, Cahill GF., Jr Amino acid balance across tissues of the forearm in postabsorptive man. Effects of insulin at two dose levels. J Clin Invest. 1969 Dec;48(12):2273–2282. [PMC free article] [PubMed]
  • Pernow B, Wahren J, Zetterquist S. Studies on the peripheral circulation and metabolism in man. IV. Oxygen utilization and lactate formation in the legs of healthy young men during strenuous exercise. Acta Physiol Scand. 1965 Aug;64(4):289–298. [PubMed]
  • Hermansen L, Hultman E, Saltin B. Muscle glycogen during prolonged severe exercise. Acta Physiol Scand. 1967 Oct-Nov;71(2):129–139. [PubMed]
  • Wahren J. Human forearm muscle metabolism during exercise. IV. Glucose uptake at different work intensities. Scand J Clin Lab Invest. 1970 Mar;25(2):129–135. [PubMed]
  • Pruett ED. Plasma insulin concentrations during prolonged work at near maximal oxygen uptake. J Appl Physiol. 1970 Aug;29(2):155–158. [PubMed]
  • Häggendal J, Hartley LH, Saltin B. Arterial noradrenaline concentration during exercise in relation to the relative work levels. Scand J Clin Lab Invest. 1970 Dec;26(4):337–342. [PubMed]
  • Porte D, Jr, Williams RH. Inhibition of insulin release by norepinephrine in man. Science. 1966 May 27;152(3726):1248–1250. [PubMed]
  • GOLDSTEIN MS, MULLICK V, HUDDLESTUN B, LEVINE R. Action of muscular work on transfer of sugars across cell barriers; comparison with action of insulin. Am J Physiol. 1953 May;173(2):212–216. [PubMed]
  • Rowell LB, Brengelmann GL, Blackmon JR, Twiss RD, Kusumi F. Splanchnic blood flow and metabolism in heat-stressed man. J Appl Physiol. 1968 Apr;24(4):475–484. [PubMed]
  • Owen OE, Felig P, Morgan AP, Wahren J, Cahill GF., Jr Liver and kidney metabolism during prolonged starvation. J Clin Invest. 1969 Mar;48(3):574–583. [PMC free article] [PubMed]
  • Cahill GF, Jr, Herrera MG, Morgan AP, Soeldner JS, Steinke J, Levy PL, Reichard GA, Jr, Kipnis DM. Hormone-fuel interrelationships during fasting. J Clin Invest. 1966 Nov;45(11):1751–1769. [PMC free article] [PubMed]
  • Felig P, Wahren J. Influence of endogenous insulin secretion on splanchnic glucose and amino acid metabolism in man. J Clin Invest. 1971 Aug;50(8):1702–1711. [PMC free article] [PubMed]
  • Blackard WG, Nelson NC. Portal and peripheral vein immunoreactive insulin concentrations before and after glucose infusion. Diabetes. 1970 May;19(5):302–306. [PubMed]
  • VENDSALU A. Studies on adrenaline and noradrenaline in human plasma. Acta Physiol Scand Suppl. 1960;49(173):1–123. [PubMed]
  • BEARN AG, BILLING B, SHERLOCK S. The effect of adrenaline and noradrenaline on hepatic blood flow and splanchnic carbohydrate metabolism in man. J Physiol. 1951 Dec 28;115(4):430–441. [PubMed]

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