• 1.

    McKenzie EC, Holbrook TC, Williamson KK, et al. Recovery of muscle glycogen concentrations in sled dogs during prolonged exercise. Med Sci Sports Exerc 2005;37:13071312.

    • Search Google Scholar
    • Export Citation
  • 2.

    Bräu L, Nikolovski S, Palmer TN, et al. Glycogen repletion following burst activity: a carbohydrate-sparing mechanism in animals adapted to arid environments? J Exp Zool 1999;284:271275.

    • Search Google Scholar
    • Export Citation
  • 3.

    Raja G, Bräu L, Palmer TN, et al. Repeated bouts of high-intensity exercise and muscle glycogen sparing in the rat. J Exp Biol 2003;206:21592166.

    • Search Google Scholar
    • Export Citation
  • 4.

    Costill DL, Bowers R, Branam G, et al. Muscle glycogen utilization during prolonged exercise on successive days. J Appl Physiol 1971;31:834838.

    • Search Google Scholar
    • Export Citation
  • 5.

    Kirwan JP, Costill DL, Mitchell JB, et al. Carbohydrate balance in competitive runners during successive days of intense training. J Appl Physiol 1988;65:26012606.

    • Search Google Scholar
    • Export Citation
  • 6.

    Kaciuba-Uscilko H, Kruk B, Szczpaczewska M, et al. Metabolic, body temperature and hormonal responses to repeated periods of prolonged cycle-ergometer exercise in men. Eur J Appl Physiol Occup Physiol 1992;64:2631.

    • Search Google Scholar
    • Export Citation
  • 7.

    McInerney P, Lessard SJ, Burke LM, et al. Failure to repeatedly supercompensate muscle glycogen stores in highly trained men. Med Sci Sports Exerc 2005;37:404411.

    • Search Google Scholar
    • Export Citation
  • 8.

    Ronsen O, Lea T, Bahr R, et al. Enhanced plasma IL-6 and IL-1ra responses to repeated vs. single bouts of prolonged cycling in elite athletes. J Appl Physiol 2002;92:25472553.

    • Search Google Scholar
    • Export Citation
  • 9.

    Ronsen O, Haugen O, Hallén J, et al. Residual effect of prior exercise and recovery on subsequent exercise-induced metabolic responses. Eur J Appl Physiol 2004;92:498507.

    • Search Google Scholar
    • Export Citation
  • 10.

    Stich V, de Glisezinsk I, Berlan M, et al. Adipose tissue lipolysis is increased during a repeated bout of aerobic exercise. J Appl Physiol 2000;88:12771283.

    • Search Google Scholar
    • Export Citation
  • 11.

    Paul P, Issekutz B Jr. Role of extramuscular energy sources in the metabolism of the exercising dog. J Appl Physiol 1967;22:615622.

  • 12.

    McKenzie EC, Jose-Cunilleras E, Hinchcliff KW, et al. Serum chemistry alterations in Alaskan sled dogs during five successive days of prolonged endurance exercise. J Am Vet Med Assoc 2007;230:14861492.

    • Search Google Scholar
    • Export Citation
  • 13.

    Weber JM, Brichon G, Zwingelstein G, et al. Design of the oxygen and substrate pathways. IV. Partitioning energy provision from fatty acids. J Exp Biol 1996;199:16671674.

    • Search Google Scholar
    • Export Citation
  • 14.

    Reynolds AJ, Fuhrer L, Dunlap HL, et al. Effect of diet and training on muscle glycogen storage and utilization in sled dogs. J Appl Physiol 1995;79:16011607.

    • Search Google Scholar
    • Export Citation
  • 15.

    Lewis LD. Diet evaluation, formulation and preparation for horses. In: Lewis D, ed. Equine clinical nutrition. Media, Pa: The Williams & Wilkins Co, 1995;147174.

    • Search Google Scholar
    • Export Citation
  • 16.

    Lowry OH, Passonneau JV. Measurement of enzyme activities with pyridine nucleotides. In: A flexible system for enzyme analysis. New York: Academic Press Inc, 1973:93108.

    • Search Google Scholar
    • Export Citation
  • 17.

    Spriet LL, Peters SJ, Heigenhauser GJ, et al. Rat skeletal muscle triacylglycerol utilization during exhaustive swimming. Can J Physiol Pharmacol 1985;63:614618.

    • Search Google Scholar
    • Export Citation
  • 18.

    Phinney SD, Bistrian BR, Evans WJ, et al. The human metabolic response to chronic ketosis without caloric restriction: preservation of submaximal exercise capability with reduced carbohydrate oxidation. Metabolism 1983;32:769776.

    • Search Google Scholar
    • Export Citation
  • 19.

    Helge JW, Watt PW, Richter EA, et al. Fat utilization during exercise: adaptation to a fat-rich diet increases utilization of plasma fatty acids and very low density lipoprotein-triacylglycerol in humans. J Physiol 2001;537:10091020.

    • Search Google Scholar
    • Export Citation
  • 20.

    Simi B, Sempore B, Mayet MH, et al. Additive effects of training and high-fat diet on energy metabolism during exercise. J Appl Physiol 1991;71:197203.

    • Search Google Scholar
    • Export Citation
  • 21.

    Zachwieja JJ, Costill DL, Pascoe DD, et al. Influence of muscle glycogen depletion on the rate of resynthesis. Med Sci Sports Exerc 1991;23:4448.

    • Search Google Scholar
    • Export Citation
  • 22.

    Hyyppä S, Saastamoinen M, Reeta Pösö A. Effect of a post exercise fat-supplemented diet on muscle glycogen repletion. Equine Vet J Suppl 1999;30:493498.

    • Search Google Scholar
    • Export Citation
  • 23.

    Kim CH, Youn JH, Park JY, et al. Effects of a high-fat diet and exercise training on intracellular glucose metabolism in rats. Am J Physiol Endocrinol Metab 2000;278:E977E984.

    • Search Google Scholar
    • Export Citation
  • 24.

    Pehleman TL, Peters SJ, Heigenhauser GJ, et al. Enzymatic regulation of glucose disposal in human skeletal muscle after a high fat, low carbohydrate diet. J Appl Physiol 2005;98:100107.

    • Search Google Scholar
    • Export Citation
  • 25.

    Kuipers H, Keizer HA, Brouns F, et al. Carbohydrate feeding and glycogen synthesis during exercise in man. Pflugers Arch 1987;410:652656.

    • Search Google Scholar
    • Export Citation
  • 26.

    Issekutz B Jr, Issekutz AC, Nash D. Mobilization of energy sources in exercising dogs. J Appl Physiol 1970;29:691697.

  • 27.

    Roberts TJ, Weber JM, Hoppeler H, et al. Design of the oxygen and substrate pathways. II. Defining the upper limits of carbohydrate and fat oxidation. J Exp Biol 1996;199:16511658.

    • Search Google Scholar
    • Export Citation
  • 28.

    Trevino GS, Demaree R Jr, Sanders BV, et al. Needle biopsy of skeletal muscle in dogs: light and electron microscopy of resting muscle. Am J Vet Res 1973;34:507514.

    • Search Google Scholar
    • Export Citation

Advertisement

Assessment of alterations in triglyceride and glycogen concentrations in muscle tissue of Alaskan sled dogs during repetitive prolonged exercise

View More View Less
  • 1 Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078.
  • | 2 Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210.
  • | 3 Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108.
  • | 4 Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078.
  • | 5 Department of Statistics, College of Arts and Sciences, Oklahoma State University, Stillwater, OK 74078.
  • | 6 Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University, Stillwater, OK 74078.

Abstract

Objective—To assess changes in muscle glycogen (MG) and triglyceride (MT) concentrations in aerobically conditioned sled dogs during prolonged exercise.

Animals—54 Alaskan sled dogs fed a high-fat diet.

Procedures—48 dogs ran 140-km distances on 4 consecutive days (cumulative distance, up to 560 km); 6 dogs remained as nonexercising control animals. Muscle biopsies were performed immediately after running 140, 420, or 560 km (6 dogs each) and subsequently after feeding and 7 hours of rest. Single muscle biopsies were performed during recovery at 28 hours in 7 dogs that completed 560 km and at 50 and 98 hours in 7 and 6 dogs that completed 510 km, respectively. Tissue samples were analyzed for MG and MT concentrations.

Results—In control dogs, mean ± SD MG and MT concentrations were 375 ± 37 mmol/kg of dry weight (kgDW) and 25.9 ± 10.3 mmol/kgDW, respectively. Compared with control values, MG concentration was lower after dogs completed 140 and 420 km (137 ± 36 mmol/kgDW and 203 ± 30 mmol/kgDW, respectively); MT concentration was lower after dogs completed 140, 420, and 560 km (7.4 ± 5.4 mmol/kgDW; 9.6 ± 6.9 mmol/kgDW, and 6.3 ± 4.9 mmol/kgDW, respectively). Depletion rates during the first run exceeded rates during the final run. Replenishment rates during recovery periods were not different, regardless of distance; only MG concentration at 50 hours was significantly greater than the control value.

Conclusions and Clinical Relevance—Concentration of MG progressively increased in sled dogs undergoing prolonged exercise as a result of attenuated depletion.

Contributor Notes

Dr. McKenzie's present address is Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR 97331.

Dr. Hinchcliff's present address is Faculty of Veterinary Science, University of Melbourne, Werribee, VIC, Australia, 3030.

Supported by the Defense Advanced Research Projects Agency (DARPA). Approved for public release, distribution unlimited.

The authors thank Rick Swenson, Kelly Williams, Dr. Lawren Durocher, Christina Phillips, Joshua Stern, Dr. Stuart Nelson, and Mark Nordman for technical assistance.

Address correspondence to Dr. Davis.