muscle glycogen resynthesis





Ball State University,

COSTILL, D.L.,D.D. PASCOE,W.J. FINK, R.A. ROBERGS, S. I. BARR,ANDD. PEARSON.Impaired muscle glycogen resynthesis after eccentric exercise. J. Appl. Physiol. 69(l): 46-50, 1990.-Eight men performed 10 sets of 10 eccentric contractions of the knee extensor muscles with one leg [eccentrically exercised leg (EL)]. The weight used for this exercise was 120% of the maximal extension strength. After 30 min of rest the subjects performed two-legged cycling [concentrically exercised leg (CL)] at 74% of maximal OtL uptake for 1 h. In the 3 days after this exercise four subjects consumed diets containing 4.25 g CHO/kg body wt, and the remainder were fed 8.5 g CHO/kg. All subjects experienced severe muscle soreness and edema in the quadriceps muscles of the eccentrically exercised leg. Mean (*SE) resting serum creatine kinase increased from a preexercise level of 57 t 3 to 6,988 * 1,913 U/l on the 3rd day of recovery. The glycogen content (mmol/kg dry wt) in the vastus lateralis of CL muscles averaged 90, 395, and 592 mmol/kg dry wt at 0, 24, and 72 h of recovery. The EL muscle, on the other hand, averaged 168,329, and 435 mmol/kg dry wt at these same intervals. Subjects receiving 8.5 g CHO/kg stored significantly more glycogen than those who were fed 4.3 g CHO/kg. In both groups, however, significantly less glycogen was stored in the EL than in the CL. muscle soreness; creatine work

kinase; glycogen depletion;


MUSCLE SORENESSwas first theorized to be associated with muscle tissue damage in 1902 (10). Supporting

evidence for this hypothesis, however, has only recently been provided by Friden et al. (6, 7) and Hikida et al. (9). These and other studies have shown that forced lengthening of contracted muscle, eccentric exercise, will produce ultrastructural damage that appears to be related to the onset of muscle soreness within 24-72 h after the activity. It has also been noted that eccentric exercise interferes with muscle glycogen synthesis, resulting in lower glycogen values 1 and 10 days after an eccentric effort than were observed immediately after the activity (11, 12). These studies did not, however, describe the pattern of change in muscle glycogen content during the period when the subjects experienced the greatest soreness (i.e., 24-72 h) after eccentric exercise. Nor are data available to describe the role of dietary carbohydrate (CHO) on the rate of glycogen resynthesis. In an effort to describe the influence of eccentric exercise and dietary CHO on muscle glycogen resynthesis, a single-leg design was employed. That is, one of the subject’s legs was exercised eccentrically (i.e., eccentric contractions of knee extensor muscles) and concentrically (i.e., cycling), whereas the 46

after eccentric exercise







other leg was exercised only using concentric cycling. In addition, the subjects were fed diets either high or low in CHO to determine the effect of CHO dose on the rate of glycogen resynthesis. METHODS

The eight men who served as subjects in this investigation were normally active but had not engaged in any strength training in the year preceding this experiment. The characteristics of these volunteers are shown in Table 1. Each subject was fully informed of the stresses and risks associated with this research before giving his written agreement to participate. The subjects were initially tested to determine their maximal O2 uptake . WO 2 max ) during cycling and their leg strength using an Eagle I knee extension machine (model 4107, Cybex, Ronkonkoma, NY). These data were subsequently used to determine the resistance used during eccentric exercise and submaximal cycling. As illustrated in Fig. 1, the subjects performed different exercise protocols with each leg. First they performed 10 sets of 10 eccentric contractions of the knee extensor muscles with one leg, lowering a weight that was 120% of that leg’s maximal extension force production (1RM). This leg will be referred to as the eccentrically exercised leg (EL). Assistants lifted the weight before each exercise, thereby eliminating any resistance during each knee extension. Thirty minutes after the eccentric exercise the subjects performed 60 min of cycling with both legs, using a work load estimated to require 70% VO, max.The leg that performed only concentric cycling will hereafter be referred to as CL. Muscle biopsies were taken from the vastus lateralis of each leg immediately after and at 24 and 72 h after the cycling bout. Since the biopsy procedure has been shown to inhibit glycogen resynthesis in the area immediate to sampling, all repeated biopsies were taken at least 3 cm distal to the previous incision (4). A portion of these specimens were mounted and frozen in isopentane cooled over liquid N2 for histochemical determination of glycogen [periodic acid-Schiff stain (PAS) (16)] fiber composition [myosin adenosinetriphosphatase, pH = 4.3 and 4.61, and the presence of inflammatory cells (hematoxylin and eosin stain) (2,13). A second specimen was frozen, divided, dried, and weighed for enzymatic determination of muscle glycogen and synthase activity, which was measured in its I form without glucose 6phosphate and in its D form in the presence of 10 mmol/ 1 glucose 6-phosphate (8, 13). Estimates of glycogen

0 1990 the American



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1. Characteristics








VO 2











FIG. 1. Exercise and dietary regimens cally exercised leg (EL) and concentrically


for eccentrically-concentriexercised leg (CL).

2. Analyses of diets used in HI and LO regimens


Fuel Source

Protein Fat Carbohydrate Values percentage

represent of total





g/l ,000 kcal

% Total

g/l ,000 kcal


34.5 49.1 104.7

13.9% 44.2% 41.9%

31.4 12.7 190.8

12.5% 11.4% 76.1%

the content calories.


per 1,000 kcal




content in the type I and II fibers were determined spectrophotometrically as described by Vellestad et al. (19). Before each muscle biopsy and at 48 h after exercise, a blood sample (5 ml) was taken from a forearm vein for determination of serum creatine kinase (CK) (15). In the 3 days after the exercise trials four of the subjects were fed a diet containing 4.3 g CHO. kg body wt-‘*day-’ (LO diet), whereas the other subjects consumed a diet containing 8.5 g CHO . kg-‘. day-l (HI diet). The caloric content of the diets during that period averaged 12,175 kJ/day or 172.4 kJ. kg-’ *day-‘. Representative samples of the LO and HI diets were analyzed by Medallion Laboratories (Minneapolis, MN). The results of these analyses are shown in Table 2. During this 3day recovery period the subjects refrained from hard muscular activity. Muscle soreness was subjectively rated by palpation of the proximal, medial, and distal areas of the vastus lateralis, using a rating scale that ranged from 0 (no soreness) to 10 (extreme soreness). Palpation and recording of the soreness were always done by the same person. Soreness scores (proximal, medial, and distal) were averaged each day for statistical comparisons. Mean (*SE) data were treated for statistical differences using a repeated-measures analysis of variance (ANOVA). Significant differences identified by ANOVA were isolated using the Newman-Keuls post hoc test. The significance level for all comparisons was set at P c 0.05.

measurements maximal heart

RL-lRM, kg



195kl (17). rate.

LL-lRM, kg

34.OkO.4 Knee



35.9t0.3 was determined








Values are means f: SE. Percentage of body fat was estimated from skinfold each leg (right, RL; left, LL) for a single repetition maximal (1RM) lift. HR,,,,




of subjects




The mean (GE) resistance used during eccentric exercise was 43.1 t 0.3 kg, whereas the power output during two-legged cycling averaged 203.5 t 17.0 W. During this 60 min of cycling the subjects’ O2 uptake and heart rates were, on average, 3.0 t 0.2 l/min (74% vo2 max) and 165 t 1.8 beats/min, respectively. Within the first 24 h after this activity, all of the subjects experienced soreness and swelling in the quadriceps muscle of the EL. These symptoms became progressively more acute after 24-72 h of recovery. Although there was no soreness immediately after the exercise, the mean (&SE) ratings of soreness increased to 3.3 t 0.3, 5.9 t 0.7, and 5.0 t 0.9 after 24,48, and 72 h of recovery, respectively. As a consequence of severe swelling and pressure in the thigh extensor muscles of the EL, several of the subjects experienced a loss in the range of their knee motion. Resting serum CK increased from an immediate postexercise level of 57 t 3 U/l to 513 t 170, 3,466.7 t 1,362, and 6,988 t 1,913 U/l on the lst, 2nd, and 3rd days of recovery. Three of the subjects were found to have CK values in excess of 8,014 U/l on the 3rd day of recovery. These subjects experienced considerably more soreness, impairment of knee motion, and swelling than the other subjects. It should also be noted that one subject (S7) had a CK value of 30,196 U/l and a 21% increase in the cross-sectional area of the midthigh, as determined by computed tomography (CT), resulting in a complete loss of knee flexion. Figure 2 presents the mean values for all muscle glycogen and synthase activities at 0, 24, and 72 h of recovery in both the EL and CL. These data represent the combined result of the subjects on both the HI and LO CHO diets. Although the EL performed both eccentric and concentric exercise, the postexercise glycogen content of that leg was not as low as that of the CL, which performed only concentric cycling. The earlier study by Kuipers et al. (11) showed little or no decline in muscle (vastus lateralis) glycogen after eccentric cycling. We have no explanation for the smaller use of glycogen in the EL of the present study, but it is possible that during the two-legged cycling the subjects may have favored the EL, since it had already performed intense eccentric effort. It might also be argued that the eccentric exercise served as a warm-up for EL, thereby reducing the muscle’s reliance on glycogen during cycling. This is unlikely, since we have recently observed no sparing of muscle glycogen as a result of warming up (unpublished observations). Twenty-four hours after the exercise there was no difference in glycogen content of the vastus lateralis of the EL and CL groups (Fig. 2). At 72 h of recovery,

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600 3





500 1



cJ g z s

400 2 300 -






g g

a 5

200 l


100 1 0 -







,, 24


LO(n= different

..’, El






centrically different

2. Muscle glycogen content (CL) and eccentrically for CL and EL.


, 48


I, 60

24-HR I



3. Changes in muscle glycogen for subjects 4) CHO diets. All means at 72 h of recovery (P < 0.05).



, 36


on HI (n = 4) and were significantly





and synthase (EL) exercised

activity ratio in conlegs. * Significantly

however, the CL contained significantly more muscle glycogen than the EL. Glycogen synthase activity ratio (I form/D form), on the other hand, was significantly higher in the CL than EL immediately after the exercise but was similar in both legs at 24 and 72 h of recovery. Based on the change in muscle glycogen content during the days of recovery, it is clear that significantly less glycogen was stored in the EL than the CL. It should be noted that although the glycogen content of the CL showed a significant increase (P < 0.05) from 24 to 72 h of recovery, there was only a small increase (P > 0.05) during that same period in the EL. The subjects who experienced the greatest soreness and highest CK values also experienced the smallest resynthesis of muscle glycogen. In fact, subject ST, mentioned above, had a decrease in muscle glycogen of 164 mmol/kg dry wt in the first 24 h of recovery and no storage in the following 48 h ‘A comparison of the muscle glycogen values of the subjects on the HI and LO CHO diets revealed that in all casesthe CL stored significantly more glycogen than the EL, regardless of the amount of ingested CHO (Fig. 3). It should be noted that, even in the EL, muscle glycogen resynthesis was increased with increasing amounts of dietary CHO. As illustrated in Fig. 4, optical density of the PASstained muscle sections (24 h after exercise) indicated that the glycogen content in type I and II fibers of CL were significantly greater than those measured in the EL. In neither leg, however, was there any difference in



Significantly exercised






FIG. 4. Optical density of PAS-stained type I and II muscle fibers of eccentrically (EL) and concentrically (CL) exercised legs. Samples represent measurements on sections from samples taken after 24 h of recovery.

the density of the PAS stains between the fiber types. As illustrated in Fig. 5 hematoxylin and eosin stains of muscle sections taken from the EL 24 h after the exercise revealed frequent sites of leukocyte infiltration, which were not observed in the preexercise or CL samples. DISCUSSION

Earlier studies have observed lower muscle glycogen 1 and 10 days after eccentric exercise than was seen immediately after the exercise (11, 12). Although we observed slower rates of glycogen resynthesis, we did not find lower muscle glycogen values in the days after the eccentric exercise. It should be noted, however, that in the study by Kuipers et al. (11) no attempt was made to manipulate or control the intake of CHO during the recovery period. Blom et al. (l), on the other hand, reported significant increases in muscle glycogen in the first 24 h of recovery from treadmill running that produced delayed onset muscle soreness. Despite feeding of 600 g CHO/day, the subjects showed little or no increase in glycogen during the next 48 h. Thus past and present studies demonstrate a reduced rate of glycogen storage

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FIG. 5. Microscopic view of muscle section taken before (A) and 24 h after eccentric exercise (B). Note presence of leukocytes in sample taken after 24 h of recovery.

subsequent to eccentric exercise that induces delayed onset muscle soreness. It might be argued that in the present study the difference in the rate of glycogen synthesis for the EL and CL was influenced by the amount of glycogen used by the two legs during exercise (Fig. 2), since we have observed that the rate of glycogen repletion in the first 6 h after exercise is proportional to the amount of glycogen used during the activity (21). The small rise and, in some cases, a decline in muscle glycogen of the EL during the first 24 h of recovery, however, suggest that the rate of glycogen storage was reduced as a consequence of the eccentric exercise. As noted by Blom et al. (1) reduced glycogen synthesis persists for 72 h or more after the activity despite the intake of a rich CHO diet (600 g CHO/day). In the present study, however, increasing the intake of CHO was found to enhance glycogen storage, suggesting that the muscle trauma associated with eccentric exercise did not totally inhibit glycogen resynthesis (Fig. 3). This leads us to speculate that the rate of glycogen storage may be limited by glucose availability and that greater storage might have been achieved with the intake of more CHO. Spectrophotometric measurements of muscle sections stained for PAS revealed that type I and II fibers had similar glycogen contents 24 h after the exercise regimen (Fig. 4). On the average, however, the CL was found to have a darker PAS stain in both fiber types than that measured in EL. This finding does not agree with the biochemical measurement of muscle glycogen, which shows a small insignificant difference between EL and CL (Fig. 2). Nevertheless, these findings suggest that there may have been a greater difference in muscle glycogen storage between the two legs (EL and CL) than that observed in the whole muscle specimens.

In addition to muscle soreness and decrements in muscle glycogen storage, eccentric exercise has been shown to produce ultrastructural damage within the affected muscle (7, 9, 12). Several studies have reported rupturing of the sarcolemma and degenerated or disorganized myofibrils after exhaustive eccentric exercise (6, 9, 11). As observed in the present study, such tissue damage results in inflammatory cell infiltration of the muscle, including the presence of macrophages, polymorphonuclear leukocytes, and lymphocytes. The presence of these inflammatory cells is known to increase glucose utilization and lactate production within the muscle (3, 5, 14, 18). These previous studies have suggested that -70% of the glucose uptake and 50% of the lactate production can be accounted for by the cellular infiltrate within wounded skeletal muscle. Part of this increased glucose uptake by the muscle can be attributed to the oxidation of glucose by the inflammatory cells present in the injured region of the muscle (5). Shearer et al. (14) have shown that inflammatory cells release a soluble factor(s) that can increase glucose metabolism in skeletal muscle by at least 118%, with a 147% increase in the conversion of glucose to lactate. These findings suggest that the reduced rate of glycogen storage observed in the eccentrically exercised muscles may be the result of competition between the inflammatory and muscle cells for the available glucose and/or an increased glycolysis in the previously exercised muscle. In conclusion, the muscle trauma associated with eccentric exercise has been shown to reduce the rate of muscle glycogen storage. The most likely explanation for this diminished resynthesis is that the traumatized muscle is infiltrated with inflammatory cells, which have a large affinity for glucose oxidation. In addition, inflammatory cells release a factor that stimulates glucose oxidation and lactate production by the surrounding

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muscle cells. These processes appear to present a competition between the inflammatory cells and the glycogen-depleted muscle fibers for blood glucose, thereby reducing the amount of muscle glycogen stored. The impairment in glycogen storage after eccentric exercise can be partially overcome by ingesting larger quantities of CHO. In the present study, an intake of 8.5 g/kg resulted in glycogen concentrations in the EL that were similar to those observed in the CL after 3 days of a CHO intake of 4.3 g/kg. Thus glycogen synthesis is impaired after eccentric exercise, although the muscles demonstrate the ability to increase glycogen storage with larger amounts of dietary CHO. This research was supported by a grant from Ross Laboratories, Columbus, OH. Present address of S. I. Barr, School of Family and Nutritional Science, University of British Columbia, Vancouver, BC V6T lWS, Canada. Address reprint requests to D. L. Costill. Received

21 August

1989; accepted

in final


12 March


REFERENCES 1. BLOM, P. C., D. L. COSTILL, AND N. K. VQ)LLESTAD. Exhaustive running: inappropriate as a stimulus of muscle glycogen supercompensation. IMed. Sci. Sports Exercise 19: 398-403, 1987. 2. BROOKE, M. H., AND K. K. KAISER. Three “myosin adenosine triphosphatase” systems: the nature of their pH lability and sulphydryl dependence. J. Histochem. Cytochem. 18: 670-672,197O. 3. CALDWELL, M. D., J. D. SHEARER, A. S. MORRIS, B. MASTROFRANCESCO, W. L. HENRY, AND J. E. ALBINA. Evidence for aerobic glycolysis in lambda-carrageenan wounded skeletal muscle. J. Surg. Res. 37: 63-68, 1984. 4. COSTILL, D. L., D. R. PEARSON, AND W. J. FINK. Impaired muscle glycogen storage after muscle biopsy. J. Appl. Physiol. 64: 22452248,1988. 5. FORSTER, J., A. S. MORRIS, J. D. SHEARER, B. MASTROFRANCESCO, K. INMAN, R. G. LAWLER, W. BOWEN, AND M. D. CALDWELL. Glucose uptake and flux through phosphofructokinase in wounded rat skeletal muscle. Am. J. Physiol. 256 (Endocrinol. Metab. 19): E788-E797, 1989.


6. FRIDEN, J. M., J. SEGER, M. SJOSTROM, AND B. EKBLOM. Adaptive response in human muscle subjected to prolonged eccentric training. Int. J. Sports Med. 4: 177-183, 1983. 7. FRIDEN, J. M., M. SJOSTROM, AND B. EKBLOM. Myofibrillar damage following intense eccentric exercise in man. Int. J. Sports Med. 4: 170-176,1983. 8. HENRIKSSON, J., M. M.-Y. CHI, C. S. HINTZ, D. A. YOUNG, K. K. KAISER, S. SALMONS, AND 0. H. LOWRY. Chronic stimulation of mammalian muscle: changes in enzymes of six metabolic pathways. Am. J. Physiol. 251 (Cell Physiol. 20): C614-C632, 1986. 9. HIKIDA, R., R. STARON, F. HAGERMAN, W. SHERMAN, AND D. COSTILL. Muscle fiber necrosis associated with human marathon runners. J. Neural. Sci. 59: 185-203, 1983. 10. HOUGH, T. Ergographic studies in muscular soreness. Am. J. Physiol. 7: 76-92, 1902. 11. KUIPERS, H. H., F. VERSTAPPEN, AND D. L. COSTILL. Influence of a prostaglandin-inhibiting drug on muscle soreness after eccentric work. Int. J. Sports Med. 6: 336-339, 1985. 12. O’REILLY, K. P., M. J. WARHOL, R. A. FIELDING, W. R. FONTERA, C. N. MEREDITH, AND W. J. EVANS. Eccentric exercise-induced muscle damage impairs muscle glycogen repletion. J. Appl. Physiol. 63: 252-256, 1987. 13. PASSONNEAU, J., AND V. LAUDERDALE. A comparison of three methods of glycogen measurement in tissues. Anal. Biochem. 60: 405-412, 1974. 14. SHEARER, J. D., J. F. AMARAL, AND M. D. CALDWELL. Glucose metabolism of injured skeletal muscle: the contribution of inflammatory cells. Circ. Shock 25: 131-138, 1988. 15. SIGMA CHEMICAL CO. Creatine Kinase (CK). Sigma Diagnostics Procedure 47-UV. St. Louis, MO: Sigma. 16. SIGMA CHEMICAL CO. Periodic Acid-Schiff (PAS) Staining System. Sigma Diagnostics Procedure 395. St. Louis, MO: Sigma. 17. SLOAN, A. W. Estimation of body fat in young men. J. Appl. Physiol. 23: 311-315, 1967. 18. TISCHLER, M. E., AND J. M. FAGAN. Response to trauma of protein, amino acid, and carbohydrate metabolism in injured rat skeletal muscle. Metab. Clin. Exp. 32: 853-868, 1983. 19. VOLLESTAD, N. K., 0. VAAGE, AND L. HERMANSEN. Muscle glycogen depletion patterns in type I and subgroups of type II fibres during prolonged severe exercise in man. Acta Physiol. Stand. 122: 433-441,1984. 20. YELLOW SPRINGS INSTRUMENT Co. YSI Glucose Analyzer 23A. Yellow Springs, OH: YSI. J. J., D. L. COSTILL, D. D. PASCOE, R. A. ROBERGS, 21. ZACHWIEJA, AND W. J. FINK. Influence of muscle glycogen depletion on the rate of resvnthesis. Med. Sci. SDorts Exercise. - - --In I-Dress. 4 1 - --

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Impaired muscle glycogen resynthesis after eccentric exercise.

Eight men performed 10 sets of 10 eccentric contractions of the knee extensor muscles with one leg [eccentrically exercised leg (EL)]. The weight used...
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