Pro- and macroglycogenolysis during repeated exercise: roles of glycogen content and phosphorylase activation

2001 ◽  
Vol 90 (3) ◽  
pp. 880-888 ◽  
Author(s):  
J. Shearer ◽  
I. Marchand ◽  
M. A. Tarnopolsky ◽  
D. J. Dyck ◽  
T. E. Graham
Keyword(s):  
Oxygen Uptake ◽  
Glycogen Phosphorylase ◽  
Glycogen Content ◽  
Rest Period ◽  
Exercise Bout ◽  
Glycogen Concentration ◽  
Repeated Exercise ◽  
Glycogen Utilization ◽  
The Relationship ◽  
Male Subjects

This study examined the relationship between preexercise muscle glycogen content and glycogen utilization in two physiological pools, pro- (PG) and macroglycogen (MG). Male subjects ( n = 6) completed an exercise and dietary protocol before the experiment that resulted in one leg with high glycogen (HL) and one with low glycogen (LL). Preexercise PG levels were 312 ± 29 and 208 ± 31 glucosyl units/kg dry wt (dw) ( P ≤ 0.05) in the HL and LL, respectively, and the corresponding values for MG were 125 ± 37 and 89 ± 43 mmol glucosyl units/kg dw ( P ≤ 0.05). Subjects then performed two 90-s exercise bouts at 130% maximal oxygen uptake separated by a 10-min rest period. Biopsies were obtained at rest and after each exercise bout. Preexercise glycogen concentration was correlated to net glycogenolysis for both PG and MG for bout 1 and bouts 1 and 2 ( r ≤ 0.60). In bout 1, there was no difference in the rate of PG or MG catabolism between HL and LL despite a 26% increase ( P ≤ 0.05) in glycogen phosphorylase transformation ( phos a %) in the HL. In the second bout, more PG was catabolized in the HL vs. LL (38 ± 9 vs. 9 ± 6 mmol glucosyl units · kg dw−1 · min−1) ( P ≤ 0.05) with no difference between legs in phos a %. phos a% was increased in HL vs. LL but does not necessarily increase glycogenolysis in either PG or MG. Despite both legs performing the same exercise and having identical metabolic demands, the HL catabolized 2.3 ( P ≤ 0.05) times more PG and 1.5 ( P ≤ 0.05) times more MG vs. LL in bouts 1 and 2, indicating that preexercise glycogen concentration is a regulator of glycogenolysis.

Muscle glycogen recovery after exercise during glucose and fructose intake monitored by13C-NMR

1996 ◽  
Vol 81 (4) ◽  
pp. 1495-1500 ◽  
Author(s):  
Adrianus J. Van Den Bergh ◽  
Sibrand Houtman ◽  
Arend Heerschap ◽  
Nancy J. Rehrer ◽  
Hendrikus J. Van Den Boogert ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Glycogen Depletion ◽  
Glycogen Concentration ◽  
Fructose Intake ◽  
Glycogen Stores ◽  
Male Subjects ◽  
C Nmr

Van Den Bergh, Adrianus J., Sibrand Houtman, Arend Heerschap, Nancy J. Rehrer, Hendrikus J. Van Den Boogert, Berend Oeseburg, and Maria T. E. Hopman. Muscle glycogen recovery after exercise during glucose and fructose intake monitored by13C-NMR. J. Appl. Physiol. 81(4): 1495–1500, 1996.—The purpose of this study was to examine muscle glycogen recovery with glucose feeding (GF) compared with fructose feeding (FF) during the first 8 h after partial glycogen depletion by using13C-nuclear magnetic resonance (NMR) on a clinical 1.5-T NMR system. After measurement of the glycogen concentration of the vastus lateralis (VL) muscle in seven male subjects, glycogen stores of the VL were depleted by bicycle exercise. During 8 h after completion of exercise, subjects were orally given either GF or FF while the glycogen content of the VL was monitored by13C-NMR spectroscopy every second hour. The muscular glycogen concentration was expressed as a percentage of the glycogen concentration measured before exercise. The glycogen recovery rate during GF (4.2 ± 0.2%/h) was significantly higher ( P < 0.05) compared with values during FF (2.2 ± 0.3%/h). This study shows that 1) muscle glycogen levels are perceptible by 13C-NMR spectroscopy at 1.5 T and 2) the glycogen restoration rate is higher after GF compared with after FF.

scholarly journals A Single Bout of Constant-Load Exercise Test for Estimating the Time Constant of Oxygen Uptake Kinetics in Individuals With Stroke

2021 ◽  
Vol 45 (4) ◽  
pp. 304-313
Author(s):  
Kazuaki Oyake ◽  
Yasuto Baba ◽  
Yuki Suda ◽  
Jun Murayama ◽  
Ayumi Mochida ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Time Constant ◽  
Ventilatory Threshold ◽  
Exercise Bout ◽  
Relative Difference ◽  
Constant Load ◽  
Oxygen Uptake Kinetics ◽  
Uptake Kinetics ◽  
Single Bout ◽  
The Relationship

Objective To examine the relationship between the time constant of oxygen uptake kinetics during the onset of exercise (τVO2) estimated from a single exercise bout and that obtained from three averaged exercise bouts in individuals with stroke.Methods Twenty participants with stroke performed three bouts of a constant-load pedaling exercise at approximately 80% of the workload corresponding to the ventilatory threshold to estimate τVO2. The VO2 data from the first trial of three bouts were used to estimate τVO2 for a single bout. Additionally, data collected from three bouts were ensemble-averaged to obtain τVO2 for three averaged bouts as the criterion.Results There was a very high correlation between τVO2 for a single bout (34.8±14.0 seconds) and τVO2 for three averaged bouts (38.5±13.4 seconds) (r=0.926, p<0.001). However, τVO2 for a single bout was smaller than that for three averaged bouts (p=0.006).Conclusion τVO2 for a single bout could reflect the relative difference in τVO2 for three averaged bouts among individuals with stroke. However, it should be noted that τVO2 for a single bout may be underestimated compared to τVO2 for three averaged bouts.

Ventilatory threshold is related to walking tolerance in patients with intermittent claudication

VASA ◽  
2012 ◽  
Vol 41 (4) ◽  
pp. 275-281 ◽  
Author(s):  
da Rocha Chehuen ◽  
G. Cucato ◽  
P. dos Anjos Souza Barbosa ◽  
A. R. Costa ◽  
M. Ritti-Dias ◽  
...  
Keyword(s):  
Blood Flow ◽  
Oxygen Uptake ◽  
Intermittent Claudication ◽  
Lower Limb ◽  
Ventilatory Threshold ◽  
Reactive Hyperemia ◽  
Ankle Brachial Index ◽  
Metabolic Parameters ◽  
Walking Distance ◽  
The Relationship

Background: This study assessed the relationship between lower limb hemodynamics and metabolic parameters with walking tolerance in patients with intermittent claudication (IC). Patients and methods: Resting ankle-brachial index (ABI), baseline blood flow (BF), BF response to reactive hyperemia (BFRH), oxygen uptake (VO2), initial claudication distance (ICD) and total walking distance (TWD) were measured in 28 IC patients. Pearson and Spearman correlations were calculated. Results: ABI, baseline BF and BF response to RH did not correlate with ICD or TWD. VO2 at first ventilatory threshold and VO2peak were significantly and positively correlated with ICD (r = 0.41 and 0.54, respectively) and TWD (r = 0.65 and 0.71, respectively). Conclusions: VO2peak and VO2 at first ventilatory threshold, but not ABI, baseline BF and BFHR were associated with walking tolerance in IC patients. These results suggest that VO2 at first ventilatory threshold may be useful to evaluate walking tolerance and improvements in IC patients.

The relationship between integrated EMG and oxygen uptake during treadmill and bicycle exercise

1976 ◽  
Author(s):  
T. Fukunaga ◽  
K. Yuasa ◽  
M. Kobayashi ◽  
T. Miyagawa ◽  
H. Fujimatsu ◽  
...  
Keyword(s):  
Oxygen Uptake ◽  
Bicycle Exercise ◽  
Integrated Emg ◽  
The Relationship

scholarly journals The Influence of Maturation on the Oxygen Uptake Efficiency Slope

2012 ◽  
Vol 24 (3) ◽  
pp. 347-356 ◽  
Author(s):  
Michael P. Rogowski ◽  
Justin P. Guilkey ◽  
Brooke R. Stephens ◽  
Andrew S. Cole ◽  
Anthony D. Mahon
Keyword(s):  
Oxygen Uptake ◽  
Body Mass ◽  
Cycle Ergometer ◽  
Group Differences ◽  
Healthy Male ◽  
Uptake Efficiency ◽  
Graded Exercise ◽  
Oxygen Uptake Efficiency Slope ◽  
Male Subjects ◽  
One Way Anova

This study examined the influence of maturation on the oxygen uptake efficiency slope (OUES) in healthy male subjects. Seventy-six healthy male subjects (8–27 yr) were divided into groups based on maturation status: prepubertal (PP), midpubertal (MP), late-pubertal (LP), and young-adult (YA) males. Puberty status was determined by physical examination. Subjects performed a graded exercise test on a cycle ergometer to determine OUES. Group differences were assessed using a one-way ANOVA. OUES values (VO2L·min1/log10VEL·min−1) were lower in PP and MP compared with LP and YA (p < .05). When OUES was expressed relative to body mass (VO2mL·kg−1·min−1/log10VEmL·kg−1·min−1) differences between groups reversed whereby PP and MP had higher mass relative OUES values compared with LP and YA (p < .05). Adjusting OUES by measures of body mass failed to eliminate differences across maturational groups. This suggests that qualitative factors, perhaps related to oxidative metabolism, account for the responses observed in this study.

Maximal Oxygen Uptake and Daily Physical Activity in 7- to 12-Year-Old Boys

1993 ◽  
Vol 5 (4) ◽  
pp. 357-366 ◽  
Author(s):  
Hazzaa M. Al-Hazzaa ◽  
Mohammed A. Sulaiman
Keyword(s):  
Physical Activity ◽  
Heart Rate ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Open Circuit ◽  
Daily Physical Activity ◽  
Activity Level ◽  
Activity Levels ◽  
School Time ◽  
The Relationship

The present study examined the relationship between maximal oxygen uptake (V̇O2max) and daily physical activity in a group of 7- to 12-year-old boys. V̇O2max was assessed through the incremental treadmill test using an open circuit system. Physical activity level was obtained from heart rate telemetry outside of school time for 8 hrs during weekdays and during 40 min of physical education classes. The findings indicated that the absolute value of V̇O2max increased with age, while relative to body weight it remained almost the same across age, with a mean of 48.4 ml · kg−1 · min−1. Moreover, heart rate telemetry showed that the boys spent a limited amount of time on activities that raise the heart rate to a level above 160 bpm (an average of 1.9%). In addition, V̇O2max was found to be significantly related to the percentage of time spent at activity levels at or above a heart rate of 140 bpm, but not with activity levels at or above a heart rate of 160 bpm.

GLYCOGEN IN THE DECIDUAL TISSUE OF THE RAT UTERUS

1962 ◽  
Vol 25 (1) ◽  
pp. 69-76 ◽  
Author(s):  
H. C. CECIL ◽  
J. BITMAN ◽  
M. R. CONNOLLY ◽  
T. R. WRENN
Keyword(s):  
Glycogen Content ◽  
Endometrial Tissue ◽  
Rat Uterus ◽  
Glycogen Concentration ◽  
Decidual Tissue ◽  
Wet Weight ◽  
Glycogen Deposition

SUMMARY Glycogen was investigated in uteri of intact and progesterone-treated spayed rats with and without deciduomata. Samples of whole uterus, endometrium and myometrium were analysed. With development of deciduoma in intact animals the glycogen concentration of whole uterus increased from 68 to 125 mg./100 g. wet weight. There was no change in the myometrial glycogen concentration; i.e. 74 mg./100 g. without deciduoma and 73 mg./100 g. wet weight in the decidual myometrium. The endometrial glycogen content of decidual tissue was 221 mg./100 g. wet weight. Since myometrial glycogen was constant, the increases observed in the decidual tissue of whole uteri must be due to an increase in the amount of endometrium and/or an increase in the concentration of glycogen in the endometrium. As the deciduoma developed the proportion of endometrium increased from 9% in the uninjured horn to 34% in the injured horn. Thus, an increase in the amount of endometrium contributes to the increase in the glycogen concentration. Similar changes were observed in whole uterus, myometrium and endometrium of the spayed animals treated with progesterone. Previous work on uterine glycogen in rats indicated that oestrogens cause glycogen deposition and this occurs only in the myometrium, while progesterone exhibits no effect. The present results demonstrate that progesterone is responsible for the glycogen increase by stimulating the growth of endometrium—a glycogen-rich tissue. Since no endometrial tissue could be obtained from horns without decidual development, this study could not determine whether progesterone had any effect on glycogen deposition.

scholarly journals Cardiorespiratory Fitness and Body Composition in Postmenopausal Women

2014 ◽  
Vol 43 (1) ◽  
pp. 139-148 ◽  
Author(s):  
Helena Moreira ◽  
Betânia Passos ◽  
Josiane Rocha ◽  
Vivianne Reis ◽  
André Carneiro ◽  
...  
Keyword(s):  
Body Composition ◽  
Oxygen Uptake ◽  
Metabolic Rate ◽  
Postmenopausal Women ◽  
Aerobic Fitness ◽  
Basal Metabolic Rate ◽  
Visceral Fat ◽  
Central Adiposity ◽  
Visceral Fat Area ◽  
The Relationship

Abstract The object of the study was to analyze the relationship between aerobic fitness and body composition in postmenopausal women. We hypothesized that postmenopausal women that had higher adiposity had lower cardiorespiratory capacity, regardless of the characteristics of menopause. The sample included 208 women (57.57 ± 6.62 years), whose body composition and the basal metabolic rate were evaluated by octopolar bioimpedance (InBody 720) and the oxygen uptake by the modified Bruce protocol. Most of the sample showed obesity and a high visceral fat area. The visceral fat area and the basal metabolic rate explained 30% of the variation of oxygen uptake, regardless of age, time, nature or hormone therapy. The values of the latter variables were reduced in the presence of high central adiposity (-6.16 ml/kg/min) and the basal metabolic rate of less than 1238 kcal/day (-0.18 ml/kg/min). The women with oxygen uptake above 30.94 ml/kg/min showed lower values of total and central adiposity when compared with other groups. With an increase of aerobic fitness, there was a growing tendency of the average values of the soft lean mass index, with differences between the groups low-high and moderate-high. These results suggest worsening of the cardiorespiratory condition with an increase of central adiposity and a decrease of the BMR, regardless of age and menopause characteristics.

scholarly journals Vastus lateralis oxygenation during prolonged cycling in healthy males

2006 ◽  
Vol 31 (1) ◽  
pp. 48-55 ◽  
Author(s):  
Kotaro Kawaguchi ◽  
Yukiko Hayashi ◽  
Kiyokazu Sekikawa ◽  
Mitsuru Tabusadani ◽  
Tsutomu Inamizu ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Oxygen Uptake ◽  
Blood Volume ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Vastus Lateralis ◽  
Muscle Oxygenation ◽  
Cardiovascular Drift ◽  
Systemic Oxygen ◽  
The Relationship

This study examined the relationship between acute cardiorespiratory and muscle oxygenation and blood volume changes during prolonged exercise. Eight healthy male volunteers (mean maximum oxygen uptake ([Formula: see text]O2max) = 41.6 ± 2.4 mL/kg/min) performed 60 min submaximal cycling at 50% [Formula: see text]O2max. Oxygen uptake ([Formula: see text]O2) was measured by indirect spirometry, cardiac output (CO) was estimated using a PortapresTM, and right vastus lateralis oxyhemoglobin/ myoglobin (oxyHb/Mb), deoxyhemoglobin/myoglobin (deoxyHb/Mb), and total hemoglobin/myoglobin (total Hb/Mb) were recorded using near-infrared spectroscopy (NIRS). After 40 min of exercise, there was a significant increase in [Formula: see text]O2 due to a significantly higher arteriovenous oxygen difference ((a - v)O2diff). After 30 min of exercise CO remained unchanged, but there was a significant decrease in stroke volume and a proportionate increase in heart rate, thus indicating the occurrence of cardiovascular drift. During the first few minutes of exercise, there was a decline in oxyHb/Mb and total Hb/Mb, whereas deoxyHb/Mb remained unchanged. Thereafter, oxyHb/Mb and total Hb/Mb increased systematically until the termination of exercise while deoxyHb/Mb declined. After 40 min of exercise, these changes were significantly different from the baseline values. There were no significant correlations between the changes in the NIRS variables and systemic [Formula: see text]O2 or mixed (a - v)O2diff during exercise. These results suggest that factors other than localized changes in muscle oxygenation and blood volume account for the increased [Formula: see text]O2 during prolonged submaximal exercise. Key words: near infrared spectroscopy, cardiovascular drift, systemic oxygen consumption.

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