PMID- 12902321
OWN - NLM
STAT- MEDLINE
DCOM- 20040108
LR  - 20181113
IS  - 0193-1849 (Print)
IS  - 1522-1555 (Electronic)
IS  - 0193-1849 (Linking)
VI  - 285
IP  - 6
DP  - 2003 Dec
TI  - Effects of depletion exercise and light training on muscle glycogen 
      supercompensation in men.
PG  - E1304-11
AB  - Supercompensated muscle glycogen can be achieved by using several carbohydrate 
      (CHO)-loading protocols. This study compared the effectiveness of two "modified" 
      CHO-loading protocols. Additionally, we determined the effect of light cycle 
      training on muscle glycogen. Subjects completed a depletion (D, n = 15) or 
      nondepletion (ND, n = 10) CHO-loading protocol. After a 2-day adaptation period 
      in a metabolic ward, the D group performed a 120-min cycle exercise at 65% peak 
      oxygen uptake (VO2 peak) followed by 1-min sprints at 120% VO2 peak to 
      exhaustion. The ND group performed only 20-min cycle exercise at 65% VO2 peak. 
      For the next 6 days, both groups ate the same high-CHO diets and performed 20-min 
      daily cycle exercise at 65% VO2 peak followed by a CHO beverage (105 g of CHO). 
      Muscle glycogen concentrations of the vastus lateralis were measured daily with 
      13C magnetic resonance spectroscopy. On the morning of day 5, muscle glycogen 
      concentrations had increased 1.45 (D) and 1.24 (ND) times baseline (P < 0.001) 
      but did not differ significantly between groups. However, on day 7, muscle 
      glycogen of the D group was significantly greater (p < 0.01) than that of the ND 
      group (130 +/- 7 vs. 104 +/- 5 mmol/l). Daily cycle exercise decreased muscle 
      glycogen by 10 +/- 2 (D) and 14 +/- 5 mmol/l (ND), but muscle glycogen was equal 
      to or greater than preexercise values 24 h later. In conclusion, a CHO-loading 
      protocol that begins with a glycogen-depleting exercise results in significantly 
      greater muscle glycogen that persists longer than a CHO-loading protocol using 
      only an exercise taper. Daily exercise at 65% VO2 peak for 20 min can be 
      performed throughout the CHO-loading protocol without negatively affecting muscle 
      glycogen supercompensation.
FAU - Goforth, Harold W Jr
AU  - Goforth HW Jr
AD  - Naval Health Research Center, San Diego, California 92186, USA.
FAU - Laurent, Didier
AU  - Laurent D
FAU - Prusaczyk, William K
AU  - Prusaczyk WK
FAU - Schneider, Kevin E
AU  - Schneider KE
FAU - Petersen, Kitt Falk
AU  - Petersen KF
FAU - Shulman, Gerald I
AU  - Shulman GI
LA  - eng
GR  - R01 DK049230/DK/NIDDK NIH HHS/United States
GR  - K-23 02734/PHS HHS/United States
GR  - R01 AG023686-01A1/AG/NIA NIH HHS/United States
GR  - P30 DK-45735/DK/NIDDK NIH HHS/United States
GR  - R01 DK-063192/DK/NIDDK NIH HHS/United States
GR  - R01 AG023686/AG/NIA NIH HHS/United States
GR  - P30 DK045735/DK/NIDDK NIH HHS/United States
GR  - R01 DK-49230/DK/NIDDK NIH HHS/United States
GR  - M01 RR-00125/RR/NCRR NIH HHS/United States
GR  - M01 RR000125/RR/NCRR NIH HHS/United States
PT  - Clinical Trial
PT  - Comparative Study
PT  - Controlled Clinical Trial
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PT  - Research Support, U.S. Gov't, P.H.S.
DEP - 20030805
PL  - United States
TA  - Am J Physiol Endocrinol Metab
JT  - American journal of physiology. Endocrinology and metabolism
JID - 100901226
RN  - 0 (Dietary Carbohydrates)
RN  - 9005-79-2 (Glycogen)
SB  - IM
MH  - Adaptation, Physiological/physiology
MH  - Adult
MH  - Dietary Carbohydrates/administration & dosage/*metabolism
MH  - Exercise/*physiology
MH  - Glycogen/*physiology
MH  - Humans
MH  - Male
MH  - Metabolic Clearance Rate
MH  - Muscle, Skeletal/*physiology
MH  - Physical Education and Training/*methods
MH  - Physical Endurance/*physiology
PMC - PMC2995524
MID - NIHMS251039
EDAT- 2003/08/07 05:00
MHDA- 2004/01/09 05:00
PMCR- 2010/12/01
CRDT- 2003/08/07 05:00
PHST- 2003/08/07 05:00 [pubmed]
PHST- 2004/01/09 05:00 [medline]
PHST- 2003/08/07 05:00 [entrez]
PHST- 2010/12/01 00:00 [pmc-release]
AID - 00209.2003 [pii]
AID - 10.1152/ajpendo.00209.2003 [doi]
PST - ppublish
SO  - Am J Physiol Endocrinol Metab. 2003 Dec;285(6):E1304-11. doi: 
      10.1152/ajpendo.00209.2003. Epub 2003 Aug 5.