Document Detail

Muscle power and metabolism in maximal intermittent exercise.
MedLine Citation:
PMID:  3700299     Owner:  NLM     Status:  MEDLINE    
Muscle power and the associated metabolic changes in muscle were investigated in eight male human subjects who performed four 30-s bouts of maximal isokinetic cycling at 100 rpm, with 4-min recovery intervals. In the first bout peak power and total work were (mean +/- SE) 1,626 +/- 102 W and 20.83 +/- 1.18 kJ, respectively; muscle glycogen decreased by 18.2 mmol/kg wet wt, lactate increased to 28.9 +/- 2.7 mmol/kg, and there were up to 10-fold increases in glycolytic intermediates. External power and work decreased by 20% in both the second and third exercise periods, but no further change occurred in the fourth bout. Muscle glycogen decreased by an additional 14.8 mmol/kg after the second exercise and thereafter remained constant. Muscle adenosine triphosphate (ATP) was reduced by 40% from resting after each exercise period; creatine phosphate (CP) decreased successively to less than 5% of resting; in the recovery periods ATP and CP increased to 76 and 95% of initial resting levels, respectively. Venous plasma glycerol increased linearly to 485% of resting; free fatty acids did not change. Changes in muscle glycogen, lactate, and glycolytic intermediates suggested rate limitation at phosphofructokinase during the first and second exercise periods, and phosphorylase in the third and fourth exercise periods. Despite minimal glycolytic flux in the third and fourth exercise periods, subjects generated 1,000 W peak power and sustained 400 W for 30 s, 60% of the values recorded in the first exercise period.(ABSTRACT TRUNCATED AT 250 WORDS)
N McCartney; L L Spriet; G J Heigenhauser; J M Kowalchuk; J R Sutton; N L Jones
Related Documents :
3698159 - Supercompensation of muscle glycogen in trained and untrained subjects.
3547009 - Effect of pre-exercise carbohydrate feedings on endurance cycling performance.
10069389 - Application of metabolic control analysis to the study of toxic effects of copper in mu...
25488849 - Effects of respiratory muscle and endurance training using an individualized training d...
3132449 - Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion.
22349209 - Acute effects of a caffeine-taurine energy drink on repeated sprint performance of coll...
11466439 - Circulating insulin-like growth factor i mediates the protective effects of physical ex...
12485319 - Time efficacy of a single dose of montelukast on exercise-induced asthma in children.
16727979 - Breed and other effects on reproductive traits and breeding soundness categorization in...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  60     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1986 Apr 
Date Detail:
Created Date:  1986-06-09     Completed Date:  1986-06-09     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1164-9     Citation Subset:  IM; S    
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Acid-Base Equilibrium
Adenosine Triphosphate / metabolism
Energy Metabolism
Glycerol / blood
Glycogen / metabolism
Muscle Contraction*
Muscles / metabolism*
Oxygen Consumption
Phosphocreatine / metabolism
Physical Exertion*
Triglycerides / metabolism
Reg. No./Substance:
0/Triglycerides; 56-65-5/Adenosine Triphosphate; 56-81-5/Glycerol; 67-07-2/Phosphocreatine; 9005-79-2/Glycogen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Cutaneous vascular responses to heat simulated at a high altitude of 5,600 m.
Next Document:  Intramuscular and surface electromyogram changes during muscle fatigue.