Dietary effects on exercising muscle metabolism and performance by 31P-MRS
| Autor: | R. S. Fishman, R. L. Hesslink, D. E. Larson, M. I. Hrovat, David M. Systrom |
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| Rok vydání: | 1994 |
| Předmět: |
Adult
Male medicine.medical_specialty Magnetic Resonance Spectroscopy Physiology Respiratory physiology Phosphates Phosphocreatine chemistry.chemical_compound Oxygen Consumption Physiology (medical) Internal medicine Dietary Carbohydrates medicine Humans Respiratory system Exercise physiology Muscle Skeletal Exercise Respiratory exchange ratio Chemistry Skeletal muscle Dietary Fats Diet Endocrinology medicine.anatomical_structure Biochemistry Respiratory Mechanics Breathing Female Energy Metabolism Respiratory minute volume |
| Zdroj: | Journal of Applied Physiology. 77:1108-1115 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/jappl.1994.77.3.1108 |
| Popis: | To determine how diet modulates short-term exercise capacity, skeletal muscle pH and bioenergetic state were examined by 31P-magnetic resonance spectroscopy in nine healthy volunteers. Subjects performed incremental quadriceps exercise to exhaustion after 5 days of high-carbohydrate (HCHO) or high-fat (HFAT) diet randomly assigned in crossover fashion and separated by a 2.5-day period of ad libitum mixed diet. Simultaneous measurements were made of pulmonary gas exchange, minute ventilation, and quadriceps muscle pH and phosphorylation potential. At rest and peak exercise, respiratory exchange ratio and minute ventilation were higher after HCHO than after HFAT (P < 0.05), reflecting greater CHO utilization. Peak O2 consumption (VO2) was not increased after HCHO (P > 0.05), but exercise duration was (339 +/- 34 s for HCHO vs. 308 +/- 25 s for HFAT; P < 0.05). HCHO was associated with a blunted early fall of phosphocreatine (PCr)/Pi vs. VO2 (-4.1 +/- 0.7 x 10(-2) min/ml for HCHO vs. -5.6 +/- 1.2 x 10(-2) min/ml for HFAT; P < 0.05). On both study days, the slope of PCr/Pi vs. VO2, before and after the PCr threshold, was correlated with exercise time. The results suggest that a diet rich in CHO improves exercise efficiency through beneficial effects on intracellular phosphorylation potential. |
| Databáze: | OpenAIRE |
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