Balance of carbohydrate and lipid utilization during exercise: the "crossover" concept.

@article{Brooks1994BalanceOC,
  title={Balance of carbohydrate and lipid utilization during exercise: the "crossover" concept.},
  author={George A Brooks and Jacques Mercier},
  journal={Journal of applied physiology},
  year={1994},
  volume={76 6},
  pages={
          2253-61
        }
}
The "crossover" concept represents a theoretical means by which one can understand the effects of exercise intensity and prior endurance training on the balance of carbohydrate (CHO) and lipid metabolism during sustained exercise. According to the crossover concept, endurance training results in muscular biochemical adaptations that enhance lipid oxidation as well as decrease the sympathetic nervous system responses to given submaximal exercise stresses. These adaptations promote lipid… 
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References

SHOWING 1-10 OF 56 REFERENCES
Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration.
TLDR
It is concluded that, whereas carbohydrate availability is regulated directly in relation to exercise intensity, the regulation of lipid metabolism seems to be more complex.
Metabolism of substrates: energy substrate metabolism during exercise and as modified by training.
The question of what is the source of fuel for oxidation by muscle during exercise has been addressed. A review of experiments spanning more than 60 years supports the concept that the major energy…
Metabolism of substrates: energy substrate metabolism during exercise and as modified by training.
TLDR
Endurance training results in a shift of the metabolism toward a greater use of fat during the same absolute and relative exercise loads, which produces a glycogen sparing that is associated with improving endurance capacity.
Effect of prolonged exercise on muscle citrate concentration before and after endurance training in men.
TLDR
The lower G-6-P concentration after training suggests that the training-induced reduction in carbohydrate utilization results from attenuation of flux before the PFK step in glycolysis and is not due to citrate-mediated inhibition of PFK.
Effect of endurance training on plasma free fatty acid turnover and oxidation during exercise.
TLDR
E endurance exercise training results in decreased plasma FFA turnover and oxidation during a 90- to 120-min bout of submaximal exercise because of a slower rate of FFA release from adipose tissue.
Endurance training decreases plasma glucose turnover and oxidation during moderate-intensity exercise in men.
TLDR
To assess the effects of endurance training on plasma glucose kinetics during moderate-intensity exercise in men, seven men were studied before and after 12 wk of strenuous exercise training to determine glucose turnover and oxidation.
Gender differences in substrate for endurance exercise.
TLDR
It is concluded that, during moderate-intensity long-duration exercise, females demonstrate greater lipid utilization and less carbohydrate and protein metabolism than equally trained and nourished males.
Adaptations of skeletal muscle to endurance exercise and their metabolic consequences.
  • J. Holloszy, E. Coyle
  • Biology
    Journal of applied physiology: respiratory, environmental and exercise physiology
  • 1984
TLDR
The major metabolic consequences of the adaptations of muscle to endurance exercise are a slower utilization of muscle glycogen and blood glucose, a greater reliance on fat oxidation, and less lactate production during exercise of a given intensity.
Metabolic adaptations to training precede changes in muscle mitochondrial capacity.
TLDR
It is concluded that, in the voluntary exercising human, altered metabolic events are an early adaptive response to training and need not be accompanied by changes in muscle mitochondrial capacity.
Level of physical fitness and adipocyte lipolysis in humans.
TLDR
Results indicate that training increases suprailiac fat cell lipolysis, which seems to adapt maximally within about 4 mo, and the amount of training required to induce maximal adaptation in humans is identified.
...
...