What is the overall summary of this paragraph? Do you think that the structure of the two components of starch has any thing to do with the study results? Why? Why not?
Guezennec et al. (1993) studied the difference in carbohydrate oxidation during exercise when amylose and amylopectin were consumed prior to exercise. Amylopectin was oxidized more quickly during exercise than was the amylose. Goodpaster et al. (1996) tested whether high amylose or high amylopectin foods fed prior to endurance exercise had different effects on metabolism or performance when compared to placebo or glucose feedings. A lower glycemic response was seen for both starches compared to glucose during the 30 min prior to exercise. However, in contrast to the results of Guezennec et al. (1993), the starches did not differ from one another in their glycemic responses in this pre-exercise period. Furthermore, all carbohydrate treatments increased the reliance on carbohydrate as a fuel during exercise. When compared to the placebo, the high-amylopectin starch was as effective as the glucose feeding in enhancing endurance performance but, in spite of similar glycemic effects of the two starches, the increased amount of work done during the 90 min performance test when the high-amylose starch was consumed was not statistically significant from the placebo. The authors felt that the lower digestibility of the high-amylose starch contributed to its reduced benefit on exercise performance. This study did not support a benefit of a lower glycemic food, i.e., starch, over a higher glycemic food (glucose) fed prior to exercise.
What is the overall summary of this paragraph? Do you think that the structure of the two components of starch has any thing to do with the study results? Why? Why not?
Guezennec et al. (1993) studied the difference in carbohydrate oxidation during exercise when amylose and amylopectin were consumed prior to exercise. Amylopectin was oxidized more quickly during exercise than was the amylose. Goodpaster et al. (1996) tested whether high amylose or high amylopectin foods fed prior to endurance exercise had different effects on metabolism or performance when compared to placebo or glucose feedings. A lower glycemic response was seen for both starches compared to glucose during the 30 min prior to exercise. However, in contrast to the results of Guezennec et al. (1993), the starches did not differ from one another in their glycemic responses in this pre-exercise period. Furthermore, all carbohydrate treatments increased the reliance on carbohydrate as a fuel during exercise. When compared to the placebo, the high-amylopectin starch was as effective as the glucose feeding in enhancing endurance performance but, in spite of similar glycemic effects of the two starches, the increased amount of work done during the 90 min performance test when the high-amylose starch was consumed was not statistically significant from the placebo. The authors felt that the lower digestibility of the high-amylose starch contributed to its reduced benefit on exercise performance. This study did not support a benefit of a lower glycemic food, i.e., starch, over a higher glycemic food (glucose) fed prior to exercise.
