Hawley, J. A., Palmer, G. S., & Noakes, T. D. (1997). No effect of carbohydrate loading on 1 hr cycle performance. Medicine and Science in Sports and Exercise, 29(5), Supplement abstract 1279.

The effects of supplementing normal diets of trained cyclists (N = 6) with additional carbohydrate (CHO increased by 57%) on muscle glycogen utilization during a 1-hour cycling time trial were investigated.

Despite increased muscle glycogen in the CHO-supplement group prior to performance, there was no difference between the conditions in distance cycled during the time trial. Both muscle glycogen utilization and total CHO oxidation were similar under both dietary conditions.

It was concluded that CHO supplementation did not produce performance benefits for completing intense, continuous exercise for one hour.

Implication. There may be some interaction of event, individual, level of original CHO intake, and state of training that does not foster CHO supplementation being a beneficial factor. As with any dietary regimen, experimentation and assessment of effect and value needs to be conducted before it becomes an entrenched procedure for every individual.

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