Apple puree effective natural alternative carbohydrate source for fuelling half-marathon running performance

Carbohydrate supplementation during endurance exercise is known to improve performance, but the effects of food-based approaches in running exercise are understudied. Therefore, K M Reynolds et al conducted a study to investigate the performance and gastrointestinal (GI) effects of a carbohydrate supplement containing a natural fructose source compared with a highly processed fructose source in a combined glucose-fructose supplement, during a half-marathon.

The study has been published in ‘European journal of sport science.’

Eleven trained runners (9 males, 2 females; age 32 ± 8 y, 89:53 ± 13:28 min half-marathon personal record) completed a familiarisation (8 miles) and two experimental trials (13.1 miles) on an outdoor running course, with blood and urine samples collected before and after the run. Subjective GI measures were made throughout the run. Carbohydrate was provided as a natural fructose source in the form of apple puree (AP) or highly processed crystalline fructose (GF) in a 2:1 glucose-to fructose ratio (additional required glucose was provided through maltodextrin). Participants and investigators directly relating to performance were blinded from the study’s aims until they had completed all visits.

Key results of the study were:

• There were no pre-trial differences for body mass (P = 0.460), urine specific gravity (P = 0.226), heart rate (P = 0.751), physiological (P ≥ 0.182), or subjective variables (P ≥ 0.211).

• Weather conditions were not different between carbohydrate sources: temperature, relative humidity and wind speed.

• Half-marathon performance was not different between carbohydrate sources (AP 89:52 ± 09:33 min, GF 88:44 ± 10:09 min; P = 0.684).

• There were no interaction effects for GI comfort (P = 0.305) or other GI symptoms (P ≥ 0.211).

• There were no differences between carbohydrate sources in ad libitum fluid intake (AP 409 ± 206 mL; GF 294 ± 149 mL; P = 0.094) or any other urinary (P ≥ 0.724), blood-based (P ≥ 0.215) or subjective (P ≥ 0.421) measures.

The authors concluded that – “Apple puree as a natural fructose (and to a lesser extent glucose) source provided an alternative to a highly processed fructose source to fuel prolonged running performance in trained runners. There were no elevated GI symptoms experienced in the apple puree trial compared to a highly processed fructose source and no differences in physiological parameters. Natural carbohydrate sources based on a fruit puree may provide a suitable alternative to traditional carbohydrate supplements for running distance of half-marathon or longer. Future research may need to investigate the impact of higher ingestion rates and/or longer durations, or more intense running exercise.”

Further reading:

Apple puree as a natural fructose source provides an effective alternative carbohydrate source for fuelling half-marathon running performance

Kirsty M. Reynolds et al

EUROPEAN JOURNAL OF SPORT SCIENCE 2023, VOL. 23, NO. 10, 2011–2020

https://doi.org/10.1080/17461391.2023.2207074