Effects of glucose–fructose versus glucose ingestion on stride characteristics during prolonged treadmill running

Abstract

Scarce research has examined the effects of carbohydrate composition on running stride characteristics. On two occasions, 14 males and 6 females completed a 120-min sub-maximal run followed by a 4-mile time trial. Participants consumed glucose (GLU) or glucose–fructose (GLU–FRU) beverages supplying 1.3 g/min carbohydrate. Substrate use, psychological affect [Feeling Scale (FS)], and stride characteristics (stride frequency, stride length, and contact time) were assessed. Effects were expressed as Cohen’s d (90% confidence limits [90% CL]). CLs for stride frequency differences at 53 min (90% CL = 0.04–0.21) and 113 min (90% CL = 0.02–0.24) did not cover 0, indicating a positive effect of GLU–FRU. However, effect sizes were small (d = 0.13) and likely-to-very-likely trivial. Energy expenditure differences at sub-maximal end were very likely trivial (d = 0.08; 90% CL = 0.00–0.17), while FS ratings were possibly higher for GLU–FRU at 50 (d = 0.19; 90% CL = −0.10–0.48) and 110 min (d = 0.16; 90% CL = −0.13–0.45). During the time trial, stride length was possibly higher with GLU–FRU (d = 0.13; 90% CL = −0.08–0.33). Glucose–fructose co-ingestion has no significant effect on stride characteristics during constant-velocity running but may result in slightly higher stride length during self-paced running.