Effects of 120 vs. 60 and 90 g/h Carbohydrate Intake during a Trail Marathon on Neuromuscular Function and High Intensity Run Capacity Recovery.

BACKGROUND

Current carbohydrate (CHO) intake recommendations for ultra-trail activities lasting more than 2.5 h is 90 g/h. However, the benefits of ingesting 120 g/h during a mountain marathon in terms of post-exercise muscle damage have been recently demonstrated. Therefore, the aim of this study was to analyze and compare the effects of 120 g/h CHO intake with the recommendations (90 g/h) and the usual intake for ultra-endurance athletes (60 g/h) during a mountain marathon on internal exercise load, and post-exercise neuromuscular function and recovery of high intensity run capacity.

METHODS

Twenty-six elite trail-runners were randomly distributed into three groups: LOW (60 g/h), MED (90 g/h) and HIGH (120 g/h), according to CHO intake during a 4000-m cumulative slope mountain marathon. Runners were measured using the Abalakov Jump test, a maximum a half-squat test and an aerobic power-capacity test at baseline (T1) and 24 h after completing the race (T2).

RESULTS

Changes in Abalakov jump time (ABK), Abalakov jump height (ABK), half-squat test 1 repetition maximum (HST) between T1 and T2 showed significant differences by Wilcoxon signed rank test only in LOW and MED ( < 0.05), but not in the HIGH group ( > 0.05). Internal load was significantly lower in the HIGH group ( = 0.017) regarding LOW and MED by Mann Whitney test. A significantly lower change during the study in ABK ( = 0.038), ABK ( = 0.038) HST ( = 0.041) and in terms of fatigue ( = 0.018) and lactate ( = 0.012) within the aerobic power-capacity test was presented in HIGH relative to LOW and MED.

CONCLUSIONS

120 g/h CHO intake during a mountain marathon might limit neuromuscular fatigue and improve recovery of high intensity run capacity 24 h after a physiologically challenging event when compared to 90 g/h and 60 g/h.