Effects of Different Beverages Consumption on 21 km Running Performance and Physiological Functions in Female Recreational Marathon Runners / 中国运动医学杂志

ABSTRACT

Objective To compare the effect of a carbohydrate-electrolyte-protein solution (CEPS,2％ protein plus 4％ carbohydrate),carbohydrate-electrolyte solution (CES,6％ carbohydrate),and non-caloric sweetened placebo (PLA)on 21 km running performance of female recreational marathon runners.Methods In a randomized cross-over design,12 female recreational marathon runners (age33.4 ± 2.1 years,body mass index21.10 ± 0.6 kg/m2,and maximal oxygen consumption48.5 ± 1.9 mL/kg/min)performed a 21 km time trial (TT)run on three occasions separated by at least 28 days.During the first 5 km,participants ran on the treadmill with 70％VO2max.Thereafter,the participants ran at whatever speed they wished for the remaining 16 km of the performance run.In each main trial,participants ingested the CEPS,CES,or PLA at a rate of 150 mL every 2.5 km.The blood samples,gas samples,heart rate,core temperature,and subjective measures were conducted every 5 km throughout the exercise.Results Time of TT run completion was slightly shorter (P ＜ 0.05)in the CES trial (97.8 ±1.6 min)than in the PLA trial (102.4 ± 2.4 min),with no significant differences between the CEPS trial (100.7 ± 2.9 min)and the other two trials (P＞0.05).There were no differences in core temperature,blood lactate,heart rate,CHO oxidation rate,fat oxidation rate,CHO oxidation amount,and fat oxidation amount among the different trials (all P＞0.05).The average blood glucose was higher in CES trial than PLA trial (P＜0.05).The average respiratory exchange rate was higher in CEPS trim than PLA trial (P＜0.05).Conclusion Compared with ingesting the PLA,ingesting the 6％ CES improves the 21 km TT run performance in recreational female runners.However,no additional benefit of CEPS was observed on endurance performance.