title: Carbohydrate electrolyte solutions enhance endurance capacity in active females.
abstract: The purpose of the present study was to investigate the effects of supplementation with a carbohydrate-electrolyte solution (CES) in active females during a prolonged session of submaximal running to exhaustion. Eight healthy active females volunteered to perform a session of open-ended running to exhaustion at 70% of their maximal oxygen consumption on a treadmill during the follicular phase of their menstrual cycle on two occasions. During each run, the subjects consumed either 3mL·kg(-1) body mass of a 6% CES or a placebo drink (PL) every 20 min during exercise. The trials were administered in a randomized double-blind, cross-over design. During the run, the subjects ingested similar volumes of fluid in two trials (CES: 644 ± 75 mL vs. PL: 593 ± 66 mL, p > 0.05). The time to exhaustion was 16% longer during the CES trial (106.2 ± 9.4 min) than during the PL trial (91.6 ± 5.9 min) (p < 0.05). At 45 min during exercise, the plasma glucose concentration in the CES trial was higher than that in PL trial. No differences were observed in the plasma lactate level, respiratory exchange ratio, heart rate, perceived rate of exertion, sensation of thirst, or abdominal discomfort between the two trials (p > 0.05). The results of the present study confirm that CES supplementation improves the moderate intensity endurance capacity of active females during the follicular phases of the menstrual cycle. However, the exogenous oxidation of carbohydrate does not seem to explain the improved capacity after CES supplementation.
authors.affiliation: Department of Health and Physical Education, Hong Kong Institute of Education, Rm D4-2/F-13, 10 Lo Ping Road, Tai Po, Hong Kong, 00852, China. fhsun@ied.edu.hk.
authors.forename: Feng-Hua
authors.initials: FH
authors.lastname: Sun
authors.affiliation: Department of Sports Science and Physical Education, Chinese University of Hong Kong, G08, Kwok Sports Building, Chinese University of Hong Kong, Shatin, Hong Kong, 00852, China. hsswong@cuhk.edu.hk.
authors.forename: Stephen Heung-Sang
authors.initials: SH
authors.lastname: Wong
authors.affiliation: Department of Health and Physical Education, Hong Kong Institute of Education, Rm D4-2/F-13, 10 Lo Ping Road, Tai Po, Hong Kong, 00852, China. shchen@ied.edu.hk.
authors.forename: Shi-Hui
authors.initials: SH
authors.lastname: Chen
authors.affiliation: Department of Sports Science and Physical Education, Chinese University of Hong Kong, G08, Kwok Sports Building, Chinese University of Hong Kong, Shatin, Hong Kong, 00852, China. ericpoontc@gmail.com.
authors.forename: Tsz-Chun
authors.initials: TC
authors.lastname: Poon
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000378:metabolism / Q000494:pharmacology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D004573:Electrolytes / Q000494:pharmacology*; D005221:Fatigue / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008597:Menstrual Cycle; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology; D005082:Physical Exertion; D012420:Running / Q000502:physiology*; D012996:Solutions
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004573:Electrolytes; D012996:Solutions
keywords: exercise to exhaustion; follicular phase; running