title: Ecologically Valid Carbohydrate Intake during Soccer-Specific Exercise Does Not Affect Running Performance in a Fed State.
abstract: This study assessed the effect of carbohydrate intake on self-selected soccer-specific running performance. Sixteen male soccer players (age 23 ± 4 years; body mass 76.9 ± 7.2 kg; predicted VO2max= 54.2 ± 2.9 mL∙kg-1∙min-1; soccer experience 13 ± 4 years) completed a progressive multistage fitness test, familiarisation trial and two experimental trials, involving a modified version of the Loughborough Intermittent Shuttle Test (LIST) to simulate a soccer match in a fed state. Subjects completed six 15 min blocks (two halves of 45 min) of intermittent shuttle running, with a 15-min half-time. Blocks 3 and 6, allowed self-selection of running speeds and sprint times, were assessed throughout. Subjects consumed 250 mL of either a 12% carbohydrate solution (CHO) or a non-caloric taste matched placebo (PLA) before and at half-time of the LIST. Sprint times were not different between trials (CHO 2.71 ± 0.15 s, PLA 2.70 ± 0.14 s;p =0.202). Total distance covered in self-selected blocks (block 3: CHO 2.07 ± 0.06 km; PLA 2.09 ± 0.08 km; block 6: CHO 2.04 ± 0.09 km; PLA 2.06 ± 0.08 km;p =0.122) was not different between trials. There was no difference between trials for distance covered (p ≥0.297) or mean speed (p ≥0.172) for jogging or cruising. Blood glucose concentration was greater (p <0.001) at the end of half-time during the CHO trial. In conclusion, consumption of 250 mL of 12% CHO solution before and at half-time of a simulated soccer match does not affect self-selected running or sprint performance in a fed state.
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK. M.Funnell2@lboro.ac.uk.
authors.forename: Mark P
authors.initials: MP
authors.lastname: Funnell
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK. Nick.R.Dykes@gmail.com.
authors.forename: Nick R
authors.initials: NR
authors.lastname: Dykes
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK. Elliot_Owen@hotmail.co.uk.
authors.forename: Elliot J
authors.initials: EJ
authors.lastname: Owen
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK. S.A.Mears@lboro.ac.uk.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Mears
authors.affiliation: The Gatorade Sports Science Institute, PepsiCo Global Nutrition, Leicester LE3 9QH, UK. Ian.Rollo@Pepsico.com.
authors.forename: Ian
authors.initials: I
authors.lastname: Rollo
authors.affiliation: School of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire LE11 3TU, UK. L.James@lboro.ac.uk.
authors.forename: Lewis J
authors.initials: LJ
authors.lastname: James
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance; D001628:Beverages / Q000009:adverse effects*; D019422:Dietary Sucrose / Q000009:adverse effects*; D004311:Double-Blind Method; D004739:England; D015444:Exercise; D006801:Humans; D007534:Isomaltose / Q000009:adverse effects / Q000031:analogs & derivatives; D008297:Male; D064306:Non-Nutritive Sweeteners / Q000009:adverse effects; D064427:Nutritive Sweeteners / Q000009:adverse effects*; D005082:Physical Exertion; D011134:Polysaccharides / Q000009:adverse effects; D019518:Postprandial Period; D012420:Running; D012916:Soccer; D064133:Sports Nutritional Physiological Phenomena; D013395:Sucrose / Q000009:adverse effects / Q000031:analogs & derivatives; D013843:Thiazines / Q000009:adverse effects; D055815:Young Adult
chemical_list: D019422:Dietary Sucrose; D064306:Non-Nutritive Sweeteners; D064427:Nutritive Sweeteners; D011134:Polysaccharides; D013843:Thiazines; D013395:Sucrose; D007534:Isomaltose; C008315:maltodextrin; C026285:trichlorosucrose; C006362:acetosulfame; C008189:isomaltulose
keywords: LIST; ecological validity; endurance; sports drink; sprinting