title: Carbohydrate mouth rinse and caffeine improves high-intensity interval running capacity when carbohydrate restricted.
abstract: We tested the hypothesis that carbohydrate mouth rinsing, alone or in combination with caffeine, augments high-intensity interval (HIT) running capacity undertaken in a carbohydrate-restricted state. Carbohydrate restriction was achieved by performing high-intensity running to volitional exhaustion in the evening prior to the main experimental trials and further refraining from carbohydrate intake in the post-exercise and overnight period. On the subsequent morning, eight males performed 45-min steady-state (SS) exercise (65% [Formula: see text]) followed by HIT running to exhaustion (1-min at 80% [Formula: see text]interspersed with 1-min walking at 6 km/h). Subjects completed 3 trials consisting of placebo capsules (administered immediately prior to SS and immediately before HIT) and placebo mouth rinse at 4-min intervals during HIT (PLACEBO), placebo capsules but 10% carbohydrate mouth rinse (CMR) at corresponding time-points or finally, caffeine capsules (200 mg per dose) plus 10% carbohydrate mouth rinse (CAFF + CMR) at corresponding time-points. Heart rate, capillary glucose, lactate, glycerol and NEFA were not different at exhaustion during HIT (P > 0.05). However, HIT capacity was different (P < 0.05) between all pair-wise comparisons such that CAFF + CMR (65 ± 26 min) was superior to CMR (52 ± 23 min) and PLACEBO (36 ± 22 min). We conclude that carbohydrate mouth rinsing and caffeine ingestion improves exercise capacity undertaken in carbohydrate-restricted states. Such nutritional strategies may be advantageous for those athletes who deliberately incorporate elements of training in carbohydrate-restricted states (i.e. the train-low paradigm) into their overall training programme in an attempt to strategically enhance mitochondrial adaptations of skeletal muscle.
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Andreas M
authors.initials: AM
authors.lastname: Kasper
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Scott
authors.initials: S
authors.lastname: Cocking
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Molly
authors.initials: M
authors.lastname: Cockayne
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Marcus
authors.initials: M
authors.lastname: Barnard
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Jake
authors.initials: J
authors.lastname: Tench
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Liam
authors.initials: L
authors.lastname: Parker
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: John
authors.initials: J
authors.lastname: McAndrew
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Carl
authors.initials: C
authors.lastname: Langan-Evans
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: Graeme L
authors.initials: GL
authors.lastname: Close
authors.affiliation: a Research Institute for Sport and Exercise Sciences, Liverpool John Moores University , Liverpool , UK.
authors.forename: James P
authors.initials: JP
authors.lastname: Morton
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001786:Blood Glucose / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology*; D004040:Dietary Carbohydrates; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D009067:Mouthwashes / Q000494:pharmacology*; D010807:Physical Endurance / Q000187:drug effects; D012420:Running / Q000502:physiology*; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D009067:Mouthwashes; D002110:Caffeine
keywords: HIT; Train-low; fatigue; mouth rinse