title: Diet-induced metabolic acidosis and the performance of high intensity exercise in man.
abstract: The influence of four isolated periods of dietary manipulation upon high intensity exercise capacity was investigated in six healthy male subjects. Subjects consumed their 'normal' (N) diet (45 +/- 2% carbohydrate (CHO), 41 +/- 3% fat, 14 +/- 3% protein) for four days after which they exercised to voluntary exhaustion at a workload equivalent to 100% VO2max. Three further four-day periods of dietary manipulation took place; these were assigned in a randomised manner and each was followed by a high intensity exercise test. The dietary treatments were: a low CHO (3 +/- 1%), high fat (71 +/- 5%), high protein (26 +/- 3%) diet (HFHP); a high CHO (73 +/- 2%), low fat (12 +/- 2%), normal protein (15 +/- 1%) diet (HCLF); and a normal CHO (47 +/- 3%), low fat (27 +/- 2%), high protein (26 +/- 2%) diet (LFHP). Acid-base status and blood lactate concentration were measured on arterialised-venous blood at rest prior to dietary manipulation on each day of the different diets, immediately prior to exercise and at 2, 4, 6, 10 and 15 min post-exercise. Other metabolite concentrations were measured in the blood samples obtained prior to dietary manipulation and immediately prior to exercise. Exercise time to exhaustion after the HFHP diet (179 +/- 63 s) was shorter when compared with the N (210 +/- 65 s; p less than 0.01) and HCLF (219 +/- 69 s; p less than 0.05) diets.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Environmental & Occupational Medicine, University Medical School, Aberdeen, Scotland.
authors.forename: P L
authors.initials: PL
authors.lastname: Greenhaff
authors.forename: M
authors.initials: M
authors.lastname: Gleeson
authors.forename: R J
authors.initials: RJ
authors.lastname: Maughan
mesh_terms: D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000378:metabolism*; D004032:Diet; D004573:Electrolytes / Q000097:blood; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D008297:Male; D005082:Physical Exertion
chemical_list: D004573:Electrolytes; D007773:Lactates