Mirjam Limmer, Angi Diana Eibl, Petra Platen
Journal: Journal of the International Society of Sports Nutrition 2018;15(1):25
PMID: 29855319
Alkaline diets and supplements have recently gained attention as a means to bring balance to the overly acidic Western diet. While the effects of the acid-base balance of diets on high-intensity athletic performance have not yet been extensively researched, it is hypothesised an acidizing diet can reduce exercise performance during anaerobic activities. The aim of this randomised, single-blind, crossover trial was to investigate the influence of an acidising or alkalising diet on 400-m sprint performance among 14 moderately trained students. Participants completed a baseline 400-m sprint and were then randomised to consume either an acidising or alkalising diet for four days. Each intervention period concluded with a 400-m sprint and a three-day washout period. Blood lactate concentrations, blood gas parameters and urinary pH were measured to determine extracellular buffering capacity. This study found the alkalising diet improved 400-m sprint time and higher blood lactate significantly compared with the acidising diet. Blood pH values remained unchanged between groups. Based in these results, the authors conclude it is possible to improve anaerobic exercise performance through alkalisation through diet rather than supplementation.
BACKGROUND
Sodium bicarbonate (NaHCO) is an alkalizing agent and its ingestion is used to improve anaerobic performance. However, the influence of alkalizing nutrients on anaerobic exercise performance remains unclear. Therefore, the present study investigated the influence of an alkalizing versus acidizing diet on 400-m sprint performance, blood lactate, blood gas parameters, and urinary pH in moderately trained adults.
METHODS
In a randomized crossover design, eleven recreationally active participants (8 men, 3 women) aged 26.0 ± 1.7 years performed one trial under each individual's unmodified diet and subsequently two trials following either 4 days of an alkalizing (BASE) or acidizing (ACID) diet. Trials consisted of 400-m runs at intervals of 1 week on a tartan track in a randomized order.
RESULTS
We found a significantly lower 400-m performance time for the BASE trial (65.8 ± 7.2 s) compared with the ACID trial (67.3 ± 7.1 s; p = 0.026). In addition, responses were significantly higher following the BASE diet for blood lactate (BASE: 16.3 ± 2.7; ACID: 14.4 ± 2.1 mmol/L; p = 0.32) and urinary pH (BASE: 7.0 ± 0.7; ACID: 5.5 ± 0.7; p = 0.001).
CONCLUSIONS
We conclude that a short-term alkalizing diet may improve 400-m performance time in moderately trained participants. Additionally, we found higher blood lactate concentrations under the alkalizing diet, suggesting an enhanced blood or muscle buffer capacity. Thus, an alkalizing diet may be an easy and natural way to enhance 400-m sprint performance for athletes without the necessity of taking artificial dietary supplements.
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