Journal Title (Medline/Pubmed accepted abbreviation): J. Sports Sci. Med.
Summary of background and research design
Background: Docosahexaenoic acid (DHA) is an omega-3 fatty acid found in fish oil. It has been shown to increase performance, but the mechanism is unknown. Because of the effects DHA has shown with neural development and neural functioning (including the brain), one hypothesis is that this is at least part of the mechanism by which DHA improves sports performance.
Hypothesis: DHA will improve the accuracy of participants in a test of complex reaction time (also called decision-reaction time) and delay fatigue in elite soccer players.
Subjects: 34 elite professional female soccer players from 2 Spanish soccer leagues, age 21.2 ± 2.6 yrs old.
Experimental design: randomized, double-blind, placebo-controlled. The Levante team was assessed at the end of the season, the Valencia team was assessed at the beginning of the next season.
Treatments:The subjects of 5 daily capsules containing 700 mg of DHA or a placebo (olive oil) per day with breakfast, for a total daily dose of 3.5 g.
Protocol:Participants consumed the supplements for 4 wks. At the beginning and the end of the supplementation period, the participants completed 7-day dietary records and assessments of complex reaction efficiency (time and accuracy). The complex reaction time assessment involved a simulation of driving large machinery. The participants had buttons and pedals and received visual and auditory input, with instructions on which buttons/pedals to push when. The computer program assessed accuracy and speed of their reactions, which were used to calculate efficiency.
Summary of research findings
- The participants that consumed DHA improved on the complex reaction time assessment in regard to both efficiency and time, but not accuracy.
Interpretation of findings/Key practice applications
Increased intake of DHA may improve reaction time, which may improve sports performance.
The presentation of data in Table 1 is difficult to interpret. There are no unit labels presented for the data shown in the table and there was no explanation in the text of the article how the accuracy or efficiency values were determined. It is also confusing in that the text of the Results section described the accuracy being decreased by DHA supplementation, but the accuracy values reported in Table 1 increase from pretest to posttest. Without some indication of how these values were determined (i.e., Is a larger score an improvement or detriment in accuracy?), it is difficult to interpret these data.