Comparison of the Metabolites of Water Polo Players before and after Competition by the Metabolomic Approach

BACKGROUND: The metabolic characteristics of body fluids of excellent water polo players before and after competition have not been reported. The purpose of the study was to compare the metabolites in the urine of water polo players before and after competition by (1)H-NMR-based metabolomic approach. METHODS: Twenty-six young water polo players participated in the study voluntarily. The urine and blood samples of players were collected one week before competition (A), immediately after competition (B), and one week after competition (C). Metabolomic analysis was conducted on the urine samples. Urine routine items and biochemical indicators in blood samples were detected. RESULTS: Metabolomic results showed that the contents of eleven metabolites including lactic acid, acetoacetate, and succinic acid in the urine of the subjects increased and four metabolites such as dimethylamine, choline, and glucose decreased at stage B. Most metabolites at stage C had basically returned to the levels at stage A. Pyruvate metabolism, pantothenate and CoA biosynthesis, synthesis, and degradation of ketone bodies were mainly involved in the above process. Urine conventional analysis results showed that the urine pH decreased dramatically and the levels of PRO and URO significantly increased at stage B, and the three indicators had similar values between stages A and C. The other indicators did not have obvious difference among the three stages. Analysis of blood biochemical indicators showed that the levels of LDH, BUN, CK, and AST significantly increased at stage B and did not show an obvious difference between stages A and C. The results are helpful for coaches to arrange the athletes' diet reasonably and to conduct scientific training for athletes.