Blood metabolic profiling associated with a short-term intensive training period in elite male water polo athletes: an exploratory metabolomics study.

A total of 363 metabolites were identified in serum samples, of which 33 were differentially expressed between pre- and post-training time points.

• Sixteen elite male water polo athletes from the Chinese national team were recruited.
• Blood samples were collected at 7:00 AM at two time points: before (E1) and immediately after (E2) one week of official training.
• Athletes underwent a one-week complete break prior to E1 to establish a resting metabolic baseline.
• Non-targeted LC-MS/MS was used for metabolic profiling, with data analyzed via XCMS, MetaboAnalyst 6.0, SPSS 21.0, and GraphPad Prism.

After one week of routine training, 11 metabolites were significantly up-regulated and 22 were significantly down-regulated.

• All differential metabolites met a significance threshold of p < 0.01.
• Up-regulated metabolites numbered 11 and down-regulated metabolites numbered 22 out of the 33 total differentially expressed metabolites.
• The study design was a within-subject pre-post comparison with n = 16 athletes.

KEGG pathway analysis identified the top eight metabolic pathways altered by training, with lysine degradation and vitamin B6 metabolism highlighted as key pathways.

• MetPA (Metabolite Pathway Analysis) was used to further highlight the key pathways.
• Lysine degradation was significantly altered at p < 0.01.
• Vitamin B6 metabolism was significantly altered at p < 0.05.
• Overall findings pointed to adjustments in amino acid and lipid metabolism.

Three metabolites were identified as potential markers of training-week changes in water polo athletes.

• N6,N6,N6-trimethyl-L-lysine was significantly decreased post-training (p < 0.01).
• 2-aminoadipic acid was significantly decreased post-training (p < 0.01).
• 4-pyridoxic acid was significantly increased post-training (p < 0.01).
• These three metabolites were selected on the basis of significant alterations post-training.

Non-targeted LC-MS/MS metabolomics was identified as a valuable tool for monitoring metabolic adaptations at the molecular level in aquatic athletes.

• The study was described as an exploratory pilot study.
• Findings offer preliminary insights for guiding fitness and performance optimization in elite athletes.
• The metabolic changes observed were associated with adjustments in amino acid and lipid metabolism following intensive training.