High-Intensity Interval Training Decreases Resting Urinary Hypoxanthine Concentration in Young Active Men—A Metabolomic Approach

Abstract

High-intensity interval training (HIIT) is known to improve performance and skeletal muscle energy metabolism. However, whether the body’s adaptation to an exhausting short-term HIIT is reflected in the resting human metabolome has not been examined so far. Therefore, a randomized controlled intervention study was performed to investigate the effect of a ten-day HIIT on the resting urinary metabolome of young active men. Fasting spot urine was collected before (−1 day) and after (+1 day; +4 days) the training intervention and 65 urinary metabolites were identified by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance (NMR) spectroscopy. Metabolite concentrations were normalized to urinary creatinine and subjected to univariate statistical analysis. One day after HIIT, no overall change in resting urinary metabolome, except a significant difference with decreasing means in urinary hypoxanthine concentration, was documented in the experimental group. As hypoxanthine is related to purine degradation, lower resting urinary hypoxanthine levels may indicate a training-induced adaptation in purine nucleotide metabolism.

The Effect of Training on Erythrocyte Energy Status and Plasma Purine Metabolites in Athletes

“…In highly-trained athletes, but not in the control group, the increased amount of intense training loads in the subsequent phases of the annual training cycle resulted in adaptive changes in plasma purine derivatives concentration. The significantly lowest levels of plasma Ino and Hx in the competition phase indicate either their reduced release from the skeletal muscle [20,21] or their more effective reutilization to IMP and further incorporation to the adenylate pool through a purine nucleotide cycle (not present in RBC) [22]. Our observation that high-intensity training brings about reduced purine loss is consistent with earlier findings.…”

“…Our observation that high-intensity training brings about reduced purine loss is consistent with earlier findings. Following a 1-and 4-day high-intensity interval training (HIIT), a decreased urinary Hx concentration was shown in young active men, signifying a training-induced adaptation in purine nucleotide metabolic pathways [21]. Stathis, et al [20] observed that in recreationally active individuals the skeletal muscle concentration of Ino was reduced after a 30-second sprint performance test after a seven-week sprint training, which indicated a reduction of exercise purine loss.…”

“…The second athletic group included sprint-trained men (SP; n = 11), aged 23.55 ± 3.27 (20-30) years, practicing competitive sport for 8.18 ± 0.98 (7-10) years, specializing in the 100 m, 200 m, and 4 × 100 m relay races. The control group consisted of recreationally-trained runners (RE; n = 11), aged 22.73 ± 2.15 (20)(21)(22)(23)(24)(25)(26) years, competing in half marathons, marathons, or road/cross-country running, but not subjected to a periodized training regimen. Over the research period, there were no significant differences between the studied groups as regards age (p = 0.737), body height (181.6 ± 3.20, 181.91 ± 8.36, and 183.91 ± 2.88 cm for EN, SP, and RE, respectively; p = 0.570), and training experience in competitive athletes (p = 0.875).…”

Targeted ultra‐performance liquid chromatography/tandem mass spectrometric quantification of methylated amines and selected amino acids in biofluids

“…The observed deviations may be in part artificial and are probably related to the applied background subtraction procedure, since no bias >10% was observed for isotope‐labelled compounds, for which no background subtraction was necessary. Moreover, a recent method comparison with 1 H‐NMR demonstrated excellent correlation in urine, with R 2 >0.87 for those compounds which were accessible with both methods . For plasma, the estimated accuracy was as good as for urine, at least for the majority of compounds.…”

“…Moreover, a recent method comparison with 1 H-NMR demonstrated excellent correlation in urine, with R 2 >0.87 for those compounds which were accessible with both methods. 48 For plasma, the estimated accuracy was as good as for urine, at least for the majority of compounds. However, some compounds showed a somewhat lower accuracy, especially those with histidine or arginine moieties.…”