Effect of Training Load Structure on Purine Metabolism in Middle-Distance Runners

• Autores: Jacek Zielinski, Krzysztof Kusy, Tadeusz Rychlewski
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 43, Nº. 9, 2011, págs. 1798-1807
• Idioma: inglés
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• Resumen

  • There are no studies analyzing the effect of training loads on purine metabolism during long training periods.

    Purpose: The study's purpose was to evaluate the effect of training load changes and subsequent detraining on purine metabolism in middle-distance runners during a 1-yr cycle.

    Methods: In four characteristic points of the training cycle, loads assigned to five intensity zones, pre- and postexercise plasma hypoxanthine (Hx) and uric acid, and erythrocyte Hx-guanine phosphoribosyltransferase (HGPRT) activity were determined in 11 male middle-distance runners at the national level, practicing competitive sport for 8.1 ± 0.3 yr and with a mean age of 22.3 ± 0.7 yr, body mass of 73.0 ± 3.4 kg, and body height of 180 ± 2.2 cm.

    Results: In the competition phase (CP), training loads in aerobic compensation and threshold zones decreased by 65.4% and by 20.5%, respectively. At the same time, anaerobic training loads increased by 132.5% in the V?O2max zone and by 74.6% in the lactic acid tolerance zone. Postexercise Hx decreased significantly in CP by 6.2 µmol·L-1 and increased in the transition phase (TP) by 17.4 µmol·L-1. Both pre- and postexercise HGPRT activity increased significantly in CP by 9.3 nmol·mg-1·h-1 and by 4.9 nmol·mg-1·h-1, respectively, and decreased significantly in TP by 10.6 nmol·mg-1·h-1 and by 12.0 nmol·mg-1·h-1, respectively. A significant uric acid increase of 54 µmol·L-1 was revealed merely in TP.

    Conclusions: The effect of anaerobic training on purine metabolism is significant despite of a very short total duration of anaerobic loads. Elevated preexercise HGPRT activity in CP suggests adaptation changes consisting in a "permanent readiness" for purine salvage. The detraining in TP leads to reverse adaptation changes. Probably, plasma Hx concentration and erythrocyte HGPRT activity may be considered as a useful measure of training status.