Thyroid hormones response in simulated laboratory sprint duathlon

José Ramón Alvero-Cruz, Mauro Ronconi, Margarita Carrillo de Albornoz, Jerónimo C. García Romero, Daniel Rosado Velázquez, Mario de Diego Acosta


Increased activity of the pituitary-thyroid axis, plays a role in adaptations to exercise. The aim of this study was to assess changes in thyroid hormones (TH) in a simulated laboratory competition of sprint duathlon. Eight duathletes trained males [mean (SD), age 24.8 (6.8) years, height 174.4 (6.8) cm, body mass 67.12 (8.1) kg] participate in this study. The duathletes performed two graded maximal exercise in random order, one on cycle-ergometer and other on a treadmill, to determine their VO2peak. Simulated laboratory competition was carried out during 20 min Run1, 40 min Bike and 12 min Run2 sectors. A blood sample was drawn to determine serum concentrations of TSH, T4, T3 and were analyzed by chemiluminiscence. A one-way analysis of variance (ANOVA) was used to analyze differences among sectors and Pearson correlation coefficients were calculated between TH and exercise intensity. Athletes perform a high intensity exercise reaching high mean values of aerobic power (89.6 ± 6.1, 85.1 ± 8.7 and 87.1 ± 6.9 of %VO2 in Run1, Bike and Run2 respectively). TSH shown differences between -30 min and Run2 (p< 0.05), and did not found changes in T3 and T4 during exercise (p>0.05). Significant inverse correlations between T3 (r= -0.86) and T4 (r= -0.86) and percent VO2 (p


Duathlon sprint; Thyroid hormones


Carrillo De Albornoz Gil, M. TSH and free thyroid hormones changes during incremental maximal aerobic exercise. [PhD thesis]. Málaga: University of Málaga, 2010.

Ciloglu, F., Peker, I., Pehlivan, A., Karacabey, K., Ilhan, N., Saygin, O., Et Al. Exercise intensity and its effects on thyroid hormones. Neuro Endocrinol Lett. 2005; 26(6):830-4.

Gullu, S., Altuntas, F., Dincer, I., Erol, C., Kamel, N. Effects of TSH-suppressive therapy on cardiac morphology and function: beneficial effects of the addition of beta-blockade on diastolic dysfunction. Eur J Endocrinol. 2004; 150:655-61.

Edwards, J.G., Bahl, J.J., Flink, I.L., Cheng, Y.S., Morkin, E. Thyroid hormone influences beta myosin heavy chain (beta MHC) expression. Biochem Biophys Res Commun. 1994; 199:1482-1488.

Koistinen, P., Martikkala, V., Karpakka, J., Vuolteenaho, O., Leppäluoto, J. The effects of moderate altitude on circulating thyroid hormones and thyrotropin in training athletes. J Sports Med Phys Fitness. 1996; 36:108-111.

Lucia, A., Hoyos, J., Pérez, M., Chicharro, J. Thyroid hormones may influence de slow component of VO2 in professional cyclist. Japan J Physiol. 2001; 51:239-242.

Miller, R.G., Boska, M.D., Moussavi, R.S., Carson, P.J., Weiner, M.W. Nuclear magnetic resonance studies of high energy phosphates and pH in human muscle fatigue. Comparison of aerobic and anaerobic exercise. J Clin Invest. 1988; 81:1190-1196.

Pakarinen, A., Hakkinen, K., Alen, M. Serum thyroid hormones, thyrotropin and thyroxin binding globulin in elite athletes during very intense strength training in of one week. J Sports Med Phys Fitness. 1991; 31:142-6.

Ronconi, M., Alvero-Cruz, J.R. Heart rate and oxygen uptake responses in duathlon's sprint competition. Apunts Med Esport. 2011 (accepted).


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