Responses of blood hormones to the maximal rowing ergometer test in college rowers
Jurimae, J.; Jurimae, T.
Journal of Sports Medicine and Physical Fitness 41(1): 73-77
2001
ISSN/ISBN: 0022-4707 PMID: 11317151 Document Number: 540165
The purposes of this study were to investigate the resting levels and the acute hormonal response of total testosterone (Ttot), free testosterone (Tfree), cortisol (C) and Tfree : C ratio to the 6-minute "all-out" rowing ergometer test. A cross-sectional study was conducted to investigate the responses of blood hormones to the maximal rowing ergometer test in college rowers. Eight college level male rowers (22.0+or-2.8 yrs, 191.8+or-4.1 cm, 85.4+or-4.3 kg, BMI: 23.2+or-1.3 kg.m-2) took part in this investigation. A graded exercise test at the intensities of 150, 200 and 250 W (6-minute each) and a 6-minute "all-out" test on a rowing ergometer (Concept II, Morrisville, USA) were performed at separate measurement sessions. Heart rate (HR) was recorded at the end of each load during a graded exercise test. Individual physical working capacity of rowers was calculated at the maximum HR recorded during a 6-minute "all-out" test. Venous blood samples were obtained 3 minutes before and immediately after the 6-minute "all-out" test to determine the concentration of Ttot, Tfree, Tfree : C ratio, glucose and lactate (LA) in blood. Results. Mean power was 354.3+or-26.8 W and HR 190.9+or-5.1 beats.min-1 during the "all-out" test. Mean blood LA concentration at the end of the "all-out" test was 13.46+or-1.44 mmol.l-1. The "all-out" test on the rowing ergometer did not change significantly the concentration of Ttot (before: 17.54+or-4.34; after: 20.03+or-4.80 nmol.l-1), Tfree (before: 0.423+or-0.111; after: 0.436+or-0.112), C (before: 477.50+or-119.34; after: 477.63+or-132.51 nmol.l-1) and Tfree : C ratio (before: 0.922+or-0.282; after: 0.973+or-0.320x10-3). The transformation of these hormone values to effect sizes (ES) demonstrated that "all-out" test only moderately (ES<0.61) influenced these hormone levels. Significant relationships were observed between the resting levels of Ttot and Tfree, and mean power of the 6-minute "all-out" test (r=0.65 and r=0.86, respectively). There was a non-significant increase in the level of Ttot following the "all-out" rowing ergometer test which was significantly related to mean power (r=0.73) and covered distance (r=0.67). The results suggest that there are no significant changes in hormone levels during a 6-minute "all-out" rowing ergometer test. However, rowing performance is positively related to the resting values of Ttot and Tfree, and the non-significant changes in Ttot level following a 6-minute "all-out" test.