Effect of low-dose combined oral contraceptive on aerobic capacity and anaerobic threshold level in active and sedentary young women☆
Received 6 October 2009; received in revised form 3 November 2009; accepted 9 November 2009. published online 07 December 2009.
Abstract
Background
The purpose of this study was to evaluate the effect of long-term use of oral contraceptives (OC) containing 0.20 mg of ethinylestradiol (EE) combined with 0.15 mg of gestodene (GEST) on the peak aerobic capacity and at the anaerobic threshold (AT) level in active and sedentary young women.
Study Design
Eighty-eight women (23±2.1 years old) were divided into four groups — active-OC (G1), active-NOC (G2), sedentary-OC (G3) and sedentary-NOC (G4) — and were submitted to a continuous ergospirometric incremental test on a cycloergometer with 20 to 25 W min−1 increments. Data were analyzed by two-way ANOVA with Tukey post hoc test. Level of significance was set at 5%.
Results
The OC use effect for the variables relative and absolute oxygen uptake V̇O2 mL kg−1 min−1; V̇O2, L min−1, respectively), carbon dioxide output (V̇CO2, L min−1), ventilation (VE, L min−1), heart rate (HR, bpm), respiratory exchange ratio (RER) and power output (W) data, as well as the interaction between OC use and exercise effect on the peak of test and at the AT level did not differ significantly between the active groups (G1 and G2) and the sedentary groups (G3 and G4). As to the exercise effect, for all variables studied, it was noted that the active groups presented higher values for the variables V̇O2, V̇CO2, VE and power output (p<.05) than the sedentary groups. The RER and HR were similar (p>.05) at the peak and at the AT level between G1 vs. G3 and G2 vs. G4.
Conclusions
Long-term use of OC containing EE 0.20 mg plus GEST 0.15 mg does not affect aerobic capacity at the peak and at the AT level of exercise tests.
aUniversidade Federal de São Carlos, 13565905 São Carlos-SP, Brazil
bUniversidade Metodista de Piracicaba, Faculdade de Ciências da Saúde, 13400911 Piracicaba-SP, Brazil
cUniversidade de São Paulo, Faculdade de Medicina de Ribeirão Preto, Departamento de Ginecologia e Obstetrícia, 14048900 Riberão Preto-SP, Brazil
Corresponding author. Universidade Metodista de Piracicaba, Faculdade de Ciências da Saúde, Rodovia do Açúcar, km 156; 13400911 Piracicaba-SP, Brazil. Fax: +55 19 3124 1515x1558.
☆ This research was supported by CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, Process no. 370448/2007-3) and FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo, Process no. 2006/56788-1).
ABSTRACT