Effect of low-dose combined oral contraceptive on aerobic capacity and anaerobic threshold level in active and sedentary young women.

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 VO(2) mL kg-(1) min(-1); VO(2), L min(-1), respectively), carbon dioxide output (VCO(2), 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 VO(2), VCO(2), 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.