ABSTRACT
This chapter suggests that for most female judoka, their competitive years coincide with their reproductive years. Therefore, they are exposed to fluctuations in hormones throughout the menstrual cycle or through oral contraceptive use. These hormones affect many physiological functions. The hormone fluctuations throughout the natural menstrual cycle do not appear to affect body weight. During the luteal phase (after ovulation) core temperature increases and this may have a negative effect on performance, especially in hot, humid conditions. High oestrogen has a positive effect on muscle strength and adapting strength training programmes to the menstrual cycle results in better training adaptations. There are many different types of oral contraceptives and the synthetic versions of oestrogen and progesterone also have physiological effects. Despite popular belief, oral contraceptive use does not appear to affect body weight. During the active pill phase core temperature is increased, which has similar implications as shown during the luteal phase of the menstrual cycle. Some research has suggested that explosive muscle strength may be improved during active pill consumption. Menstrual irregularities are common in judoka and it is important that annual health screening includes this aspect. Menstrual irregularities have many negative effects on health and performance and should be prevented or treated.
