Hi, I have been reading lately that high-intensity training can lead to estrogen levels dropping, which in turn could affect fertility. Is that true? And if so, what intensity would lead to such a condition? I am currently preparing a marathon, running between 30 and 50 miles a week. Do I need to worry? Thanks for your help,
There are indeed well documented links between high intensity training and hormonal changes in women. Extreme weight loss associated with regular high intensity training and the resulting reduction in calories available for menstruation, disrupts the release of vital female hormones (oestrogen and progesterone).
Prolonged deficit of these hormones results in loss of menstruation (amenorrhea) and weakening or thinning of the bones (osteopenia or osteoporosis).
Interruption of the normal monthly menstrual cycle greatly reduces fertility and subsequently chances of conception will also be affected.
The average female athlete who trains between 10-20 hours/per week requires 2,200 – 2,500 calories to support a normal metabolism including menstrual cycle. Amenorrheic athletes training to the same levels have been found to have a daily calorie intake of 1,700.
Basicallyyou need to make sure that your calorie intake measures up to the demands of your sport or activity level, not only for maintenance of normal body weight and metabolic function but also to maintain normal hormone levels.
Angela Benjamin MSc MCSP