to exercise only at 140 bpm heart rate or below, for example, may be over-cautious for many athletes.If you're having an uncomplicated pregnancy and you were already running beforehand, then as long as everything is progressing as it should be and your doctor
, it is generally accepted menstruation has limited impact on exercise performance. Women have run well, set records and won championships at all phases of the menstrual cycle. Clinical studies have shown no change in heart-rate, strength or endurance during