Weight-bearing exercise is any activity where your skeleton supports your body weight against gravity. Walking, jogging, dancing, and hiking qualify. Swimming and cycling though excellent for cardiovascular health are not weight-bearing and do not stimulate bone formation in the same way.
For postmenopausal women where bone loss accelerates due to oestrogen decline, a combination of weight-bearing cardio and resistance training twice a week is more effective than either alone. Consistent cumulative activity over years matters more than intensity.