SINGAPORE – At a sheltered court in Ang Mo Kio Avenue 10, Madam Susan Park guides nearly 40 seniors through a seated exercise routine.The 63-year-old demonstrates stretches and cardio movements. Later, she walks among the participants, encouraging them to keep up with the beat. Madam Park spends about two hours, four to five times a week, at active ageing centres run by social service agency Allkin Singapore. She leads morning exercises, sets up chairs for events or acts as tech support for seniors who need assistance with their cellphones.