Online registration may not be allowed for all activities. To enroll into a group exercise class, please reserve your spot via our mobile app [https://ymcagbw.org/mobileapp#faq-question-949250480]. Please contact us during regular business hours for registration information. Fierce improves overall health using interval training, functional resistance and core exercises. Designed for all fitness levels. This is a prerecorded class taught by a YMCA instructor that plays on-site at the branch. Category Group Exercise Location Group Exercise Studio at Lionville Branch Instructor Leslie Seifert