Are you looking for a way to switch up your workout? Get started with a five-class pack at Orangetheory Fitness in Brooklyn Heights. Orangetheory features a one-hour interval-training class designed to maximize the effect known as afterburn, which keeps your body chipping away at calories at a higher rate even after you’ve stopped sweating.  During a class, you complete intervals on low-impact treadmills and water rowers, and then move to the floor for strength and core training using weights, medicine balls, and TRX systems. Offer includes a fitness bag, water bottle, and towel.