Book through the UG app before you go — the schedule shifts week to week, but $30 gets you into any single class.
boxingHiit · Southold
Underground Training
Small-group HIIT studio tucked behind the post office on Main Road — Body Sculpt, Kettlebells, TRX + Core, LIFT, The Circuit and BOSU classes, plus private and private-group training. $30 for a single class; class packs and the live schedule are in the UG app. Classes run early-morning weekdays and weekend mornings.