What's the difference between LOOK Delta and SPD cleats for indoor riding?

LOOK Delta cleats are larger, protrude from the shoe sole, and are the standard for Peloton and most major studio chains. They provide a very stable platform but make walking difficult. SPD cleats are smaller, sit recessed in the shoe tread, and are easier to walk in. They're common on many indoor cycles and smart trainers. If you ride at multiple studios, dual-compatible shoes that accept both cleat types are your best option. For Peloton specifically, you need LOOK Delta unless you swap the pedals.