Your primary way to stay in a calorie deficit is through what you eat. Think of exercise as a way to increase calorie burn and support your deficit — not as the main way to create it. On the days you exercise, focus on weight training with compound movements that work multiple muscle groups. For example, squats work your legs, glutes, and core, making them far more effective than isolation exercises like bicep curls, which only train a single muscle. The general purpose for weight training is to stimulate your muscles to help preserve them in a caloric deficit. For you with PCOS, weight training is even more important: it helps regulate hormones, improves insulin sensitivity, and keeps your metabolism strong.