Yes, spin class is generally considered safe and beneficial during the first trimester for most low-risk pregnancies, provided you were already active before conceiving. According to ACOG guidelines in 2026, indoor cycling is a preferred alternative to road cycling because the stationary bike eliminates the risk of falling as your balance shifts. However, the "First Trimester Rule" is to prioritize hydration and temperature control. Because your core temperature rises faster during pregnancy, you should avoid "hot" spin studios and ensure a fan is pointed directly at you. You should also use the "talk test": you should be able to hold a full conversation while riding; if you're too winded to speak, you're pushing too hard. Always inform your instructor (discreetly if you aren't "announcing" yet) so they don't push you for maximum sprints, and listen to your body—it is more than okay to take extra breaks as your blood volume increases.