How do I start exercising when I am completely out of shape?

Start small and make it sustainable. Begin with 10 to 15 minute walks daily, which builds the habit without overwhelming your body. After a week or two, gradually increase duration or add simple bodyweight exercises like modified push-ups, chair squats, or marching in place. The key is consistency over intensity, so resist the urge to go hard right away since that usually leads to soreness, burnout, or injury. Pick something you actually enjoy, whether walking, swimming, cycling, or a beginner fitness class, because you are far more likely to stick with it. Aim for three to four sessions per week and give yourself rest days. Progress will come faster than you expect once you build the habit.