In good physical shape, fit, and healthy are some antonyms of the phrase 'out of condition.' If someone is out of shape, he or she might feel lethargic, weak, and unfit. On the contrary, if someone is in good physical shape, they have a sturdy and strong body, which helps them in activities that require physical strength, such as exercising, sports, or manual labor. Other antonyms for out of condition include robust, energetic, vigorous, active, and athletic. People who are in good shape usually lead healthier lives, have more energy, and are less prone to diseases. Therefore, it is essential to maintain a good physical condition by exercising regularly, eating healthily, and avoiding bad habits like smoking or excessive drinking.