To dream of a gym represents feeling about trying to be the best at something. Attempt to achieve perfection or improve yourself. Attempting to achieve an accomplished status. Attempting to improve or outperform previous achievements.
Negatively, dreaming about a gym may reflect attempts to be better at something than other people. Anxiety or concern that you will not be able to stop someone from being better than you at something. Jealousy or embarrassment motivating you. Wasting your spare time practicing or improving yourself for a goal that requires a much more serious focus. Wasting time improving yourself for a conflict you may never have the opportunity to confront.
Alternatively, a gym may reflect your mindset regarding areas of your life that are important to always look good with. Practice or maintenance to avoid looking like a loser. Strengthening professional skills or abilities. Vanity or feeling pressure to look good in some area of your life (not only physical).
Example: A woman dreamed of being in a gym playing basketball with her boyfriend and feeling that he wasn’t very good at it. In waking life she was starting to feel that her boyfriend wasn’t going to be a very good serious long-term partner. The gym in this case may have reflected her feelings about using specific social occasions to test and improve the relationship. She felt her boyfriend was failing to prove he was mature enough to marry her because of small persistent embarrassments he caused her.
Example 2: A man dreamed of seeing weightlifters at a gym. In waking life he was wasting his time trying to overcome a serious obstacle that required his full attention. He was focused on the challenge part-time instead of full-time. Although he was getting quite skilled, the challenge he faced required 100% of this time to overcome.