Dreaming of the chest means overcoming a difficult obstacle, and you are about to make the victory rounds. You want to pound your chest with clench fist and let out a big roar to signify completing a successful project or tour.
The chest also represent power and vigor as it consist of powerful muscle groups that stand out if your workout targets that area.
If arms are crossed over your chest, you are guarding some secrets from being revealed. Reevaluate whether the secrets are really detrimental if it gets out. Or consider letting someone else shoulder the secret together with you.