Is it permissible to participate in a strength competition where the sponsoring bodies cover its costs and prizes, but participation requires paying a registration fee, which was said to be for the organizers' effort and not for the prizes?

It is permissible to offer and receive a prize in horse races, camel races, and archery contests if the prize is from one of the competitors or from an external party, based on the Prophet's (peace be upon him) saying: "There is no prize except for an arrow, a hoof, or a camel." Scholars have differed regarding contests other than these three, and regarding religious competitions, but the preponderant opinion is that they are permissible. Therefore, if the championship is permissible in itself and free from the exposure of 'awrah (private parts) and boxing, then it is permissible to participate in it and receive a prize. There is no harm in paying registration fees for the organization of the competition.