According to the relevant information in the Civil Code, as the case may be: 1. If there is no renewal clause in the lease contract of the shopping mall, it is legal for the shopping mall to introduce a new gym instead of renewing the old one.

2. It is illegal to set the renewal clause in the lease contract, and the shopping mall needs to renew the lease of the old gym according to the terms of the contract.

Renewing the contract is a continuation of the original contract. If the lessee wants to continue to lease the original house after the expiration of the contract, both parties may voluntarily renew the lease through negotiation.