ERC20 INJ token rewards will be distributed at the end of the competition.
After you have delegated INJ to validators and waited some time, you will have accrued delegation rewards which can be claimed from the Wallet page. Under the Delegation Rewards table, you are shown a Total Reward (INJ) balance. Click Claim and sign the transaction.
Once your rewards are claimed, your Injective Chain balance under My Balances should increase by the claimed reward amount.
You can re-stake these rewards by delegating them to validators on the Validators page.
If you add more delegations to a validator with whom you are already delegating tokens to, all claimable rewards associated with your earlier delegation will be auto-claimed and sent to your Injective Chain balance.