<IfModule mod_rewrite.c>
    RewriteEngine On

    # If already inside public, do nothing
    RewriteCond %{REQUEST_URI} !^/gym/public/

    # If file or folder exists, do nothing
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d

    # Otherwise send to public
    RewriteRule ^(.*)$ public/$1 [L]
</IfModule>