Discounts can be added to any Athlete's membership.  

To create a discount:

1. Go to Wodify Admin > 'Financial' > 'Settings'
2. Click 'Taxes/Discounts' > 'New Discount'
3. Discounts can either be in Percentage or Flat Amount terms
4. Click Save

The discount is now available to add to Athlete Memberships when using the 'Custom' option: