On a deserted beach about an hour south of Agadir, there's a stunning hotel called Ksar Massa. It's such a magical peaceful place and a great retreat. It's used by a company called fitscape which arranges fitness holidays. Lots of running on the beach, swimming, cycling, etc. We had an amazing time.
www.fitscape.co.uk/morocco-coast.php
Google map: tinyurl.com/yb67f82