Coach Dave Ertl posted a training plan for RAGBRAI that is designed to increase a riders stamina and enable the rider to successfully complete a seven day bike tour. The plan assumes a max mileage of about 75 miles/day. It does not involve intervals and appears to be focused on endurance. Here's the link to his 2017 plan https://ragbrai.com/2017/03/12/ragbr...ets-get-ready/

Tom