This is a marathon plan for runners who already have a strong base. You should be able to run 13.1 miles non-stop and more than 3 times per week to use this plan. Runners will need the ability to track pace and heart rate to use this plan. Threshold pace can be converted to threshold power for those using Stryd pods. Additional core strength work is recommended at least twice per week during the training. Those can be accomplished on rest days, but leave at least one rest day as a complete rest day.