Over the past few years, runners have really embraced the idea of recovering as hard as they train. Those training for marathons added more rest and active recovery days into their schedule last year, with 51 percent of days in the 16 weeks before the 26.2-mile race being rest days, according to the Strava Year In Sport report. That’s 57 days of rest compared to 55 days of training—or basically alternating a run day and a rest day every week.