“The vast majority of runners, however, seldom train at a truly comfortable intensity. Instead, they push themselves a little day after day, often without realizing it. If the typical elite runner does four easy runs for every hard run, the average recreationally competitive runner – and odds are, you’re one of them – does just one easy run for every hard run. Simply put: Running too hard too often is the single most common and detrimental mistake in the sport.”
