The long run: it’s arguably the most essential aspect of any marathon training plan, but to get the most out of that weekly long-distance workout, there’s an important rule that the overall essence of your training schedule should probably follow.
Ryan Knapp, head coach for Race Across USA and the Comfort Zone Camps Grief Relief team and founder of Miles to Go Endurance, believes that a solid marathon training plan ensures that each weekly long run is never greater than fifty percent of the overall mileage covered for the week.
“Ideally, your long run shouldn't be more than 20 to 30 percent of the weekly mileage,” he said. “Those mid-week runs should be getting longer as you go just like everything else.”
The major reason a marathon training plan should be structured this way is that it helps to prevent injury. Covering an adequate amount of miles during the week will help to ensure that your body can handle the long distance you’ll be tackling on the weekends (or whenever your long runs are scheduled).
As with almost any other endeavor that involves improving some aspect of your fitness, improvements aren’t made with just one really big workout each week, but as a result of several well-planned workouts that teach the body to adapt to increased stimulus over time.
To be sure, this rule—like almost any other rule you’ve heard about running— isn’t absolute; there are plenty of popular training plans that many runners have used successfully that do not adhere to it. The best marathon training plan (whether it follows this rule or not), is the one that works best for you and your needs as a runner.
That said, it is one a piece of marathon training advice that a majority of coaches and experts consider an important aspect of a well-built training plan.