How Long Should Your Longest Marathon Training Run Be?
Runners preparing for a marathon often ask, “How long should my longest training run be?” It’s a critical question, and the answer varies depending on the training philosophy you follow. Traditional plans, such as those from Hal Higdon and Jeff Galloway, typically suggest a peak long run of 20 miles, often done three to four weeks before race day. However, some, like Bob Anderson, founder of Runner’s World and My Best Runs, argue that pushing beyond 20 miles can better prepare the body and mind for the full 26.2-mile challenge.
Hal Higdon’s popular marathon training plans recommend a maximum long run of 20 miles, usually completed about three weeks before the race. Higdon believes this distance provides sufficient endurance while allowing adequate recovery. Similarly, Jeff Galloway, known for his run-walk-run method, suggests 20 miles as the peak long run, emphasizing injury prevention and recovery.
The reasoning behind stopping at 20 miles is that it’s far enough to build endurance but short enough to avoid excessive fatigue and potential injury. The final 6.2 miles, according to this approach, are covered by race-day adrenaline and the cumulative fitness gained throughout training.
Bob Anderson, who has run 11 marathons and countless other races, questions the wisdom of capping the long run at 20 miles. “Why not do 25 miles or even more so your body is not experiencing a new distance on race day?” he says. Anderson believes that extending the long run to 23, 25, or even 28 miles builds both physical and mental resilience, reducing the risk of hitting the infamous “wall.”
Anderson’s personal experience underscores his point. He ran the Boston Marathon in 3:32:17 at age 65. In preparation, he completed one 23-mile training run but had planned to do another of at least 25 to 26 miles. “I had a 3:30 going but fell apart just before 26 miles,” Anderson recalls. “My worst mile was mile 26. I really think if I had gotten in a 25-26 mile training run, I would have clocked my goal of 3:30—but I will never know.”
While pushing past 20 miles increases fatigue, Anderson suggests adjusting the pace—keeping these longer runs slower—and allowing ample recovery. He notes that elite runners often train beyond marathon distance, albeit at an easy effort, to condition their bodies for race day.
So, what’s the right approach for you? It depends on your experience level, injury history, and goals. Beginner runners might find the 20-mile limit safest, while intermediate runners could benefit from extending to 22-23 miles. Experienced runners, like Anderson, may find 25 miles provides the conditioning needed to succeed on race day.
Regardless of the distance, the longest training run should be completed three to four weeks before the marathon. This timing allows your body to recover, adapt, and peak for race day without excessive fatigue.
There is no one-size-fits-all answer to how long your longest marathon training run should be. The traditional 20-mile approach works for many, but some runners may benefit from longer runs. Ultimately, listen to your body, consider your goals, and choose a plan that builds confidence while minimizing injury risk.
On race day, the goal is to feel prepared, strong, and ready to tackle the distance—whether you stopped at 20 miles in training or went the extra five.
posted Friday February 21st
by Boris Baron
