Touted as one of the most important aspects of endurance training programs, the long run is non-negotiable when it comes to preparing for a marathon. Oftentimes it is the main element that sets you apart from someone training for a 10K. What's more, it is the long run that can convince even a novice that a marathon is within reach.
Therein lies one of the long run's greatest benefits. It teaches a runner that the marathon distance is possible.
The marathon distance is not for the faint of heart. There's a reason it is on many people's bucket lists; it's a monumental accomplishment. In addition to the physical difficulty involved in running 26.2 consecutive miles, many soon-to-be marathoners are most intimidated by the mental aspect. They find themselves asking: Am I really capable of running that far?
The slow build-up of your long run every week allows you to slowly build your confidence in the same way you build muscle strength. While one mile may be a struggle six months from race day, steady increases from one week to the next will help make that final goal seem more realistic.
The long run also plays a major role in helping you increase your coping skills and mental toughness. You never know what's going to occur on race day: blisters, stomach aches, leg cramps, rain and wardrobe malfunctions happen. It's better to learn to deal with them in training, willing yourself to finish a long run even when the circumstances aren't ideal. You'll soon feel confident that you can handle just about anything when you toe the line on race morning.
In addition to the psychological benefits of the long run, it also helps to train your body for the marathon distance. From increased VO2 max (or aerobic capacity) to a stronger heart and increased capillary growth in the muscle fibers, the payoffs are many.
One of the biggest physiological benefits is increased muscle strength. As you run longer, your body will first rely on slow-twitch muscles. As those fatigue, you become dependent on the fast-twitch muscles. If you haven't run long enough in training to strengthen those fast-twitch fibers, you're likely to be hurting on race day. The only way to build those muscles is to go long.
Long runs also assist the body in storing a greater amount of glycogen, which is where your body gets energy during a long, hard effort. As the body depletes its glycogen stores, it then goes to the fat stores for energy. Once this transition occurs, many marathoners feel as if they have "hit the wall." The long runs train your body to store more of that glycogen, thus increasing your ability to run longer without getting fatigued.