Running Expert: Jeff Gaudette
The marathon long run is overrated…I’ll pause to let the sound of your gasps fade. In my experience, too many runners focus on trying to get in multiple 20 or 22 milers in their training segment at the expense of improving more important physiological systems. More importantly, runs of over 3 hours offer little aerobic benefit and significantly increase injury risk. This is why many of the Marathon FitnessClasses peak at 16 or 18 miles for the long run. Instead, your FitnessClasses focus on improving your aerobic threshold, teaching your body to use fat as a fuel source, and building your overall tolerance for running on tired legs through accumulated fatigue.
Since the long run is such an ingrained element of marathon training, and suggesting they are overrated almost sounds blasphemous, I am going to provide you with scientific research, relevant examples, and suggestions on how to better structure your training to support my claim and help you run your next marathon faster.
The Science
Most runners training for the marathon are averaging anywhere from 9 minutes to 12 minutes per mile on their long runs (3:45 to 5-hour finishing time). At a pace of 10 minutes per mile, a runner will take roughly 3-hours and 40-minutes to finish a 21-mile run. While there is no doubt that a 21-mile run (or longer) can be a great confidence booster, from a training and physiological standpoint, they don’t make too much sense. Here’s why:
Recent research has shown that your body doesn’t see a significant increase in training benefits after running for 3-hours. The majority of physiological stimulus of long runs occurs between the 90 minute and 2:30 mark. This means that after running for 3 hours, aerobic benefits (capillary building, mitochondrial development) begin to actually stagnate or decline instead of getting better. So, a long run of over 3 hours builds about as much fitness as one lasting 2 hours and 30 minutes.
To add insult to injury, running for longer than 3 hours significantly increases your chance of injury. Your form begins to breakdown, your major muscles become weak and susceptible to injury, and overuse injuries begin to take their toll. This risk is more prevalent for beginner runners whose aerobic capabilities (because of cross training and other activities), exceed their musculoskeletal readiness. Basically, there bodies aren’t ready to handle what their lungs can.
Not only are aerobic benefits diminished while injury risk rises, recovery time is significantly lengthened. The total amount of time on your feet during a 3 plus hour run will break down the muscles and completely exhaust you, which leads to a significant delay in recovery time and means you can’t complete more marathon specific workouts throughout the following week, which I believe, and research has shown, are a more important component to marathon success.
Why is the long run so popular
Given the overwhelming scientific evidence against long runs of over 3 hours, why are they so prevalent in marathon training?
First, many people have a mental hurdle when it comes to the 20 mile distance. The marathon is the only distance that you can’t safely run in training before your goal race. Therefore, like the 4 minute mile and the 100 mile week, the 20 mile long run becomes a mental barrier that feels like a reachable focus point. Once you can get that 2 in front of your total for the day, you should have no problem running the last 10k. Unfortunately, this just isn’t true from a physiological standpoint.
Second, the foundation for marathon training still comes from the 1970′s and 1980′s at the beginning of the running boom. Marathoning hadn’t quite hit the numbers it has today (you could sign up for most marathons, including Boston, the day before the race) and the average finishing time at most races was 3 hours (today that number is near 4.5 hours).
Therefore, the basis for how to train for a marathon came from runners who averaged close to 6 minutes per mile for the entire race. So, 20 and 22 milers were common for these athletes as a run of this distance would take them about 2.5 hours to finish at an easy pace.
Moreover, when you hear the term “hitting the wall” you immediately think of the 20 mile distance. “Hitting the wall” frequently occurred at 20 miles because your body can store, on average, 2 hours of glycogen when running at marathon pace. 2 hours for a 6 minute mile marathoner occurs almost exactly at 20 miles.
In short, the basis for a lot of our notions and understanding about marathon training are passed down from generation to generation without regard for the current paces of today’s marathoners. Therefore, we also need to reassess where the long run fits into the training cycle and how we can get the most benefit from training week in and week out.
How to train better
Your marathon FitnessClass downplays the role of the long run and instead focuses on improving your aerobic threshold (the fastest pace you can run aerobically and burn fat efficiently) and utilizes the theory of accumulated fatigue to get your legs prepared to handle the full 26 miles.
For example, your FitnessClass strings out the workouts and mileage over the course of the week, which increases the total amount of quality running you can do, along with decreasing the potential for injury. We shorten your long run to the 16 to 18-mile range and buttress it against a shorter, but steady paced run the day before. This will simulate the fatigue you’ll experience at the end of the race, but reduce your risk of injury and excess fatigue. As a side note, we also implement this training philosophy for the half marathon distance. By adding a steady run the day before the long run, you can simulate late race fatigue without having to run the full distance and teach your body how to finish strong and fast.
In addition, when you have shorter long runs, you’re able to increase the total quality and quantity of tempo and aerobic threshold workouts throughout your training week. Instead of needing 4-5 days to fully recover from a 3 hour plus run, we can recover in one or two days and get in more total work at marathon pace or faster. Developing your aerobic threshold is the most important training adaptation to get faster at the marathon distance because it lowers the effort level required to run goal pace and teaches your body how to conserve fuel while running at marathon pace.
Finally, with a focus on shorter, more frequent long runs, you can implement faster training elements, such as fast finish long runs, which allow you to increase the overall quality of your long runs. These fast finish long runs help you increase the pace of the overall run, get you familiar and adapted to running marathon pace while tired, and also increase your body’s ability to store energy for the end of the race and use fat as a fuel source more efficiently.
When you balance out the gains you can get from finishing a long run fast and upbeat with the negatives from an extended long run, you can see why a shorter, faster long run is the better training option for almost all marathoners aiming to finish over 3:30.
-Jeff
This is a somewhat controversial topic, so I welcome your comments, thoughts and questions.