5 Best Marathon Time Predictor Workouts
Photos by Marques Jackson Photography.
By Erin Kelly, Doctor of Physical Therapy
Want to sign up for your next (or first!) marathon but need help setting a time goal for the big race? Marathon time predictor workouts can help. While many runners pick an arbitrary number, like sub-4 hours or even running a Boston-qualifying time, these marathon prediction workouts can help you set realistic training goals and offer insights on your predicted finish time.
Related Post: Marathon Pace Chart for All Levels
Marathon time predictor methods can help you set a realistic race time goal. They can also provide the information you need to make your marathon training adapt to your goal. Additionally, these workouts and equations are a great way to stay on track throughout your training, allowing you to adjust your goal if needed.
Need a marathon training plan to keep you on track for your big race goal? Head to the Runstreet Training Center to start today.
5 Best Marathon Time Predictor Workouts
Here are five marathon time predictor workouts and equations you can use to train for your next race:
1. Yasso 800s
Most runners are familiar with Yasso 800s, a speed workout created by former Runner’s World chief running officer Bart Yasso that doubles as a marathon time predictor workout. The workout consists of running 10 X 800-meter intervals at a consistent pace, with an equal amount of active recovery time as the paced interval between repetitions.
Yasso 800s specifically challenge your ability to maintain your pace as the intervals increase and fatigue sets in, testing both your running endurance and willpower. You can run them on a track, treadmill, or even on a road if the distance is carefully measured.
Yasso 800s can be a helpful marathon predictor workout and an excellent speed training workout. The time you run your 800 intervals (in minutes) correlates with the time you can expect to run your marathon (in hours and minutes). For example, if you can run 10 X 800s at a 4-minute pace (with a 4-minute active recovery between each 800), your marathon prediction time is 4 hours. If you can run 10 X 800s at a pace of 3 minutes and 30 seconds per 800-meter interval, your marathon prediction time would be 3 hours and 30 minutes.
While there’s no scientific data to back up claims that Yasso 800s are an accurate marathon time predictor workout, there’s lots of anecdotal evidence from athletes and marathon runners that celebrate Yasso 800s as a helpful marathon time prediction tool. Plus, Yasso 800s are a great workout to build speed and endurance, preparing you for the marathon.
Related Post: Tips for Running a Marathon for Beginners
2. Jeff Galloway’s ‘Magic Mile’ Method
Lifetime runner, American Olympian, and author of Galloway’s Book on Running Jeff Galloway established the ‘Magic Mile’ prediction formula based on his work with over 300,000 runners over 40 years. This marathon time predictor workout is fairly simple, straightforward, and easy to execute. The workout involves a warm-up followed by running a one-mile time trial.
For this workout, you should aim to run one mile “about as hard as you can” — but not so hard that you puke. Once complete, the mile time in minutes and seconds multiplied by 1.3 reveals your estimated marathon time. This method assumes three things: Runners do the training required for the time and goal, the temperature on race day is 60 degrees Fahrenheit or cooler, and runners pace themselves correctly.
Using the Magic Mile prediction formula, a runner who runs a mile at a 7-minute flat pace would have an estimated marathon time of 3 hours, 58 minutes, and 35 seconds. For slightly more accurate results, runners can run four one-mile time trials and take the average time to use within this marathon time predictor formula.
Again, while this method isn’t backed by science, it comes from an experienced source and has been used successfully by many runners. Of course, it’s important to remember that the endurance necessary for a marathon is much greater than that required for a mile time trial, so there’s room for error.
Related Post: How to Do Mile Repeats to Get Faster
3. 10k Time Trial
A 10k race, or 6.2-mile time trial, is another way to help predict your marathon finishing time. Popular run coach and endurance athlete Hal Higdon has said that newer runners can predict their marathon time by taking their recent 10k finishing time and multiplying it by five. For experienced marathoners, he recommends multiplying your 10k time by 4.66.
While this simple time trial paired with a mathematical equation may be accurate for some, there’s no specific research to back it up. The endurance necessary to complete a 10k is not comparable to a 26.2-mile race, so take this marathon time predictor method with a grain of salt.
4. Incremental Graded Exercise Test
If you have access to a treadmill, you can perform a graded exercise test that may help estimate your marathon performance. A 2013 prospective cohort correlational study had runners training for a marathon complete a graded exercise test that, when factored into an equation, estimated their marathon finish time. Researchers then compared the study participant’s actual marathon finish times to the estimated finish times and found the equation was surprisingly accurate.
The graded exercise test involves running on a treadmill at incrementally increasing speeds and gradients or inclines. Essentially, the longer you last during the test, the faster your predicted marathon time. Results from the study show that tapping out of the test before 15 minutes translates to a marathon time of over 4 hours and 53 minutes, while lasting up to 45 minutes predicts a marathon time of 2 hours, 58 minutes, and 19 seconds.
You can see more specific details, including the various steps of the test, below:
The biggest perk of this marathon time predictor workout is that it can be easy to replicate on a treadmill, and it has research behind it to support its validity. Like the marathon, it also gets increasingly more difficult with time, challenging a runner’s endurance and mental fortitude.
5. Peter Riegel’s Mathematical Formula
Several different calculation methods can be used to predict your marathon time. The most popular is an algorithm developed by engineer and runner Peter Riegel in the 1980s. While dated, the formula is based on the idea that as the race gets longer, you slow down by a certain amount due to fatigue. The Riegel equation is as follows:
Marathon time = (Half marathon time) * 2R,
Where R = 1.06
The popular mathematical formula is decent enough, but not an exact science, as many have found that the equation tends to underestimate a runner’s estimated marathon time. Critics like Andrew Vickers, a competitive runner and statistician, say a more accurate equation to predict your marathon time is to multiply your half marathon time by 2.19.
Although these algorithms are based on data sets of marathon times of real runners, they lack important context like a runner’s training consistency and average weekly mileage.
Which Marathon Time Predictor Workouts Are Best?
While there are many different workouts, time trials, and formulas that can help you predict your estimated marathon time, it’s important to remember that none of these methods take your running experience, weekly mileage, speed and tempo workouts, or cross-training into account and therefore lack important pieces of the puzzle. Although these marathon time predictor workouts and equations can give you a ballpark estimation of your marathon time or what goal time you are capable of, it’s important to realize that these numbers aren’t 100% accurate.
One of the best ways to use these marathon time predictor workouts and equations is to pick one or two that can help measure progress throughout your training cycle. Choose a workout, like Yasso 800s or a 10k time trial, and schedule it at the beginning of your training cycle, midway through your training cycle, and then again just before your taper. This way, you can use these marathon time predictor workouts to stay on track with your goals and track improvements.
Training Tools to Improve Your Running
However you choose to use them, these marathon time predictor workouts and equations can be valuable tools throughout your training. They also offer great speed workouts to improve your race pace and endurance.
For more resources on marathon training, check out Runstreet’s Marathon Training Guide for all running levels. If you need a custom marathon training plan, head to our Runstreet Training Center for help. Happy running to you! 😊
Related Posts: 10 Best Marathon Recovery Tips, How to Do Yasso 800s, 16-Week Marathon Training Plan
Erin Kelly is a writer, run coach and doctor of physical therapy. She's passionate about crafting compelling stories and helping individuals reach their athletic (and personal!) goals. You can follow her on Instagram at @runfromyourpr0blems.