Figuring out how fast you should try to run your first marathon is a critical exercise because if you pick the wrong pace you could very well never finish the marathon. Add this to the fact that you actually never test your marathon pace at a marathon distance prior to the actual marathon and you have a big unknown and high risk staring you in the face.
Another reason why it is so important to figure this out is that most training programs scale all the workouts to your marathon pace and once again you run the risk of over or under training if you have it wrong. You will often read “run at MP + 90 seconds for 5 miles”. What this means is to run at marathon pace + 90 seconds. So if your marathon pace is 8 minute miles then you should run that exercise at 9:30 pace.
Oh, and to avoid confusion for those who train to run/walk marathons we are talking about the running pace, not the overall pace which includes walking.
There are a variety of ways to determine your pace.
- Jeff Galloway, in his book “Marathon, You can Do it” calculates the marathon pace based on a measured mile. You get on a track once a month and run a mile as fast as possible. This is your measured mile. Multiply this times 1.3 and that is your marathon pace. If you run that mile in 8 minutes then your marathon pace is estimated at 10:24 pace.
- The next method is to use a predictor based on your performance in another race of some kind. You can find many such predictors on the web. The most famous is the McMillan Running Calculator. So you can plug in your last 5k race time and get a projected marathon pace and completion time. This assumes you have actually trained and can run it with equivelent performance.
- The next method is to base it entirely on your heart rate. This requires a bit of experimentation but you need to figure out where your various heart rate zones are for your own genetics and level of conditioning. This requires knowing your max heart rate and your resting heart rate and then performing some formulaes. There are many calculators on the web one of which is MarathonGuide.com’s Calculator. Once you have your heart rate zones then you want to run your marathon below your lactate threshhold (where you start sucking wind). This is usually in the aerobic threshold zone. So once you know where that line is you can run a variety of tests to determine your max pace that keeps your heart rate below that line.