I am going to edit this page as the underlying numbers change throughout training (hopefully for the better). Determining your marathon pace is actually a pretty 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 (like me) 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 yourt heart rate below that line.
OK onto “my pace calculations.
- Using the measured mile method. I have not yet done my measured mile and anything would be a guess at this point.
- Using a pace calculator and some recent 5K runs at a 10:37 pace my marathon pace would be 12:08 and I would finish in 5 hours and 18 minutes
- Using heart rate method I seem to be able to sustain a pace of 11:00 with an average heart rate of 160 which seems to be comfortable with breath and endurance. This is slightly below 80 percent of max HR, so just about right. Using a run/ walk ratio of 6:1 where I run for 3 minutes at 11:00 and walk for 30 seconds I would come in at an average of 11:34 per mile and finish the marathon in 5 hours and 6 minutes.
For me to do the marathon under 5 hours I need to have an average pace (including walking) of better than 11:27. A laudible goal and one I seem close to.
Why I am I so slow
There are really several things which explain my slow speed:
- Conditioning issues. Compared to where I was 2-3 years ago I am in amazing shape. Compared to someone who has maintained their conditioning, I am in poor shape. Although I have dropped my resting heart rate from 88 to 61 over that time, it is still fairly high from a runners perpective. My cardiovascular system needs a lot of training to more efficiently handle my oxygen management. It is very likely over the remaining 21 weeks that this will gradually improve.
- Endurance issues. Cardiovascular issues aside, my running endurance is extremely poor. All this training specifically is addressing these shortcomings. Every week that I continue this program my body is reprogramming my cells to be able to burn fat more efficiently, modifying the network to carry blood to my muscles and improving the density of the muscles.
- Weight issues. Even though I lost 70 pounds, I am still do not have a lean runner’s body. I could very conceivably still have 25 pounds of fat on my body. That weight takes a toll when running both in terms of foot impact cost and how hard the heart has to work to move blood around the body. Muscles have to work harder to move the extra weight. It is likely that as my body gets more efficient at burning fat I will get leaner. I certanily hope so.