So you are worried about what competition pace should be for your full or half marathon. You are worried that you are going to bonk at the 10- or 20-mile mark. How do you know how fast to run this goal race in the first place?
A good place to start is what pace are you running for your long runs. The long runs are supposed to be run at an easy pace – easy pace, by the way, should be slower than your goal marathon or half marathon pace. So when I was training seriously, my goal marathon pace was in the 5:30s per mile. Do you think every weekend I went out and ran 12-20 miles @ 5:30 pace??? No way! Even if I were able to run that pace week in and week out, come race day my body would have been wrecked. So on my long easy runs I would run 30 to 60 seconds slower than my MP (marathon pace).
Now, if you have run a half or full marathon before and know what your pace was for that race, you can work backwards. So if you run a 10 min/mi pace then your long easy runs should be run at 10:30 to 11:00 pace.
Understand, these are tips to get you to the finish line. If you are a more advanced runner, than some of your long runs are going to have time or distance durations of paces at 10K, half, and marathon thrown in there – but for you newbies out there, your first goal should be to finish.
Using Shorter Runs
If you have never run a full or half marathon before then jump in a race or do a time trial at a shorter distance (5K to half marathon). Once you have your time from this race/trial then you can plug that into a pace calculator to get your projected time for the longer race.
So, if you go out and run an all-out 5 mile time trial by yourself and it takes you 1 hour (12 min/mi) to finish, then according to the McMillan Race Pace Calculator your marathon time would be 5:52:35 or (13:27 min/mi) and your half marathon time would be 2:47:32 (12:47 min/mi).
Time Trial or Race
I would try to use a race/trial that was roughly about half the distance of your goal race (So, a 10K and half marathon) – this will give you a more accurate assessment of where you are in regards to your running shape. The reason being is some individuals are naturally quicker than others and running, for example, a 5K time trial to figure out one’s marathon projected time may give one a false sense of security if he/she hasn’t put in the miles or time needed to be prepared to run a full marathon.
I am that sort of runner myself. Even though I am nowhere near marathon shape right now I am in good mile shape (4:30). If I plug a time of 4:30 for a mile into the calculator, it spits out my projected marathon time of 2:32.12. (5:49 min/mi) And while I have run a faster marathon in my life, I know there is no way at this juncture that I could run a 2:32 marathon with the sort of endurance work (or lack thereof) I have done recently.
Start Paying Attention
The bottom line is set yourself up for success come race day. Just because your friend wants to run a sub-4:30 hour marathon doesn’t mean you should try that, too. Your training times will let you know where you should be come race day. If you are not paying attention to your pace – start now! Not because you have huge aspirations to be the next Olympic hopeful, but because a good plan on race day is almost as important as the good training that leads up to the race.
Rule of thumb: Add or subtract 20-30 seconds per mile for each major distance you go up or down (5K, 10K, Half, and Full) to figure out your goal times.The slower your pace at a shorter distance, the more seconds you will need to add to your per mile average for the longer races.
Example: If you run an 8 min/mi for a 5K then approximately your paces for longer distances would be:
10K pace will be 8:20
Half pace will be 8:40
Full pace will be 9:00
But if you run a 10 min/mi 5k, then approximately your paces for longer distances would be:
10K pace will be 10:25
Half pace will be 10:55
Full pace will be 11:30
Now that you know what paces to run – you can start racing smarter. Good luck!