I'll take you up on that DP.
Quick recap: 18 months ago I ran 3hr 27. That was on training 3 times a week, typical weekly mileage 25-35 miles. Fast forward to now. Been running every day or 6 times/week for last 6 months, averaging 60-65mpw. Broken PB's for 10k (38m 5s) and half marathon (81 min 50 sec, 3 weeks ago). I now have 3 weeks until Boston UK marathon and my target is to break 3hrs, ideally going as close to 2hr 55 as my form will take me.
Current pacing thinking: first mile - stick at 6:45 ish. Mile 2-3 adjust pace a little based on heart rate. I know from previous marathons the exertion I can maintain for 3.5hrs so I plan to stick to this and see what pace I run. Training runs indicate 6:40/mile is realistic with target heart rate.
I admit its not much of a plan, but how would you play it DP?
Cheers
My first observation is you must have a lot of natural talent unless you came form a very athletic background. As such I think you have some great potential to run much faster in time, so any goal time should be seen a stepping stone to much faster performances.
You can definitely go under 3 hours so I would make that a goal. The difficulty is there is a fairly big difference between 2:59 and 2:55. Your Half marathon time indites 2:55 is realistic, 60-65MPW is sufficient although on the lower end and with a lack of racing experience at this distance I would say it is a risky goal.
This calculator is fairly accurate, taking into account prior races as well as training volume
https://projects.fivethirtyeight.com/marathon-calculator/
Putting in your race times at 60mpw yields 2:58., 65MPW yields 2:57:19. Those times go down quite nicely as you bump volume to 85MPW.85mpw is about what I find optimal between training, recovery, work and family.
I think a 2:58 goal time would be suitable, with the hope that you could make a strong finish and get 2:57, but enough of a margin if there is a small mishap to still get sub-3.
In 2017 I had a 37min10 10k and a 1:20 HM on a hilly twisty course (neither had any taper and followed hard workouts in the week). I was running 80-90MPW and nailing every workout and LR. I went in to a Marathon with exception of 2:54 being realistic but it just wasn't my day and I suffered bad cramps at mile 16 and struggled to clip under 3. Since then the weather has thwarted me at every opertunity so I have only managed to shave a few more minutes down to 2:56:15 even although I know form training I have been in low 2:50s shape. So that is something to bear in mind. When you run slower, weather has less of an impact, and running 5/seconds a mile slower has less effect on finishing time let alone percentage of goal time. Once you get to sub-3, every minute seems like quiet a big jump in required fitness
Pacing strategy you seem to be well grounded. You want that first mile to be the slowest by far, so i would suggest something more like 6:55. cut 5 seconds each consecutive mile until you are close to goal pace. It is very important to look at your watch religiously in these first miles and force yourself at a slow pace. It is incredibly difficult to start correctly.
Going 10 seconds faster than your true race pace early on can cost you minutes later in the race., Your body is a lot less efficient until the muscles have warmed up.
After about 3-4 miles you should be close to goal pace. You now need to do some testing and have a good think about how you feel. 5 seconds faster than you true pace will be disastrous. 5 seconds slower will lead to a slightly slower time but you should be able to make up a small amount at the end. You have to look at your HR and effort levels to see if you can spot the sweet spot between the 5 seconds too fast and 5 seconds too slow. If in doubt keep that 5 seconds slower than Goal pace until you get to half way.
You then want to concentrate on being relaxed, good form, and very efficient. You an hopefully let your HR drift slightly downward. This is typically an enjoyable part of teh race but somewhat intimidating with the distance to go. main focus should be on efficiency rather than eeking out a few seconds here and there. Always give way to the hills by keeping effort constant. You loose time on ahill, nothing you can do about it.
Once you get to around mile 12-14 the race starts to become real. Pace will drop slightly if you are not paying attention. This is mostly mental, so you just have to keep checking your watch and forcing to keep up. There is anticipation that things are going to get much harder soon and you still have a long way to go. Sadly that is true if you are racing close to your limits, every mile will get progressively harder. It is important to make sure to keep on top of gels and hydration until now, because you can't catch up. Be mentally strong. Enjoy the crowd
By about mile 18-20 you likely feel like **** but are still moving close to goal pace. If you are not feeling close to death then you can start to see if you can start cutting 5-10 seconds off your goal pace. If you hit close to your limit you might find it incredibly hard to maintain, but 5 to 10 seconds is a little more comfortable. It is fine to let that happen if it really feels better but important to keep the slip in pace to no more than 5-10 seconds. It is a slippery slope that quickly leads to mental defeat and 10 seconds becomes 50 seconds a mile slower when you loose the mental battle. On the contrary, sometimes forcing yourself to speed up can actually help. You may feel no worse running 10 seconds under goal pace, and you get the mental boost that at least you are going fast. Forcing a faster pace can make you improve running form, which is much more important. Letting your running form become really sloppy will slow you down for the same energy output, so it is just a waste. forcing a faster pace could increase running economy and your HR might barely increase.
Be warned that if you feel great at about mile 18-20 and start running 10-20 second under goal pace, you might be premature. I've seen this happen before. Some how your body hasn't fully realized how tired it is and you haven't comprehended that 6-10 miles at goal pace is a friggin long way still. A good friend once left me for dust mile 20, at mile 23 he was staggering and lurching to one side, finally finishing 12 minutes behind me.