Tuning Up For a Marathon by Running a Half Marathon

Yesterday I ran the Point Mugu Half Marathon* at Naval Base Ventura County. After 20 weeks of training, mostly mileage buildup and long runs, it was good timing to gauge my marathon fitness level by running a half marathon.

Now it wouldn't be prudent to run the half marathon within a month of the marathon date. Since the Santa Barbara Marathon is on December 6th, that wasn't an issue.

The marathon is the "main event" in my training schedule, so I didn't treat yesterday's half marathon too seriously.  If I had, I would have tapered off my mileage for the event to gear up for a top performance.  For a full-blown competitive half marathon performance I might taper off the mileage for a week.  For yesterday's race, I ran light (only 4 miles) the day before the race.

Running a half marathon as a training run provides the opportunity to practice the important skill of taking in fluids on the run.  The art of grabbing a cup of water/sports drink from a volunteer and drinking its contents, is a good one to practice.  I hate stopping during the middle of a race.  It ruins my momentum. So it is important to know how to grab that cup and down it efficiently.

In this race, there were 6 or 7 water stops. I grabbed liquid at all of the stops except the final one (which was only a mile or so from the end of the race).  Each stand had both water and Gatorade.  I was running alone pretty much the entire race, so as I approached the stop, I yelled out " Do you have Gatorade?" This triggered the Seabee volunteer to have a cup ready for me.  Worked fine for me.

The approach that I use to consuming the liquid is to squeese the top of the cup, turn it sideways, and pour it in.  Makes it much easier to drink "on the run."

OK, so back to the race itself.  I'm happy to report that I finished in 3rd place overall in 1 hour, 23 minutes, 53 seconds.  Not a bad showing for the race, particularly given I have done no form of "speed work" on a track or otherwise. 

The "rule of thumb" I've been using for years is, assuming you do adequate long runs, take your half marathon time and multiply by 2.1 to get your full marathon approximate fitness level.  For yesterday's performance, I take 64 (rounded up) minutes x 2.1 = 176.4 minutes = 2 hours, 56 minutes, 24 seconds (.4 minutes x 60 seconds = 24 seconds).

So, all else equal, yesterday's half marathon performance indicates I have the ability to run a sub 3-hour marathon.

Another rule of thumb for estimating marathon time is to take your 10K time and multiply by 4.7. So if you can run a 10K in 45 minutes, assuming you've done your marathon (e.g. long run) training, in theory you are fit to run a 3 1/2 hour marathon.

These are just rules of thumb, but they have always worked pretty well for me. It is also fun to work backwards based on your desired marathon time.  If you're looking to run a 4 hour marathon, divide 240 minutes by 4.7 to determine a 51 minute 10K should get you close to that goal.

That said, I'll we doing 3 or 4 5K and 10K races in these final 11 weeks pre-marathon, interspersed with 2 to 3 more long runs.

* The Point Mugu Half Marathon course has its pros and cons.  Race was completely flat as the entire course is within 1/4 mile of the Pacific Ocean.   Very low key race with less than 100 competitors.  Most of course is nowhere near cars and traffic!  Miles 5 through 9.5 (approximate) were directly adjacent to the ocean!  Race entry fees were extremely low.  Within a minute after the start of the race we were blessed with a live performance of the National Anthem by a Naval band. Well organized, well marked course. And, the entire race was under overcast skies, which was quite nice!

The cons I suppose were that other than close proximity to the ocean, the course is a bit lacking in terms of scenery (in fact, it was quite swampy and smelly over a few sections of the course). Around mile 7 or 8 I heard some target practice going on, which had the unintended effect of pushing my pace to get outta there!