Half-Marathon Training: Do Your Long Runs Fast



The start of the 2012 Santa Cruz Half-Marathon,
complete with time stamp

Over the past couple years, I've been training for a number of half-marathons and stumbled upon a workout that's really paid dividends on race day.  It all started when I started running on the Sawyer Camp Trail on the San Francisco Peninsula.  The six mile trail is marked every half mile so I started getting in the habit of wearing a watch and timing my pace for out and back runs of up to 12 miles.  Of course, my inner competitor emerged on these runs and each mile I did went faster and faster.  Next week, I'd come back and run it hard all over again.  Surprisingly, instead of tearing myself down with these fast paced long runs, I started making major gains in my training I've seldom experienced in over thirty years of running.  From then on, I make sure to do my long runs fast whenever I train for a half-marathon.

Now running long runs fast goes against most conventional wisdom, as most people will tell you to slow down during long runs to avoid injury and over training.  I disagree with this conventional wisdom.  Here's why:

1. Running form tends to get a little sloppy when you run slow, and I can't think of a better way to injure yourself than spending a lot of time running with sloppy form.  At higher speeds, running form gets more efficient and so you can actually run at higher intensity at little or no more risk for injury than if you ran slower.
2. One of the most important and underrated running skills is "pace sense", understanding what running pace you can maintain over a certain distance.  Fast long runs are great at developing pace sense near the pace you'll run in the half-marathon, and that's not something you'll gain on long slow distance runs a couple minutes per mile slower than race pace.  How often have you gone out "feeling easy" in a half-marathon only to come through the first mile split was 30-45 seconds under goal pace?   You can avoid getting caught up in the early race frenzy and excitement if you've put in plenty of miles around your half-marathon goal pace.
3. Fast paced long runs, when done right, are similar to running intensity and duration you'll experience on race day.  In addition, running several miles in succession at consistent pace requires a mental discipline you'll develop on long fast runs.  The race will seem more like "just another weekend run" when you have plenty of fast long runs under your belt.  You don't get this type of training effect with long slow distance.

How far should these runs be?  I consider a "long run" to be any run that's between 25-33% of your weekly mileage.

So how fast should you do them?  I go no faster than what I call "hard to hold a conversation pace".  When you're at your fast long run pace, you could say a sentence or two between gasps for breaths, but it you kept talking for maybe 30 seconds, you'd have to stop and catch your breath. 
Sometimes you'll hear these runs called "tempo runs" but since tempo runs are a bit vaguely defined  concept and often refer to runs of 2-6 miles, I prefer to call them "fast long runs".

I suggest you first ease into these runs, slowly ramping up the intensity to find a pace that works for you.  Wearing a GPS watch or running on trail with mile markers really helps on these runs.   It may take a few weeks to determine what pace you can handle and that's OK.   Part of the training effect is learning what an ideal pace is for these runs and just what you can handle.

Make no mistake, these runs will take a lot out of you so you have to be careful to make sure your recovered after each one.  Two years ago I made the mistake of doing two fast long runs within six days and ended up with hip bursitis which knocked me out of running for a couple weeks, and I never made it to the starting line for the half-marathon I was training for.  So I've developed my own rules of thumb to prevent these runs from tearing myself down, which will work well for most runners.

1. The long run should never be longer than 33% of your weekly mileage, and 25-30% is best.
2. Two days before the fast long run, don't do any workout that is above a medium daily effort.  The day before should be a medium to easy effort, and sometimes I completely take the day off before a fast long run.
3. May sure the day after a fast long run is an easy run, and two days afterwards, your run not exceed a medium effort.  
4. Make sure you can hold the pace for the entire duration of the run.  If you have to slow down the last few miles to finish, you're going too fast.  You should feel as if you could do one more mile and still maintain your pace at the end of your run.
5. Don't do these more than once a week.   Every other week is probably best to keep yourself fresh.

Your limits may vary.  It's important to make sure you're well recovered from these efforts before taking on any other hard running efforts like speedwork, trail running, shorter tempo runs or another long run (fast or slow).    I've been surprised how much progress I can make simply by running a fast long run once every week or two with no other hard workouts in my training.

No doubt about it, running long runs fast is hard work but like all well directed hard work, will pay off on race day.