La Marathon 2016: Part 2

Running Dosage

In my last post we discussed the three big factors that relate to running injury risk: Structure, Mechanics, and Dosage. This post will focus on Dosage. Exercise is medicine, and just like a drug we can prescribe the amount and how often to take it. The three main parts of this dosage are frequency, intensity, and time, or F.I.T. for short. Looking at training plans on the internet, you’ll see an infinite number of ways to combine these three variables. Like with any medication, we can also overdose on running, which would make our graph look like this:

You see that our mechanics and structure are ok, but our large dosage has put us into the injury range. Not good! We’ll let the coaches debate the perfect F.I.T. formula and instead I’ll give some general advice on running Dosage.

The first thing is to at least get a plan! Even if it isn’t a very good one, at least it’s a plan that can be changed and adjusted as needed. If it produces great results, you can follow it again. If you don’t like the results, get a new plan next race. Google can pull up multiple plans for any distance race. Your favorite local running shoe store can probably help as well. They have great advice and many of them offer free group training runs. You should also consider getting a coach.

Also, ease into any changes. We can often link an injury to a recent change in training, such as new shoes, new running group, or adding in speed or hill work. While these changes can be good in the long run, too much too soon can set you back. For example, rather than going all-in with eight 400 meter repeats for your first speed workout, start with just a few easy 400’s. Next week add a few more, the following week pick up the pace a little. Taking 2 – 4 weeks to work something new into your routine will help keep you injury free.

For the beginner, perhaps someone considering doing a 5K for the first time, I’d recommend starting with walking. Once you can walk briskly 3 times a week for 30 minutes, start adding in some jogging. Walk 4 to 4 ½ minutes, and then jog for 30 – 60 seconds, repeat 6 times for a total of 30 minutes. Do this 3 times a week and only increase the jogging time by no more than 30 to 60 seconds weekly. If you are really out of shape or injury prone, stick to 30 seconds maximum increase. In 8 – 10 weeks you’ll be running 30 minutes straight, which will be pretty close to a 5K for most people.

Once you can run 30 minutes non-stop, consider either adding a fourth day of running or increasing your time. Keep in mind the 10% rule; it’s a simple way to keep you from changing things too quickly. Some examples of how to apply it: Last week you ran 30 minutes 3 times, or 90 minutes total. This week you can add 10% more, or 9 minutes. You can do that by starting a fourth day with a 9 minute run. Or we can stick with just 3 days of running and add 3 minutes to each day. Don’t worry if you round up or down a minute or two.

For runners of all experience levels, I would also recommend easy/low Intensity running. For the beginner, trying to run too fast too soon is a recipe for disaster. It takes most runners about 3 years of consistent running to start maxing out their speed. So don’t get upset if you aren’t very fast after just a few months. Not getting injured keeps you training consistently, and consistency makes you faster.

For the more seasoned runners, consider low heart rate training. A full discussion about this is beyond the scope of this blog, but here is the take home message: The vast majority of elite endurance athletes do 80% of their training in the low intensity/purely aerobic zone, with 20% at high intensity. Contrast this with the majority of recreational runners who spend only 50% of training at low intensity and 50% at moderate intensity. About 98% of the energy used to run a marathon comes from aerobic metabolism, so spending the majority of your time training the aerobic system makes sense. For those without a heart rate monitor, know that you are probably in your aerobic zone when you can easily carry on a conversation. If you want to know more, check out: Total Heart Rate Training by Joe Friel, The Big Book of Endurance Training and Racing by Phil Maffetone, and 80/20 Running by Matt Fitzgerald. Training at an easier Intensity for most of your runs can not only keep you injury free, but even lead to faster race times!

Lastly, hear is some advice on how to know when to push through some pain, or pull back. I like to use these guidelines that were developed by Dr. Bob Wilder:

  1. You can run with mild pain, 1 – 3/10 on the 10 point pain scale, but not moderate or severe, ≥ 4/10.
  2. No running if you are limping or changing your gait to decrease pain.
  3. If the pain decreases as you warm up, it’s generally OK to push through. If it worsens the further you go, you need to back off.
  4. Your long run shouldn’t be more than 35% of your total weekly mileage.

I also recommend you consider seeing a doctor if you have pain that is sharp or in a joint, or if the same spot hurts for 3 runs in a row. It’s best to get diagnosed and treated quickly before it becomes a worse problem.

Thank you for reading and Happy Running!

Kasey Hill, M.D.