Train Slow to Race Fast
There is way too much information to cover on this topic to make it completely informative, so I have included links throughout the article if you need clarification on a topic. I think this topic is an extremely important concept and yes, it’s long, but probably worth your time to read it.
There are two different conversations I’ve had in the office regarding low heart rate training and injury. When patients are all banged up from running, I need to ask about their training habits. One conversation ends up with me being called a nutter – “Are you serious? You think people can get faster by training slower?”. This patient rarely returns for subsequent treatment because they lost what little respect they had for me.
The other scenario ends with the patient saying something like “Of course I do low heart rate training – doesn’t everyone do that?”
There seems to be a wide disparity amongst runners on how to train. I’m hoping that this article can close the gap a bit.
There are a couple premises that need to be summarized with low intensity training:
Here’s premise #1:
A) Running (not sprinting) is primarily an aerobic exercise.
B) Because of “A”, you need a good aerobic engine to be a good runner
C) The only way to get a good aerobic engine is by training aerobically.
D) The only way to do “C” is to avoid going past aerobic threshold
E) This means keeping the heart rate low while training (no, I don’t mean “every” training session, but more often than you think)
Here’s premise #2:
A) Many studies (and logic) say that if you want to be a good runner, you need to put in a lot of miles
B) If runners ran at a high intensity too often, they would get burnt out – mentally, physiologically (over training) and musculoskeletally (injured) – yes, I just made up the word “musculoskeletally”
C) Another way of looking at it is that runners need to run slower in order to run more miles in a week
A step by step explanation…
In order to talk about training, we need to learn a couple principles. Initially, I spent about an hour typing in an explanation about the difference between aerobic vs. anaerobic exercise. In the end, it was too long so if you are unsure of the difference, click here
Here’s a big key: The duration of exercise we used to think was anaerobic is changing. I “stole” this chart from Jay Johnson:
So, for example, many people would think that running an 800 is anaerobic, but as you can see, it’s more aerobic than anaerobic. “So what” you ask? Well, it means that if you’re competing in an 800m race, most of your training should be low intensity aerobic training – that’s what!
Take for example, this new study that just came out in June 2012: Just a case study, but pretty compelling and well designed. Basically, the researchers took a guy who was really good at the 1500m race. His PR was 3:38. Not world class, but really, really good. By referencing the chart above, you will see that running a 1500m race is 77% aerobic. The researchers looked at his training and found that he was only doing 20% of his training volume under aerobic threshold (i.e. slow running). Not only that, his “low intensity” training was too fast, so they slowed him down during the low intensity training and also increased the volume of his low intensity training to 55% of the weekly volume. The result? From year 1 to year 2, his Vo2 max increased from 72 up to 79 ml/kg/min and his 1500m time dropped 6 seconds – from 3:38 to 3:32. Only 6 seconds you say? Well, in that league, it’s the difference of being really good and being world class.
If that guy got faster by increasing his low intensity training and he was only doing a 1500m race, how much do you think you should be doing if you race longer – like a 5K, half marathon or marathon?
So, in that example, this guy was doing his low intensity training too fast. He needed to slow down. So how do you know how fast is “too” fast. There are a few different ways to find out what “zone” you should be training in.
1) One way is to go get a Vo2 max test. The problem with that is that it’s a timed issue with the speeds and outcome being a mystery to the subject. Also, the apparatus on your face capturing the gas exchange can feel suffocating. This creates a bit of anxiety in people, which gets people’s heart rates artificially high, and other things.
2) Another way is to go by a percentage of max heart-rate. This is typically done by 220 minus your age. However, this is a problem because you don’t know what your max heart rate unless you go get it tested in a lab.
3) The easiest and I think (anecdotal) the best method is called the “Maffetone method” and takes into account your age, recent illness, injury history, how long you’ve been training and best of all, you don’t need to go to a lab to find out your numbers! (go ahead Vo2 max fan boys, flame away). Basically, the Maffetone method determines your heart rate at your aerobic threshold. To find this max aerobic heart rate, take 180 – your age, then add or subtract based on illness, injury, experience etc. It’s all on the website link above.
A common problem is that when people do their low intensity exercise, they don’t go low enough. There is a lot of ego and pride at work. For example, Mark Allan (6X Ironman World champ in the 1990’s) talks in this article about how before he started winning, he never did low heart rate training. When he was introduced to the idea, he had to run with his heart rate under 155 bpm. He was so embarrassed about having to run so slowly (8:15/mile) that he would only run at night when nobody would recognize him. As his aerobic engine got bigger and more efficient, he lowered his pace down to 7:15 with his heart rate still at 155 bpm, and after a year, he was down to 5:20/mile still with a 155 bpm. All because his body learned how to burn fat as fuel and his aerobic capacity increased.
Matt Fitzgerald talks about a study where 30 female runners were asked to describe their training. According to these self-reports, the women did three easy runs, one moderate-intensity run, and 1.5 high-intensity runs per week. But data collected from heart-rate monitors that the researchers gave to the women to wear through one full week of training told a different story. In reality the women did less than half of their training in the low-intensity range, almost half in the moderate-intensity range, and less than 9 percent in the high-intensity range.
How much low intensity should I do?
It has been estimated that well trained, world elite athletes perform about 75% of their training below the aerobic threshold  . This likely helps the athletes sustain high muscular power output for longer periods  and also to help them recover quickly from each workout. 
So I just do low intensity training?
There is good evidence that adding some high intensity interval training to athletes who are already at a high volume of training is very beneficial [4-7]
However, if you plan on racing middle to long distance, you’d better focus mostly on the low-intensity, aerobic engine, low heart-rate, sub aerobic threshold, guilt producingly slow running. It will help you in the long run, and help stay out of our office.
Again, I’m not saying not to do speed work, all I’m saying is most runners don’t do enough low intensity training and those who do are often not going slow enough.
For more info, here is a good article: