How Fast Should I Run Slow Distance?

The problem with how many runners approach long distance training is illustrated in the article title question: “how fast”? The answer will surprise many a Striders runner.
Many runners are overdoing it in terms of speed in their long runs. By slowing down they may actually get faster in races.  Many runners see the weekly long run as a practise run for a race. Therefore the faster you can run it the better the indication right? Wrong. This article examines some reasons as to why slowing down may make you faster.

Energy Systems
Run training mustn’t be seen as practising to race, but rather seen as developing the energy systems our body uses in order to race. If you develop your energy systems intelligently you will be able to achieve faster race times, and less injuries along the way.

Training should be seen across a 7 day perspective at an absolute minimum, or even better in cycles. Speed is taken care of in technical (speed intervals and hill repeats), not in the weekly long run. Running too fast in the weekly long run can lead to injury, burn out but more importantly it can fail to adequately develop your aerobic energy system.

One of the most influential thinkers in this field is Phil Maffetone who developed the MAF principle (Maximum Aerobic Function). Maffetone highlights his research about aerobic capacity as follows:

“The body’s aerobic system is based in fatigue-resistant muscle fibres fuelled by fat. It has long been recognized that the vast majority of endurance-based sports, such as running, cycling, triathlon and cross-country skiing, require most energies be derived from aerobic metabolism. For example, 99 percent of the energy needs for a world-record marathon comes from the aerobic system. For an Ironman triathlon it’s more than that, and in relatively shorter races such as a 10k run, it’s still 95 percent. Even during a one-mile event, 65 percent of energy needs are aerobic-dependent.”

Maffetone has developed and refined the 180 Formula:
To find your maximum aerobic training heart rate, there are two important steps.
1.    Subtract your age from 180.
2.    Modify this number by selecting among the following categories the one that best matches your fitness and health profile:
a)  If you have or are recovering from a major illness (heart disease, any operation or hospital stay, etc.) or are on any regular medication, subtract an additional 10.
b)  If you are injured, have regressed in training or competition, get more than two colds or bouts of flu per year, have allergies or asthma, or if you have been inconsistent or are just getting back into training, subtract an additional 5.
c)  If you have been training consistently (at least four times weekly) for up to two years without any of the problems just mentioned, keep the number (180–age) the same
d)  If you have been training for more than two years without any of the problems listed above, and have made progress in competition without injury, add 5.
For example, if you are 30 years old and fit into category (b), you get the following: 180–30=150. Then 150–5=145 beats per minute (bpm).
In this example, 145 must be the highest heart rate for all training. This allows you to most efficiently build an aerobic base. Training above this heart rate rapidly incorporates anaerobic function, exemplified by a shift to burning more sugar and less fat for fuel.
Initially, training at this relatively low rate may be difficult for some athletes. “I just can’t train that slowly!” is a common comment. But after a short time, you will feel better and your pace will quicken at that same heart rate. You will not be stuck training at that relatively slow pace for too long. Still, for many athletes it is difficult to change bad habits.
If it is difficult to decide which of two groups best fits you, choose the group or outcome that results in the lower heart rate. In athletes who are taking medication that may affect their heart rate, wear a pacemaker, or have special circumstances not discussed here, further consultation with a healthcare practitioner or specialist may be necessary, particularly one familiar with the 180 Formula.

•    The 180 Formula may need to be further individualized for people over the age of 65. For some of these athletes, up to 10 beats may have to be added for those in category (d) in the 180 Formula, and depending on individual levels of fitness and health. This does not mean 10 should automatically be added, but that an honest self-assessment is important.
•    For athletes 16 years of age and under, the formula is not applicable; rather, a heart rate of 165 may be best.

Once a maximum aerobic heart rate is found, a training range from this heart rate to 10 beats below could be used. For example, if an athlete’s maximum aerobic heart rate is determined to be 155, that person’s aerobic training zone would be 145 to 155 bpm. However, the more training closer to the maximum 155, the quicker an optimal aerobic base will be developed.
For more details read the full article here:

You can read a critique of the Maffetone approach here:

The great Comrades marathon legend Bruce Fordyce famous maxim for preparing for the race is:

better under done than over cooked.

I have seen this from both end of the spectrum. My fastest ever Comrades was achieved whilst ‘underdone’. This meant that I was able to race the long distance with fresh, un-burned legs with little lag. The chains that bind (from running too much, too fast) were unshackled and I was able to get more out of my body on race day.

The problem with ‘racing when you train’ instead of ‘train when you train, race when you race’ is that we build up a lot of accumulated damage which the taper cannot deal with (it’s not uncommon for me to see runners clocking up 4:30min per/km long runs during a marathon taper).

If you do too much damage to yourself on a weekend long run you will not be able put in a top effort in your technical training in the week ahead. Put enough of these kinds of weeks end to end and you start to degrade your racing capacity. It looks great on Strava and you’ll get plenty of comments but you really should be getting pasted for being silly.  Serious runners aren’t weekend warriors, they train over an entire week and their conditioning is the sum of the parts.

Time On Legs
The key outcome of a long run is time on legs. Getting your body used to a long aerobic output is the key purpose of the long run, even to the degree that km’s run are not as important as time racked up. The distance serves the time rather than the other way around.  Taking this approach can also take pressure off yourself and save you running plenty of unnecessary ‘junk miles’ which can threaten to do you harm rather than build you up.

Building in long distance training is what we are trying to achieve, rather than carnage. Quite often the training regime we take on is breaking us down rather than building us up. We are training too much, too fast, and not taking enough time to recover.

Bruce Fordyce writes:
“Speed work and long runs should never mix. Speed work continues to be important. But not in long runs, where the emphasis should be the time spent on your legs. Adhering to this principle is one of the reasons I was fast over the shorter distances and had a good hill-climbing ability.”

Hear Rate Training
Given the MAF theory it may be time for you to seriously think about running with a heart rate monitor. I’ve only ever done it on rare occasions histoically due to the discomfort of a heart rate monitor strap.  I’ve also done myself an injury training for my last Comrades when the strap caused some chafing that had me dancing around my shower like a cat on a hot tin roof.

Modern developments in technology now offer us the capacity to have our heart rate constantly monitored. Watch based optical sensors now offer a more attractive way for many to monitor their heart rate. I researched long and hard before buying my latest Garmin 235. The tests between the 235 (with optical sensor) and the strap based monitors stack up well.

Read the review here:

I settled for the Garmin 235. Best decision I’ve made in a long time. My watch constantly monitors my heart rate and daily activities including sleeping patterns. I have a much better overall read on my current vital statistics both during exercise and at rest. Every single run I do has the associated heart rate activity matched to the usual stats on speed and time.

I can now spend time analysing each run, and take note of the averages, especially heart rate, cadence and speed.

Give It To Me In A Nutshell
If you follow the Maffetone principal that is determined by your age (and a few other potential factors) then stick to your MAF heart rate. At first it will seem slow but if you give yourself time to grow your aerobic capacity you will run faster at a lower heart rate. Put the horse before the cart.

If you don’t want to get too scientific about it, let me take a stab and say that if your long runs (25km+) are at 5min pace you are going too fast and at that speed you should be doing a sub 3 marathon in a canter. You will be better off being closer to 5:30min per/km or even slower. Remember the golden rule: if you race when train you’ll only be able to train when you race. Over to you.

Disclaimer (and general butt covering): Much of coaching is scientific, but as with any science there is a range of views and plenty of subjectivity. I’m by no means a world expert, and I’m always open to correction. I’ve learned from bitter personal experience and learned from others as well in terms of the subject of this article. Happy long running and look after that body of yours. Stan Fetting.

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