Category: Running

Written by Calvin Lee, MD

I have a degree in Neuroscience and have done research in physiology and cell biology.  I am a board certified General Surgeon and I worked as a trauma surgeon.  I am currently an acupuncturist and cosmetic physician specializing in Botox, Juvederm, and Kybella injections.  The world of applied exercise physiology is vast and I present some of my opinions.  In general, even for the experts, much of how all this comes together is still a mystery.  These are just my thoughts, none of this is specific medical advice, and in the end, I’m a back of the pack runner who likes exercise physiology.

First what is conversational pace running?

It’s a running pace where one could hold a conversation while running.  One could have gradations in conversational pace: such as slightly difficult conversation pace or super easy conversational pace.  So it’s a range of running speed where one’s not gulping for air between each word; phrases of words should come out understandably.

How about heart rate monitoring – how does that compare to conversational pace running.

Some of us just don’t talk while running.  Thus we have another way to measure this “conversational pace” by using heart rate monitoring.  I like heart rate monitoring because I think it’s more objective.  But heart rate varies from day to day, from time of day, and from what we did the day before, etc.  So it’s not perfect either.

60-80% of maximum heart rate is conversational pace.  Garmin watches will present this as Zone 2 and Zone 3.  I estimate my own personal maximum heart rate based on recent experience and for me conversational pace running will fall between 110 and 150 bpm (beats per minute).

Wait, what’s the difference between pace and speed.

They are both a description of how fast we are running.  Pace is measured in how many minutes we would finish a mile.  Speed is usually miles per hour (mph – in the USA anyway).  Most runners use pace, but if you are a treadmill runner – you might like speed measurements because that number you adjust is measured in miles per hour (mph).  Basically just talking about the same thing but using different units.

The running world is ruled by those who like using pace.  But some of us (like me) like using miles per hour.  I made this conversion chart for mph to pace.

What’s the difference between easy miles, conversational miles, and building aerobic base?

Basically same thing in my simple mind.

Why should we spend dedicated period of time devoted to conversational pace running?  Can’t we just run at varying speeds and some of it just turns out to be conversational pace?

A time frame of several weeks to several months, depending on your coach, should be spent on building a base of conversational pace running.  This base building period could have other types of running, but I believe that each workout should have a focus on a desired outcome.  And that each time frame – period of time – should have a predominant focus.  We just have one body and it will adapt to most things we throw at it, but if we were to focus what we throw at it, it can grow more strategically.

Some coaches call this periodization – spending several months on a particular goal, then moving on to a different one afterwards, and so on.  For example one could work on conversational pace base building for 3 months, then move on to strength training, then move on to speed training with added plyometrics for a few months, etc.  It’s not to say that we only do one type of exercise for a period of months, but we should have a predominant type of exercise in the mix.

Thus, I prefer to call a period of conversational pace running – building aerobic base.  I’m using aerobic to mean the utilization of oxygen by the muscles.  If we run too fast we don’t have enough oxygen for the muscles to use and thus energy has to be made through alternative pathways which we call anaerobic metabolism.  There is no “storing” of oxygen in the muscles – it uses what it can extract from the blood stream which flows by.  The amount of oxygen presented is influenced by 1. cardiac output, 2. blood surface area (capillaries, etc), 3. amount of oxygen in the blood itself – red blood cells and the oxygen carrying capacity of hemoglobin.

What benefits do we get from spend time in conversational pace running?

I’ve come up with a list of things that improve after a series of conversational paced runs.  And much this is more of an improvement than with faster running.

• Our bodies become more efficient at burning fat.
• Our mitochondria grows larger – mitochondria are organelles within cells.  We are particularly interested in our muscle cells.  Mitochondria converts fat and glycogen into energy units called ATP.  Skeletal muscle cells themselves cannot divide, but they can lay down more protein, get larger, change proportion from fast twitch to slow twitch and grow more mitochondria.
• We grow more mitochondria! (so they become larger and more numerous)
• Lactic acid does accumulate during purely aerobic exercise – this is why we can go long distances at conversational pace.  Lactic acid is something that slows us down and gives us that burning feeling in muscles when we run at faster speeds.  Lactic acid is a byproduct of anaerobic metabolism, not aerobic metabolism.  Anaerobic means without oxygen.
• We use both Fat and Glycogen (stored carbohydrates) at conversational pace running.  As opposed to faster running which just uses glycogen.
• The slower one goes, the higher proportion of fat is burned relative to glycogen burned.   And with the slower speed, we can go longer distances.  Thus if we have the time, effectively we’ll burn more calories from fat.
• The slower running allows our bones and ligaments to strengthen.  To me this is building our base of defense against injury.
• Our nervous system starts to develop that “muscle memory” for steady easy runs, and that contributes to running economy – the efficiency of running.
• Our lungs and muscles develop a richer, fuller network of capillaries which can extract oxygen.  This will lead to a higher VO2(max) – which is a good measure of athletic ability.
• Because we can run for longer periods of time at conversational pace, our heart continues adapting by becoming larger and improving our stroke volume.  These are also factors contributing to a higher VO2(max).

Why do conversational pace running?

1. The Kenyans do it.
2. We become more efficient fat burning machines.
3. We get bigger and more mitochondria.
4. We can train longer.  And longer training means bigger and more mitochondria.
5. Injury prevention: Our joints, ligaments, and bones will thank us.
6. Nerve training: we develop more relaxed running.
7. More capillaries for the lungs and muscles.
8. Improved cardiac output.
9. Improved VO2 (max).

What about running faster than conversational pace?

To be a complete runner, we should do that too.  There is a time for that, but it’s probably best after building up a few months of conversational paced running (building aerobic base).  Good things come to those who wait.  The better our aerobic base, the better our tools for building our anaerobic ability – which includes to moving out the lactate threshold.  With the right tools, we’ll more efficiently tackle the lactate threshold challenges in the future.  But with those reasons above, we will automatically be faster in distances from 1 mile and above.

But with all these advantages, I conclude for myself that the majority of my running should fall into conversational pace rather than killer mode training.

We will get faster automatically by investing in conversational pace running

In the end most of our runs will probably be conversational paced or upper end conversational paced, otherwise we’ll burn out of our enjoyment for running.

Conversational pace running will automatically give us speed which comes from a better army of mitochondria, higher VO2 (max) (from better heart pump, better oxygen extraction from the lungs from the more numerous lung capillaries, and better oxygen delivery from the more numerous muscle capillaries), better running economy, and my favorite reason: better bones, ligaments and joints to withstand the next set of challenges which may involve actually running faster with interval training.  One of the most important things for improving our running is to avoid injury.

Next topic for later:  Lactate threshold!