Running Advice and Supplementary Training (RAST), Issue 7.
Mark Thomas, Athletics Coach, Team Bath AC.
VO2max, Heart Rate and Running Pace.
In this issue of RAST I again get into some of the science of running, discussing the pace at
which you should be running and how this relates to heart rate and another fitness parameter,
VO2max. I also discuss stride rate and breathing rate. I have tried to keep this document as simple
as I can (without too much loss of scientific accuracy) but if you don’t understand something
please ask me and I will try to explain it. I think it is worth reading this document through to
the end as it explains why we should run at particular speeds. This is a bonus issue with three
pages rather than the usual two.
VO2max and vVO2max.
VO2max is much discussed in the literature on running: it is the amount of oxygen the body uses
when working at maximum sustained effort. There are two measures of VO2max: absolute
VO2max (the amount of oxygen the body uses when working at maximum effort, measured as
litres per minute (L/min)) and relative VO2max (absolute VO2max divided by bodyweight in
kilograms, measured as litres per minute per kilogram (L/min/Kg)). An unfit person taking up
exercise might be able to improve both these measures of VO2max slightly but for a reasonably
fit person VO2max does not alter much with training and it is not a good indicator of how fast
you can run. Despite this, and the difficulty of measuring VO2max in the first place (see below),
there are whole training programs based on the idea of running at paces that elicit VO2max or
percentages of VO2max.
A much better predictor of your race times than VO2max is vVO2max which is the minimum
running velocity, measured as meters per second (m/s), that produces VO2max, i.e. the slowest
speed that causes you to use oxygen at the maximum rate. This can improve markedly with
training: your body learns to use the oxygen more efficiently and, hopefully, you learn to run
with better technique and not waste energy on unnecessary movement. (For short distances you
can run faster than vVO2max but this puts you into oxygen debt by utilising the lactate energy
system – see RAST, Issue 5.)
VO2max and vVO2max have to be measured in a laboratory so most people will not know these
values. (If you are really interested in knowing them then some Sports Centres have the
equipment to measure them, though they will charge to do so.) However, you can get a rough
estimate of your VO2max by dividing your maximum heart rate (MHR) by your resting heart
rate (RHR) and multiplying by fifteen. For example, if your MHR = 180 beats per minute
(bpm), your RHR = 50 bpm and you weigh 70 Kg then your absolute VO2max ≈ 180/50 x 15 =
54 L/min and your relative VO2max ≈ 54/70 = 0.77 L/min/Kg. (The reason for the relationship
between heart rate and VO2max is that oxygen is transported around the body in the blood, the
blood is pumped around the body by the heart, and the more oxygen the muscles need the faster
the heart beats.) You can get a rough measure of your vVO2max by running as fast as you can
for six minutes then dividing the distance you have run (in metres) by 360 (seconds, equals 6
minutes). If, for example, you can run 1,800 metres in six minutes then vVO2max ≈ 1,800/360
= 5 m/s. To see if you are improving conduct this test every 4-6 weeks.
There are three common training sessions that are used to improve vVO2max. These are known
as the 30-30, 60-60 and 3-3 sessions. For the 30-30 session you would run at vVO2max for 30
seconds and then at half vVO2max for 30 seconds. This cycle is repeated for as long as you can
maintain vVO2max pace. If your vVO2max is 5 metres per second then in 30 seconds you will
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Running Advice and Supplementary Training (RAST), Issue 7.
Mark Thomas, Athletics Coach, Team Bath AC.
cover 150 metres and you then have 30 seconds recovery during which you run 75 metres. The
60-60 and 3-3 sessions operate on the same principle but use time periods of 60 seconds and 3
minutes, respectively.
Stride Rate.
Most top runners run at a stride rate of about 90 strides (i.e. 180 steps) per minute. You should
aim to run at about this stride rate. If your stride rate is significantly less than 90 per minute
then you are probably either over-striding and/or not moving your legs as fast as you could. If
your stride rate is significantly more than 90 per minute then you are probably not extending
your legs as far on each step as you could do and wasting energy on too much movement.
Breathing and Breathing Rate.
When you run about 15% of your energy is spent powering the respiratory muscles, i.e. those
involved in breathing. When you do a warm-up you are not just warming up the leg muscles,
you are also warming up the respiratory muscles. If you can strengthen the respiratory muscles
and make them more efficient then there will be more energy available to power your other
muscles. To strengthen the respiratory muscles you can practice breathing against resistance.
One approach is to use a POWERbreathe apparatus. Thirty breathes twice a day through the
apparatus will strengthen the respiratory muscles. Used immediately before running it will
warm up the respiratory muscles. A second approach is to restrict your breathing while you are
running. For this you can use a Respibelt. This straps around your chest and makes breathing
more difficult. Medical Warning: before purchasing or using either of these products read the
contraindications and warnings listed on the websites and, if necessary, seek medical advice
from your GP.
Most top runners have a 2-2 breathing pattern. This means that they breathe in for two steps
and breathe out on the next two steps. You may have a 4-4, 3-3 or irregular breathing pattern.
In these breathing patterns you may be breathing more deeply on each breathe but you will
probably not be getting as much oxygen into your blood as you would if using a 2-2 breathing
pattern: the shallower depth of each breathe in a 2-2 pattern is compensated for by the greater
breathing rate. You should aim to have a 2-2 breathing pattern to get the maximum amount of
oxygen into your blood.
Nobody really knows what causes a stitch, or how to prevent or treat them. A stitch may be
related to how the muscles involved in breathing, particularly the diaphragm, work while you
are breathing. If you get a stitch try changing your breathing pattern. For example if you have
a 2-2 breathing pattern that starts on the left foot then try changing it to start on the right foot.
Alternatively, try an irregular breathing pattern, for example 3-2 where you breathe in for three
steps and breathe out for two steps. However, changes in your breathing pattern are not
guaranteed to cure a stitch.
Heart Rate.
Many runners try to run at paces at a certain heart rate or at a certain percentage of their
maximum heart rate (MHR). To determine a percentage MHR you first have to know your
resting heart rate (RHR), your MHR and your heart rate reserve (HRR). First, determine your
RHR, in terms of beats per minute (bpm), first thing in the morning while lying in bed and
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Running Advice and Supplementary Training (RAST), Issue 7.
Mark Thomas, Athletics Coach, Team Bath AC.
before any exercise. Second, determine your MHR: run quickly uphill for two minutes, record
your pulse rate, run back down and up again. Repeat until your pulse rate does not increase.
Calculate your HRR by subtracting your RHR from your MHR. Divide the result by 100. If
you want to run at 75% of your MHR then multiply by 75 and add your RHR. For example,
your RHR might be 55 bpm and your MHR 175 bpm.
Calculate your HRR by subtracting your RHR from your MHR. HRR = 175 - 55 = 120.
Divide the result by 100. 120/100 = 1.2.
Multiply by the percentage MHR at which you want to run, e.g. 75%. 1.2 x 75 = 90.
Add your RHR. 90 + 55 = 145 bpm.
Therefore, this person, when running at 75% of their MHR will be running with a heart rate of
145 bpm.
Turning this problem around, if you know what heart rate you run at and want to calculate what
percentage of your MHR this is then subtract your RHR from your running heart rate. Divide
the result by your HRR. Multiply by 100. What percentage of your MHR is 160 bpm (your
heart rate while running) if your MHR is 175 bpm and your RHR is 55 bpm?
Subtract your RHR from your running heart rate. 160 - 55 = 105.
Calculate your HRR by subtracting your RHR from your MHR. HRR = 175 - 55 = 120.
Divide the first of these two numbers by the second. 105/120 = 0.875.
Multiply by 100. 0.875 x 100 = 87.5%.
Therefore, when running at 160 bpm you are running at 87.5% MHR.
Your heart rate slows as you get older. You should be recording your RHR every day in your
training diary (see RAST, Issue 1) so you may notice this over a period of several years. Your
heart will also beat more slowly as you get fitter because it gets more efficient at pumping
blood. If you don’t measure your RHR regularly then you should re-measure it and your MHR
every month. These measurements should then be used to recalculate your running pace. Be
aware that your heart rate will increase if you are dehydrated, if atmospheric conditions are hot
or humid, or if you are at high altitude.
Running Pace.
If you run at 60%-70% MHR then you will be running slowly and developing your endurance
and aerobic capacity. You will be using fat as your fuel source rather than glycogen. This pace
should be used for your weekly long run and any recovery runs you do. (See RAST, Issue 5.)
Running at between 70% and 80% MHR will develop your cardiovascular system increasing
the ability of your body to transport oxygen to the muscles and carbon dioxide away from them.
Your heart rate will probably fall in this range when you run a marathon.
Somewhere between 80% and 90% MHR you will find your anaerobic threshold (also known
as lactate threshold and turnpoint). This is the point at which the generation of lactic acid
exceeds the ability of the body to remove it from the muscle. Training at this point will develop
the ability of your body to cope with lactic acid and may push the anaerobic threshold higher.
Your heart rate will probably fall in this range when you race distances up to 10Km.
Training at 90%-100% MHR will develop your speed. Training at this level will be possible
only for short periods.
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