From: Dave Szafran. An article from Road Runner Sports,
about Heart Rate Monitor Training.

Maybe you’ve heard the sound in a race: a high-pitched beep, beep,
beep. Or maybe you’ve wondered about those straps that you’ve seen
wrapped around runners’ chests (usually shirtless males!) Whether
you’ve heard them, seen them or just wondered about them, it’s time you
tried one yourself. What are we talking about? Heart rate monitors; 
other than a good pair of running shoes, they’re the single most
valuable training tool of this century...or the last!

What will a Heart Rate Monitor do for Me?
Simply put, using a heart rate monitor will make you a better runner.
Here’s how it works.
The monitor accurately measures the number of times your heart beats in
one minute. Knowing that figure helps you gauge how your body’s
responding to training. And knowing how your body responds helps you
plan your workouts to reflect your increasing fitness level.

“Yeah, but I’ve seen runners at the track stopping to take their pulse
during a workout. Isn’t that good enough?” you might ask. 
Unfortunately, the answer is no. Once you stop your heart rate starts
to slow down. For instance, let’s say you run a 400m interval, then you
stop to take your pulse before you run an easy 400m recovery jog. As
soon as you stop, your heart rate will begin to drop. By the time
you’ve caught your breath, felt for your pulse in your neck and started
counting, it might have dropped two beats or more from what it was in
the last 200m of the interval. And coming to a complete stop after a
hard interval can cause dizziness and even nausea, so you shouldn’t
forgo the recovery lap in favor of taking your pulse. Wearing a monitor
is the only way to get a true reading of how hard your heart is working.

How do I Use a Heart Rate Monitor?
A heart rate monitor consists of two pieces: 
1. The watch/chronograph/display, which you wear on your wrist.
2. The strap you wear around your chest. It has a plastic transmitter
that fits snugly against your chest in the hollow spot between your rib
cage. The transmitter plastic relays your beats per minute to the watch
where they’re displayed. Try Nike’s HRM Triax 100 (NIK-006)
Monitors vary considerably in both price and features. If you’re
running or jogging solely for fitness and possibly to lose weight,
you’ll probably want the most basic model, one that simply displays
your heart rate and nothing else. (A couple of good ones to start with:
Polar® Tempo (CIU-034) or Polar Beat (CIU-030).) If you’re planning on
running intervals on the track, choose a model that not only displays
your heart rate, but stores lap and split times as well as your heart
rate during each interval. (Try the Polar M21 (CIU-036), Pacer (CIU
025) or S210 (CIU-038.)) All the models above the two most basic
designs feature alarms to signal you when you’re in the correct target
training zone (more about target zones later.) 


Tip: Initially you may have to experiment with the tension on the chest
strap. Although you may think it feels too tight, you’ll be more
uncomfortable and insecure if it starts to slip down while you’re
working out. Don’t be afraid to tighten it, you’ll grow accustomed to
the feel very soon. It’s important to remember that the plastic piece
must fit right against your chest, if it doesn’t the beats will be
sporadic or you won’t pick them up at all.

Women should wear a sports bra designed so the strap slips through it,
particularly if they’re small-breasted and have a small rib cage. (Most
women around here use the Polar Heart Monitor bra (CIU-12).)No one,
male or female, should wear the chest strap over cloth, as transmitter
can’t transmit through a shirt or singlet. If you have trouble picking
up the beats, try a little saline solution on the back of the plastic
transmitter. Never use any other substance on the transmitter (like
petroleum jelly or a sports cream.) You may also need an Electrode
cream (GET-001) to get an accurate reading. 

Tip: Don’t be concerned if your heart rate starts suddenly jumps up 
during a run, say from 125 to 170, then back down again. Check out your 
surroundings. Sometimes when you run under high tension wires the 
transmitter will go a little “haywire” for a few seconds. You might
also notice that if you’re running next to someone who’s also wearing a
monitor, your monitor might start beating in time with theirs (or vice
versa)! Run a little further apart, or move to the other runner’s
opposite side. 

What do the Numbers Mean?
To understand what the numbers displayed on the watch mean, you need to
know:
1. Your resting heart rate (referred to as RHR)
2. Your maximum HR (referred to as MHR or sometimes Max HR)

How do you determine your RHR? It’s easy! Measure your pulse when you
wake up in the morning. Tip: Relieve your bladder first. Once you’ve
used the restroom, lay back down in bed and rest quietly for a minute
or so. Then place your index finger and middle finger of one hand
against the wrist of your opposite hand. Tip: Always use two fingers to
take your pulse, never your thumb! Measure the number of beats for 10
seconds and multiply that figure by 6. Voila! You now know your RHR. 

My RHR is 70. What does that mean?
An average RHR for men is between 60-80 beats per minute (BPM). Women
average slightly higher RHRs. A RHR of 100 isn’t unusual for someone
who’s sedentary. On the other hand, world-class runners can have RHRs
as low as 40 and even under 30 is not uncommon. It’s important to
remember that the more fit you are, the lower your RHR will be. 

Tip: Keep a record of your RHR every morning. If it rises by even as
little as two to three beats, you’re probably over-training, you may be
getting sick, or you’re dehydrated.. Back off on your training, monitor
your body for other signs of a cold or upper respiratory infection and
cut back on your intake of coffee and tea. Also make sure you’re
drinking enough fluid during the day. 

OK, Now that I Know my RHR, How do I Find Out My MHR?
Figuring out this number isn’t quite so easy. There are several ways to
determine your MHR:
1. Use the formula 220-(minus) your age. Unfortunately, this method can
be off by as many as 30 beats per minute, depending on your sex and
your fitness level. 
2. Use the formula 220-your age if you’re a man and 226-your age if
you’re a woman. According to longtime running coach, Roy Benson, this
formula makes more sense because women (usually) have slightly smaller
hearts than men. Smaller hearts make up for their size by beating
faster. But again, this formula can still be off by several beats,
depending on how long you’ve been running. 
3. Use this formula: subtract ½ of your age from 205. According to 
Benson, this formula makes more sense than the previous two because of 
the “old physiological chestnut that states, if you use it, you don’t 
lose it.” In other words, if you’ve stayed fit most of your adult life 
you’re younger biologically than chronologically. Still, even this 
formula might give you a number that’s way off, depending on where you 
are on the bell shaped curve used to predict MHR.
4. Take a treadmill test. Wired to an EKG in a medical laboratory
setting, you’ll get an accurate measurement of your MHR. Unfortunately,
this kind of test is very expensive and unless you’re willing to pay
for it yourself, your insurance company will undoubtedly balk at the
idea of paying several hundred dollars for you to find out how you can
train most effectively!
5. Wear a heart rate monitor in a 10K. Run as hard as you can the
last .2 and check your HR as soon as you cross the finish line. 
6. Coach Benson suggests this sub-maximal, low stress test. Strap on
your monitor and go out for a comfortable run of three to four miles.
Tip: The course should be flat. Start out by jogging slowly for ten 
minutes, just long enough to work up a sweat. Note your HR during the 
warm-up. Once you’re warmed-up begin to gradually increase your pace. 
Don’t run too fast. Coach Benson suggests that you run at a pace where 
you can easily say out loud: “Great! I feel as if I could run at this 
pace forever!” Continue running for another two to three miles. 
Eventually you will reach the point where you’ll be able to talk out
loud only in short sentences. At this stage of the run you will be
breathing harder. It’s important that you don’t run so fast that you
can no longer talk. This particular test identifies 80% of your maximum
HR; it’s not as stressful as a treadmill test or running a hard 10K.
(And it’s fun to run at a comfortable pace!) Check out your HR once you
reach the point where you can talk only in short sentences. Use that
number in the following formula to determine your MHR:
MHR = RHR (Resting Heart Rate) + (Measured HR – RHR) / .8 
For example, let’s say your RHR is 70 and your HR reached 162 at the
end of the test. Using the formula, your MHR would be 185. Here’s the
math:
MHR = 70 + (162 – 70) / .8
MHR = 70 + (92 / .8)
MHR = 70 + 115
MHR = 185

Training by the Numbers
Once you know your MHR you can base your training on that figure. It’s
important to understand that to benefit from HR training, you don’t
have to be an elite runner who races every other weekend. HR training
is for anyone, from a fitness runner who runs three times a week to
stay in shape to age-group aces who are looking to set PR’s. Here’s how
you use your MHR to set up a training schedule. 

If you’re a new runner, or someone who runs two or three miles a few
days a week, your target HR training zone is 60-75% of your MHR. In
other words, if you’ve determined that your MHR is 185, you’ll be 
running the majority of your runs with your heart rate between 111-139. 

On the other hand, if you’re hoping to get faster, or want to try a
race for the first time you’ll need to do some of your training runs in
the 80-85% zone (148-157). Here’s how the training zones breakdown:

-Easy, recovery jogs (should be the majority of your
training) @ 60-70% of MHR
-Long, slow runs (once a week, or once every other week)
@ 60-75% of MHR
-Steady-state runs* (once a week, depending on your
fitness) @ 75-80% of MHR
-Tempo runs** (once a week, depending on your fitness)
@ 80-85% of MHR
-Speed-work***(once a week, depending on your fitness) 
@ 90-95% of MHR

*Steady-state run: Help you achieve a sense of pacing. Ideally you
should run each mile at the same pace. They can be as short as 2 miles
or as long as 14-15. These aren’t fast workouts; if you’re training for
a half-marathon for instance, you might run 4 miles at your half
marathon race 
pace.
**Tempo runs: These are also known as lactate threshold runs. They are
run at a controlled pace: if you’re a new runner they should be 15-30
seconds per mile slower than your 10K race pace (which translates to 80
85% of your MHR). More advanced runners might run only 10-20 seconds
slower than 10K pace. Tempo runs aren’t long, they should be anywhere
from 2-6 miles.
***Speed-work: Speed-work can consist of timed intervals on a track,
400 meters to a mile, or fast, short bursts of speed on the road or a
trail. Many runners prefer to do their speed-work on the road since
road workouts more accurately simulate racing conditions. 

A Real-life Testimonial!
Training with a heart rate monitor made a significant difference in my
training, in fact I wish I would have started using one earlier in my
running career. I tried a heart rate monitor for the first time in
1995, 14 years after I first started running and racing. I quickly
learned that I was running way too hard on my so-called “easy” days. 
Because I had become comfortable running at a fairly quick pace
everyday, I wasn’t reaping the benefits of rest days. During most of my
runs my HR was 75% of maximum, sometimes even 80%. I’m sure training at
such a high HR everyday caused my immune system to weaken over the
years. I was lucky, I never sustained a serious injury that prevented
me from running, but I often had upper respiratory infections, colds
and a slight fever. Once I discovered the joys of truly running “easy”
most days, I was able to train much harder on my “hard” days, my racing
times improved and I stopped feeling “under the weather” most of the
time.