Harry's Guide to Heart Rates

Step 1: Finding Your Real Maximum Heart Rate
Step 2: Keeping Track of Your Resting Heart Rate
Step 3: Must-Know Heart Rate Facts
Step 4: Respecting Your Limits
Step 5: Preparing for Hard Exercise
Step 6: Assessing Where You Are
Finding Your Real Maximum Heart Rate

The "220-minus-your-age" formula is a rough and often inaccurate guide to individual heart rate. While it's good enough for getting started, it's not good enough for guiding you through the long haul, especially since it's so easy to get your actual maximum heart rate through a simple test you can do yourself. You may have heard of other formulas for calculating your heart rate, with the Karvonen method the most frequently mentioned. And while it is somewhat more accurate than the old formula, nothing is as good as actual measurements of your physiology. So, let's get right into how to measure your own max, and then talk about the subtleties of what it means and how to use it.
YOU MUST ASK YOUR DOCTOR IF IT IS SAFE FOR YOU TO GO TO MAXIMAL EXERTION BEFORE DOING THIS TEST!
If your doctor suggests a stress test first, then ask the doctor who administers the test if you can stay on the treadmill until you have reached your maximum heart rate. Doctors do NOT need this information for your health, and generally stop the test well before you reach your max.
Once your doctor has cleared you for maximal exertion, here's how to do the test.
· First, you need to buy a heart-rate monitor (which you will use for the rest of your life, so this is a totally worthwhile purchase).
· Second, decide on a form of aerobic exercise that involves power as well as speed. Think about using a machine at the gym with variable settings. Good examples would be a treadmill at maximum angle where you vary the speed, the Stairmaster-type machines where you vary the intensity, or stationary bikes where you can increase the resistance. You can also do this outdoors, but if you use a real bike or run, you will need to find a very, very long hill for the last part of this test.
· Third, pick a day when you are well rested and well hydrated, and have made the previous day's workout a light one.
To find your true maximum heart rate, go ahead and do a standard aerobic work out for 20 minutes at 80 percent of your theoretical maximum heart rate. Then go up to 90 percent for three minutes, and then sprint for 10 to 20 seconds, going as hard as you can. Once you get to the point where you really truly can't keep up with the machine just by working your hardest, and feel yourself flagging, you can stop.
Keep an eye on the heart monitor. You will reach your true maximum heart rate within a few seconds after stopping exercise. Write that number down, and use it in place of the age-based calculation, because that is the real number, while the calculated number is purely theoretical.
Maximum heart rate does vary somewhat with specific exercises. For cycling it is usually 5 to 10 points lower than for rowing or running. If you're seriously devoted to more than one specific sport, you might want to go ahead and test your heart rate for each one. But for most of us, it's such a minor variation that it's not worth the trouble.
Keeping Track of Your Resting Heart Rate

People often ask how to gauge whether they're working hard enough -- or too hard. This is an important question because it is surprisingly easy to overtrain when you are exercising six days a week. Normally, in the inadequate American scheme of exercise, we do three or four workouts a week. While not enough to give you optimal fitness, this plan does have the slight advantage of giving you an enforced full rest day between most of your workouts -- thereby giving your body a chance to fully recover. Once you move to six days a week, you will need to respect your body's current fitness level and work within that as it grows over the course of time. That means that if you do an extra hard workout one day, you may have to make the next day's workout lighter in order to give your body a full shot at recovery and growth.
The best way to monitor this is by keeping an eye on your resting heart rate. This is a little tricky, because it is affected by a number of factors, but basically it goes as follows:
Check your heart rate in the morning when you first wake up, before getting out of bed. The best way to do this is to learn how to take your carotid pulse in your neck. Put two fingers on your windpipe and then slide them off to the side, down into the groove on the side of the windpipe. On either side, your carotid artery is down there, fairly deep, pumping away day and night. Poke around until you find it, and get used to finding it and keeping your fingers on it until you can accurately count your pulse. Since your heart rate should be on the slow side in the morning, it is easiest to count for 20 seconds and multiply by three, though some people prefer to count for the full minute and skip doing any math before their first cup of coffee!
It's important to do this before you get out of bed, because the simple act of standing up in the morning activates your adrenalin system and will raise your resting heart rate by a few beats. Check your morning heart rate for a week or two and notice any variation. You should come out with a pretty consistent number, accurate within two or three beats on days when you are fully rested and recovered. By using this number as your guideline, you can then track your body's readiness for a given day's workout. Any day your resting heart rate goes five beats above normal, something is going on.
One explanation is that you are not fully recovered from the day before, and should take it easy that day. Other explanations are that you are coming down with a cold, you are mildly dehydrated, you woke up thinking about something stressful, or you had too much to drink the night before.
If it is something simple like dehydration and you can identify it, go ahead and aggressively consume fluids over the course of the day and do a full workout. But on any day when something else is going on -- a little cold or an incomplete recovery from the day before -- respect that limit, and schedule an easier workout for the day.
One of the reasons Olympic athletes pay coaches, and that those coaches make them check their resting heart rates, is so somebody can tell them when to do a lighter workout. Interestingly, the trouble with most serious athletes is not getting them to push themselves hard enough, but to get them to slow down when appropriate. Serious athletes the world over, or at least their coaches, have learned that backing off is often the best road to ultimate fitness. Pushing through the mild decreases in metabolic fitness that come with day-to-day variation is just not a good idea.
Must-Know Heart Rate Facts

Now that you know how to figure out your heart rate let's talk about the caveats:
First, your max heart rate is sport-specific. You will generally have a different peak heart rate for different sports because some of it depends on how many muscles your heart has to supply with blood. My 190 number is for rowing and the NordicTrack, which are the two most aerobically demanding sports. For cycling, which uses fewer muscles, my max is 182. If you have a favorite machine at the gym, use that to get your max heart rate. If you rotate among a few, try them all (but give it a full two days rest between each max heart-rate test, or the mild residual fatigue from the maximal effort will skew your results).
Second, your max heart rate varies with other stresses on your body. Elite athletes who over-train experience reductions in max heart rate. The same is true if you are dehydrated, sleep-deprived, etc. (though the effect is usually not large). And a heart rate at rest or during exercise varies with those factors and others, such as altitude, temperature, and caffeine. Luckily, for the purposes of the intermediate Younger Next Year program, these effects are minor enough that you can ignore them.
All of this means that your percentage of max heart rate is the most useful single number you can use to regulate your exercise, but it is not a perfect guide. It is plenty good enough for the intermediate Younger Next Year program, so you can stop here if you want, but if you are interested in more advanced training concepts, read on. If you do decide to stop here, check your max heart rate every four months, just to keep an eye on it. It does go down with age, and, to an extent, up with training.
One of the most frequently asked questions from people on the program is this:
My heart rate gets to 75 or 80 percent of my max as soon as I start exercising, or within a very short time, what does this mean?

First, because there are some heart conditions that can cause this, it means you should check with your doctor. Assuming you have done this, and everything is fine, the first step is to find your true maximum heart rate as outlined above. Once you have done that, consider the other factors that are probably at work. If you are reasonably fit, you may simply have a brisk adrenalin response to exercise. This will probably wear off with continued exercise, so my advice is to stick with the prescribed heart rate targets and see what happens over 20 minutes or so. It is most likely that you will find that your heart rate falls as you warm up.
If you are sedentary, then it's probably a combination of being in worse shape than you thought and having a brisker heart rate response as mentioned above. Again, the advice is to simply stick with it, going as slow as necessary to keep your heart rate down in the recommended ranges. This may leave you crawling along at a snail's pace for a while, which is fine.
Remember that only about 20 percent of Americans engage in any sustained exercise, and many of them are doing a lot less than they think. That means there's a pretty good chance you are starting out in worse shape than you think. The great news is that you simply have that much more to gain!
Respecting Your Limits

Your optimal heart-rate zones for a given day and for a given training schedule will vary according to what's going on with your body on that specific day, and what your goals are for that specific workout, and how that fits into your overall workout plan.
Leaving aside, for a moment, what's happening with your body, we designed the intermediate program to have an easy-hard strength rotation for a very specific reason. If you have done the hard aerobic day right, and followed it with a strength day, your body needs a recovery day. The old advice is to take a day off to let your body regenerate. It turns out that active recovery at an easy pace is far more effective. And when that easy pace is a long, slow day at 60 percent, you are not only recovering from your hard days, but you are also building new capillaries and aerobic capacity in response to the low-intensity stimulus, and in a way you could not do by either another hard day or a complete day off.
That's why it's so important to really respect that 60-percent limit. It feels ridiculous sometimes, especially if you are outdoors. Competitive cyclists have a hard time getting used to this concept, because they keep getting passed by kids riding their bikes to the candy store! In fact, the whole point of wearing a heart monitor on these days is to SLOW YOU DOWN. I know it seems counterintuitive, but unless you want to argue with every Olympic athlete out there, you are going to have to accept it.
Also realize that the longer the slow training the better, so if you can dedicate a weekend morning to a two- to four-hour bike ride or walk, that's great. Where Chris and I ride, there are a lot of hills, and I spend a lot of time in the granny gears, going up the hills at about the pace of an ant. I can walk on level ground indefinitely at 50–60 percent, but if there is even a slight incline, the same thing happens. With steep hills, I actually have to pause between steps to keep my heart rate down. It took a while, but I have actually come to love this time. My senses are sharpened by the exercise, and there is something very Zen about the whole outdoor experience. At the gym, I would be watching an hour of TV to make it through this!
Preparing for Hard Exercise

On the hard days, you should warm up for 5–10 minutes. That's serious advice, and it now takes me a full 10 minutes to warm up. What's happening while you warm up is that your body is redistributing blood to the muscles that are active. Your circulatory system is moving blood away from your gut, kidneys, liver, etc., and into the specific muscles that are being used. Not only that, but your joints and tendons are waking up as well, becoming more supple and flexible. So don't skip the warm-up--or the warm-down--because you want to keep that extra blood flowing through the exercised muscles for a few minutes after you stop exercising. That will give the blood time to carry away the metabolic waste products from the muscles, and speed your recovery for the rest of the day.
Once you are warmed up, head into harder exercise. I find it helps to extend the warm-up into a kind of ramping effect, much like the maximal heart rate test. I generally start at 75 percent for 3 minutes, then move up to 80 percent. On some days, I will stay at 75 percent longer, depending on how I feel.
The next level of hard aerobics gets into the more advanced physiology. There is no specific magic to 80 percent. It's simply the pace that most fit people can hold for the duration of this exercise. If you want to exercise longer at 70 percent, or shorter at 85 percent, that's fine. We will discuss this in greater detail in the advanced forum, but remember that the hard aerobic window is from 70–85 percent, so pick your workout accordingly. Few people can sustain 85 percent for very long. If you can go for 30 minutes at 85 percent (and using your actual, as opposed to calculated, heart rate), then congratulations, you are superbly fit!
If I am cycling or hiking, I often make a conscious choice to stay down in the lower aerobic range much of the time so I can go longer. On the other hand, if I have a plane to catch or a meeting to attend, I may warm up for 5 minutes, ramp up to 85 percent, and stay there for 15–20 minutes as a way of squeezing a hard work-out into a hard day. What I don't do is stay over 85 percent, because then I have wandered into my anaerobic zone and it will be mildly counterproductive to my overall program.
Assessing Where You Are

The other major factor is what you bring into exercise on each and every day. The best measure of this is your resting heart rate, and if you can get in the habit of checking it before you get out of bed each morning, you will be well ahead of the game. It's no surprise that your body is affected by how much sleep you had, how well-hydrated and nourished you are, whether you had alcohol the night before and how much, whether you are fighting a minor cold, how much stress you are under, and on and on. The best single measure of this is your resting heart rate. With time you will get to know your true resting heart rate. Mine is 50. On days when it is significantly above that, say 55, I know my body is not ready for a maximal workout. If it is a hard aerobic day, I will bring my effort down to 75 percent, or even 70 percent, and I'll be sure to hydrate over the course of the day. I have a strong preference for maintaining the duration of exercise over the intensity of exercise, so I still shoot for an hour, but there are days when I cut short even a low-intensity workout. It's the smartest long-term strategy, and remember ... we are in this for the long haul, not the short-term.
Interestingly, I am lousy at predicting whether I will have a good or bad day based on how I feel. My resting heart rate is a pretty good guide, but my subjective feeling is not. There are days when I drag myself to the gym, short on sleep, feeling worn out from too much travel, expecting a short day at 75 percent. But more often than not, I will end up doing 45 minutes at 80 percent and feel great. Other days, I will feel fine, but the workout itself drags, and by 30 minutes my heart rate is still climbing even as I slow down and call it a day.
The heart rate climbing is an important signal, and something you should pay attention to. Technically it corresponds to something called the lactate inflection point, which we'll cover in more detail in the advanced forum. In brief, once your body has used up its aerobic reserves, you start to poop out. Bikers call it "bonking," runners call it "hitting the wall"; it means that your body is done for the day and it's time to stop. The signal for this is that your heart rate starts to steadily climb even though you are simply holding the same pace or level of intensity. There is a critical difference between your heart rate drifting and climbing. Your heart rate will very slowly drift upwards over a hard exercise session, so if you hold a steady pace, and start at 75 percent, you will drift up to 80 percent over 20–40 minutes, depending on how fit you are. That's normal and fine. It's when your heart rate climbs up over the course of a few minutes that you are done, and should hit the showers. Although there is still debate on this, drifting probably largely reflects the increased heart rate needed to pump additional blood through the skin to deal with the temperature increase of exercise, while climbing reflects the muscles going beyond their aerobic limits and dumping more waste products into the circulation. (I'll run through the complicated details in the advanced section.)

By the way, I often use this to limit my 85 percent workouts, even when I feel well. If I want to squeeze in a hard workout, I'll try to go until my heart rate climbs. Sometimes I will even go up to 90 percent to speed it up further. Don't do this until you are pretty fit (a good guide is that you can maintain 80 percent for at least 30 minutes), and don't do it often because it's not a great way to train, but it is an effective way to get some good exercise in the face of modern life!
So, that's actually the beginning of moving from the intermediate to the advanced exercise platform. It depends on getting a solid base of fitness, and on beginning to understand your body in a more sophisticated and powerful way. The whole point of the advanced forum is to take that process ever further, to get you fascinated and involved in your own physiology and in building the individual variations into your fitness program that will serve your life best.