Heart Rate Monitor Explained Determining Training Intensities This is a good place to stop and ask yourself if you even care about what training intensity you have reached in a given workout. The following, for some athletes, takes the fun and spontaneity out of their sport. This isn’t disputed but, once an athlete has established a good connection between his/her sensory feeling (perceived exertion) of exercise and an accurate, objective measurement (heart rate monitor), that athlete is given control of their performance destiny. It’s assumed that, if you are reading this, your intent is to improve your performance in endurance sports. If this is not the case, you may ignore the following. Throughout these programs, we will refer to varying levels of intensity with regard to how hard or easy your effort should be in any specific workout. Verbal description, however, does not always convey a clear definition of intensity level. When we say hard, what does that mean to you? How many levels of hard are there? In order to make this definition of intensity consistent for everyone, it makes sense to establish a table of graduated levels that are dependant on one's individual physiological trait(s). The two criteria we’ll discuss are: Rate of Perceived Exertion (RPE) and Heart Rate (HR). While the heart rate monitor (HRM) will give you an accurate reading of what your heart is doing (and allow you to correlate HR with a given training level/zone), your perceived exertion allows you to evaluate your how difficult a training session is by assigning numbers to your perception of each incremental level of difficulty. Heart rate monitors provide an external, objective measurement which, though an excellent tool, can’t account for factors like environmental conditions, muscle fatigue, psychological states, etc.). RPE enables you to subjectively measure your level of effort and, when combined with a HRM, provides a more complete picture of one’s level of effort. Because of these points, it makes sense to combine the two when communicating the varying intensities of workouts. Before getting into RPE and HR, Owen Anderson Ph.D., has described some of the shortcomings of using a HRM to determine target training intensities in an article from his Running Research News (Vol. 12, #4 May, ‘96). If nothing else, it will help an athlete to understand some of the situations encountered when trying to train strictly by HR alone: “ . . .if you use a monitor to measure the intensity of your workout or race, you’re probably headed for trouble.” He mentions “cardiac drift”, the heart’s tendency to slowly increase in rate over the course of a run (due mainly to dehydration), even though the pace and level of effort may remain constant. “. . .Heart rates can rise by as much as 20 beats per minute during constant-­‐velocity runs lasting less than 30 minutes!!” It’s enough to make you want to throw your HRM out the window (except that you paid good money for it), right? He goes on, “To see what can actually happen, let’s say that you want to develop the ability to run a half-­‐marathon at 90 percent of your max heart rate -­‐ a laudable goal. And let’s say that -­‐ in deference to the specificity of training principle -­‐ you’ve decided to run a variety of different workouts at that specific intensity. That sounds good in theory. Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained “The first time out, on a fairly hot and humid day, you run for an hour at your desired heart rate -­‐ 90 percent of maximal. Your average running pace for the whole workout turns out to be seven minutes/mile. “The next time you train at 90 percent, it’s a perfect day for running -­‐ cool and dry. You zip along for an hour again at 90 percent of max, but when you get through, you discover a startling fact: Your pace was 6:45 per mile! “The third time out, it’s hot and humid and windy. You’re still stuck like glue on 90 percent of max heart rate, though, and so your hour passes at a comparatively lethargic pace of 7:20 per mile (remember that when it’s hot and humid, heart rate rises more quickly that usual, bringing your to a specific rate at a slower running pace; running against wind compounds the problem). “On your fourth encounter with 90 percent of max heart rate, weather conditions are fine again, but you’ve just had a fight with your spouse. You’re tense and excitable, sending your heart rate to higher-­‐than-­‐usual levels. So, you reach 90 percent of max too easily. In fact, at 90 percent, your running is only 7:30 per mile.“. . . Suddenly it’s race day, and by golly you’re pretty sure you can handle the half-­‐marathon at 90 percent of max heart rate. But when you finish the race, are people going to ask you, “Hey, what heart rate did you have out there?” Or will they ask you about your time? And are you going to care more about your heart rate or your actual finishing time? “The point is that if you have even an ounce of competitive spirit, you’re going to be more concerned about your overall performance than the rate at which your heart was flapping during the race. Paradoxically, though, you’ve been training to run the race with a particular heart rate -­‐ not in a particular time. You’re at the mercy of your heart -­‐ and that expensive strap you’ve got around your chest. Wouldn’t it make more sense to choose a sensible goal pace for your half-­‐marathon (say about 10 to 15 seconds slower per mile than 10-­‐k velocity), a pace which will bring you to the finish line in the time that you want, and then learn to handle that pace under a variety of different conditions during training? Practicing that pace will give you the precise neuromuscular coordination and the precise leg-­‐muscle functioning that you’ll want on race day. Who cares if your heart strays above some pre-­‐defined rate of ticking? Believe me, your ticker will be none the worse for wear on the following day.” Dr. Anderson goes on to point out that it is more valuable to train at a desired pace rather than a particular heart rate (within reason and assuming the goal is a particular pace). “. . . your legs will become fatigued far faster than your heart does. You don’t have to worry about the heart getting fatigued: That old fellow can pound away at high rates for long periods of time. Your leg muscles are your weak link. “After all, the heart is an imperfect indicator of what ‘s happening to your leg muscles. An increase in heart rate might indicate increased stress n your leg muscles, or it might just represent tension, drift, or the fact that a little more blood has settled in the skin on a hot day. Don’t enshrine an imperfect indicator as the absolute dictator of your training and racing. He concludes with, “The bottom line -­‐ or rather the bottom lines? If you can avoid the pitfalls associated with heart-­‐monitor training, using a heart monitor can be enjoyable and helpful, but bear in mind that even if you use your heart monitor Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained to classify all your workouts as hard, moderated, or easy -­‐ and even after your monitor has told you whether you’ve had a hard or easy day, week, or month, your monitor can never tell you how you should be training. Your monitor is only a device which collects data; it’s not a program planner. “And the information your heart monitor collects refers specifically only to your heart; it doesn’t tell you whether your leg muscles are really ready to handle the rigors of your goal running speed: only training at a specific pace can do that.” Beautiful. And all that time I thought I could just rely on old Polar! Turns out those feelings, both good and of being trashed, are every bit as important as what the old HRM is telling you. The bottom line is that you need to incorporate both your heart rate and perceived level of effort when determining the levels of intensity at which you train. Ratings of Perceived Exertion The scale below was developed in the early ‘70s by a Swedish scientist named Dr. Gunnar Borg (“Did I need to know that?”). He determined that athletes could, through a numbered scale, predict accurately how hard they were exercising based on how they felt and correspond these numbers, quite accurately, to heart rate. Some experienced athletes have sharpened their awareness to the degree that they can identify their lactate threshold exactly from their subjective feelings. Take a look at these and think about your most recent workout. How would you rate this most recent effort? Begin to connect your true ‘feelings’ of intensity with prescribed levels. Are you someone that does not feel that a workout is worth while unless you are in the 16 to 17 range of the original scale? Are you the person that would be happy staying at or below 12 in all your training? The answers to these questions can, many times, indicate trends in an athlete’s racing performance and provide hints for improvement. Rating 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Perceived Effort Very, Very Light Very Light Fairly Light Somewhat Hard Hard Very Hard Very, Very Hard Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained Now that we are familiar with these two determinants of intensity (heart rate & perceived effort), we can combine them for the purpose of communicating how hard or easy a particular workout is to be performed: Intensity Determination Table Rating 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Perceived Effort Very, Very Light Very Light Fairly Light Somewhat Hard Hard Very Hard Very, Very Hard Prescribed Intensity Level 1 Easy (active recovery) Level 2 Medium (aerobic endurance) Level 3 Tempo (steady state) Anaerobic Threshold Level 4 Hard (VO2 Max, Hammering!!!) % of MHR % of ATHR ¯ˉ70% MHR ¯ˉ77% ATHR 71-­‐80% MHR 78-­‐90% ATHR 81-­‐90% MHR 91-­‐100%ATHR 91%+ MHR 101%+ ATHR Target Heart Rate Zones 1. Level 1 / Easy-­‐-­‐ less than 70% MHR or 77% of ATHR. This could also be called ‘active rest’. This is where you will be in the early season and in between hard workout days during the season. For many people (who, me?) this is the hardest place to be. That feeling of "I'm not working hard enough" seems to be difficult for many people. This is the zone, however, where you can maintain your fitness while recovering from harder work. One of the biggest problems in training is the inability to go easy and allow one's body to recover and benefit from the hard work already done. 2. Level 2 / Medium-­‐-­‐ 71-­‐80% MHR or 78-­‐90% ATHR. This could also be called ‘aerobic endurance’. Technically, everything below about 85 -­‐ 90% is "aerobic" but, depending upon how fit one is, the line between aerobic and anaerobic training can be lower or higher. This is a good zone to stay in for your long rides and runs where the focus is to spend time on one's legs installing the plumbing (circulatory system) and Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained energy systems (mitochondria) that will allow your muscles to work more efficiently. This is a relatively easy zone to be in, but requires steady, moderate effort. 3.
Level 3 / Tempo-­‐-­‐ 81-­‐90% MHR or 91-­‐100% ATHR. This could also be called ‘tempo’. This is where many people spend the majority of their time because they "feel like" they're working only at or above 78%. Depending on one's level of fitness, the frequency and duration spent in this zone will either drop you into an over-­‐training abyss or gradually maximize your athletic potential. As you raise your AT, this zone should feel easier and easier. It is not an “easy” level of intensity but one that you should be able to hold for long periods. In the early “base building” part of the season, this will be the upper limit of higher intensity training. 4. Level 4 / Hard-­‐-­‐ 91%+ MHR or 101%+ ATHR. This could also be called the ‘hammering’ zone. This is the zone where intervals will be done during the race season. Like “tempo”, excessive time spent in this zone will quickly lead to diminishing returns. In this case, abuse doesn’t take long to manifest itself as symptoms of over-­‐training. Used in the right amount, this is where major gains in anaerobic capacity for shorter races (Olympic distance and under) can be made. Definitions Anaerobic Threshold (AT) -­‐ Referred to by some physiologists as the point at which enough anaerobic metabolism occurs such that more lactic acid is produced than can be rapidly cleared from the body. This occurs from 60 to 95% of VO2 max depending on an individual’s fitness level. You know this level as that where breathing becomes labored but maintainable. If you continue to raise this pace, you soon will hit VO2 max, beyond which, you will reach failure (puking and bleeding from your lungs). AT is a trainable level. *Also referred to as lactate threshold. Maximum Heart Rate (MHR) -­‐ the highest attainable heart rate. This value is genetically determined and, although there are formulas to predict it, the best way to determine your MHR is to actually go out and achieve it. Eg. Running -­‐ go to a track, warm up 15 minutes, run 1 x 400m hard, 1 x 400m harder, and then 1 x 800m building from hard to all out over the final 300m. Take 1 minute recovery after each 400 and remember to cool down at least 10 minutes (jogging or walking) after the 800. MHR is not a trainable level -­‐-­‐ it is what it is. VO2 Max -­‐ refers the maximum amount of oxygen that a person can take in and utilize. In short, this level can only be maintained for one or two minutes before one is forced to stop from exhaustion. Max VO2 is a trainable level. Aerobic -­‐ literally “with oxygen”. Generally speaking, this ranges from singing your alma mater’s fight song -­‐ to holding a conversation -­‐ to speaking in one word sentences during exercise. As you can see, there is a broad scope of intensities within the definition, “aerobic”. In terms of heart rates, aerobic training occurs above 55% of MHR and below AT (got it?). Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained Resting Heart Rate -­‐ Resting heart rate is an easy number to determine. The best time to take it is upon waking in the morning. When you wake up, before you get out of bed, slide your middle and fore finger into the groove on your neck (next to your Adams apple) to feel for your pulse. Grab a watch or look at your clock, relax, and count the number of pulse beats for fifteen seconds. Multiply this number by four and that is your RHR in beats per minute or bpm (you can also count the beats for a minute). Getting into the habit of checking it regularly will allow you to keep track of your fitness and warn of overtraining and/or impending illness. As you begin to know what your RHR is under normal circumstances, you will recognize when you aren’t fully recovered from a workout the day before or might be getting sick by seeing an increase of five or more bpm. Determining ATHR Determining ATHR is a little more involved. Using an equation (220 -­‐ age) multiplied by some percentage is an efficient but, sometimes, inaccurate method. One of the most accurate methods for determining max HR is to go to an exercise physiologist’s lab and get tested in your intended activity. If you don’t have access to this, you can perform a fairly accurate test on your own. Before you go out to do this, it is crucial to make sure you are physically ready to attempt such a test (yes, this is the warning / disclaimer). Getting the physical "OK" from your doctor is a prerequisite. Even if you are well trained this is a good step to take to avoid any possible injury or complication that is lurking. This one variable can be as individual as any other genetic trait and is not trainable. It is what it is. Before we get into the actual test, I would like to stress an important point regarding HR parameters. Your resting heart rate, max HR, anaerobic threshold HR, VO2 max HR, and target training HR, are all personal numbers. These are unique to you and, therefore, not comparable to others from a competitive point of view. Yes, it's interesting to know that your training partner's HR is much higher / lower than yours when going up a particular hill but this is not a difference to get either cocky or depressed about. If you are both relatively fit, the difference will probably remain the same from a state of rest all the way up to max HR. Focus your attention on your own HR and disregard that of others. The various levels of workout intensity are based on your max or anaerobic threshold heart rates. If we are basing target heart rates on max HR -­‐ and you and I decide to do a workout at an 80% effort -­‐ and my max HR is 170 and yours is 190, my workout HR should be around 136 while yours should be around 152. Are you working harder than me? Am I more fit than you? Neither. As you can see, we are both working at the same level of intensity. We are both at 80% of our max HR's. One other point to keep in mind – especially if you run or swim as part of your regular fitness routine – you will have differing heart rate parameters in each of the different sports. Generally you can expect your swimming HR to be lower than cycling, and your cycling HR to be lower than that of running. This is caused by the fact that in running you are supporting your full body weight and using the larger muscle groups of the legs. Cycling, while using these large muscle groups, is a weight supported activity and thus Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained the lower HR (unless you are standing up ‘out of the saddle’). Swimming uses smaller muscle groups as the prime movers (the arms) while water supports and cools the body. The recommended test for the bike is taken from, Joe Friel’s, The Cyclists Training Bible. There are testing protocols for both magnetic trainer and computrainer users (if you are using a computrainer, refer to p. 39 of the workout manual). Is this the only way to determine ATHR? No. There are many protocols for testing anaerobic threshold but this is one that we use and works quite well. Note: the only change made is to make the interval at each workload 1½ minutes instead of 1 minute. This allows more time for the heart rate to stabilize and give a true reading. Magnetic or Wind Trainer Set-­‐Up 1. Test must be done with a stationary bike that accurately displays speed (or watts). You can use your own bike on a stationary trainer with a rear wheel computer hook-­‐up. 2. Select “manual” mode. 3. You will need an assistant to record information. 4. Warm-­‐up equipment for 5-­‐10 minutes. Test 1. Throughout the test, you will hold a predetermined speed or power level. Start at 15 mph (or 100 watts) and increase by 1 mph (or 20 watts) every 1.5 minutes until you can no longer continue. Stay seated throughout the test. Shift gears at any time. 2. At the end of each 1.5 minutes, tell your assistant how great your exertion is using the original Borg scale (place it where it can be seen). 3. Your assistant will record your exertion rating and your heart rate at the end of the 1.5 minutes and instruct you to increase speed (watts) to the next level. 4. The assistant will also listen closely to your breathing to detect when it becomes unnaturally labored. This point is the “VT” or ventilatory threshold. 5. Continue until you can no longer hold the speed (watts) for at least 15 seconds. 6. The data collected should look something like this: Speed Power Heart Rate Exertion 15 100 110 9 16 120 118 11 17 140 125 12 18 160 135 13 19 180 142 14 20 200 147 15 21 220 153 17 “VT” 22 240 156 19 23 260 159 20 7. Compare “VT” heart rate / power with an exertion rating in the range of 16-­‐18 Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained to determine lactate threshold (anaerobic threshold). To help confirm this, realize that athletes are seldom able to go more than five minutes beyond their lactate threshold (anaerobic thresholds) on this test. You now have an estimate of anaerobic threshold to compare with other indicators, including actual race (time-­‐trial) heart rates and subsequent tests. AT Heart Rate Evaluation Form Name_____________________________Resting HR_______Cal.#_______Date____________ Time Workload Heart Rate Perceived Exertion 7 (easiest) to (minutes) (watts/speed) (bpm) 20 (hardest) 0:00 to 5 -­‐ 10:00 Warm Up 0:00 -­‐ 1:30 100 watts 1:30 -­‐ 3:00 120 3:00 -­‐ 4:30 140 4:30 -­‐ 6:00 160 6:00 -­‐ 7:30 180 7:30 -­‐ 9:00 200 9:00 -­‐ 10:30 220 10:30 -­‐ 12:00 240 12:00 -­‐ 13:30 260 13:30 -­‐ 15:00 280 15:00 -­‐ 16:30 300 16:30 -­‐ 18:00 320 18:00 -­‐ 19:30 340 19:30 -­‐ 21:00 360 21:00 -­‐ 22:30 380 22:30 -­‐ 24:00 400 24:00 -­‐ 25:30 420 25:30 -­‐ 27:00 440 27:00 -­‐ 28:30 460 28:30 -­‐ 30:00 480 30:00 -­‐ 31:30 500 31:30 -­‐ 33:00 520 33:00 -­‐ 34:30 540 Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained Now that you know your anaerobic threshold HR we can use this number to gauge the intensity of your workouts depending on the time of the season we are in and on our race specific goals. These levels of intensity can be broken up into 3 to 5 HR ranges or zones. Throughout the training week, your day to day target HR will change according to the workout given and the purpose of that workout. During the adaptation and base phases, the majority of your training time should be spent below ATHR. Calculate your different target zones based on your ATHR heart rate* in the different sports. Example: My anaerobic threshold heart rate (ATHR) for running is tested to be 170 beats per minute. Since the ‘easy’ or ‘active rest zone is ¯ˉ77% ATHR, my easy zone for running is: .77 x 170 = 130.9 or 131 So, my easy zone is less than 131 bpm. Target Zone Worksheet Cycling HR Zone HR 1 (<70% MHR or <77% of ATHR) HR 2 (71-­‐80% MHR or 78-­‐90% ATHR) HR 3 (81-­‐90% MHR or 91-­‐100% ATHR) HR 4 (91%+ MHR or 101%+ ATHR) *If using one’s MHR, simply insert the corresponding % into each training intensity level The following is a good example of a test you could do quite regularly to determine whether or not you are in an over-­‐trained state. Cycling, a known distance at a sub-­‐AT heart rate, under controlled conditions can let you know how tired you are. If you know what time you’re capable of for a given distance at a certain heart rate, covering a distance that is significantly shorter at that same heart rate might indicate the need for more recovery time. Sub-­‐AT Fatigue Test Example Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained On a stationary trainer that can measure distance/speed via a rear wheel bike computer, ride 15 to 20 minutes at 15-­‐20 beats below your ATHR. Over the course of the training year, you will establish, based on what distance you cover, how fatigued you are. Make sure that conditions are the same every time you perform this test (eg. Tire pressure, stationary trainer used, cadence, weather conditions). This is important to ensure an accurate correlation for each test. - Warm up for 10-­‐20 minutes steadily working up to a HR that is 15 to 20 beats below ATHR - Start your watch and maintain that HR for the predetermined amount of time (15-­‐20 minutes). - Shift as necessary to maintain the constant sub-­‐AT HR (plus or minus 2-­‐3 bpm). - Remain seated and stay in one position (aero or hands on bars) throughout the test. - Record the distance covered, perceived effort, and all relevant conditional variables. If the distance covered is significantly shorter than previous tests, it is a good indication that you may be over-­‐trained and need to modify your training for the next few days accordingly. If you use a Computrainer, refer to p. 42 of the workout manual. As said at the start of this, if you aren’t interested in having to wear a heart rate monitor in your daily training, don’t. You could estimate target training zones simply based on perceived exertion alone. The heart rate monitor, however, doesn’t lie, and is particularly useful for days when you want to be sure you are at an easy to medium intensity. Since your anaerobic threshold is trainable (that’s point in all of this, right?) and is used to determine target training heart rates, it is suggested that you do an AT test every six to eight weeks to keep track of where you are. If you ride a few 5 and/or 10-­‐mile time trials throughout the year, you may not need an AT test. A 10-­‐mile time trial is a great way to determine what your ATHR is. In a very fit person, AT can be as high as 90-­‐92% of max HR. As the season progresses, even a rise of 2-­‐4 beats in ATHR is a significant improvement. We want to emphasize the importance of working in the ‘hard’ / level 4 zone judiciously. If you have the time to recover well (you are getting plenty of sleep, eating well, and generally able to take care of yourself) you will be able to handle more. There is no question that you have to work at a very high level in order to race at a high level, but try to get a feel for how much is enough without going over that "red line" and blowing yourself up. The following* has some useful explanations of HR vs. perception of effort. It is a good guide for anyone interested in avoiding overtraining. Using Heart Rates to Monitor Your Training* Heart Rate Training & Determining Training Intensity
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Heart Rate Monitor Explained “Using a combination of resting heart rate (RHR), training heart rates (THR) and training speed (TS) you will be better able to check on your reaction to training. 1. RHR normal, THR normal, TS normal. Indicates training and recovery are well balanced. 2. RHR normal, THR elevated above predicted normal, TS above normal. This is particularly likely during base training and indicates you are training too hard. Slow down. 3. RHR normal, predicted THR cannot be reached, TS can’t be reached. This indicates fatigue in major muscle groups, such as ‘dead legs’ in cycling; your legs are so tired that they are not able to take you to the speed/intensity that you are capable of in training when ‘fresh’. Abandon programme for the day and have an easy day, eg. ‘spinning’ in cycling, or go home and have a day off. This occurs more often when you are doing speed work like intervals or sprints. 4. RHR elevated, THR elevated, TS below normal. This indicates serious tiredness. Have a day off, you may be ill. 5. RHR normal, THR goes from normal to elevated considerably above normal while training or racing, speed constant or begins to drop. You may be dehydrated. Be very careful! 6. RHR normal, THR above normal, TS normal. You are tired. 7. RHR normal, THR normal, TS below normal. You are tired or have ‘dead legs’. 8. RHR above normal, THR normal, TS normal. You are probably experiencing mild mental stress/anxiety. 9. RHR normal, THR begins to drop and cannot be held in a long workout, speed drops. You’ve ‘hit the wall’, or ‘bonked’. 10. RHR normal, THR slow to drop after an effort (eg. interval) or after a workout, TS normal or marginally below normal. You are fatigued or overtrained.” *Taken from “The Power to Perform: a comprehensive guide to training and racing for endurance athletes” by Jon Ackland and Brett Reid, published by Reed Publishing (NZ) ISBN 0 7900 0359 7 Heart Rate Training & Determining Training Intensity
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