Maximum Target Heart Rate

Factual Questions
1

As I’m trying to keep New Years resolutions going, I was just looking up some info on target heart rates for excersize.

I found lots of sites where they show the formula to determine target rate: “maximum heart rate/minute” = 220 - your age. Your workout target rate is then a % of that, depending on your objectives.

I’m curious if anyone can help me (or point me to somewhere) to explain the origin of “MHR = 220 - Age” formula. I found lots of sites that tell you the relationship, but nowhere that explains how that formula was determined, i.e.: upon what research was it based.

The simplicity of the relationship, dropping one beat/minute/year of age, seems so nice and simple that it strikes me like a simplistic “one-size fits all” proxy measurement akin to BMI. I’m not a doctor, but it strikes me that there should be many other variables affecting target heart rate beyond age, e.g.: fitness level, weight, medical history etc.

Thanks for your thoughts.

2

Ignore it. It’s highly inaccurate. The one beat per year only applies to the never fit. If you’ve been working out, it tends to stay the same.
The only way for an accurate rate is either a treadmill test, monitored step test or one of several self-tests that involve pushing yourself to the point of failure.
Before self-testing, get clearance from your doctor.
Fitness level, weight and so on have no effect on MHR.

3

The "220 - Age” formula was empirically derived from treadmill observations. It was never a rigorous formula, but more of a “BMI” - type rule-of-thumb.
In recent years the formula has been updated to be "208 – 0.7(age)”, and this is what my cardiologist used for my recent Stress-Echo test.

FWIW, I asked him about this, because I regularly exceed my calculated max (168) when I run, and he said that it’s just a guide, and not an absolute.

4

The first question one should ask is, “Why do I want to know my maximum heart rate?”

The answer for most people is, “Because I’m a non-athlete beginning an exercise program, and I want a way to guess at the BPM ranges for the zone-based training plan upon which I am about to embark.” 220-age is fine for that, but experienced athletes who use heart rate monitors know what their real-world maxima are, and those don’t often correspond to the formula.

I’ve been a serious bicycle racer since I was 11 years old, and started training with a heart rate monitor at 15. When I was 16, the formula would say my max was 204 BPM, but I routinely hit 210 and occasionally hit 220. The formula would imply that I was -16 years old at the time.

I slacked way off between going to grad school and having kids, and only started using a heart rate monitor again a couple of years ago. I’m 44 now, but I still hit 190-195. But it’s not that “I have the max HR of a 25-year-old” or something like that. I’m 5’8” tall, and body size has a lot to do with heart rates. I have tall friends my age whose max is about 160 BPM. Their resting heart rates are also lower than mine even though we”re in similar shape.

RunningCoach covered this already, but I agree: your observed max is more useful as long as you’re an experienced athlete or have been tested in a lab to the point of failure. I say this because many sedentary people simply aren’t used to pushing themselves very hard. Without heart rate zones, some of these people would think they were working hard well before they reached their anaerobic threshold.

There’s a truism in endurance sports: the winner is often the person willing to suffer the most (both in training and in competition). By definition, suffering is hard. It’s also a skill that can be learned.

I’m not saying recently sedentary people are lazy; I’m suggesting that some of them are simply unused to sustained aerobic exercise. In a very general sense: if you can carry on a conversation as you run, you’re not getting much of a training effect.

So an otherwise-healthy sedentary person my height might see a max HR of 160 from one of his first runs and use it to conclude that, in terms of zones, he should be at around 120 BPM to see an aerobic training effect. Because I happen to know that I can hit 195 BPM, I’d need to be at about 145 BPM. While the 220-age formula says I’d need to be at around only 132 BPM to be in the aerobic zone, that’s closer than 120 BPM. I probably hit 120 BPM doing housework.

5

Is there any danger that you will damage your heart (or other vital system) by exceeding any given heart rate level? Or is this just about knowing that you’re doing it hard enough?

My rate when I’m feeling like I’m really working out hard is certainly above 85% of my “max.” What’s the downside?

6

Above 85%, you’re going anaerobic, otherwise known as “lactate threshold”. At best, you could hold that effort for an hour but that would be an all out effort and the oxygen debt would bring you to a halt.
Far too high an effort for day to day, you would(assuming you could even replicate the effort the next day) break down and get ill or injured.
The body can’t rebuild that quickly, you would need several days to recover from that level of intensity. That’s not working out, that’s all-out competition.

The process of recovering and building up after a workout is actually when the fitness gains are made, not from the workout itself.

7

There’s probably not too much risk for an experienced athlete, since they would likely get lightheaded before they could really do any damage. And they understand their body and how things feel, so they would know when to stop.

Going too high in HR is probably more of a concern for a beginner than an athlete. A beginner’s metabolic systems may not be up to the challenge right away. One common outcome is that they are very sore the next day because their aerobic capacity wasn’t sufficient. Their body had to use a non-aerobic form of energy, which causes muscle soreness later on. A heart attack would also be a risk. There could be clots that get knocked loose or their arteries may not be supple enough to easily expand to handle the increased bloodflow.

Along with taking max HR with a grain of salt, the same is true for conversions of HR to calories. Fitness monitors can estimate your calories burned from your HR, but that is based on calculations from the general population. Your specific calories burned will likely be different.

8

Actually, it’s exceeding the muscle’s capacity for work that causes the soreness. A marathon (even for the world class guys) is entirely aerobic.

Going anaerobic in and of itself is not damaging, oxygen debt quickly puts an end to that fun if you push too hard.

9

I would add that it’s pretty difficult for anyone who’s basically healthy to hurt themselves by exceeding a particular heart rate. If that weren’t true already, natural selection would quickly make it true.

Besides, trained athletes aren’t backing off because they know that they’ll die if they try to go faster. If this were the case, we’d see all sorts of posthumous medals awarded at every Olympic Games. Maximum efforts are inherently self-limiting. Trained athletes don’t go faster than they do because they simply can’t.

I’ll defer to actual physicians on this, but I doubt many people have died because their heart was beating faster than some biologically predefined rate. Sedentary people keel over all the time when they set out to shovel the first snow of winter, yes. But I’d expect they’re dying of cardiac problems stemming from exertion, such as clots and arterial plaques breaking off in a blaze of embolistic glory.

I sincerely doubt that their hearts, which were somehow rated for, say, 168 BPM, were pushed to 168.2 BPM and simply said, “Nope. You’re dead now.”

10

True. I’ve seen results for a pro cycling team where there were all individually tested, stress-test like. Despite everyone being w/in about 3 years of age, the individual max heart rates were 15-20 points different.

11

Was there any correlation between HR and power output? Like, did having a higher max mean they produced more power?

12

Nope. Max HR is genetic and won’t be altered by training.

13

Aren’t those two sentences at odds?

Are there are also genetic factors in an individual’s MHR, just as for VO[sub]2[/sub] Max? Although training can move either, it seems like each person has a barrier that is hard/impossible to train past. I was never a competitive athlete but I used to run until I switched to cycling for my knees. I do a lot of weight training. I had a stress test last year and the tech running the test told me that the objective was to hit 220 minus my age, which works out to 160. I got into the low 150s and then reached failure (that is, if I had forced myself to keep going I probably would have passed out). I can imagine her eyes bugging out if she told me to hit 160 and I hit 220. I used to use a heart rate monitor band while cycling and found I could sustain 136. I could get into the 140s but not sustain it.

14

There isn’t much of a correlation between maximum heart rate and power. One quasi-standard measure for cycling fitness is watts per kilogram. Within a given cycling specialty (e.g., climbing, sprinting, time trialing, etc.) riders of different heights and weights (and max HRs) typically generate quite similar power when normalized for mass.

Taller climbers (5’10"-6’2" tend to generate the same number of watts/kilo as really short riders (5’3"-5’5"), while the short riders almost certainly have higher maximum heart rates. If anything, there’s an inverse correlation between max heart rate and power output. In absolute terms, the taller riders are generating more power than the shorter riders but with lower maximum heart rates. But the taller riders weigh more, so their w/kg numbers are quite similar to those of the shorter riders.

Climbers are the most straightforward case because wind resistance is somewhere between minimal and negligible at climbing speeds. Sprinters and time trialists are harder to compare because both aerodynamic drag and the power required to over come it increase nonlinearly. But the differences between riders are small enough that you occasionally see smaller riders (like Mark Cavendish and Charly Mottet) excel at these higher-speed disciplines.

15

Not at all. If someone never worked out, then MHR will decline. A regular workout routine will maintain MHR at whatever level it was at the time.
As an example, when I was 20, I had my MHR treadmill tested. I maxed out at 193, 7 bpm below the formula. When I was 44, I ran a 10k just two days before my accident (last time I was able to attempt MHR), I finished at 190 and had reached 192-193 in previous races. The formula predicts my MHR should be 176 at that age.

MHR and VO[sub]2[/sub] Max is very much genetic. Generally, you are born with most of your VO[sub]2[/sub] Max, training will add 15-25% in general. What really makes a difference is the increasing the % of VO[sub]2[/sub] Max (and improved running economy) you can maintain for a distance.

16

How tall are you? I bet you’re significantly taller than me. I’m 5’8".

And again, if the lab tech told you the “goal” was 220 minus your age, the tech was misinformed. 220 minus your age has never been anything more than a gross approximation.

Running Coach, I wasn’t aware that regular exercise can stave off a decline in max HR. I don’t doubt you at all, but if you have a cite, I’d love to learn more about that.

17

Sorry, I meant did the athletes with higher HR also produce more power as compared to the athletes with a lower HR? Like, did the guy with a 200 max HR produce 300 watts and some other guy with a 180 max HR produce 280 watts or something like that.

18

Filmore: I answered that in post 14.

There’s no significant correlation between max HR and power if you normalize for mass. If you don’t, there’s an inverse correlation: the lower your heart rate, the more power you make. But that’s because bigger riders tend to both have lower heart rates and need to make more power to offset their greater mass. So the convention is to normalize for mass and compare watts/kilo.

19

I mentioned this to my doctor (a cyclist) last week, as I seem to be doing aerobics (elliptical trainer) at higher than the heart rate all the charts suggested. He said that the charts are vague at best, and we agreed that hitting somewhere in the range between breaking a sweat and running short of breath was good enough. So, if you’re sweating and you can still breathe through your nose or carry on a conversation, you’re aerobic.

20

Sorry i didn’t get back sooner, life intrudes.
Lot of contradictory accounts and studies on the Web.
I did find this that may explain.
Max Heart Rate: Age-Related Decline