Questions about anaerobic training, HR, and HIIT

SJ46

I know that this is going to be TLDR for some of you, please feel free to skip down to my questions!

Today I tried a workout at a new Orange Theory Fitness. The class focuses on HIIT and circuits with 26 min on the treadmill running intervals and three blocks of circuits utilizing hand weights, TRX, and a rowing machine. During class you wear a HRM and your HR is posted on a screen. The goal is to spend 12-20 min in the orange zone which is supposed to be 84-91% of your max heart rate.

Background on me: I consider myself a fit individual. I typically do 5-6 cardio classes a week, either BodyStep which is a step class with intervals and plyometrics or BodyCombat which is like cardio kickboxing, and 2-3 heavy lifting days focusing on the lifts in Starting Strength (though I don't get enough deadlifts in!). Yes, I know too much cardio but that's what I like - it gets me to the gym and more importantly keeps me sane. According to my HRM my average heart rate is generally around 145 for a 50 min cardio class. I have been told by my doctor that I have a very low RHR (I have seen it as low as the low 50s) and am in excellent cardiovascular health. Generally when my HR is in the 160s I start to feel winded and above 165 I would say my RPE is a 7 or 8. In the 170s my RPE is 8-9 and if I hit above 175 I am definitely at 9.

My experience today: You need to know that this week I've been fighting off a cold but still made it to the gym, Tues was my day off. This morning I felt rotten when I woke up but due to a personal commitment I didn't feel like I could stay home.

I started class on the treadmill, figured I should get that out of the way since I don't like to run. A few minutes in I started to feel much better which was pretty encouraging. During this part of the class my HR was much higher than I would have guessed based off my RPE. When my HR was in the 160s I would say my RPE was around 5, in the 170s it was 6-7, and in the 180s it was 7-8. During the circuits, which did not allow for any recovery, my HR was higher and my RPE was between 7-9. There was one instance following a set of jump squats that I would say I was 9 maybe 10. I was under the impression we were supposed to go all out during the sprints and the circuits so that's what I did.

Here are my stats for the class:
Duration: 55 min
Avg HR: 172 (88% of MHR)
Max HR: 193 (98% of MHR)
Time in Zone:
Red (92-100%): 18:15, 33% of class
Orange (84-91%): 23:15, 42% of class
Green (71-83%): 12:15, 22% of class

After class the trainers talked to us about what the numbers mean. I was held up as an example of someone who has a high resting heart rate and doesn't do a lot of cardio. What? Really?

My questions:
1. Why was my HR so high during class? I never had burning muscles nor did I feel like jello so I assume I did not hit my lactate threshold. Another thing confusing me is I thought if my HR was high due to me not feeling the greatest or because of overtraining then I would have felt worse during the class and had higher RPEs, no? I would say my work output was pretty high so it's not like I was doing a smaller amount of work at a higher HR.

2. I assume they used 220-age to calculate our MHRs. I understand that this is an estimation and may not be accurate for everyone. I would think spending 33% of class time in my MHR range would be very difficult, while I was working pretty hard I didn't think I was working hard enough, based off of how I felt, to have spent that much time in that range. What is wrong with my thinking here?

3. What is the benefit of spending so much time in the anaerobic zone while exercising? Can you do too much anaerobic exercise in one session?

4. What is your opinion of OTF, if you have experience? What is your opinion of this type of training in general?

All in all I really enjoyed the class and I still feel much better than when I woke up this morning so I'm glad I went. I am considering trying out a few more sessions there, maybe add it in once a week and take out some of the other cardio that I generally do. I am going to try to attach the HR data, hopefully it will work.

Thanks to anyone that took the time to read all of this!



ETA: sorry, I can't get the picture to resize but if you open it in another window you can see the rest of it.

erickirb

1. You worked you *kitten* off

2. The first thing I would point out is that your HR was probably not as high as they think, as I am sure your Max HR is much higher than the 220-age generic calc. I have a friend had hers tested at 33 years old came out with a max HR of 205, so if you HR max HR is in the 205-210 range then time in zones, and % of max calculation will all be off. and 220-age is even less accurate for women than men.

3. I prefer anaerobic, that said as long as you give yourself enough recovery and fuel your body, then it would be difficult to get too much.

I would also not consider this true HIIT, if it were true HIIT you should not be able to go for much more than 20 or so minutes.

Azdak

Hmm...I'll have to get back to you. This is going to require a real keyboard.

MoreBean13

Mostly just bumping, better leave this one to the experts.

But my initial thoughts are that your HR data from this instance are probably off because of being sick. It's extremely unlikely that you spent 18 minutes working at 92+% of your MHR and felt fine afterwards. That much anaerobic cardio would floor ANY athlete. Tabata workouts are 4 minutes long and anyone who truly does them at max HR knows they're BEASTLY and getting through 2 tabata cycles is brutal and 4.5 would be like professional-level athlete fitness.

So, I would probably junk the data from this workout until you're healthy and re-do it. If the numbers come out similar, I would assume your MHR doesn't line up with 220-age and I would probably go through a test to determine your real MHR so you can reset all the zones for yourself. (get someone to help you with the test- it's pretty awful).

Cre8veLifeR

I just posted a similar question the other day pertaining to anaerobic VS aerobic training. I had to do some research!

OT claims that working that hard creates "after burn". It DOES burn a crap load of calories. that's for sure!

So, your questions as I understand them: Because you have a low resting HR (mine is 49!) that means you have a high VO2 max threshold. In an anaerobic state our bodies are burning through glycogen stores to workout, rather than oxygen in an aerobic state. Since you (and I also) do a LOT of weight training, we have really healthy glycogen stores, since it stores in the liver and the muscles. So we CAN workout in an anaerobic state for a longer time before our KREBS cycle kicks in, and when that kicks in in a non-aerobic state, lactic acid is the result. It you are athletic you may be able to go 1.5 - 2 hours before you deplete your glycogen and need to refuel.

I asked the same thing because when I run or do extreme cardio, I am in the 85-95%+ for my MHR as well, and can sustain it for a long time and don't feel like I am going to have a heart attack. But go try lifting weights after a workout like that and THEN you will feel the jello effect since we have utilized our energy stores and haven't allowed recovery.

The afterburn effect IS true - you do burn more calories when your body is at rest (your BMR), BUT, I have also read that these kinds of workouts can really exhaust a person and so you are actually LESS active in the long run (like over the next few days) while your body recovers, so you technically LOWERING the BMR because you aren't moving as much as you normally do. So that really only applies of you go about your normal activities.

I tried Orange Theory too and I liked it as well - but I think it depends on your overall fitness goals. If you are striving to be an endurance athlete then these kinds of workouts totally increase your VO2 Max, which is really the purpose of intense cardio workouts. If you want to be a body builder, then obviously this is not an appropriate workout. It's important to build LBM as an endurance athlete in order to, well, compete better (more muscle strength and endurance) but also to build up healthy glycogen stores. Also, I found a different THR formula for athletes - it gave me a few more beats lol. It's 217 - (age X .85).

I notice, as a side note, that I really experience terrible lactic acid build up when I do intense cardio followed by isometic exercises!!

I'm not a scientist - this is what I have learned and hope I learned it right -- if I didn't I hope someone will answer so I too can learn! The body is a complicated thing!!!

shazbox1

I'm certainly not an expert, but I have read a few things so will give it a shot.

1. Having a cold can increase your heart rate overall. So this may be the case today, since you have been dealing with one for a while.

2. It is only an estimate, so that could be off. Other intervals programs I have seen involve doing a fitness test before you start to figure out some measurement of heart rate and then use percentages of that as 'zones'.

3. Doing anaerobic exercise trains your anaerobic system, which lets you operate better in an anaerobic situation (i.e., doing sprints or sustained efforts in a race). I imagine that you can definitely do too much in a workout, but I would also guess that your body would generally let you know when you have done too much.

4. Never heard of OTF before.

EDIT: I also agree with what Cre8veLifeR said. Much more scientific sounding

TAsunder

That sounds like a fun class. I have taken boot camp classes that included treadmill sprints and enjoyed them.

My resting heart rate is somewhere in the low 50s as well. I regularly average > 165bpm when doing some activities (like running). I do not feel that my RPE is over 8 until my heart rate is over 180 usually. I have never thought twice about it.

mariabee

Just bumping for the information here, great post!

maybeazure

I'm not really an expert either, but I'll share my experience with the whole heart rate thing, because I pay attention to it. First, I know that my "maximum heart rate," must be higher than the charts say because I've gotten it up to 181 before, the chart says it should be 177, and yet I'm not dead.

I like high intensity workouts...mostly running. I have gotten so that I can stay in the 90% range for about 20 minutes out of a 30 minute workout. It kind of sucks while it's happening, but I feel great afterwards, which is why I keep doing it. I have also had the experience of my heart rate being higher than it feels like it should be to me. I was concerned enough about it that I asked my doctor, who said that the important part of the whole heart rate thing as far as health goes, isn't how high it goes, but how quickly it recovers after you stop exercising. It should go down 12 beats within a minute, or something like that.

You said that you do a lot of cardio, but that you don't like running much, which makes me guess you don't do it much, so your body might not be as adapted to it as other kinds of cardio, like circuit training. That might mean that your heart needed to work harder, which isn't a bad thing, as long as you are healthy...which it sounds like you are.

shazbox1

Some more info from good old Wikipedia Heart Rate page:

Maximum heart rates vary significantly between individuals. Even within a single elite sports team, such as Olympic rowers in their 20s, maximum heart rates have been reported as varying from 160 to 220.

Further, note that individuals of the same age, the same training, in the same sport, on the same team, can have actual HRmax 60 bpm apart (160–220):[11] the range is extremely broad, and some say "The heart rate is probably the least important variable in comparing athletes."

SJ46

Thanks for the responses, keep 'em coming if you have something to add!

I guess a big part of my confusion lies in my assumption that I should have had a higher respiration rate than I had today to correlate with such a high HR, I also thought my RPE would be much higher. Since I am not a runner I expected a higher HR but I also expected to feel awful.

Azdak

Overall, it seems likely that something was affecting your HR response to this workout and it was an exaggerated response. You don't include your age, so it is hard to tell how your exercise HR compares to your possible HR max.

The illness could contribute, as could the 26 min of treadmill running. If you don't do that much running, or if you normally don't do that much higher-intensity cardio before doing a circuit type workout, then your HR could be elevated by cardiovascular drift (the drift could also be caused by being dehydrated). So before we even consider your overall HR response, we have to determine whether it was your "usual" HR, or, as described above, an exaggerated HR response.

1. If you have an underlying infection, getting over an illness, somewhat dehydrated, etc, then, yes, you can have an elevated HR without feelings of increased RPE. This can also happen when you are doing a new workout that includes some vigorous movements that you aren't used to doing. As someone else said, you basically need some additional workout data points to put this one day in perspective.

2. If you spent 33% in your HRmax range, then it likely is not your actual HRmax range. However, back to #1, your HR could have been elevated higher at levels of work that were not truly maximal.

3. The "Orange Zone" is not really what I would call "anaerobic", at least the way the term is normally used. It's more akin to "threshold" or "tempo" training. While working at a higher intensity with a large glycolytic component, aerobic metabolism still plays a role. Semantics aside, it is an intensity level that many physiologists feel provides the most "bang for the buck" for the average exerciser when compared to either LISS (low-intensity steady state) or all-out HIIT. Can you do too much in one session? You can always do too much of anything. From a cardio standpoint, high-intensity exercise tends to be self-regulating in healthy individuals--you become fatigued and have to stop before you could injure your heart, for example. However, higher-intensity exercise does put greater strain on muscles, joints, tendons, etc. Excessive exercise leading to fatigue can result in mistakes or form deterioration that can definitely lead to injury. A high volume of high-intensity exercise sessions per week can increase the incidence of overuse injuries.

4. OTF and it's training philosophy. There is nothing unique about OTF except the packaging. It is another prepackaged form of circuit/interval training that just happens to use HR as a monitoring parameter. I checked the website and the claims, justification, etc behind the method is a bunch of hooey, but that doesn't mean the workout itself is bad. (Ex: the "muscle confusion" explanation behind P90X is gibberish as well, but the workouts can still be effective). The centers themselves are a franchise, so that means that the programs/centers are drop-in modules that can be run by anyone with investment capital.

So, if you like it and find the bells and whistles motivational/enjoyable, then by all means go back for more. As far as I can tell, the workouts themselves are fine.

In general, my feeling it that high-intensity circuit training is something that should be done with restraint. Personally, I would only do them twice a week, especially if you are lifting heavy 2x a week. After that, some endurance workouts are still beneficial for a balanced program.

Azdak

Thanks for the responses, keep 'em coming if you have something to add!

I guess a big part of my confusion lies in my assumption that I should have had a higher respiration rate than I had today to correlate with such a high HR, I also thought my RPE would be much higher. Since I am not a runner I expected a higher HR but I also expected to feel awful.

Again, if the HR is an exaggerated response due to illness, cardiovascular drift, higher body temp, then the HR will not reflect the actual intensity.

To give you a personal example, when I do a 60 min endurance workout where I keep the workload exactly the same for the entire 60 min, my HR will be 20-25 beats/min higher during min 55-60 than it was during min 3-8. Again, workload is exactly the same, breathing is the same, and RPE is the same.

It may be that your other workouts have given you a level of conditioning so that you can tolerate the running better than you thought.

Azdak

I just posted a similar question the other day pertaining to anaerobic VS aerobic training. I had to do some research!

OT claims that working that hard creates "after burn". It DOES burn a crap load of calories. that's for sure!

The "afterburn" effect is modest at best for any exercise. It's easy to make claims of "increased burn for 36 hours" (based on only 1 or 2 outlier studies), but the total burn is still only 100-150 extra calories. "36 hours" is not that impressive when the increase is only 3-4 calories an hour. If the OTF system IS pushing you into a "tempo training" zone for most of the workout, then, yeah, you probably do get a decent burn (not sure it's an actual "crapload", but decent). That's one of the benefits of this type of training--you get a good-sized burn like you do w/endurance training and you get a modest afterburn as well.

So, your questions as I understand them: Because you have a low resting HR (mine is 49!) that means you have a high VO2 max threshold. In an anaerobic state our bodies are burning through glycogen stores to workout, rather than oxygen in an aerobic state. Since you (and I also) do a LOT of weight training, we have really healthy glycogen stores, since it stores in the liver and the muscles. So we CAN workout in an anaerobic state for a longer time before our KREBS cycle kicks in, and when that kicks in in a non-aerobic state, lactic acid is the result. It you are athletic you may be able to go 1.5 - 2 hours before you deplete your glycogen and need to refuel.

Umm....some of this is sorta/kinda in the neighborhood, but it's not that cut and dried. First of all, resting heart rate has no effect on one's "threshold". A low HR rest can be a result of training, but it does not have any real effect on training ability itself. You are always using a mixture of fuel substrates, always using a mixture of energy systems. At higher intensities, yes, there is a shift to a higher mix of carbs vs fats as fuel, but it's not either/or--and average people rarely exhaust their glycogen stores. I've never heard the idea that lifting weights leads to increased glycogen storage. It would not be surprising if there was some increase just because of the increased activity. However, doing endurance exercise is well know to significantly increase stored glycogen, so there is nothing special about weight training in this regard. The KREBS cycle does not "kick in" --it is always functioning--nor does it produce lactic acid (just the opposite). If one does exhaust glycogen and has to depend on fat as the sole source of fuel, you'll know it--it's called "hitting the wall".

I asked the same thing because when I run or do extreme cardio, I am in the 85-95%+ for my MHR as well, and can sustain it for a long time and don't feel like I am going to have a heart attack. But go try lifting weights after a workout like that and THEN you will feel the jello effect since we have utilized our energy stores and haven't allowed recovery.

There are different variables that can be involved, but my experience has been that this is due more to fatigue and other related factors rather than "lack of energy". I have always preferred to put my focus on cardio so I always do it first. I have had plenty of workouts where I did 40-60 min of intense, red-line cardio followed by heavy weight lifting. I had plenty of "energy" for both. Lifting relies to a great extent on the phosphagen system which is not really utilized during aerobic exercise

The afterburn effect IS true - you do burn more calories when your body is at rest (your BMR), BUT, I have also read that these kinds of workouts can really exhaust a person and so you are actually LESS active in the long run (like over the next few days) while your body recovers, so you technically LOWERING the BMR because you aren't moving as much as you normally do. So that really only applies of you go about your normal activities.

This a great observation/comment and needs to be included in any conversation about "afterburn" (although I think you may be confusing "BMR" with "TDEE" --total daily energy expenditure).

I tried Orange Theory too and I liked it as well - but I think it depends on your overall fitness goals. If you are striving to be an endurance athlete then these kinds of workouts totally increase your VO2 Max, which is really the purpose of intense cardio workouts. If you want to be a body builder, then obviously this is not an appropriate workout. It's important to build LBM as an endurance athlete in order to, well, compete better (more muscle strength and endurance) but also to build up healthy glycogen stores. Also, I found a different THR formula for athletes - it gave me a few more beats lol. It's 217 - (age X .85).

Again, you are moving in the right direction, recognizing that training effects should match training goals. However, it's not necessarily important for an endurance athlete to "build LBM". Increased strength is important, but building muscle can sometimes be detrimental to the performance of an elite endurance athlete (a tiny increase in weight for whatever reason can have a significantly negative impact on climbing performance in the Tour de France, for example). Since most of us are not elite athletes, a small increase in LBM often does have a positive effect that overcomes the slight negative of the increased weight.

Again, I think you are off base with the connection between "lifting/increased LBM ----> necessary for increased glycogen" idea.

There are "more accurate" formulas for estimating HR max than the traditional "220-age", as you state. However, the difference is not that huge and those equations still are limited by a high(ish) standard of error, e.g. 8-12 beats/min. That is the inherent variability of the human population.

I notice, as a side note, that I really experience terrible lactic acid build up when I do intense cardio followed by isometic exercises!!

I'm not a scientist - this is what I have learned and hope I learned it right -- if I didn't I hope someone will answer so I too can learn! The body is a complicated thing!!!

You have obviously tried to find out scientific information and explanations. Sometimes, it can be hard to put everything in context. Since you invited comment, I chose to do so. Hope this is helpful and did not come across as criticizing your answers or your efforts.

SJ46

Azdak - thank you for chiming in, I was hoping you would as you seem to be the resident expert here on HR. I have a feeling my HR was elevated due to not feeling well and I agree that my HR was so high during the circuit training due to the treadmill workout that preceded it. I definitely plan on going back, I have to now - for science! If only I could clone myself so I can see how my HR is affected regardless of which part of class I do first, all else being equal.

Just to make sure I understand (at an elementary level):
Your HR can be elevated due to things like (but not limited to) illness and temperature. When you exercise while your HR is elevated due to one of these reasons your HR doesn't reflect the work your body is doing and the energy you are using. This means you can be doing the amount of work that you usually do at 150 bpm but your HR may be 170 bpm. This does not cause an increase in RPE or respiration because at a metabolic level your energy use is the same. Correct (on a basic level)?

This leads me to a new question about MHR. Is your MHR supposed to be a measure of how many beats your heart can beat per minute or is it more of a reflection of your percent increase from your RHR? Both? Or is there a relationship between RHR and MHR?

Because I am an intellectually curious individual, aka a nerd, I was looking through NSCA's Essentials of Strength Training and Conditioning and came upon a table titled "Physiological Variables in Aerobic Endurance Training." It lists RHR and MHR for previously untrained subjects both before and after training as well as elite aerobic endurance athletes.

Before training: RHR 74, MHR 194
After training: RHR 61, MHR 190
Elite endurance athletes: RHR 45, MHR 185

I have noticed similar changes in my HR, generally I find it almost impossible to get my HR to 180, today excepted. I am hoping you can elaborate on this relationship. Thanks!
SJ

_Terrapin_

HR guideline 220 (for men) 226 (for women) I'll just keep reading and posting since this is long, but congrats on the workout; probably a higher HR per min due to your body fighting a cold.

_Terrapin_

So when working out and reaching or nearing your metabolic threshold it can lead to fatigue. The workout you did probably provided for some metabolic crashing; out too fast and tough to recover. I played a fair amount of doubles volleyball over the years and quick games in high heat and humidity were preferred since we knew we could rest and recover during the breaks. But these were breaks after two matches. You were going constantly during this period. So my inclination is doing the cardio(aerobic first) pushed you quicker to the threshold then doing it last. Also, your RHR is close to if not the same as mine; having a stress test years ago revealed a large healthy heart pumping blood at 48 beats per min. Hope this helps.
Yanked the quote below where they reference going out steady as opposed to too quick for runners....

'This metabolic threshold represents the exercise intensity where we start to produce those waste products of anaerobic metabolism that can eventually lead to fatigue. You see this all the time when watching endurance Olympic events, such as a long distance running race."

Azdak

Azdak - thank you for chiming in, I was hoping you would as you seem to be the resident expert here on HR. I have a feeling my HR was elevated due to not feeling well and I agree that my HR was so high during the circuit training due to the treadmill workout that preceded it. I definitely plan on going back, I have to now - for science! If only I could clone myself so I can see how my HR is affected regardless of which part of class I do first, all else being equal.

Just to make sure I understand (at an elementary level):
Your HR can be elevated due to things like (but not limited to) illness and temperature. When you exercise while your HR is elevated due to one of these reasons your HR doesn't reflect the work your body is doing and the energy you are using. This means you can be doing the amount of work that you usually do at 150 bpm but your HR may be 170 bpm. This does not cause an increase in RPE or respiration because at a metabolic level your energy use is the same. Correct (on a basic level)?

This leads me to a new question about MHR. Is your MHR supposed to be a measure of how many beats your heart can beat per minute or is it more of a reflection of your percent increase from your RHR? Both? Or is there a relationship between RHR and MHR?

Because I am an intellectually curious individual, aka a nerd, I was looking through NSCA's Essentials of Strength Training and Conditioning and came upon a table titled "Physiological Variables in Aerobic Endurance Training." It lists RHR and MHR for previously untrained subjects both before and after training as well as elite aerobic endurance athletes.

Before training: RHR 74, MHR 194
After training: RHR 61, MHR 190
Elite endurance athletes: RHR 45, MHR 185

I have noticed similar changes in my HR, generally I find it almost impossible to get my HR to 180, today excepted. I am hoping you can elaborate on this relationship. Thanks!
SJ

Those numbers are a general representation of what might happen with training. Over time with aerobic training, HRmax, if it changes at all, is more likely to decrease a bit. To be honest, this is probably neither a positive nor a negative response to training--it just is.

Maximum heart rate-- or HRmax-- refers to beats per minute. For simplicity sake, we often refer to exercise intensity in terms of percent of HRmax. It is more detailed, but more accurate to express exercise heart rates in terms of Heart Rate Reserve (HRR). HRR is the difference between HRmax and HRrest.

The relationship between HRR and VO2max is more consistent than between HRmax and VO2max. (Ex: 70% of HRmax is about 57% of VO2max; 70% of HRR is about 70% of VO2max). HRR also takes into account differences and changes in HRrest over time.

To determine HRR, subtract HRrest from HRmax. To determine exercise HR for a given intensity, multiply HRR by the exercise intensity, and then add HRrest.

We can use your numbers from above to see the difference.

The HRR for the untrained person is 120 (194-74)
To figure a 70% target HR, we multiply 120 by .70 = 84, and then add HRrest (74), for a heart rate of 158.

You can see the difference with training.

Now the HRR is 129 (190-61)
70% target is (129*.70) + 61 or 151

The difference for the elite athlete is more striking

HRR is 140; 70% target HR is 143

It's easy to see why some people think they are doing less and burning fewer calories when they see these changes.

Azdak

So when working out and reaching or nearing your metabolic threshold it can lead to fatigue. The workout you did probably provided for some metabolic crashing; out too fast and tough to recover. I played a fair amount of doubles volleyball over the years and quick games in high heat and humidity were preferred since we knew we could rest and recover during the breaks. But these were breaks after two matches. You were going constantly during this period. So my inclination is doing the cardio(aerobic first) pushed you quicker to the threshold then doing it last. Also, your RHR is close to if not the same as mine; having a stress test years ago revealed a large healthy heart pumping blood at 48 beats per min. Hope this helps.
Yanked the quote below where they reference going out steady as opposed to too quick for runners....

'This metabolic threshold represents the exercise intensity where we start to produce those waste products of anaerobic metabolism that can eventually lead to fatigue. You see this all the time when watching endurance Olympic events, such as a long distance running race."

Small correction (s): lactic acid is not a "waste product". While it's accumulation is associated with onset of fatigue, lactate is actually a dynamic metabolite that is used as fuel in a number of processes. Lactate is constantly being produced and cleared--you don't "start to produce" lactate at threshold. At that point it begins to accumulate because production increases while clearance decreases.

SingingSingleTracker

It lists RHR and MHR for previously untrained subjects both before and after training as well as elite aerobic endurance athletes.

Before training: RHR 74, MHR 194
After training: RHR 61, MHR 190
Elite endurance athletes: RHR 45, MHR 185

Certain professional elite endurance athletes are known to have RHR of 30-34, MHR 200-203.

Forget the 220 - age formula. 226 - age for females.

The only way to get an absolutely accurate MHR calculation is to get a physiological test at a sports science center.

I've even seen a formula that "claims" to be a more accurate formula - yet it is still not perfect. It is 210 minus half your age, then subtract 5% of your body weight in pounds. Add four for a male and 0 for a female.

Although that claims to be more accurate, it's still not perfect.

If I followed the formulas...

220-52 = 168 MHR for me on that one.
Or the other supposedly "more accurate" formula is 179 for me.

Hmmm....

When I train I am often in the 180's and have registered as high as 187 - 194 on the bike during super hard 2 and 3 minute full out intervals.

Again, the only way to get an absolute accurate MHR reading is in physiological test at a sports science center.

As others have said above, your heart rate can fluctuate from workout to workout based on sleep, caffeine, illness, temperature, rest/recovery (or lack thereof), stress, and other health issues. Bike riders use power meters to measure watts which are used to set the training zones as being more important than heart rate. A typical test is an all out 20 minute effort to use the average watts to set traning zones. Average HR is also recorded and entered into the calculator to set zones: http://lwcoaching.com/trainingplans/levelCalcs.htm

I took my last "test" for the all out 20 minute effort with a head cold and produced my best power at this point of the year compared to previous years, but my HR was way off thanks to the cold. It doesn't matter as I watch the power produced on the bike rather than my HR. Next all out test is a week from tomorrow. Provided I stay healthy I should get a better HR reading.

anglergirl3

QUOTE: "The goal is to spend 12-20 min in the orange zone which is supposed to be 84-91% of your max heart rate."

OTF goer here - Amazing stats! Congrats to you on your achievements.

anglergirl3

QUOTE: "The afterburn effect IS true - you do burn more calories when your body is at rest (your BMR), BUT, I have also read that these kinds of workouts can really exhaust a person and so you are actually LESS active in the long run (like over the next few days) while your body recovers, so you technically LOWERING the BMR because you aren't moving as much as you normally do. So that really only applies of you go about your normal activities."
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