Understanding Aerobic vs Anaerobic exercise

Aaron_K123

Hi all. I'm trying to understand the benefits of being in an aerobic heart rate range during exercise and what the drawbacks, if any, are to going above that range.

My understanding is the aerobic range is 60-85% of your maximum heart rate which for a male can be calculated as 220 minus age (35 for me) so 185 for MHR. So my aerobic range is therefore 111 to 157 BPM.

Okay my understanding is that in aerobic range most of your calories burned (50-85%) come from fat and presumably the rest come from your glycogen stores.

If you go above 85% of your MHR then you start to be anerobic in which case only about 15% of your calories burned come from fat and you will find this intensity difficult to maintain.

So with that background here is my question. I just went for a 10k run which I ran in about 1 hour so a 6 mile an hour pace approximately. I had my polar f4 HRM on at the time and it logged that my average heart rate was 162 with a peak of 178. While watching it I noticed that within only about a minute of running my heart rate was already 150+.

What that suggests to me is that the pace I am running, which feels like a light jog, is putting me into the anerobic range but yet I can keep it up for an hour. Is this correct? Was figuring going for a light-jog pace for an hour would have me aerobic not anaerobic and if I hit anaerobic shouldn't I have difficulty maintaining that pace? Confused by this.

Aaron_K123

One other question with regards to this.

Our bodies are not magical energy producing machines. We eat food which has a caloric value and we expend energy in the form of calories from our normal body functions plus activity. If your BMR is 1800 and you eat 2400 calories then burn 800 anaerobically sure during the anaerobic exercise perhaps your body mostly relies on your glycogen and barely touches your fat but later on when your body requires calories for its normal function and cannot get them from your intake it is going to burn fat isn't it? So does it really matter in the end?

AJ_G

It makes absolutely zero difference whether you're burning calories from glycogen or fat stores. Don't over think it. If you burn a bunch of calories from fat stores and not from glycogen, the next time you eat carbs, they will be stored as fat. If you burn a bunch of calories from glycogen stores and not from fat stores, the next time you eat carbs they will be stored as glycogen. All that matters at the end of the day is a calorie deficit and if you're running a calorie deficit, then you will have the exact same result either way. All that really matters is calorie burn when it comes to cardio, don't worry about what heart rate range you're in...

Aaron_K123

It makes absolutely zero difference whether you're burning calories from glycogen or fat stores. Don't over think it. If you burn a bunch of calories from fat stores and not from glycogen, the next time you eat carbs, they will be stored as fat. If you burn a bunch of calories from glycogen stores and not from fat stores, the next time you eat carbs they will be stored as glycogen. All that matters at the end of the day is a calorie deficit and if you're running a calorie deficit, then you will have the exact same result either way. All that really matters is calorie burn when it comes to cardio, don't worry about what heart rate range you're in...

Yeah logically that is what I had concluded as well (as in my second post here). That said people seem to obsess over this so I thought perhaps I was missing something.

fitandfortyish

I think you are right, Anerobic exercise is unsustainable for a long period of time-I think of athletes who do sprint sports where they go at maximum effort for a short time. Aerobic, on the other hand is sustainable, but in think it's confusing because there are different intensities involved--like what you noted on your HRM.

I've done both for fat burning, resistance plus HIIT, and resistance plus steady state cardio at a higer intensity and a medium intensity (both at a longer time frame than HIIT). Personally I had success with both but the steady state must be done for longer. Ultimately, for fat burning, I didn't see a difference. --some will probably argue that tho.

zoeysasha37

Bump no time to read this now, but will later

froeschli

Ever managed to get above 185 on strenuous exercise? Then it can't be your max heart rate. 220-age is a statistic. If you were joe average, it might be right for you. I don't remember the exact percentages and numbers, but it was like 30% of the population are +- 10 of that max heart rate number, the next 30% are +-20 etc.
So if you are serious about heart rate training zones, look into a sub-max or even a max effort test to figure out/approximate your actual maximum heart rate. You'll have to do a separate test for each sport, since your heart rate reacts differently to running, swimming, cycling etc...

Aaron_K123

Ever managed to get above 185 on strenuous exercise? Then it can't be your max heart rate. 220-age is a statistic. If you were joe average, it might be right for you. I don't remember the exact percentages and numbers, but it was like 30% of the population are +- 10 of that max heart rate number, the next 30% are +-20 etc.
So if you are serious about heart rate training zones, look into a sub-max or even a max effort test to figure out/approximate your actual maximum heart rate. You'll have to do a separate test for each sport, since your heart rate reacts differently to running, swimming, cycling etc...

No, the highest I've seen my HRM go was about 181

WakkoW

http://www.nytimes.com/2001/04/24/health/maximum-heart-rate-theory-is-challenged.html

That formula was never intended to be used for the unwashed masses.

The doc who came up with it did it in prep for a meeting.

DavPul

You're seriously over thinking this. Just go work out

rileysowner

It makes absolutely zero difference whether you're burning calories from glycogen or fat stores. Don't over think it. If you burn a bunch of calories from fat stores and not from glycogen, the next time you eat carbs, they will be stored as fat. If you burn a bunch of calories from glycogen stores and not from fat stores, the next time you eat carbs they will be stored as glycogen. All that matters at the end of the day is a calorie deficit and if you're running a calorie deficit, then you will have the exact same result either way. All that really matters is calorie burn when it comes to cardio, don't worry about what heart rate range you're in...

Yeah logically that is what I had concluded as well (as in my second post here). That said people seem to obsess over this so I thought perhaps I was missing something.

People obsess over it because they have been fed that it is important. Same as people are still thinking that eats 6 small meals a day revs up your metabolism and it somehow superior for all people in terms of weight loss, not to mention a whole host of other things. As stated overall calorie burn and maintaining a deficit is what is important. The zones are only important for specific fitness goals like working on improving endurance. Some marketer decided they could use it in HRMs, so people are thinking it is important.

rileysowner

http://www.nytimes.com/2001/04/24/health/maximum-heart-rate-theory-is-challenged.html

That formula was never intended to be used for the unwashed masses.

The doc who came up with it did it in prep for a meeting.

Exactly, very little scientific evidence for it. I know last summer I out on a rather intense bike ride. My HR was at about 95+% of my supposed maxHR for a long period of time. If that maxHR of 220-my age was correct I should have been gasping for air and my heart thumping out of my chest. It wasn't, which made it clear to my my maxHR was not 220-my age.

Aaron_K123

Yeah that all makes sense. Wasn't really "worried" about it and I overthink everything as a policy, kind of how I operate. But yeah in this case sounds like best to just not worry about it.

I must say the general thread responses on the fitness forum seem on the whole much more sane than the responses you get in the weight loss forum.

rileysowner

I must say the general thread responses on the fitness forum seem on the whole much more sane than the responses you get in the weight loss forum.

At least part of that is because in the weight loss forum people want to attribute their weight loss to something other than a calorie deficit among other craziness.

Having said that, there just as many crazy responses in the Fitness section, you just have to hit the right topic.

SingingSingleTracker

Hi all. I'm trying to understand the benefits of being in an aerobic heart rate range during exercise and what the drawbacks, if any, are to going above that range.

My understanding is the aerobic range is 60-85% of your maximum heart rate which for a male can be calculated as 220 minus age (35 for me) so 185 for MHR. So my aerobic range is therefore 111 to 157 BPM.

Okay my understanding is that in aerobic range most of your calories burned (50-85%) come from fat and presumably the rest come from your glycogen stores.

If you go above 85% of your MHR then you start to be anerobic in which case only about 15% of your calories burned come from fat and you will find this intensity difficult to maintain.

So with that background here is my question. I just went for a 10k run which I ran in about 1 hour so a 6 mile an hour pace approximately. I had my polar f4 HRM on at the time and it logged that my average heart rate was 162 with a peak of 178. While watching it I noticed that within only about a minute of running my heart rate was already 150+.

What that suggests to me is that the pace I am running, which feels like a light jog, is putting me into the anerobic range but yet I can keep it up for an hour. Is this correct? Was figuring going for a light-jog pace for an hour would have me aerobic not anaerobic and if I hit anaerobic shouldn't I have difficulty maintaining that pace? Confused by this.

As has been mentioned, the formula of subtracting your age from a set number (be it 220 or 225) is not an accurate way.

Training Zones can be divided in several different manners. I like to use the Training Zones that Dr. Andrew Coggan outlines. You would need to conduct a Functional Threshold Power Test (or MAP Test) to figure out your training zones (and they change with training and base miles, so the test is usually performed every 6 weeks). You can read about that in many places, but here is one: http://www.flammerouge.je/factsheets/functhresh.htm

This little handy chart mentions both the % of FTP (Functional Threshold Power) and the % of heart rate as well as a typical duration that an athlete can maintain them. The "time" column includes some comical stuff, but in general - the more difficult/hard the training zone, the less amount of time one is able to maintain that zone. Of course, a world class marathon runner or professional cyclist can maintain some of the higher zones much longer than the rest of us non-professional athletes.

trainingzones

I also like to break the main 6 Zones (Forget the Zone 7 Neuromuscular Power) from that chart down to this...

1. Old lady pace
2. Chatty pace
3. Feel good hard
4. Feel bad hard
5. I am going to die
6. Flat out

Running will register a higher heart rate than cycling at the same power output. Cyclists measure power in watts using a power meter and train by the power, not the heart rate as heart rate can be so unreliable. So the Zone 2 (Endurance) zone is really the target base building range where I think you are talking about aerobic training and fat burning. However, this also takes place in Zone 3 (Tempo). Zone 3/4 would be the typical Zones that runners and cyclists stay in during a race with forays into the anerobic for sprints, climbs, running up steep hills, passing, etc... . And the cruelest of all intervals "over/under" where you ride right at your Functional Threshold and do intervals above it and right below it. That's real pain if you are interested and it burns some serious calories.

You need to figure out your actual HR. I'm 52, and if I did the 220-age gig, my maximum HR would be 168. However, based on my last FTP test, my HR can go a lot higher and my average HR usually works out to 171 - 174 during a mountain bike race and I do intervals up in the 180's without issue.

Zone Calculator Update #1

If your goal is to trim fat, then doing a lot of running in Zone 2 to build a good base would be the ticket. That's the Zone you can do a good 2 - 3 hour run in, and recover the next day to do some more. Although it feels easy, consecutive days of working out in Zone 2 can really create a cummulative training stress score and will exhaust you. But it is a great way to raise your FTP and burn fat at the same time.

Another trick is the "bonk training" method where you get up in the morning, drink 2 cups of coffee within 45 minutes of waking up (don't eat anything), and then go out for a Zone 1/2 run for up to 90 minutes. Come home and eat your normal breakfast. It's all explained here....

http://www.superskinnyme.com/bonk-training.html

Do a few days of that per week and those pounds will melt off.

froeschli

I think i need an extra cup of coffee before i can focus enough to read through the above post!
Thanks for the info!

Aaron_K123

Thank you for the great info SinglingSingle and others.

I have one more concern/question that could also be in the territory of myth but I want to check anyways.

The other notion I have heard is that if you do long term intensive cardio, such as running for 2-3 hours as suggested, that your body will also catabolize some muscle during the process.

My goal is to lose fat but at a pace in which I can retain all of my muscle. I am doing cardio three days a week and weight training three other days during the week. I'm making sure I have sufficient protein intake every day and I'm working at about a 600 calorie daily deficit (net). Its pretty aggressive and I would be concerned that if I picked up the cardio I might burn fat faster but at the expense of some of my muscle over the longterm. Anything to this?

SingingSingleTracker

I have one more concern/question that could also be in the territory of myth but I want to check anyways.

The other notion I have heard is that if you do long term intensive cardio, such as running for 2-3 hours as suggested, that your body will also catabolize some muscle during the process.

My goal is to lose fat but at a pace in which I can retain all of my muscle. I am doing cardio three days a week and weight training three other days during the week. I'm making sure I have sufficient protein intake every day and I'm working at about a 600 calorie daily deficit (net). Its pretty aggressive and I would be concerned that if I picked up the cardio I might burn fat faster but at the expense of some of my muscle over the longterm. Anything to this?

If you are lifting 3 days a week, and eating sufficient protein every day - you're not going to lose muscle. Scooby will explain it to you here: http://scoobysworkshop.com/does-cardio-burn-muscle/

I am in week 16 of training long hours on the bike, lifting 2x a week plus 1 core day a week and have been very careful not to lose more than 1 pound per week to avoid exactly what you mention. Pretty much running a deficit in the 100 - 600 calorie range which I would subtract from my daily needs plus exercise calories combined. On days I ate back all of my calories - no weight gain or loss would take place.

I wouldn't worry about 2-3 hour cardio events, but once you start to get over 3 hours, 4 hours, 5 hours, etc... it's a different game. I use Hammer Nutrition Perpetuem (protein) on rides/runs that are over 3 hours.

Aaron_K123

I have one more concern/question that could also be in the territory of myth but I want to check anyways.

The other notion I have heard is that if you do long term intensive cardio, such as running for 2-3 hours as suggested, that your body will also catabolize some muscle during the process.

My goal is to lose fat but at a pace in which I can retain all of my muscle. I am doing cardio three days a week and weight training three other days during the week. I'm making sure I have sufficient protein intake every day and I'm working at about a 600 calorie daily deficit (net). Its pretty aggressive and I would be concerned that if I picked up the cardio I might burn fat faster but at the expense of some of my muscle over the longterm. Anything to this?

If you are lifting 3 days a week, and eating sufficient protein every day - you're not going to lose muscle. Scooby will explain it to you here: http://scoobysworkshop.com/does-cardio-burn-muscle/

I am in week 16 of training long hours on the bike, lifting 2x a week plus 1 core day a week and have been very careful not to lose more than 1 pound per week to avoid exactly what you mention. Pretty much running a deficit in the 100 - 600 calorie range which I would subtract from my daily needs plus exercise calories combined. On days I ate back all of my calories - no weight gain or loss would take place.

I wouldn't worry about 2-3 hour cardio events, but once you start to get over 3 hours, 4 hours, 5 hours, etc... it's a different game. I use Hammer Nutrition Perpetuem (protein) on rides/runs that are over 3 hours.

That is what I thought, thanks again. I am trying to drop myself from around 24% bodyfat to 15% bodyfat in about 4 months in preparation for an event. That is going to require that I drop about 24 pounds of fat which is about 1.5 pounds a week. That is pretty fast so I was concerned about muscle loss. I'd rather keep my muscle and not hit that goal % BF than hit it and lose lean mass during. Trying to be careful with it. So far I have only lost about 5 pounds but then again I have dropped about 2.5 inches off my abdomen so I am clearly making progress.

SingingSingleTracker

I am trying to drop myself from around 24% bodyfat to 15% bodyfat in about 4 months in preparation for an event. That is going to require that I drop about 24 pounds of fat which is about 1.5 pounds a week. That is pretty fast so I was concerned about muscle loss. I'd rather keep my muscle and not hit that goal % BF than hit it and lose lean mass during. Trying to be careful with it. So far I have only lost about 5 pounds but then again I have dropped about 2.5 inches off my abdomen so I am clearly making progress.

What kind of "event" are you targeting your goal for in 4 months?

There is an excellent book by Matt Fitzgerald called Racing Weight: http://www.amazon.com/Racing-Weight-Lean-Performance-Series/dp/1934030996

One of the excellent studies mentioned in that book is that performance will not improve while losing weight. Hence, all trainer's suggestions, and training plans target losing weight in the off season and base building phase. The 12 weeks leading up to the event is best used to build, peak, and race. If weight is still being lost during that time frame, the study suggests that although you will be losing weight, your performance will not show any improvement as a result (outside of power to weight ratio going up the hills).

I only mention that so you are aware. I am currently in the 3rd week of a build, peak, and race 12 week structured training plan and sitting at 3 pounds short of my supposed target weight goal. If I make that goal - great, but it's all about improving my performance now and my body should settle into it's ideal racing weight which may or may not be the same as my target goal. I front end loaded my weight loss this year in the 12 week base period that I began in early January so that the majority of my weight loss was completed before I started the 12 week final training build, peak, and race plan. I almost made it...

All the best with your weight loss and training for your event.

Aaron_K123

I am trying to drop myself from around 24% bodyfat to 15% bodyfat in about 4 months in preparation for an event. That is going to require that I drop about 24 pounds of fat which is about 1.5 pounds a week. That is pretty fast so I was concerned about muscle loss. I'd rather keep my muscle and not hit that goal % BF than hit it and lose lean mass during. Trying to be careful with it. So far I have only lost about 5 pounds but then again I have dropped about 2.5 inches off my abdomen so I am clearly making progress.

What kind of "event" are you targeting your goal for in 4 months?

There is an excellent book by Matt Fitzgerald called Racing Weight: http://www.amazon.com/Racing-Weight-Lean-Performance-Series/dp/1934030996

One of the excellent studies mentioned in that book is that performance will not improve while losing weight. Hence, all trainer's suggestions, and training plans target losing weight in the off season and base building phase. The 12 weeks leading up to the event is best used to build, peak, and race. If weight is still being lost during that time frame, the study suggests that although you will be losing weight, your performance will not show any improvement as a result (outside of power to weight ratio going up the hills).

I only mention that so you are aware. I am currently in the 3rd week of a build, peak, and race 12 week structured training plan and sitting at 3 pounds short of my supposed target weight goal. If I make that goal - great, but it's all about improving my performance now and my body should settle into it's ideal racing weight which may or may not be the same as my target goal. I front end loaded my weight loss this year in the 12 week base period that I began in early January so that the majority of my weight loss was completed before I started the 12 week final training build, peak, and race plan. I almost made it...

All the best with your weight loss and training for your event.

Oh this "event" only requires aesthetics, basically I'm just trying to look good by a certain date. My profile picture is me three years ago when I was at 15% bodyfat and in peak shape before a focus on career side-lined my health and I put on about 30 pounds. Just trying to get back there basically and because I've been there before I know roughly how to get there.

I want to keep the muscle around for health and aesthetic reasons because it is of course very difficult to put on muscle. Once I get down to around 15% however long that takes I will probably switch to a more heavy-weight routine and eat and a small surplus to try to put on a little muscle over the long-term.

Thanks again for your help.

TAsunder

A lot of weird stuff happens to your body when you run for "2-3 hours." That's marathon training long run territory.