I wanted to do an all encompassing post related to cardiovascular training, aerobic training, conditioning, heart rate zone training, and "fat burning zone" training. These terms are often used interchangeably and thrown around by general fitness enthusiasts, athletes, and trainers, but, in my opinion, all of these terms are different despite being somewhat related at the same time.
Cardiovascular training/exercise is simply any activity which causes the muscles, heart and lungs to work harder than normal (basic tasks of living). Basically, if an activity causes an increase in heart rate, respiration, and muscular work, it technically is cardiovascular.
Given the explanation above, it should be fairly obvious any number of activities could be considered "cardiovascular": brisk walking, strength training, cycling, jogging, hiking, playing volleyball, using an elliptical machine, doing body weight exercises, etc. The take home point is that cardiovascular exercise is not limited to the traditional pieces of cardiovascular equipment found in gyms: bikes, treadmills, elliptical machines, stairsteppers, etc.
Aerobic training/exercise is cardiovascular...BUT NOT ALL CARDIOVASCULAR TRAINING IS AEROBIC! When we talk about aerobic exercise, we are basically referring to the "state"-with oxygen-in which the cardiovascular activity is being performed.
Aerobic training is basically low intensity activity. Now, this activity is obviously more demanding than general walking around at the grocery store and what not, but it is of a low enough intensity that the activity could be performed for very long periods of time without experiencing extreme fatigue. As long as the demand of the activity is low enough for the body to continuously pump oxygen rich blood to the working muscles, you can perform it until your heart (pun intended) is content or until you get so bored you choose to stop. You are using mostly type I muscles fibers, which are fatigue resistant but which are also incapable of producing high levels of tension and force. At this level of intensity (low-moderate), you are primarily using fat as a fuel source to sustain the activity (*much more on this point later!).
Anaerobic Training/Exercise (in the absence of oxygen)
If the demand or type of activity reaches a high enough level (for your fitness level), you'll reach a point where the aerobic system can no longer efficiently supply the working muscles with enough energy to meet the higher demands of the activity. The aerobic (with oxygen) system won't "cut it" anymore, and your body needs to get fuel faster, through other resources (namely glycogen and creatine phosphate). This is anaerobic exercise.
Anaerobic exercise is high intensity and/or explosive/powerful exercise. Think all out sprints, a heavy set of a strength training exercise, jumping onto a high surface, etc. Anaerobic exercise starts to call upon higher threshold type II muscle fibers, which are very powerful, but which also fatigue easily. Want a real good example of the difference between aerobic and anaerobic?? Go out and run as fast as you can for as long as possible in sprint fashion. You won't last real long, right? Now, try to run a half-marathon, or a 5K for that matter, at the same pace. It's impossible. Now, if you cut your pace in half, you'd last a lot longer. Hence, the difference between the aerobic and anaerobic system.
Now, anaerobic exercise is still cardiovascular. Anaerobic exercise causes a significant increase in heart rate, respiration, and muscular work. So, you certainly can get a good "cardiovascular workout" through things like sprinting, jumping, lifting weights, and doing body weight muscular fitness exercises.
Now that you understand what cardiovascular activity is, what aerobic and anaerobic exercise is (and is not), let's look at some other stuff related to what's already been covered.
Heart Rate Zone Training/Exercise
You may have heard in order to get "aerobic fitness benefits", you need to exercise in a certain range related to your age predicted maximum heart rate, and for a certain amount of time continuously. Typically, the recommended range is anywhere from 60-85% of maximum heart rate, for 20-60 minutes, 3-5 days/week. There are a few problems with this whole thing, in my opinion.
First of all, the guy who came up with the heart rate zone paradigm admitted he may not have been completely on point with this. Secondly, I've seen studies showing one's true maximum heart rate can be 20% higher or lower than what the age predicted theory says it should be. So, trying to prescribed aerobic/cardiovascular exercise programs based on age predicted maximums is flawed: some people are going to be under training and under exerting, while others are going to be over training and over exerting for their goals.
Also, I have a problem with the idea that aerobic cardiovascular training has to be "continuous". If I run an all out 100 yd. sprint, about 10-12 seconds of work, and my heart rate soars to 170 beats per minute, even if I stand around for 1:00 and my heart rate drops, it is still going to be in the "heart rate zone". So, I could do an interval training workout where I run ten 30 sec. incline sprints on a treadmill, resting completely for 30 sec. between each sprint, and still be in my "heart rate zone" the entire duration of the workout, even though the nature of the workout was intermittent "stop/start" in nature.
Intense anaerobic exercise will cause an increased accumulation of lactic acid (this is what makes your muscles "burn"). Your cell mitochondria has to work very, very hard in order to clear and process this lactic acid. With proper anaerobic interval type training, the cell mitochondria becomes more and more efficient at processing and eliminating lactic acid, drastically delaying fatigue and, as a result improving endurance and sub maximal intensities. IT IS CLEAR ANAEROBIC EXERCISE CAN ACTUALLY IMPROVE AEROBIC ENDURANCE EVEN THOUGH THE TRAINING ISN'T "AEROBIC".
The bottom line is that trying to exercise based off of heart rate zone recommendations is shaky at best. I'd use it as a very general set of guidelines.
The "Fat Burning Zone", The "Cardiovascular Zone", & The "Performance Zone"
If you've spent time using traditional cardiovascular exercise machines (although strength training machines are technically cardiovascular machines too) at a commercial gym, you probably have seen the little charts and graphs on the display screens of the equipment showing you what your heart rate training zone is. Most of the time, these figures also present some other information regarding what "quality", for a lack of a better term, you are training for at various percentages of your maximum heart rate: fat burning, cardiovascular, or performance conditioning (the phrasing various manufacturers use may be different but you get my point). These little graphs, in my opinion, have done more to confuse people than any other thing related to improving fitness.
The graphs and charts on the machines may tell you you are in the "fat burning zone" if your heart rate is between 60-70% of your maximum heart rate (aerobic). Technically, this is somewhat true. At this level of intensity, which is fairly low and "with oxygen", yes, your body is using fat as source to fuel muscle contraction and sustain the activity. The process of mobilizing fat to use as a fuel source for activity is very slow. This process can only take place when the demand of activity isn't all that great.
The problem with this is that people who use these machines mistakenly interpret this as "If I want to reduce my body fat and look better naked, I better not train above 70% of my max heart rate because I won't lose any body fat". This is complete bullshit. If you are exercising between 60 and 70% of your max heart rate, are using your aerobic energy system, and are using fat as source to fuel this activity, you can be 100% sure of something: the number of calories you are burning per minute is rather low. If you want to lose weight, what has to happen??? You have to expend more calories than you consume, right? Well, wouldn't it stand to reason that you might want to try to maximize your time and burn more calories each minute??
Don't worry about the fuel source, worry about the total number of calories being burned. I really think people believe that if they train in the "fat burning zone", they are literally burning the fatty tissue from their "problem body areas" as they are exercising. This is not what is going on. Aerobic exercise, at 60-70% of max heart rate, does not burn a large number of calories per minute. Now, granted, it certainly burns more calories than just walking slowly or lying around on the couch, but it still doesn't do a great job.
Plus, aerobic training typically doesn't maintain or increase lean muscle tissue because it doesn't call on high threshold type II muscle fibers. Your metabolic rate is largely determined by how much muscle tissue you have. If you want to keep your metabolic rate from free falling as you age, aerobic cardiovascular exercise is obviously not the best choice. I'm not saying sustained low intensity aerobic cardiovascular training doesn't have it's place in your toolbox and cannot be productive. I'm just saying, in the hierarchy of methods, it's going to sit fairly low.
Ok, what if you ramp up the intensity and demand of your activity, causing your heart rate to go above 70% (and up to 85%) of its maximum, and enter the "cardiovascular zone", as the machine at the gym tells you? Again, this lingo is flawed. Training below 70% of your max heart rate is still cardiovascular, so that's strike one. What the machine manufacturer is trying to tell you is that training above 70% of max heart rate is more suited towards conditioning and "heart health". Ok, fine, I'll buy this...to an extent. Sure, higher intensity exercise is certainly going to cause a greater heart rate response, and, as a result, a better conditioning stimulus. But, what if you are really out of shape??? You are telling me training below 70% of maximum isn't going to offer a significant conditioning stimulus?? I hope you see how general these theories and charts are.
Finally, what if you ramp up the intensity further, causing your heart to go above 85% (up to 90%) of it's maximum...the "performance zone"? Well, the kicker is, this really is the "fat burning zone", because, at this intensity, you are burning a significant number of calories per minute. Also, exercise at this high of an intensity will keep your body burning calories at an increased rate even after your workout is over, something traditional aerobic "fat burning zone" exercise cannot do. Ok, one more thing I want to hit on...
I used the word conditioning a couple times above. You could make a strong argument all methods of cardiovascular exercise are forms of conditioning, and this is somewhat true. However, TO ME, training to enhance conditioning involves progression, trying to get better, and generally improving your work capacity. If I run a mile at 7 mph on a treadmill one week, and I want to improve my conditioning, I damn well better try to run that same mile a little faster, maybe at 7.2 miles per hour, the next week. Training to enhance conditioning involves an overload and attempt to progress...this is the essence of training and the difference between training and exercise.
I could go get on an elliptical trainer, adjust the intensity to a point where my heart rate reaches 60% of its maximum, and just plod along for the next 30 minutes. I could continue doing this week and week out, never adjusting the intensity, and never asking more of my body. I'm not going to get in better condition doing this. Now, I may be burning some calories which can help with weight loss and weight maintenance, and I may be maintaining my general fitness and heart health. I'm not getting any worse...but I'm certainly not getting better. This is what 90% of people who go to the gym do year in and year out. This is not conditioning.
Now, on the flip side, if you are really out of shape and haven't done anything in the way of exercise for the last 20 years, doing anything for the first couple of weeks, or even months, is going to improve your conditioning, to a point, without an effort to progress and do more. However, you'll reach a point where you are getting as much out of exercise as you can.
Also, you may be advanced, happy with the condition you are currently in, and see no reason to try to progress further. This is just fine, and, in this case, your training doesn't need to be structured to promote further improvement. Keep in mind, this approach is for people who are already in shape and can afford to simply maintain. This comprises a very small minority of the general population.
So, How Much Cardiovascular Work Do You Need??
Ok, now that I've given you all this food for thought, the logical question is "How much cardio do I need?" Like anything else fitness related, it just depends on your goals.
If you are strength/resistance training, and doing so with a fair amount of intensity (challenging weights, multiple joint exercises, etc), you are, in fact, getting a cardiovascular training effect, so, you are already getting 2-4 bouts of cardio each week (depending on how often you strength train). With this being said, until we have more definitive research (and I think we will), I do not hold the opinion (and some others do), that all you need is strength training for total fitness. I firmly believe, eventually, research will definitively tell us otherwise, but, until then, you need to get some additional "non-strength training" cardio work. Also, even if it becomes a forgone conclusion all we need is resistance training for total fitness, the majority of people will continue eating like crap and they are going to need all the extra movement they can get.
If you are a general fitness enthusiast seeking well rounded results, I think doing two conditioning oriented interval type anaerobic workouts (15-20 minutes each), one additional steady state aerobic type workout (30-40 minutes)and 2-4 strength training workouts per week is probably about right.
Now, if you are one who attempts to use exercise as the primary weight maintenance or weight loss method, this isn't going to be enough, and, frankly, I don't know if any amount is going to be enough. If you've read my past blog postings, you know I'm a believer in using diet and nutrition as the primary weight loss or maintenance method. Exercise, in any form, is just too inefficient when it comes to burning calories...you are better off not eating excess calories to begin with.
Again, what I recommended above is for the general fitness/health enthusiast looking for well rounded results. But what if you are more of a specialist??
If you are trying to optimize muscular strength, or are interested in training for a specific event or sport (a marathon for example), the guidelines I discussed above are not optimal. You are going to have to make adjustments.
If you are trying to get significantly stronger and/or muscularly larger, doing a whole bunch of extra cardio/energy system work isn't a great idea. In order to get a lot stronger, you need to recover well from your strength training workouts...I'm a firm believer in this.
Adding in a bunch of interval type anaerobic training, or, on the opposite end of the spectrum, long duration steady state aerobic training, is going to sap you of energy and make getting stronger and larger more difficult. You just are not going to be able to recover well from your heavy strength workouts. However, I don't think it's wise to sit around and do nothing between workouts either. Movement is a good thing and, if you go about it the right way, can promote recovery. So, for the guy or gal trying to optimize strength gains, 2-3 20 minute lower intensity aerobic cardiovascular sessions would probably be ideal, in addition to stretching and soft tissue work.
If you are training for an extreme endurance event, like a marathon, again, the general fitness recommendations are not going to be optimal. In order to complete a marathon, you are going to have to perform higher volumes of aerobic and non strength training cardiovascular work. There is no getting around this. It is called SAID: specific adaptations to an imposed demand. You have to develop the specific cardiovascular and muscular adaptations associated with whatever sport or activity you choose to compete in. You can't perform 2 20 minute interval workouts on a stationary bike each week and go out and run a marathon. You might be able to develop the base fitness necessary to do this by doing a couple of weekly interval workouts, but, at some point, you have to get specific to the demands of the goal activity for a period of time: this means running outside and for long durations continuously.
Wow, that was a mouth (or blog) full, huh? :) Anyway, I hope this lengthy post served as an educational resource and gave you some new perspective on everything related to cardio, aerobics, fat burning, etc. The main thing I wanted to get across is that cardiovascular training can be performed doing any number of activities which increase heart rate, respiration, and muscular work. It need not be only walking or jogging on a treadmill for 30 minutes non stop. The other main point is to take the whole "zone" paradigm (heart rate zone, fat burning zone, performance zone, etc) with a grain of salt. Finally, when contemplating how much cardiovascular or aerobic work to perform, you need to consider your goals and adjust your approach accordingly.
Until next time, take care, and, if you would like to hire me to design a program which puts all of these ideas and principles into practice, taking all of the guesswork out of it on your part, don't hesitate to contact me at email@example.com