Why do I keep reading that cardio is bad for muscle gains?

[kal525]

I've been browsing this forum a lot lately and I keep noticing how opposed some people seem to be to doing cardio exercise in conjunction with strength training exercise, and I really can't understand why this is.

I keep reading that doing cardio will stop you from getting bigger, but won't it only be doing this if you are burning muscle. If you want to get big on fat that's a different story, but what is bad about spending 20 to 30 minutes per day in your "fat burning zone."

Although keeping your heartrate in this zone doesn't really qualify as cardio to me since i hardly break out a sweat, I guess I could see how having your heartrate above this zone would hinder body building since you might be burning some muscle. But if you did high intensity cardio 2 or 3 times a week and lower intensity cardio the rest of the week this shouldn't really be a problem.

Please correct me if I am wrong here, doesn't the body use energy in the following ways:

1. burns sugar in blood
2. burns fat
3. when heart rate is high and needs quick energy, burns muscle

If this is indeed the correct sequency of events, then why would cardio not be condusive to gaining muscle mass?

In my opinion having a strong heart is tantamount to having strong muscles, considering your heart is your most important muscle.

I would really appreciate if someone could clarify this topic for me as I have yet to find any detailed explanation of this opposition to cardio.

Thanks

 

[cjrmack]

cardio

I would be interested in the answer too as I workout 3 times a week and do bicycling and swimming the other 3 days. I too am confused when reading cardio is either not necessary or a "bad word". Someone please explain.

 

[Pepper]

Here is a thread you might want to read....

Click Here!

 

[kal525]

Interesting thread, however, most of it seems like a lot of confused people asking a lot of different personal questions.

What I'm after is how the body really works and how it burns calories so that I may understand what I'm burning when I'm doing cardio exercise.

The most useful thing that I read in that thread is this:

"The problem with conventional, long duration, low intensity cardio is that it has minimum impact on increasing your resting metabolic rate. However, long duration, low intensity cardio will deplete glycogen stores. When this happens, you will start primarily utilizing lean muscle for your energy needs. Long duration cardio will break down muscle tissue." - by Paul Delia


From this, it seems to me that after glycogen levels are depleted your body goes right for the muscle completely bypassing fat. If this is true, then why do they call it the "fat burning zone" if you're really burning glycogen then muscle?

To go along with that question, that thread also seemed to have many HIT(high intensity training) proponents who advocated bursts of high heart rate activity becoming more intense every minute.

Now, that type of exercise will no doube go through glycogen stores in no time at all after which I'm not sure what will happen. Will the body burn muscle or fat? From what I know now, again please correct me if i'm wrong, the body would go after the muscle because it is the most readily available form of energy to be used after glycogen and at such a high heart rate the body is gasping for energy.

So if this is the case, then neither of these types of cardio activity actually burn fat, so there must be something I'm missing somewhere in between here.

If low heart rate long duration cardio and high heart rate short duration cardio don't burn fat, then what does? It just seems like no one really knows what they're talking about and are just throwing out what they do according to what they think is right. There must be some definitive answer to how the human body gets its energy when stressed in different ways and that is what I'm looking for.

Another thing that people fail to mention is that if cardiovascular endurance and muscle gain are both important, then why wouldn't someone just overdose on carbs before running and then run to their hearts content knowing that their glycogen levels are high enough that their muscles won't get touched, again, where fat comes into the picture here I have no idea since from what i've been reading it never actually gets burned.

I'd appreciate any clarification to this wealth of shady information i keep stumbling across. Books, proven nutritional facts, etc.

Thanks

 

[Mudge]

#1 Breaking into the fat stores takes more energy.
#2 The body knows that excess muscle is a waste, and it burns calories simply to exist
#3 Ergo, the body will dump muscle first, if you are not educated in how you conduct your cardio.

Cardio before your first meal of the day is optimal. For me I have to keep it light, 20-30 minutes 3x a week, if I do 5 day a week an hour per session, I lose about a quarter inch on my arms in that single week, and I dont like that.

You cannot be a marathon trainer and a huge bodybuilder at the same time, the body will not want to do both and be good at both. We can take this example to the extreme by looking at a 260 pound bodybuilder with 4% bodyfat, think his heart is going to make it 26 miles while still breaking a world record? I think not.

The body finds homeostasis like virtually everything in nature, to break out of that mold is not going to be easy, especially if your trying to do more than one thing at a time.

 

[OceanDude]

I think you are hitting on an important point ??? no one really knows the precise mechanisms for how or under what conditions the body burns different fuel sources (glycogen, muscle/protein, fat). As best I can explain it, all these theories and suggestions about cardio/intensity levels/HIIT etc. are a ???probability??? game and very likely are not entirely generalized to everyone under all conditions of diet, fitness levels and genetic makeup. In the end most of us take educated guesses and go with what seems to work. I personally am in the HIIT camp and do only 1 day of cardio a week at 45 minutes moderate intensity ??? then follow up with a grueling HIIT cycle. I then do HIIT after every workout for 12 minutes (4 times per week). But I am always open to hard science and new insights. The latest research I have read suggests that HITT is the better form of exercise to burn fat since it ???confuses??? or tricks the body into mobilizing a moderate percentage of lipids into the blood stream simultaneous with burning a higher percentage of glycogen than does low intensity cardio. But, because the intensity level is so high, total calories consumed and mobilized ("available" calories in lipid form")by HIIT for are greater than one would get with long duration low intensity (LIT) cardio (even at LIT???s higher total % of lipid utilization in the fuel mix). There is essentially a metabolic momentum effect present with HIIT in that the body continues to burn these mobilized lipids long after the short HIIT activity is completed; since it is switched into a substantially higher metabolic gear as an adaptation for the stress. I believe LIT produces a similar metabolic shift but my understanding is its not as long lived or as high. I believe the rationale in HIIT is that since its shorter in time than LIT cardio exercise, the ???window of vulnerability??? of the body using muscle as a fuel is comparatively smaller in HIIT. There are probably hormonal issues as well that come into the ???why??? case for HIIT ??? such as stress and cortisol levels etc.

 

[kal525]

So basically, it's not really known when the body will burn fat as opposed to muscle. I have read that exercising in the morning before a meal at high intensity burns the most fat though, so I will probably stick with that.

As for a 260 lb body builder not being able to run the marathon, why not?

When training you could just overdose on carbs so that there's plenty of glycogen to burn instead of muscle, unless of course the body has the potential to burn muscle even if there is an excess amount of glycogen in the blood.

 

[RCfootball87]

In football, I have to find a thin line between bodybuilding and running. But I like bodybuilding more

 

[Mudge]

Originally posted by kal525
As for a 260 lb body builder not being able to run the marathon, why not?

I would say, heart attack. I have walked 15 miles once, and I never plan to do it again, much less run nearly twice that distance.

 

[kal525]

haha, yeah I guess a heart attack could stop you. I guess i'll have to find an equilibrium between the two.

 

[OceanDude]

Originally posted by kal525
...When training you could just overdose on carbs so that there's plenty of glycogen to burn instead of muscle, unless of course the body has the potential to burn muscle even if there is an excess amount of glycogen in the blood.

Depends on the training intensity and duration and what metabolic "gear" the body is currently in or wants to be in. This is the crux of the problem - fuel selection and utilization is an autonomous function. The brain and hormonal signaling agents all influenced by various things like respiratory rate (O2/Co2 levels) , lactic acid signals, stress etc. will result in the body???s selection of a fuel mix based on availability and levels of fuels (fat, carb, alcohol and protein), what was previously in the blood stream and how fast it can change gears. There is normally plenty of glycogen to burn for most activities but it is finite and NO amount of overeating is going to increase the body's fixed glycogen volumes; though exercise does increases volume capacity. You just can't put more gas in the tank than the tank can hold but you can eat along the way to keep it topped off. But the good news is, unless you are on a low carb form of diet and have glycogen levels way low from prior activities there is normally an abundance of this fuel to easily sustain a 1 hr workout at even intense levels. If you are talking about running super long distances then NO it will deplete.

In my opinion we can only do a limited few things to override the autonomous programming on what the body will use for fuel. Some of the things are:1) Pre-exhaust or max out glycogen, 2) choose our form and intensity of exercise and 3) use dietary and supplement tricks and timing to ???override??? or coax our autonomous programming to favor one fuel over another. The single best non-autonomous thing we can do is choose to not get fat or out of shape in the first place. Everything else is a roll of the dice and all we can do is improve the odds that the body will do as we hope. Even then, it???s still likely to do what ???we??? want it to do half-heartedly. Philosophically it makes me wonder really ???who??? or ???what??? is in control and if we are all on the same side.

 

[Mudge]

Originally posted by kal525
haha, yeah I guess a heart attack could stop you. I guess i'll have to find an equilibrium between the two.

Once you start gaining serious weight, your heart will be moving ever time you move, and you will sweat a damn lot more. If you never get there though, then you will be much closer to a normal person.

It is only utter common sense, that a heart made to support a 200 pound mans cardio needs and blood volume pumping, is not going to like being 300-400 pounds, wether it is fat or muscle.

 

[Gibson]

I have the reason

The simple reason it is bad to do both has nothing to do with what the body actually does when burning calories etc. It is bad to do both because cardio puts further stress on your body. One of the most important things when training is to keep your body as a whole (systemically) not fatigued. It is scientifically proven that you can train frequently, as much as 3 times a day without overttraining if you keep your body systemically fresh. Cardio adds extra stresses to your body.