Why can't cardio build muscle? I don't get why not.

funkycamper

A lot of people are confusing "increased strength" with "increased muscle mass". The first mechanism for increasing strength is called "neuromuscular facilitation". Essentially, you learn how to use your existing muscles fibers to generate more forces. People can increase their strength by 100% without ever substantially increasing the size of the muscle.

Any exercise activities results in physical adaptation. The exact nature of the adaptation depends on the specific demands of that activity. Once those demands are met, there will be no further adaptation.

If a sedentary person starts doing cardio. they will likely see a measurable increase in muscle strength levels--that is part of the initial adaptation to the demands of the activity. That will eventually plateau, as most cardio exercise does not place enough of a "load" on a muscle to continue overloading it. At what point that plateau occurs depends on the nature of the exercise.

However, this adaptation is not the same as resistance training. One need only look at the type of training being performed: to see consistent gains in strength training, one must work the muscle to a state of temporary "failure" in 1-12 repetitions (the actual number is not relevant, as you'll see). If that is the stimulus needed to increase strength, how can one expect to get the same results performing a movement, like running for example, that one can repeat for hundreds or thousands of repetitions without reaching "failure"?

The answer is easy: you can't. The one possible "exception" might be if one is doing a huge volume of cardio that has specific physical demands--professional cyclists and speedskaters come to mind. But we are talking about hours and hours a day of training for years, plus the resistance of climbing hills, plus the self-selection of extreme genetic types who make it to that level. For all intents and purposes, the average person will not see those effects.

Interesting. This cleared up part of my confusion. Although I still don't understand why cardio fatigue is different than weight training fatigue. If I literally can't run another step because my muscles feel gutted and like I'll fall to the ground if I run another step...and, no, I'm not talking about endurance per se, I don't think anyway, but rather a feeling of all the strength has gone out of my legs...then why wouldn't that be building muscle?

And, if we still use running as an example, wouldn't an increase in both distance and speed mean I'm creating that tension and using the muscles to the point of fatigue?

Excuse me for being dense about this.

ninerbuff

Let's make it easy to understand. You "condition" muscle with cardio and strength training. Cardio works towards muscle endurance and use "slow twitch" fibers where strength training works on muscle hypertrophy and uses "fast twitch" fibers.
If a muscle isn't getting lactic acid build up, then it's more based on muscle endurance and not muscle building. People can refer to themselves as building muscle, but science doesn't subject itself to anecdotal evidence as evidence.

funkycamper

^^^^THIS!!!^^^^
Very eloquently stated. No one is attacking the benefits of cardio, but they are much different than those of strength training with heavy weights. There are a lot of very knowledgeable people on here who will be thrilled to help you create a weight lifting program that you can work into your schedule, if you are interested. If you only want to hear support for your own opinion that cardio is physiologically equivalent to weight training, however... can't be of much help there.

I have no agenda and am not trying to prove anything. I just want to get the most benefit from the time I have to exercise. And I still am not understanding the claim that you lose muscle when you do mainly cardio. I totally understand that you don't build muscle as quickly nor can you build as much muscle with just cardio. I also totally understand that weight training is superior for building muscle. That makes sense. But the claim that you lose muscle doing cardio doesn't make sense to me at all.

If you or someone else here can help me develop a strength training program that works for me, that would be great. I just don't want to have to give up cardio to do it and I only have so much time.

Currently I usually do strength training just once a week although, once in awhile I squeeze in a second workout. Since my core is not yet very strong and since I'm recently recovered from a pretty severe back injury, I'm hesitant to do free weights at this time. I know free weights are better for you as they require using other muscles more than machines do, I feel like I need the stability machines give me to protect my back. I hope at some point to get a strong enough core to graduate to free weights. It currently takes me almost 1h15m to do all the various machines. I try to get in 20 reps per machine. I typically will start at a higher weight and lift until I can't lift that weight again, then move the weight down 5# and lift that weight until I can't do another rep, and then move down 5 more pounds to finish out the 20 reps. I lift and lower the weight slowly so I'm not using momentum to complete the lift and need my muscles for the lowering portion as well. In-between each machine, I will do about 60 seconds of stretching the muscle used while it is warmed up as I understand that muscles stretch better when warm. If I have to wait for the next machine, I'll jog in place a bit to keep my heart rate up and my muscles warmed up but, usually, I don't have a long enough wait very often to have to do this.

funkycamper

Err. No, glycogen is the first thing we burn (after ATP and Creatine). Then fat. THEN muscle.

The ONLY thing we burn is ATP, ATP is the currency for movement. All the energy systems produce ATP out of other substances.

The biproduct of burning ATP is Adenosie Bi-Phosphate, which combines with creatine phospate to get back to being adenosine TRI-phospoate for that secondary boost that can last a few seconds longer.

Order of events

Anaerobic cycle:
-Burn stored ATP in muscle
-uptake ABP that has been recombined with creatine phosphate to make a little more ATP
-Switch to glycolitic or lactic acid system which creates glucose and lactic acid from glycogen in blood, spitting out some more ATP
-Aerobic system next which uses glucose and oxygen
-Fatty acid oxydosis which uses fat for fuel, along with oxygen, providing the most ATP for until of input, but as a slow process is meant for long distances

The more time you spend in the upper portions of this cycle, the more muscle size you will build, as the more muscle you have, the more ATP and creatine muscle glycogen you can store, and the more lactic acid they can tolerate

The more time you spend int he lower portions of this cycle (aerobic portions), the more your adaption will be to REDUCE muscle size, to make those muscles MORE efficient so they use less oxygen and less sugar or fat to do the same job. It takes less ATP to push skinny little legs through a marathon then it does HUGE speed skater type legs.

So if you want HUGE legs like speed skaters, sprinters, do hill sprints, dashes of up to a quarter mile, intervals, etc... to keep moving in and out of the top of the chain which depletes in total in about 2 minutes (4 minutes if you are HIGHLY trained).

Or lift weights for 12 reps or less to failure, which is 100% anaerobic.

Thanks. This makes some sense. Although I still a bit hazy on it I think I'm starting to get it a bit.

Questions:

I am a type 2 diabetic and, as such, I definitely need to burn the excess glucose I tend to have in my system. So does this mean that I need to do the aerobic workouts instead of or always in addition to lifting weights?

But then, as I get in better shape and more efficient, you say my muscles will burn less glucose. Isn't that a bad thing for me since I want to burn excess glucose?

So would weight training build more muscle which would then help burn more glucose? Or since weight training burns ATP and not glucose, does this mean I need aerobic cardio more than weight training?

I'm getting confused again. Or am I somehow mixing apples and oranges?

funkycamper

What you are describing is more related to muscle endurance as opposed to pure strength (or size). Tension does not necessarily mean the same as "fatigue". It's the amount of actual loading on the muscle.

Thanks but I still don't understand why not. For example, if I do a spin class now with the bike tension mainly fairly loose because I can't complete the class with more tension on the bike at this time but, over time, can increase the tension on the bike making it harder to pedal, aren't I also then getting more tension to the muscles? And if I'm so fatigued by the end that I can barely walk to my car, aren't my muscles getting fatigued?

Am I simply confused by what fatigued muscles feel like? I assume it means that the ability to go one minute, one rep, one revolution longer is gone, right?

funkycamper

Let's make it easy to understand. You "condition" muscle with cardio and strength training. Cardio works towards muscle endurance and use "slow twitch" fibers where strength training works on muscle hypertrophy and uses "fast twitch" fibers.
If a muscle isn't getting lactic acid build up, then it's more based on muscle endurance and not muscle building. People can refer to themselves as building muscle, but science doesn't subject itself to anecdotal evidence as evidence.

Your fast vs. slow twitch fibers introduces something else that I'm curious about. One of my goals is to develop quickness. I have none. So are you saying that weight training will help me develop quickness? Or does quickness have nothing to do with fast twitch muscles?

How do I know when the lactic acid has built up? Is that when the muscle reaches fatigue?

Gack! I have a lot to learn, don't I?

Azdak

^^^^THIS!!!^^^^
Very eloquently stated. No one is attacking the benefits of cardio, but they are much different than those of strength training with heavy weights. There are a lot of very knowledgeable people on here who will be thrilled to help you create a weight lifting program that you can work into your schedule, if you are interested. If you only want to hear support for your own opinion that cardio is physiologically equivalent to weight training, however... can't be of much help there.

I have no agenda and am not trying to prove anything. I just want to get the most benefit from the time I have to exercise. And I still am not understanding the claim that you lose muscle when you do mainly cardio. I totally understand that you don't build muscle as quickly nor can you build as much muscle with just cardio. I also totally understand that weight training is superior for building muscle. That makes sense. But the claim that you lose muscle doing cardio doesn't make sense to me at all.

If you or someone else here can help me develop a strength training program that works for me, that would be great. I just don't want to have to give up cardio to do it and I only have so much time.

Currently I usually do strength training just once a week although, once in awhile I squeeze in a second workout. Since my core is not yet very strong and since I'm recently recovered from a pretty severe back injury, I'm hesitant to do free weights at this time. I know free weights are better for you as they require using other muscles more than machines do, I feel like I need the stability machines give me to protect my back. I hope at some point to get a strong enough core to graduate to free weights. It currently takes me almost 1h15m to do all the various machines. I try to get in 20 reps per machine. I typically will start at a higher weight and lift until I can't lift that weight again, then move the weight down 5# and lift that weight until I can't do another rep, and then move down 5 more pounds to finish out the 20 reps. I lift and lower the weight slowly so I'm not using momentum to complete the lift and need my muscles for the lowering portion as well. In-between each machine, I will do about 60 seconds of stretching the muscle used while it is warmed up as I understand that muscles stretch better when warm. If I have to wait for the next machine, I'll jog in place a bit to keep my heart rate up and my muscles warmed up but, usually, I don't have a long enough wait very often to have to do this.

You don't lose muscle doing cardio per se. You can lose muscle if you do high amounts of higher level cardio and do not eat enough protein, esp if overall calorie intake is very low. The way that "cardio burns muscle" is being presented these days is a gross distortion of physiological fact.

For now I would keep your routine simple. Stick with big-muscle exercises--leg press, leg curl, chest press, row, pulldown, shoulder press, upright row or rear-deltoid fly. Do 3 sets of each exercise (do them in pairs so you can, for example, do a chest press while "resting" your legs in between leg press sets. For now, you can do 12-15 reps, but set the weight so that you do them continuously--and so that you reach the point of "failure" between 12-15 reps.

Azdak

Err. No, glycogen is the first thing we burn (after ATP and Creatine). Then fat. THEN muscle.

The ONLY thing we burn is ATP, ATP is the currency for movement. All the energy systems produce ATP out of other substances.

The biproduct of burning ATP is Adenosie Bi-Phosphate, which combines with creatine phospate to get back to being adenosine TRI-phospoate for that secondary boost that can last a few seconds longer.

Order of events

Anaerobic cycle:
-Burn stored ATP in muscle
-uptake ABP that has been recombined with creatine phosphate to make a little more ATP
-Switch to glycolitic or lactic acid system which creates glucose and lactic acid from glycogen in blood, spitting out some more ATP
-Aerobic system next which uses glucose and oxygen
-Fatty acid oxydosis which uses fat for fuel, along with oxygen, providing the most ATP for until of input, but as a slow process is meant for long distances

The more time you spend in the upper portions of this cycle, the more muscle size you will build, as the more muscle you have, the more ATP and creatine muscle glycogen you can store, and the more lactic acid they can tolerate

The more time you spend int he lower portions of this cycle (aerobic portions), the more your adaption will be to REDUCE muscle size, to make those muscles MORE efficient so they use less oxygen and less sugar or fat to do the same job. It takes less ATP to push skinny little legs through a marathon then it does HUGE speed skater type legs.

So if you want HUGE legs like speed skaters, sprinters, do hill sprints, dashes of up to a quarter mile, intervals, etc... to keep moving in and out of the top of the chain which depletes in total in about 2 minutes (4 minutes if you are HIGHLY trained).

Or lift weights for 12 reps or less to failure, which is 100% anaerobic.

Thanks. This makes some sense. Although I still a bit hazy on it I think I'm starting to get it a bit.

Questions:

I am a type 2 diabetic and, as such, I definitely need to burn the excess glucose I tend to have in my system. So does this mean that I need to do the aerobic workouts instead of or always in addition to lifting weights?

But then, as I get in better shape and more efficient, you say my muscles will burn less glucose. Isn't that a bad thing for me since I want to burn excess glucose?

So would weight training build more muscle which would then help burn more glucose? Or since weight training burns ATP and not glucose, does this mean I need aerobic cardio more than weight training?

I'm getting confused again. Or am I somehow mixing apples and oranges?

To be honest, with that type of medical history, you really need to spend some one-on-one time with a professional. I don't know the educational background of the fitness staff at your club, but if they can't do it, you might want to find a diabetes educator--preferably someone who is knowledgeable about exercise.

natekorpusik

I'm not good at explaining things, so I'm not much help.

But personally, I think running/swimming/rowing/etc does build lean muscle. [:

Sorry to disagree, but cardio actually burns lean muscle.

Only if you aren't eating enough to fuel the work outs you are doing, and only after glycogen and fat stores have been exhausted!

Sorry to disagree again, but cardio burns lean muscle because it is an aerobic exercise. You will not immediately burn glycogen and fat, your body will burn lean muscle FIRST. Glycogen is the last item in your body to get burned. This is why a routine with both cardio and weight training is the best answer. Common misconception, but after years of training for both police and military I have found this to be true.

Err. No, glycogen is the first thing we burn (after ATP and Creatine). Then fat. THEN muscle.

garlic7girl

http://www.notyouraveragefitnesstips.com/beginners-workouts/aerobic-vs-anaerobic-exercise-low-intensity-vs-high-intensity

Check out this link. They lay it out nicely. Basically we are talking about the difference between aerobic exercise and anaerobic exercise. One using oxygen for endurance and burning fat, and the other using glycogen stores to build muscle. Hope this helps.

Thanks

fteale

I'm not good at explaining things, so I'm not much help.

But personally, I think running/swimming/rowing/etc does build lean muscle. [:

Sorry to disagree, but cardio actually burns lean muscle.

Only if you aren't eating enough to fuel the work outs you are doing, and only after glycogen and fat stores have been exhausted!

Sorry to disagree again, but cardio burns lean muscle because it is an aerobic exercise. You will not immediately burn glycogen and fat, your body will burn lean muscle FIRST. Glycogen is the last item in your body to get burned. This is why a routine with both cardio and weight training is the best answer. Common misconception, but after years of training for both police and military I have found this to be true.

Err. No, glycogen is the first thing we burn (after ATP and Creatine). Then fat. THEN muscle.

Sorry, but you are mistaken. Please quote your source. Glycogen... i.e. glucose.... i.e. sugar is burned first.... your body naturally goes in this order, Why else do we get a 20 minute rush of energy from a candy bar or red bull?

That's what I was saying. Glucose/glycogen is burned first. NOT lean muscle.

hush7hush

I do interval training. Both HIIT and resistance intervals. My legs are insanely strong. [:

You do have awesome legs.

I wish I would have seen this before just now.

ninerbuff

Thanks but I still don't understand why not. For example, if I do a spin class now with the bike tension mainly fairly loose because I can't complete the class with more tension on the bike at this time but, over time, can increase the tension on the bike making it harder to pedal, aren't I also then getting more tension to the muscles? And if I'm so fatigued by the end that I can barely walk to my car, aren't my muscles getting fatigued?

Am I simply confused by what fatigued muscles feel like? I assume it means that the ability to go one minute, one rep, one revolution longer is gone, right?

Fatigued muscles don't mean you're building muscles. It means you've exhausted your energy stores. Do this: Bump the the resistance on a bike to it's highest level. Now try to "sprint". You won't go long because of lactic acid buildup. The power you have to use to do is considered anaerobic and works the "fast twitch" fibers (power and strength). Now pedal much slower. You can go much longer at a slower pace even at that resistance. This works the "slow twitch" fibers (muscle endurance).
Look up the difference between fast twitch and slow twitch muscle fibers. That should clear it up for you.

ninerbuff

Your fast vs. slow twitch fibers introduces something else that I'm curious about. One of my goals is to develop quickness. I have none. So are you saying that weight training will help me develop quickness? Or does quickness have nothing to do with fast twitch muscles?

How do I know when the lactic acid has built up? Is that when the muscle reaches fatigue?

Gack! I have a lot to learn, don't I?

Quickness is usually genetic. You can develop it, but it's mostly a "built in" skill. You may be trying to increase speed. Or am I wrong? And yes, weight training does develop it. Things like jump squats, jump lunges and others increase power to the quads.

funkycamper

For now I would keep your routine simple. Stick with big-muscle exercises--leg press, leg curl, chest press, row, pulldown, shoulder press, upright row or rear-deltoid fly. Do 3 sets of each exercise (do them in pairs so you can, for example, do a chest press while "resting" your legs in between leg press sets. For now, you can do 12-15 reps, but set the weight so that you do them continuously--and so that you reach the point of "failure" between 12-15 reps.

Thanks. I'll give this a try. I've not done sets before. It sounds like doing less exercises but doing more sets might be a bit quicker of a workout as well, giving me time for both cardio and weight training that day.

funkycamper

To be honest, with that type of medical history, you really need to spend some one-on-one time with a professional. I don't know the educational background of the fitness staff at your club, but if they can't do it, you might want to find a diabetes educator--preferably someone who is knowledgeable about exercise.

I took a 5-day diabetes class through my local hospital. While I learned a few good tips about diet, they had nothing about exercise except to encourage walking. I did try to ask questions about specific exercise routines, if some were better than others, etc., but they had nada. Oh, they did give the advice to park farther away from the store, take the stairs instead of the elevator, etc., but that and walking were all they had. The two instructors were a dietitian and a nurse, both diabetics, and both seriously obese. The class was American Diabetes Association-certified and fully covered by my insurance. A waste of my insurance provider's money, imho. I think I would have been better off if they had spent the same dollars toward a personal trainer. But, of course, that is not covered.

funkycamper

This works the "slow twitch" fibers (muscle endurance).
Look up the difference between fast twitch and slow twitch muscle fibers. That should clear it up for you.

Thanks for the tip. I'll research this.

funkycamper

Quickness is usually genetic. You can develop it, but it's mostly a "built in" skill. You may be trying to increase speed. Or am I wrong? And yes, weight training does develop it. Things like jump squats, jump lunges and others increase power to the quads.

Actually, I'd like to develop both. I would like to be able to move quickly when needed but I would also like to improve my overall speed. When I say quick, I'm referring to things like being able to turn immediately if something should fall in my path, for example. I was guessing that increasing speed will improve quickness, too? But, if genetic, maybe not?

funkycamper

I appreciate everyone's responses. And I'm not trying to be argumentative but I have a further question as what happened today doesn't jive well with what most of you are telling me.

Eleven days ago I had a bicycle accident in which I sprained my wrist and thumb. Because of that, I haven't been doing any weight-lifting. Today, after everybody's input here, I decided to go and see if my wrist could handle a session. It could. The only machine I couldn't do was the bicep curl. Anyway....

Even though I have not been lifting at all for 11 days and have just been doing cardio, every single machine was way too easy at the weight I last used. I upped most machines 10# and a couple of the leg machines I upped 20#. In a few cases, even that increased weight was relatively easy so I made notes to increase the weights on those machines even more the next time I train.

If cardio doesn't increase muscle strength, why could I lift heavier weights on all the machines (except bicep curl) with less fatigue than I was able to do during my last weight-training session 11 days ago?

Cooriander

Great thread, I learned a lot in here, it does explain why so many high milage runners are so lean.

dolphin21

I do interval training. Both HIIT and resistance intervals. My legs are insanely strong. [:

You do have awesome legs.

I wish I would have seen this before just now.

WHATS HILT??

ninerbuff

Actually, I'd like to develop both. I would like to be able to move quickly when needed but I would also like to improve my overall speed. When I say quick, I'm referring to things like being able to turn immediately if something should fall in my path, for example. I was guessing that increasing speed will improve quickness, too? But, if genetic, maybe not?

Well that's more like reaction time and can be developed with repitition, however people's reactions are usually genetic. A race car driver can actually read signs when traveling at over 150mph when compare to the average person which is why their reactions are very good.

ninerbuff

I appreciate everyone's responses. And I'm not trying to be argumentative but I have a further question as what happened today doesn't jive well with what most of you are telling me.

Eleven days ago I had a bicycle accident in which I sprained my wrist and thumb. Because of that, I haven't been doing any weight-lifting. Today, after everybody's input here, I decided to go and see if my wrist could handle a session. It could. The only machine I couldn't do was the bicep curl. Anyway....

Even though I have not been lifting at all for 11 days and have just been doing cardio, every single machine was way too easy at the weight I last used. I upped most machines 10# and a couple of the leg machines I upped 20#. In a few cases, even that increased weight was relatively easy so I made notes to increase the weights on those machines even more the next time I train.

If cardio doesn't increase muscle strength, why could I lift heavier weights on all the machines (except bicep curl) with less fatigue than I was able to do during my last weight-training session 11 days ago?

Because your muscle is better conditioned. You can take a two week layoff from lifting at all and even no cardio and come back stronger than when you left. This isn't uncommon and many times even the most seasoned lifter will take 1-2 weeks off to re energize their body. So what you've done isn't unusual.
There will even be days where you'll lift much less than your used to. Does that mean you lost muscle? No, it just means that you're just having an off day.

ninerbuff

WHATS HILT??

HIIT is High Intensity Interval Training.

funkycamper

]Because your muscle is better conditioned. You can take a two week layoff from lifting at all and even no cardio and come back stronger than when you left. This isn't uncommon and many times even the most seasoned lifter will take 1-2 weeks off to re energize their body. So what you've done isn't unusual.
There will even be days where you'll lift much less than your used to. Does that mean you lost muscle? No, it just means that you're just having an off day.

Interesting. I'm not about to take 2 weeks off from exercising to test this but I can see some sense in it.