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

funkycamper

I've been reading here that cardio does not build muscle. I don't understand why it wouldn't. I get bored easily so I do a variety of exercises. I do C25k (although it will probably take me several months to get through the program as I usually only do it once or twice a week), Zumba, spinning, swimming, fitness walking up/down hills, bike-riding outdoors, step-aerobics, elliptical, and rowing machines. Different muscle groups are used in these and I'm toning up and losing inches without a lot of weight loss so I can only assume it's because I'm building muscle.

I do try to get some weight training in each week but the calorie burn is rather low so I only do it once a week most weeks. Although some weeks, if I'm in the mood for it, I do get in a second weight training session.

Anyway, the whole concept is confusing to me as, it seems to me, that anytime you are using your muscles to the point where the muscle is getting fatigued, you should be building muscle. Or, at the very least, strengthening the already-existent muscles and that is a good thing, too, isn't it? Right? Not right?

I'm just hoping somebody can explain this to me. Thanks in advance.

hush7hush

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. [:

moushtie

From what I understand, cardio only builds new muscle if you're doing something that really stresses them. Like walking is good cardio, burns calories, but you probably won't build new muscle.. running up hills however, really gives those legs a workout. I think some of the high intensity interval training builds some muscle too, because you're pushing your body to the limit.

Weight training may not burn too many calories in itself, but your metabolic rate is based off your muscle mass. If you keep your muscles strong while losing weight, then you'll keep your metabolic rate higher, which should mean more calories burnt on a daily basis. This is why I do strength exercises along with the cardio I do, because I want to maintain as much of the muscle I have now at my higher weight, so I'm nice and strong and fast after losing weight too

sugarbone

Cardio CAN build muscle, but not at the rate dedicated strength exercises do. If the cardio is strenuous and you can feel the burn in your muscles during and after, you're probably strengthening them.

Remember, though. You can't BUILD muscles unless you are eating a calorie surplus. You can only strengthen them but they will stay the same size. Also, as soon as you get used to that cardio exercise, keeping up the cardio will maintain that muscle but it won't strengthen forever unless you boost the intensity - like when weight lifters increase the weight they're lifting.

hush7hush

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

funkycamper

From what I understand, cardio only builds new muscle if you're doing something that really stresses them. Like walking is good cardio, burns calories, but you probably won't build new muscle.. running up hills however, really gives those legs a workout. I think some of the high intensity interval training builds some muscle too, because you're pushing your body to the limit.

Weight training may not burn too many calories in itself, but your metabolic rate is based off your muscle mass. If you keep your muscles strong while losing weight, then you'll keep your metabolic rate higher, which should mean more calories burnt on a daily basis. This is why I do strength exercises along with the cardio I do, because I want to maintain as much of the muscle I have now at my higher weight, so I'm nice and strong and fast after losing weight too

When I do fitness walking, I'm walking at a fast pace and going up and down steep hills. My legs are zonked from it. Just as zonked as they are after a C25k workout (which is kinda like HIIT training). So why wouldn't I be building muscle from the fitness walking?

In fact, all the cardio I do really stresses my muscles. I'm zonked when I'm done and have some muscle soreness and even, sometimes, extreme muscle fatigue...ya know, like I can barely walk to my car and dread climbing the stairs from my basement garage into the house type of fatigue. So I'm finding it hard to believe I'm not building muscle. Especially since I've only lost 4# but all my pants are loose...some falling off loose. So I can only assume it's because I'm toning up, i.e. building muscle.

Again, not opposed to weight training but I only have limited hours to exercise and would rather burn calories and keep my weight training to only once a week, twice at most. Also, I've been researching and new muscle burns about 30-35 calories per day. I don't dispute that building muscle is a good thing for overall fitness and I wouldn't mind more muscle to burn more calories. That's a good thing.

What doesn't make sense to me is statements on this board that cardio doesn't build muscle. In fact, I've even read posts where people claim that you will lose muscle with cardio. Huh? Now, I can see that you will lose muscle mass in your upper-body if you are doing strictly running for marathons, but that's an extreme situation and not what I'm talking about.

Again, if the muscle is getting a hard workout to the point of fatigue and soreness, how can it not be getting built regardless if the soreness and fatigue is from weight training or cardio?

funkycamper

Cardio CAN build muscle, but not at the rate dedicated strength exercises do. If the cardio is strenuous and you can feel the burn in your muscles during and after, you're probably strengthening them.

Remember, though. You can't BUILD muscles unless you are eating a calorie surplus. You can only strengthen them but they will stay the same size. Also, as soon as you get used to that cardio exercise, keeping up the cardio will maintain that muscle but it won't strengthen forever unless you boost the intensity - like when weight lifters increase the weight they're lifting.

From what I'm reading, muscle burns about 35 calories a day. If weight training only burns about 200 calories when I do it, versus burning 500 or so with intense cardio, then I'm 300 calories behind for the day in what I could have burned.

And, of course as I get fitter, I would be increasing my cardio intensity. When I first started C25k, I ran a lot slower than I do now. Heck, my walking was even slower. My spinning is faster, my bike riding is faster, I'm fitness walking up hills faster, I can do the elliptical faster and at a higher intensity. I'm still new to getting back into shape so I'm not saying I'm doing any of this super-duper faster than before but I am seeing speed and intensity gains.

Well, at least you are all saying that cardio does build muscle so I know I'm not whacked. I've just read through several other threads on these boards where people are saying that you lose muscle with cardio and that makes no sense to me at all.

funkycamper

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

I know what HIIT is but I've never heard of resistance intervals. What is that?

hush7hush

I do a lot of my exercises on machines. Elliptical, arc trainer, bike, etc. They all have resistance levels. I do intervals.

MissTomGettingThin

I run, use the eliptical, row and walk with a bit of lower body resistance training.
I do use weights on my arms.
My legs are my best feature.
I'm proud of my muscles in my legs.
cardio that works the muscles builds muscle. It has to. otherwise I'd just be bone!

Adrenaline_Queen

Cardio is to get the heart going, not to build muscles. To warm the muscles up to work out or train.

To build muscles you need to use weights. You sound like you train more than me, and I train 5 times a week. I just need to get my diet sorted. Good luck and hope that helped! xx

Also when you train you have to get out of your comfort zone, get out of breath make everything a challenge. You should see a difference... x

Adrenaline_Queen

Just read yours, I should of put more in mine, so much to do and no time, feel silly now! But I still stick to what I wrote x

Adrenaline_Queen

I run, use the eliptical, row and walk with a bit of lower body resistance training.
I do use weights on my arms.
My legs are my best feature.
I'm proud of my muscles in my legs.
cardio that works the muscles builds muscle. It has to. otherwise I'd just be bone!

Just read yours, I should of put more in mine, so much to do and no time, feel silly now! But I still stick to what I wrote x

martinh78

Cardio CAN build muscle.

Agree. I have only just started resistance training (ie done it three times) so my muscles have so far been built purely from cardio. My legs especially. I'm fed-up with reading that you have to do weights to build muscle/not end up "skinny fat" or whatever.

Remember, though. You can't BUILD muscles unless you are eating a calorie surplus.

Have to disagree with this though. Again, I'm in a calorie deficit and my muscles have definiately built up...they are much larger than they were 50 days ago. My muscles require calories to build, but not ALL of the calories I eat. So I must be eating the calories my muscles need (proteins) in surplus, and cutting back on calories they don't need elsewhere.

Keeping in mind that I don't think anyone is talking powerlifting here, we are talking about weight loss and general fitness/strength,

I look at it this way, my muscles don't care if the resistance is coming from a weights machine or the pedals of a bike, it's resistance.

elmsallmissile

What is hard to understand here cardio IS weight training, when I run I push 200 lbs + with every single step, perhaps 8000 to 9000 reps per hour, how is that not weight training?

JamesBurkes

I agree - cardio CAN build muscle. In fact, I rely on it for my leg workouts.

I have packed on an inch on my calves (now 17") from doing fast walking (almost 4 miles an hour in a hilly area) and an inch on my thighs (now 25") from cycling, RPM and the P90X Plyometrics DVD.... all within a month.

That said, while you CAN build muscle doing cardio, if building muscle is your aim it is an inefficient way of doing it. I'm sure I could have made the same gains from doing calf raises for ten minutes as I did from Power Walking for 2 hours, or from squatting for 15 minutes rather than doing an hour of cycling or plyo. However, my goals were calorie burning and fat loss, so these activities suit me better - the muscle gain is just a nice bonus.

Puckermann

Any exercise that causes tension in the muscles can cause you to add mass to that muscle. So running would hardly cause any tension but climbing hills with a bicycle would put a lot of tension on your quads.

Azdak

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.

Azdak

Another thing: when it comes to permanent weight loss and actual increases in muscle mass, the research is consistent, if not unequivocal.

While one can maintain FFM doing large volumes of cardio with appropriate refeeding and protein intake, almost all studies show that significant increases in FFM occur only when resistance training is added to cardio.

natekorpusik

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.

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.