kmac27

So I am learning that aerobic excercise doesn't really create "new muscle" as opposed to weightlifting. So does cycling really change your muscle fibers from fast twitch to more slow twitch cheracteristics or am I missing something?

Also how hard, dense can your muscles get from cycling. How about defined?

Red Rider

Short answer: Yes.

Climb some hills and tell me about fast/slow twitch. Then sprint and discuss.

Your muscles can become very defined, if your diet is in sync with your cycling. I'll bet you know plenty of cyclists who have terrific definition that's obscured by that layer of adipose tissue acquired by improper/uneducated eating.

If you're primarily a distance rider and don't ride many hills, your legs may tend to be smaller, leaner, more defined (much is dependent on your DNA). If you're a sprinter and hill climber, count on larger and defined muscles. Again, that's dependent on your DNA, as well as your eating habits.

You're genetically predisposed to the number of fast twitch & slow twitch fibers you have, as well as how big your muscles will get. You may want to consult a professional to get a program specific to you.

YMMV.

fogrider

I think weightlifting builds your muscles by building lactic acid which pretty much tears down your muscles and rebuilds more and bigger. that s why you need time to recover. aerobic tones and builds the muscles you have. but the real advanage to aerobic is it builds up your lung and heart to deliver oxygen to your muscles.

timmyquest

Do both.

Edonis13

thats me!

remixity

Well if you mash your pedals, it's pretty much the same as weight training. Aerobic exercise does bulk up the muscle matter in your heart, though. Lance Armstrong's heart, for example, is relatively huge.

I don't think it's been established that fast-twitch fibers convert to slow-twitch fibers, but obviously something goes on during cardio exercise that leads to the building and recruitment of more slow-twitch fibers.

dauphin

you are a certified personal trainer? a physician? a medical reseacher?

oldspark

How about someone who just knows what they are talking about, some of the posts on Bike Forums are way out in left field and are defended with brainless babble.

brundle_fly

The truth is;Cycling will turn you into a stick insect

pseudobrit

Everyone on BF is expert. Never question our credentials. Where's pcad to tell us credential is for wussy?

I love being a stick insect. The figure below my username is not a joke. Although winter chub and too much weight training has pushed it over 2 for the moment.

Red Rider

Personal trainer and wannabe kinesiologist.

ldesfor1@ithaca

[QUOTE=fogrider;5885341]I think weightlifting builds your muscles by building lactic acid which pretty much tears down your muscles and rebuilds more and bigger.

this is the dumbest, most useless comment ever. I'm sorry, but if you're just guessing about physiology, please dont post it in a forum where some one may accidentally take it for fact. this is wrong on so many levels. Yes, i do work in the fitness industry and this is just silly.


OP:

Get a book on physiology or at least look for some credible sources on the net and do some reading.

sorry, nothing personal. this is not a "what's your opinion" question, please dont answer it as one.

ldesfor1@ithaca

Kmac27:

I am an ACE certified personal trainer who takes his job and own cycling training seriously (but still, take my comments with a grain of salt).

Firstly, most reaserch/accepted knowledge suggests that your body has a predetermined number of muscle fibers and that no ammount of weight lifting or cycling will ever increase the number of muscle fibers one has. Check this out (the good doctor has stated clearly):


Provided by C. Subah Packer, Ph.D., associate professor, Indiana University School of Medicine, Indianapolis

"Muscles generally get bigger in response to working harder. Although the cells do not typically divide and produce more cells (a process called hyperplasia) in response to a greater workload, they do grow bigger. This increase in cell size is called hypertrophy.

The main mechanism for skeletal muscle cell hypertrophy in response to increased workload is an increase in contractile protein production. Therefore, the result of increased exercise, especially load-bearing exercise such as weight lifting, is increased synthesis of the contractile proteins, actin and myosin, by the muscle cells. The larger cells are bigger and stronger and, therefore, the whole muscle or group of muscles becomes bigger and stronger.

Conversely, lack of exercise results in a process of atrophy, which is a decrease in muscle size and strength (remember: no pain, no gain). Atrophy is likely because of down-regulation of the cell signals that stimulate contractile protein synthesis. Eventually, cell proteins break down, and if the proteins are not replaced as fast as they are lost, the cells will decrease in size and strength. The exact cell signals involved in both hypertrophy and atrophy are under investigation and have yet to be completely understood. "


-Additionally, genetics, diet, rest, and training techniques will place limiters on muscle size. For example, no amount of weight lifting will get you 20 inch biceps if your caloric intake is not great enough to maintain and develop that high level of cellular density.


To address your question about fast and slow twitch fibers:

genetics tend to predetermine the % of fast and slow twitch fibers in each individual. This makes sense as some cyclists (or any other sport's athletes) are seemingly "natural" sprinters or excel at long climbs or endurance events. This does not mean that one can not improve ones weaknesses, and fast twitch response can be vastly improved with training. Your fast twitch fibers do not increase, but the ones you do have become stronger, faster and more efficient with appropriate training and rest.

To address the muscular definition question: again genetics play a role here, but nutrition, rest and training really determine muscular definition. The more bodyfat one has, the less defined the muscles, as the layers of fat cover up the underlying muscles. Now, losing bodyfat is a whole other can of worms.
Pro cyclists are extremely defined...does that answer that question?


Hopefully this helps a bit.

-L

dauphin

finally...an intelligent post... ^^^^

Dubbayoo

No, only Jebus can do that. Muscle fibers get larger but the distribution doesn't change nor does the number.

Muscle defintion is mostly a function of calorie intake versus expenditure. I have very large muscles but little definition because a) I do more talking about riding than actual riding. b) I like pizza and c) I'm getting old.

timmyquest

+1
Bravo

asgelle

You don't believe in the conversion of type IIb to type IIa fibers?

wfrogge

[QUOTE=ldesfor1@ithaca;5886515]I agree with you but to be honest if somebody is dumb enough to take any posting here as fact they get what they deserve.....


But back on topic...

If you want to get defined you need to have a low ammount of body fat. And BTW aerobic cycling does build muscle.

Dubbayoo

Well, we could get into inducing hyperplasia with HGH and IGF-1, which is possible. I just chose to keep it simple and not to go there.

asgelle

I guess we could, but I don't see how that's germane. The USAC coach's manual gives as one response to aerobic training, the conversion of type IIb to type IIa fibers. Are you saying this is incorrect?

oldspark

No one read red rider's post?

haimtoeg

Excellent post!

Naterider

Ok. So how do you lose body fat AND gain muscle?

Magic pill???


It is difficult to eat enough healthy foods to recover properly and lose BF.

Road Fan

This has been my expereince, 'cep I'm a stick insect who likes french fries!

Road Fan

Machka 

Well, I was going to answer this, but both Red Rider and Ides have said was I was going to say. I too have kinesiology and fitness theory textbooks to quote from, which say what their texts say.