what is the importance of carbs?

mengele

can somebody explain to me what is the importance of carbs in terms of bodybuilding. Here some lads in the gyms who are eating a high carb and protein diet. I understand the importance of high protein but whats the advantage of a high carb diet?

endacl

Energy. Exercise fuel.

The_Honeybadger

Energy, fats (the good kind) are also important for bodybuilding and general health.

Transform

mengele wrote: »

can somebody explain to me what is the importance of carbs in terms of bodybuilding. Here some lads in the gyms who are eating a high carb and protein diet. I understand the importance of high protein but whats the advantage of a high carb diet?

if you understand the importance of high protein and dont understand the role carbs play then you might not know what you think you know

Hanley

If you want to get big and strong, or fit and fast, you need to train pretty hard and at a high intensity.

Carbs and protein are the primary fuel source for that kind of training.

They also help take the protein and other nutrients you ingest and "bring them" to the muscles so that they can be used for growth and repair.

But like anything else, a balance is needed and overconsumption is not good.

ford2600

The quoted bit below is taken from optimumnutrition4sport.com. As you can see how the human body fuels itself isn't simple.

Reducing food down to just macros, without focusing on food quality,micro-nutrients, quantity is a bit of a blind alley

On low activity days I'd be inclined to go low to moderate carb ( but good quality with fibre/ low GI in mind). On high intensity training days I'd be inclined to up carb quantity either side of activity. Even on low intensity training days eating back carbs is probably a good idea for most.

If you train consistently, then you need decent levels of protein, I'd be inclined to keep it consistent irrespective of training. Your body generally uses protein to repair damage muscles when you are sleeping(quality sleep matters as much as anything) so having protein available is as important on rest days as training days.

In general you'd be as well listening to podcasts on sigmanutrition.com or similar rather than some random lad in gym! Don't forget to eat adequate fat either


Energy Systems

Now for the science bit. I don’t want to go into too much detail, but understanding how your body functions is the key to understanding how food works. So very briefly, here are the different ways your body can produce ATP (i.e. energy)

PhosphoCreatine System: ADP +Cr P –> ATP

This system is used to produce the first 10-15secs of energy that we need for sprints. Obviously, this is not a system that ultra endurance athletes use very often. It doesn’t require glucose or oxygen and it is fuelled through the use of creatine, a natural molecule produced in the body consisting of 3 amino acids.

Anaerobic System (Glycolysis): Glucose –> Pyruvate + ATP + H+

This is a system more familiar to people which burns glucose quickly and coverts it to lactic acid. The result is quick energy, the type needed for high intensity exercise like interval training or hill climbs. This process doesn’t require any oxygen but the trade-off is a large production of hydrogen ions which decrease the pH resulting in muscle fatigue.

Cori-Cycle (The Lactic Acid Cycle): Lactate + ATP –> Glucose

Despite what people think, lactate is not the bad guy. The acid builds up and muscle fatigue/pain is mainly caused by an increase in hydrogen ions (which lowers the pH). The lactate produced in the muscle can be recycled in the liver and converted back to glucose. This glucose can then be shuttled to the muscle and used again to produce energy.

Aerobic System (The Krebs Cycle/Citric Acid Cycle): Glucose + O2 –> CO2 + H2O + ATP

This is the main system that our cells use to produce energy. It’s a series of enzyme controlled chemical reactions that use oxygen to breakdown glucose. The first few steps of this reaction involve converting glucose into a smaller carbon chain intermediate. What’s important to note here is that both fats and proteins can be broken down and converted into this exact same intermediate. In other words, as well as pure glucose, our cells can use fats and proteins to fuel the aerobic system. This is a complicated pathway but here is a very simple diagram to illustrate what I mean



Lipolysis/Beta-Oxidation

Lipolysis is the conversion of triglycerides into glycerol and free fatty acids. These free fatty acids can then be transferred to muscle where they are further broken down through beta-oxidation to prepare them for the Krebs Cycle. The advantage of using fatty acids is 1. The amount we can store is far greater than carbs and 2. They provide roughly twice the amount of energy per gram. So we have lots more of this type of fuel and it produces more energy. The only disadvantage is that because they are much bigger molecules than glucose, they require more oxygen for their combustion. Therefore, fatty acids from the plasma and adipose tissue are oxidised at a higher rate when the intensity is low (i.e. when you can take in more oxygen, i.e. breath more)

ITMG (Intramuscular Triglycerides) Fat Oxidation

So when fats are used to produce energy, they can come from three different locations. 1. Adipose Tissue, where the majority of itis stored 2. Muscle and 3. Blood Plasma. The fat stored in muscle is called Intramuscular Triglycerides. It is this which gives meat its marbled appearance. As ITMG’s are already present in the muscle, transport and delivery is not an issue. Therefore, the ability to use them is increased especially as exercise intensity increases.

Glycolytic Proteins/Protein Oxidation

Amino acids (such as Leucine, Isoleuncine and Valine) can also be converted into Acetly-CoA (the intermediate that both glucose and fatty acids are converted to) and then used in the Krebs Cycle. It is estimated that 5-10% of energy can come from the oxidation of proteins. However, this is not ideal if amino acids are not plentiful as it means that the source of amino acids will be from muscle tissue. This can be reduced by supplying amino acids and increasing the rate of fat oxidation to spare the use of protein.

Glucose Alanine Cycle

Just like the Cori Cycle, where a waste product is converted back into glucose, the same can be done with amino acids. The amino acids Alanine and Glutamine can be used to convert Pyruvate back into Glucose.

PowerToWait

Have a quick Google of Durianrider and 30 bananas a day. He'll fill you in.

Some of his vids are fairly amusing for 10 minutes. Mad bastard.

Carb the fūck up.