TCA Cycle Explained

The TCA Cycle (Tricarboxilic acid cycle) is simply one of 3 biochemical names for the aerobic energy pathway cycle. It is also referred in many texts as the Citric Acid Cycle, the Krebs Cycle and a few others but don’t let that throw you, they all mean the same thing. For our purpose well call it the aerobic energy cycle.

This is the main energy production pathway in the body. Energy is a molecule called ATP and it is formed via breakdown of glucose (carbs), fats and proteins (amino acids) that enter and go through these pathways. The aerobic energy pathway requires oxygen to work, it is at one end of the energy production spectrum. It has always been assumed this pathway is only utilized when performing long, slow duration exercise like cycling, walking, jogging etc.

At the other end is the anaerobic pathway that doesn’t utilize oxygen. This energy system is used for short, fast, all out exercise 30 seconds or less like sprinting, a slam-dunk, or a hard, heavy set in the weight room. There are also many related energy pathways in between these two. Recently reviews have provided some valuable info regarding these pathways and their impact on building muscle.

1. Energy (ATP) production is far more complex than previously assumed. That, in fact ATP production and regeneration for muscle contraction is formed by a complex integration of all energy pathways. No matter what type of activity you perform ATP is regenerated by precise interplay of every energy pathway. The aerobic energy pathway is shown to be highly involved in regenerating ATP when weight training. This is a revolutionary finding as most experts assumed weight training is purely an anaerobic activity. The fact is intense anaerobic exercise like weight training taxes all energy production pathways, big time!

2. This is a big problem if you are trying to build muscle. All energy pathways have steps or stages. Each step utilizes particular amino acids. The harder you train in any activity, the more you use up (metabolize) these amino acids. The problem is, these particular amino acids namely glutamate, glutamine, valine, isoleucine and leucine are also critical components of muscle growth. Research demonstrates utilization of these amino acids during and after exercise for energy production can be so extensive, little or no amount is left to effect muscle growth!

3. When the body does need these amino acids for energy production pathways it breaks down muscle to get them! This is precisely what a hard training athletes or body builder does not want and, this is why anyone that trains intensely needs protein supplementation. If you can supply the right amino acids (and it takes all 20, not just the five we’ve previously mentioned) at this critical time, you can offset the dramatic muscle breakdown that usually occurs and actually stimulate the mechanisms that produce awesome gains in muscle.

4. However the problem lies in the ability of the protein supplement to get to the muscle fast, at precisely the right time. A precise peptide bound amino acid whey protein formulation is proven by research to be absorbed and transported to muscle faster and in greater amounts than any protein or free form amino acid mix and produces the most dramatic gains in muscle.

One would think that the most critical time to supply additional amino acids to the body is post workout so that has plenty amino acids for recovery. Is providing the body with high quality protein pre and post work out enough? (especially for people like me who are not allowed to lift heavy weights anymore)

hSingh wrote:One would think that the most critical time to supply additional amino acids to the body is post workout so that has plenty amino acids for recovery. Is providing the body with high quality protein pre and post work out enough? (especially for people like me who are not allowed to lift heavy weights anymore)

hey hey

The key to remember is that 99% of your amino acids in your body are stored in muscle as muscular proteins. That means the amino acids form protein peptide chains. However, the body is CONSTANTLY building and breaking down, recycling this protein all the time.

Where does this protein go?

To the 1% Amino Acid pool that is in your blood.

What does your body do with it?

a. Excrete it, or
b. Utilize it

If your body is in a state of rest and repair, ie. Growth. You will utilize those amino acids.

The body will always maintain that homeostasis of 1% blood amino acids.

Where does your body get these amino acids from?

The 99% body supply, IF and WHEN there is no exogenous (supplemented) protein.

When do you need to supplement then?

When there is a amino acid drive, either stimulated through training (excessive protein breakdown), immune system (fighting bacteria), or general bodily growth (growing kids - adults have to train).

So during training, after training, and on a regular basis throughout the day you need amino acids to restore that 1% amino acid pool.

Thanks for the clarification.

I am trying to get more and more protein from food rather than protein shakes. These days I'm only having protein shakes pre and/or post workout. Rest of the times I have tofu, daal, and home made yogurt. Of course, it tough to get 30g of protein from tofu when compared to the protein shake. But as my training intensity has gone down dramatically, I think I'll be fine. I do test my strength from time to time with pull ups and push ups. So far I have not notice any loss in strength Unfortunately can't test my squat thanks to the L4 L5 disc material inflammation, which is slowly healing.