HIIT Question

[Nandoo]

So I've started doing HIIT but a friend of mine told me that if I don't don't work on the other muscles while in cardio I'll start to lose muscle instead of fat. Is that true?

If so, which muscles should I concentrate and how? Should I work on a specific part each day and repeat the cycle?

Thanks in advance for the answers.

 

[Valentine817]

Whats up, buddy? Ya know there are alot of fitness myths out there. I would venture to say that 50% of what the average population knows is incorrect. Although, your friend raises a valid point. It basically comes down to energy metabolism. What is the quickest source of energy? ATP (adenosine-tri-phosophate) Next quickest: Glucose. Next: Protein (amino acids). Lastly lagging behind is Fat.

Now this isn't always bad, it depends on how fast your body needs the energy. If you are doing a spring, your body needs enery ASAP. It will get this energy from ATP stores in muscle cells. Take for example a 200M sprinter, notice they sprint full out the first 100m or so, then as they begin approaching the finish line they look slower than previous. This is not because they are ill-conditioned, they are OLYMPIC athletes, the most conditioned individuals in the entire world. It is simply a product of a physiological respose to energy needed. An average individual had about 30 seconds of good ATP stores for an exercise, depending on how demaning, sprinting being the most demanding, in this case it is used up in around 12-15 seconds. Since the fastest source of energy has now been compromised the body will search for the next fastest source, which is glycogen. Glycogen is stored mainly in liver cells, upon activity, glycogen is released to fuel the exercise as glucose. But what happens when stored glycogen runs low? The body will then use Fat. it will convert fat into glucose to enter the blood stream to be used by the active cells.

So, to answer your question protein is not used as energy unless glycogen stores have depleted, and the body needs a quick source. I.e If you are doing an activity that requires quick energy. Joggins at a moderate pace will not require quick energy, therefor protein will not be utilized.

 

[evolutionX]

So I've started doing HIIT but a friend of mine told me that if I don't don't work on the other muscles while in cardio I'll start to lose muscle instead of fat. Is that true?

If so, which muscles should I concentrate and how? Should I work on a specific part each day and repeat the cycle?

Thanks in advance for the answers.

Well, you won't build muscle if you don't do anything. Muscle loss (atrophy) is usually associated with inactivity and extremely low protein intake so that there's a deficiency.

If you like HIIT and don't want to go to the gym, look over at (he has a lot of body weight and sandbag stuff. You can build sandbags for cheap)