Working out & burning ATP stores

[neigung]

What's the point of working a muscle/muscle group to the point where ATP is all used up?
Is this just an endurance/stamina training thing? Or does it have other effects?

[TigerJaw]

Originally posted by neigung
What's the point of working a muscle/muscle group to the point where ATP is all used up?
Is this just an endurance/stamina training thing? Or does it have other effects?

IIUC Exhausting your ATP supplies puts a strian on the 'energy system' for the muscle. One way in which your body adapts is to put more sarcoplasm in the muscle. Sarcoplasm is bulky and so the muscle gets bigger. (Sarcoplasmic hypertrophy)

My understanding is that exhausting you ATP supplies is the sort of thing bodybuilders get up to to increase size whereas strength atheletes do much lower reps with longer rests in between to focus on making the muscle fibres thicker (Myofibrilar Hypertrophy). This doesn't make the muscle that much bigger but leads to better strength gains.

Ford Prefect knows lots about this sort of thing.

[Ford Prefect]

ATP stores are really only there for short bursts of strength. They readily get eaten up quickly. Whether your are lifting like a BB'er or lifting using your 1-rep max, your ATP store are pretty much burned up with every set.

Do you mean training to failure? That's an entirely different thing.

[neigung]

I didn't really mean to failure, I was just curious about the point of burning ATP stores up.
Now that you mention it, what's the point of training to failure as well?

[TigerJaw]

But isn't it repeatedly exhausting your ATP and doing another set before your muscles have had time to replenish their ATP that causes your body to deposit more sarcoplasm. I came to this conclusion based on the point that sarcoplasm is what synthesizes ATP.

So what causes failure if it's not ATP exhaustion?

[Ford Prefect]

Neigung,

It is impossible to workout and just feel the moment your ATP stores have been used up and stop.

Tiger,

Kind of sort of. When you are performing a lift, you will be first exhaust your ATP stores. The by-product of this is ADP. Your ADP-CP (creatine phosphate) energy system will then kick in which will turn the ADP back into ATP to be used. This cycle will continue until no ADP/CP/ATP is left. Then your muscles will start to burn muscle glyocogen which is beleived to be stored in your sarcoplasm. The by-product of this is lactic acid and that oh so pleasant burning feeling.

In essense you must work through both your ATP and ADP-CP energy systems in order to start burning muscle glycogen which will inturn premote the growth (or additional storage) of muscle sarcoplasm and thus more glycogen.