Why do you get tired?

[Puck]

Sounds like a horoscope thing to me. You should check it before heading out.

hmmm, like to go out when Uranus is retrograde?

 

[WinterWarlock]

The body doesn't really store much ATP, that's made on-demand in the cells themselves. When you run out of ATP, that's called rigor mortis.

There are some minerals now shown that if their concentrations are too low will affect the bodies ability to produce ATP when needed...Mg being one factor.

Found this too -

In human cells, cellular respiration releases energy from energy-rich organic molecules and changes ADP into ATP.
Aerobic respiration is the main ATP-producing pathway
Anaerobic respiration produces much less ATP (because no oxygen is involved) and can only be used for short periods of time, such as in vigorous muscle exercise.

The important note from this is that less energy (ATP) is produced anaerobically than aerobically. When exercising vigorously O2 levels are reduced, especially if one is not in shape, which reduces ATP production - it then becomes a spiral down problem where the feeling of exhaustion gets more intense faster.
The note about 'energy-rich organic molecules' is also relevant - these are the carbs you should have added to your system before the exercise.

 

[Neil]

There are some minerals now shown that if their concentrations are too low will affect the bodies ability to produce ATP when needed...Mg being one factor.

http://www.newhope.com/nutritionsciencenews/NSN_backs/May_99/10for_road.cfm

 

[Ed'n Lauky]

Lactic acid, actually Lactate, will build up during anearobic conditions...You are not getting enough O2 to the muscles cells. As the lactate gets oxygenated it is converted to pyruvate and enters the Krebs cycle.Another occurence happening as a result of anearobic conditions is the build up of acid in the muscles from the hydrolsis of ATP for energy called acidosos. ( a proton is released in the process) It is suggested that this is the real culprit.

The Ca ion pumps is interesting...perhpas the ATP is getting used for energy by the muslce cells and not going to power these pumps. The answer is to get the body in the proper conditon so that it is not operating under anerobic conditions. In the presence of O2 far more ATP is generated by elctron transport chain aka Mitchell transport chain or whatever they are calling it these days.

Wow That's really interesting. And all this time I thought I was just getting old.

 

[Stash]

hmmm, like to go out when Uranus is retrograde?

Doncha think that's a bit private to be discussed here?

 

[jfb]

I have read that muscle fatigue is directly related to muscle glycogen depletion but I find that explanation to be a bit lame.

Like, if your gas tank is half empty your car has difficulty getting up a hill? Doesn't make sense to me.

If your hybrid ran out of gas but the battery still had a charge, you could go up the hill but at a lower speed.

This link compares the glucose/glycogen vs. fat systems.

 

[Little Rickie]

So why is it that one day I can walk/bike forever and another I'm draging after a relatively short time. Both are preceded by similar days of sleep/exercise/nutrition or, in many cases, I do better when I start tired. My though is that there's something in the brain that just says it wants to go that day. And "good days" usually last all day, as do "bad days".

Are you married?

Seriously your emotional state can help or hinder you. You could have been stressed emotionally or mentally, and not think much of it, but it does have an effect on you.

Biorhythms? Don't knock it our bodies are complicated machines.

 

[Stash]

Are you married?

Seriously your emotional state can help or hinder you. You could have been stressed emotionally or mentally, and not think much of it, but it does have an effect on you.

Biorhythms? Don't knock it our bodies are complicated machines.

Worse than married... I have a teenage daughter.

On that serious note I might just try to document all that stuff, including sleep, nutrition, whether I'm the best or worst dad ever, and see how if I can come up with some sort of chart. Might be interesting to look at a few months' data...

 

[WinterWarlock]

hmmm, like to go out when Uranus is retrograde?

That happens to him when he eats Black Bart chili...

 

[Neil]

Here's something. Have you ever started a really big hike while feeling like crap because of lack of sleep, abuse of euphorics or both?

I know I have and when out in the hills I tell myself that these horrid states have nothing to do with my body's energy delivery system and so I compartmentalize the pain and suffering until it goes away.

As long as I have adequate magnesium stores and my calcium channels are fully operative then 90% of the struggle is in my head and the other half is mental. Thank you Yogi Berra!

Has anyone here started a Presi traverse at 4am with a belly full of eggs?

 

[Little Rickie]

Worse than married... I have a teenage daughter. ...

I feel your pain...my daughter is 17 and I can assure you she has an effect on my mental/emotional state that influences my energy. That's one of the reasons I need to get out for a hike.

On that serious note I might just try to document all that stuff, including sleep, nutrition, whether I'm the best or worst dad ever, and see how if I can come up with some sort of chart. Might be interesting to look at a few months' data

Are you an engineer or just obsessive/compulsive?

 

[Hobbitling]

less energy (ATP) is produced anaerobically than aerobically. When exercising vigorously O2 levels are reduced, especially if one is not in shape, which reduces ATP production - it then becomes a spiral down problem where the feeling of exhaustion gets more intense faster.

yes, but that ATP isn't lost forever. your body just burns the fuel inefficiently and converts the fuel to lactic acid, which can later be used to generate ATP once you have enough oxygen.

It's like how if wood is heated without enough oxygen to burn, you get charcoal. the charcoal can then be burned as fuel later on if there is enough oxygen.

Although I'm sure there is some limit to how long your muscles can keep operating anaerobically. maybe there is a lactic acid storage limit?

 

[WinterWarlock]

yes, but that ATP isn't lost forever. your body just burns the fuel inefficiently and converts the fuel to lactic acid, which can later be used to generate ATP once you have enough oxygen.

It's like how if wood is heated without enough oxygen to burn, you get charcoal. the charcoal can then be burned as fuel later on if there is enough oxygen.

But it's energy capacity is less than the original wood...

Although I'm sure there is some limit to how long your muscles can keep operating anaerobically. maybe there is a lactic acid storage limit?

These are interesting notes I just found:

nificant source of ATP when muscular activity continues for any length of time. The final limiting factor in continued muscular activity is the build up of lactic acid. The lactic acid eventually produces muscular pain and cramps which force discontinuation of activity. Usually before this happens and after activity has ceased, lactic acid diffuses out of the muscle cells and into the blood where it enters the liver.

The body is very efficient in that lactic acid is sent in the blood (5) to the liver which can convert it back to pyruvic acid (6) and then to glucose through gluconeogenesis (8). The glucose can enter the blood (9) and be carried to muscles and immediately used. If by this time the muscles have ceased activity, the glucose can be used to rebuild supplies of glycogen through glycogenesis (10).

And

Lactic acid is the main waste product, changing the pH of the muscle cell and causing it become more acidic (more +H). This acidity inhibits muscular contraction by interfering with energy production. If lactic acid is high enough, it can damage muscle fibers