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Peg · 26-06-2006, 10:55 AM

I forgot to mention check your potassium levels. I would think with a bodybuilder's diet that you would have enough potassium, so I didn't mention it, BUT.... just in case...

Here is an excerpt from an article on training nutrition.

Why does a shortage of potassium lead to muscle cramping?
There could be 2 different effects of low K+ that could lead to cramps.

First, K+ is involved in the repolarization of the muscle membrane during an action potential. If the K+ concentration is low within the cell, the driving force on K+ is lower, and the repolarization is slower. This will have no effect on the absolute refractory period of the action potential (the time when it is impossible to initiate another action potential), but the muscle cell will be more depolarized than usual following the absolute refractory period and thus closer to the AP threshold.

The result may be that fewer action potentials are required to reach tetanus (maximal force resulting from temporal summation from multiple stimulation). The end result could be an overuse of ATP (at a fixed duration of neuromuscular stimulation) compared to the normal state, and thus a need to rely more heavily on anaerobic glycolysis to provide energy with its subsequent increase in lactate, and thus cramps.

Secondly, there may be a K+-lactate symport (secondary facilitated diffusion mechanism) that removes lactate from the muscle cell. If such a transporter exists, low K+ levels would slow the removal of lactate from the muscle cell - resulting in cramps when excess lactate accumulated.

There is no RDA for potassium, but the basic requirement is estimated to be around 2,000 mg for adults. Good dietary sources include oranges, bananas, apricots, avocados, potatoes, lean meats, dried peas and beans, coffee, tea, and cocoa. Deficiency can occur from dehydration, use of laxatives or diuretics, vomiting, or inadequate dietary sources.

26-06-2006, 10:55 AM	#4 (permalink)
Peg Getting HUGE! Join Date: Feb 2006 Posts: 1,468	potassium too I forgot to mention check your potassium levels. I would think with a bodybuilder's diet that you would have enough potassium, so I didn't mention it, BUT.... just in case... Here is an excerpt from an article on training nutrition. Why does a shortage of potassium lead to muscle cramping? There could be 2 different effects of low K+ that could lead to cramps. First, K+ is involved in the repolarization of the muscle membrane during an action potential. If the K+ concentration is low within the cell, the driving force on K+ is lower, and the repolarization is slower. This will have no effect on the absolute refractory period of the action potential (the time when it is impossible to initiate another action potential), but the muscle cell will be more depolarized than usual following the absolute refractory period and thus closer to the AP threshold. The result may be that fewer action potentials are required to reach tetanus (maximal force resulting from temporal summation from multiple stimulation). The end result could be an overuse of ATP (at a fixed duration of neuromuscular stimulation) compared to the normal state, and thus a need to rely more heavily on anaerobic glycolysis to provide energy with its subsequent increase in lactate, and thus cramps. Secondly, there may be a K+-lactate symport (secondary facilitated diffusion mechanism) that removes lactate from the muscle cell. If such a transporter exists, low K+ levels would slow the removal of lactate from the muscle cell - resulting in cramps when excess lactate accumulated. There is no RDA for potassium, but the basic requirement is estimated to be around 2,000 mg for adults. Good dietary sources include oranges, bananas, apricots, avocados, potatoes, lean meats, dried peas and beans, coffee, tea, and cocoa. Deficiency can occur from dehydration, use of laxatives or diuretics, vomiting, or inadequate dietary sources. __________________ "21st century man is not conquered by guns, nor by oppression, but by seduction." "Pride to the human heart is like lard to the pig." Aleksandr Solzhenitsyn "The best punch is the one that is both first, last, and ends the fight."