Six second rule
When doing something at maximum intensity the instantly available energy lasts for only 5 to 10 seconds2.
Examples: opening a firmly stuck jam jar, standing on tip toe, lifting or pushing a heavy object, rushing up a flight of stairs.
This relies on the muscle’s own fuel store – ATP (adenosine triphosphate) – and creatine phosphate.
When these are used up people unaffected by McArdle’s then convert glycogen stored in the muscle into glucose for energy.
McArdle’s people can’t do this due to lacking an enzyme called myophosphorylase.
A painful fixed contracture of the muscle can then develop and last for hours or days.
It is best to avoid these activities.
If you have to do them, count up to six seconds.
If the task is not complete by then, stop or put it down.
Take a break, let the muscles recover.
ATP will substantially recover in a minute and fully recover in about three minutes. Then try again.
There is more about the six second rule on the AGSD-UK web site.
Plan to give yourself extra time.
Hurrying is a main enemy of McArdle’s. The energy demand is too great and we risk muscle cramps. Try to plan ahead, allow more time and take things steadily.