The Six Second Rule

The "Six Second Rule" is as useful for people with McArdle's as the "second wind", although in a very different way. By using it you can help to avoid fixed contractures of the muscle, with their attendant muscle break down (rhabdomyolisis) and protein in the urine (myoglobinuria).

Immediate energy for 5 to 10 seconds

When doing something like lifting heavy objects or sprinting, there is an energy pathway (the phosphagen system) which is instantly available and lasts for about 5 to 10 seconds. This system relies on ATP (adenosine triphosphate) stored in the muscle and creatine phosphate to provide immediate energy. As that is exhausted people unaffected by McArdle's will start to make use of glycogen stored in the muscle, converting it to glucose for energy. However, in McArdle's the enzyme (myophosphorylase) needed in that process is missing so this energy pathway can't kick in after the initial 5 to 10 seconds. That is when a painful fixed contracture of the muscle will develop which can last for hours or days.

Protect yourself in everyday activities

Everyday examples of maximum intensity activities are: opening a new jam jar which is firmly stuck, standing on tip toe to get something off a high shelf; rushing up a flight of stairs; and crouching or squatting. These are everyday activities which it is best to avoid, but if you have to do them you need to know how to protect yourself.

Count to six

To avoid damage when doing something of maximum intensity it is a good idea to time six seconds by saying to "One thousand, two thousand..." up to six. If the task is not completed by six, stop or put it down. Take a break, let the muscles recover and try again later.

Recovery time

Research shows that the ATP will recover in under five minutes. We don't really know what factors affect its recovery, whether it varies from one to person to another, or whether we can do a lot to improve it's speed of recovery. These are all questions for future research. However, we do know that if our muscles are fit (aerobically conditioned) we will be safer.

Summary

• Avoid maximum intensity activity.
• If you have to do some, the Six Second Rule will help you avoid muscle injury.
• Count whilst doing something of maximum intensity.
• If not complete by six, stop, take a break and try again later.

Last reviewed: 12 May 2012