Hi Wiseman,
Do you have a source for that? I am no expert on this topic, but I did a quick Google search for "Muscle percent glycogen" and found on the 1st page of results 3 sources that claim glycogen makes up only 1% to 2% of muscle:
1. "Approximately 400 g of glycogen make up one to two percent of the fresh weight of resting muscle”
Biochemistry
By Pamela C. Champe, Richard A. Harvey, Denise R. Ferrie
books.google.com.hk/books?id=M_YOW50cg9oC&pg=PA123&lpg=PA123&dq=Muscle+percent+glycogen&********bl&ots=ilJQGeAcKf&sig=msrp1E0x_psSGU1BI3WQkvib8E0&hl=en&sa=X&ei=NSI1U9eiOKWeiAe4hICIDw&ved=0CE8Q6AEwBQ#v=onepage&q=percent&f=false[/url]
Page 124.
2. "In the muscles, glycogen is found in a low concentration (1-2% of the muscle mass)."
wikipedia.org/wiki/Glycogen[/url]
3. "The muscles can store about 1 - 2 percent in glycogen"
ezinearticles.com/?Glycogen---What-Is-It?&id=1114436[/url]
Thanks