Adenosince triphosphate is needed for energy near the actin and myosin muscle fiber filaments. When a nervous impulse comes from the brain or spinal chord, myosin projections called myosin heads attach to actin and form an actinomyosin cross bridge, pulling the attached actin filament. The actin slides to the center of the sarcomere. When the attached actin filament The sacromeres shorten together. The length of the muscle fiber decreases. The muscle fiber length decreases during contraction because the muscle fibers shorten in length.
For the past several blog posts, I have not created exercise programs. Look to past posts or search by muscle group, and you will find them!
Disclaimer: None of the above information can be taken as a substitute for advice from a medical professional, such as a physician.
My third book, Pocket Guide to Fitness, is available on www.louizapatsis.com, http://www.authorhouse.com, www.bn.com and http://www.amazon.com. If you look up my name on those Web sites, you will find my other books The Boy in a Wheelchair and Life, Work and Play: Poems and Short Stories.