Effect of spaceflight on the human body of muscle fibre prominent in muscles also change. Slow twitch endurance fibres used to maintain posture are replaced by fast twitch rapidly contracting fibres that are insufficient for any heavy labour. Advances in research on exercise, hormone supplements and medication may help maintain muscle and body mass. Bone metabolism also changes. Normally, bone is laid down in the direction of mechanical stress. However, in a microgravity environment there is very little mechanical stress. This results in a loss of bone tissue approximately 1.5% per month especially from the lower vertebrae, hip and femur. Due to microgravity and the decreased load
What Is the What "we really hadn’t decided whether I was just helping Valentino write his own book, or if I was writing a book about him." Valentino points out that, "I thought I might want to write my own book, but I learned that I was not ready to do this. I was still taking classes in basic writing at Georgia Perimeter College." Dave Eggers discusses the difficulties in writing a book of this nature: "For a long while there, we continued doing interviews, and I gathered the material. But all along, I really didn’t know exactly what form it would finally take—whether