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 writes: "Over the course of many years, Dave and I have collaborated to tell my story... I told [him] what I knew and what I could remember, and from that material he created this work of art." The book is typical of Eggers' style: blending non-fictional and fictional elements into a non-fiction novel or memoir. By classifying the book a novel, Eggers says, he freed himself to re-create conversations, streamline complex relationships, add relevant detail and manipulate time and space in helpful ways—all while maintaining the essential truthfulness of the storytelling. However, not all critics were impressed. Lee Siegel sees