Author: Glossary

  • Sole proprietorship

    A business structure in which an individual and the company are considered a single entity for tax and liability purposes.  

  • Small-group fitness

    Two to five individuals working under the guidance of a fitness professional to achieve optimal health and fitness benefits through a more intimate and personal setting than group exercise.  

  • Slow-twitch muscle fiber

    A red muscle fiber characterized by its slow speed of contraction and a high capacity for aerobic glycolysis. Muscle fibers that have a slow contractile speed are considered slow-twitch and are also known as type I fibers.  

  • Slightly movable joint

    Joint with limited movement where the bones are held together by strong fibrocartilaginous membranes.  

  • Sliding filament theory

    The explanation for how muscles produce force; the thick (myosin) and thin (actin) filaments slide past one another, shortening the entire length of the sarcomere.  

  • Skill-related components of fitness

    Skill-related components of physical fitness target enhanced performance in sports and improved motor skills. The components are commonly defined as agility, balance, coordination, power, speed, and reaction time.  

  • Skeletal system

    All of the bones of the body, associated cartilage, and joints. Those organs, functioning in unity, that are associated with movement, protections of other organs, and stability. The consists of the bones, joints, and ligaments, and is closely associated with the muscular system. The bones of the body that together form a structural framework and…

  • Skeletal muscle

    The skeletal muscles are voluntary muscles under conscious control; they attach to bones and allow the skeleton to move. One of the muscles that is attached to bone and is under voluntary control. A muscle attached to a bone, which makes a limb move. Muscle tissue that is attached primarily to the bone, moves the…

  • Sitting heart rate

    Heart rate taken after being seated for 30 minutes. Might be slightly higher than resting heart rate because of body position, medication, drug use, or stress.  

  • Simple carbohydrates

    Composed of monosaccharide or disaccharide units and are easily digested. A sugar that is composed of one or two sugar molecules. Carbohydrates with either a single monosaccharide or two monosaccharides linked by a glycosidic bond (disaccharides) are considered simple carbohydrates and are sometimes referred to as simple sugars. Separate entries are provided for the six…