Common Terms N-S

Nutrition (also called nourishment or aliment) is the provision, to cells and organisms, of the materials necessary (in the form of food) to support life. Many common health problems can be prevented or alleviated with a healthy diet.

Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems. Body mass index (BMI), a measurement which compares weight and height, defines people as overweight (pre-obese) when their BMI is between 25 kg/m2 and 30 kg/m2, and obese when it is greater than 30 kg/m2.

Orlistat (marketed as a prescription under the trade name Xenical by Roche or over-the-counter as Alli by GlaxoSmithKline), also known as tetrahydrolipstatin, is a drug designed to treat obesity. Its primary function is preventing the absorption of fats from the human diet, thereby reducing caloric intake. It is intended for use in conjunction with a physician-supervised reduced-calorie diet. Orlistat is the saturated derivative of lipstatin, a potent natural inhibitor of pancreatic lipases isolated from the bacterium Streptomyces toxytricini. However, due to simplicity and stability, orlistat rather than lipstatin was developed into an anti-obesity drug.

Osteoarthritis (OA, also known as degenerative arthritis, degenerative joint disease), is a group of diseases and mechanical abnormalities involving degradation of joints, including articular cartilage and the subchondral bone next to it. Clinical manifestations of OA may include joint pain, tenderness, stiffness, creaking, locking of joints, and sometimes local inflammation. In OA, a variety of potential forces—hereditary, developmental, metabolic, and mechanical—may initiate processes leading to loss of cartilage -- a strong protein matrix that lubricates and cushions the joints. As the body struggles to contain ongoing damage, immune and regrowth processes can accelerate damage. When bone surfaces become less well protected by cartilage, subchondral bone may be exposed and damaged, with regrowth leading to a proliferation of ivory-like, dense, reactive bone in central areas of cartilage loss, a process called eburnation. The patient increasingly experiences pain upon weight bearing, including walking and standing. As a result of decreased movement because of the pain, regional muscles may atrophy, and ligaments may become more lax. OA is the most common form of arthritis, and the leading cause of chronic disability in the United States.

Osteoporosis is a disease of bone that leads to an increased risk of fracture. In osteoporosis the bone mineral density (BMD) is reduced, bone microarchitecture is disrupted, and the amount and variety of proteins in bone is altered. Osteoporosis is defined by the World Health Organization (WHO) in women as a bone mineral density 2.5 standard deviations below peak bone mass (20-year-old healthy female average) as measured by DXA; the term "established osteoporosis" includes the presence of a fragility fracture. Osteoporosis is most common in women after menopause, when it is called postmenopausal osteoporosis, but may also develop in men, and may occur in anyone in the presence of particular hormonal disorders and other chronic diseases or as a result of medications, specifically glucocorticoids, when the disease is called steroid- or glucocorticoid-induced osteoporosis (SIOP or GIOP). Given its influence in the risk of fragility fracture, osteoporosis may significantly affect life expectancy and quality of life.

Osteoporosis can be prevented with lifestyle changes and sometimes medication; in people with osteoporosis, treatment may involve both. Lifestyle change includes exercise and preventing falls; medication includes calcium, vitamin D, bisphosphonates and several others. Fall-prevention advice includes exercise to tone deambulatory muscles, proprioception-improvement exercises; equilibrium therapies may be included. Exercise with its anabolic effect, may at the same time stop or reverse osteoporosis. Osteoporosis is a component of the frailty syndrome.

Phentermine, a contraction of "phenyl-tertiary-butylamine", is an appetite suppressant of the amphetamine and phenethylamine class.

It is approved as an appetite suppressant to help reduce weight in obese patients when used short-term and combined with exercise, diet, and behavioral modification. It is typically prescribed for individuals who are at increased medical risk because of their weight and works by helping to release certain chemicals in the brain that control appetite.

Physical exercise is any bodily activity that enhances or maintains physical fitness and overall health. It is performed for various reasons. These include strengthening muscles and the cardiovascular system, honing athletic skills, weight loss or maintenance and for enjoyment. Frequent and regular physical exercise boosts the immune system, and helps prevent the "diseases of affluence" such as heart disease, cardiovascular disease, Type 2 diabetes and obesity. It also improves mental health, helps prevent depression, helps to promote or maintain positive self-esteem, and can even augment an individual's sex appeal or body image. Childhood obesity is a growing global concern and physical exercise may help decrease the effects of childhood obesity in developed countries.

RDA - (recommended daily allowance) the amounts of energy and selected nutrients considered adequate to meet the nutrient needs of practically all healthy people.

RDI - (reference daily intakes) food labeling values for protein, vitamins and minerals based on population- adjusted means of the RDA.

A recumbent bicycle is a bicycle that places the rider in a laid-back reclining position. Most recumbent riders choose this type of design for ergonomic reasons; the rider’s weight is distributed comfortably over several square feet of the back and buttocks. On a traditional upright bicycle, the body weight rests on a few square inches of the sit bones, the feet, and the hands.

Repetition or "rep" - a term used most often in resistance exercises or weight lifting. A single movement, as in doing one squat (going down and then going back up would be one rep). A certain number of reps will equal a set.

Resistance training has two different, broader meaning that refers to any training that uses a resistance to the force of muscular contraction (better termed strength training), and elastic or hydraulic resistance, which refers to a specific type of strength training that uses elastic or hydraulic tension to provide this resistance. This article discusses the more limited definition, of elastic/hydraulic resistance training.

Saturated fat is fat that consists of triglycerides containing only saturated fatty acid radicals. There are several kinds of naturally occurring saturated fatty acids, which differ by the number of carbon atoms, ranging from 3 carbons (Propionic Acid) to 36 (Hexatriacontanoic acid). Saturated fatty acids have no double bonds between the carbon atoms of the fatty acid chain and are thus fully saturated with hydrogen atoms.

Fat that occurs naturally in living matter contains varying proportions of saturated and unsaturated fat. Examples of foods containing a high proportion of saturated fat include dairy products (especially cream and cheese but also butter and ghee); animal fats such as suet, tallow, lard and fatty meat; coconut oil, cottonseed oil, palm kernel oil, chocolate, and some prepared foods.

Serum saturated fatty acid is generally higher in smokers, alcohol drinkers and obese people.

Shin splints is a general term used to refer to a painful condition in the shins. It is often caused by running or jumping or sprinting, and may be very slow to heal. A formal medical term for the condition is medial tibial stress syndrome.

Sleep apnea (or sleep apnoea in British English) is a sleep disorder characterized by pauses in breathing during sleep. Each episode, called an apnea (Greek: ἄπνοια (ápnoia), from α- (a-), privative, πνέειν (pnéein), to breathe), lasts long enough so that one or more breaths are missed, and such episodes occur repeatedly throughout sleep. The standard definition of any apneic event includes a minimum 10 second interval between breaths, with either a neurological arousal (a 3-second or greater shift in EEG frequency, measured at C3, C4, O1, or O2), a blood oxygen desaturation of 3-4% or greater, or both arousal and desaturation. Sleep apnea is diagnosed with an overnight sleep test called a polysomnogram, or a "sleep study".

A sprain (from Middle French espraindre - to wring) is an injury to ligaments that is caused by being stretched beyond their normal capacity and possibly torn. A muscular tear caused in the same manner is referred to as a strain. In cases where either ligament or muscle tissue is torn, immobilization and surgical repair may be necessary. Ligaments are tough, fibrous tissues that connect bone to bone across the joints. Sprains can occur in any joint but are most common in the ankle.

Static stretching is used to stretch muscles while the body is at rest. It is composed of various techniques that gradually lengthen a muscle to an elongated position (to the point of discomfort) and hold that position for 30 seconds to two minutes. 30 seconds is the minimum duration to get the benefits of stretching, whereas two minutes is the maximum (if a position can be held for more than two minutes, a farther stretch should be performed). During this holding period or directly afterwards, participants may feel a mild discomfort or warm sensation in the muscles. Static stretching exercises involve specialized tension receptors in our muscles. When done properly, static stretching slightly lessens the sensitivity of tension receptors, which allows the muscle to relax and to be stretched to greater length. There is doubt over the effectiveness of static stretching, with some circles of sport strongly recommending against it, such as soccer, ballet, slamball and rugby league. Recently, there has been a controversy over static stretching saying that it makes you readier but weaker.

Stress is a term in psychology and biology, first coined in the 1930s, which has in more recent decades become a commonplace of popular parlance. It refers to the consequence of the failure of an organism – human or animal – to respond appropriately to emotional or physical threats, whether actual or imagined.

Stress symptoms commonly include a state of alarm and adrenaline production, short-term resistance as a coping mechanism, and exhaustion, as well as irritability, muscular tension, inability to concentrate and a variety of physiological reactions such as headache and elevated heart rate.

A stretch reflex is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length.

When muscle lengthens, the spindle is stretched and the activity increases. This increases alpha motorneuron activity. Therefore the muscle contracts and the length decreases as a result. The gamma co-activation is important in this reflex because this allows spindles in the muscles to remain taut therefore sensitive even during contraction.