Glossary of Fitness Terms

I started this glossary to provide information about terms I use in other articles on my site. However, I want it to be a useful reference for my clients, and for anyone who is interested in learning about some basic exercise science.

This is a work in progress. I will add and refine terms as time allows.

Aerobic or Cardio Exercise - The body requires oxygen and some carbohydrate to burn fat as fuel for prolonged exercise. PLEASE NOTE: Very low intensity aerobic exercise is fueled by up to 100% fat and is often called the “fat-burning zone”. However, aerobic exercise of higher intensity burns more calories overall, including more fat calories, for a session of a given length.

Borg scale - A scale of the Rate of Perceived Exertion (RPE), which assigns a number to the exertion the exerciser experiences. This is easier to monitor than heart rate, and can also be safer to use because it takes other factors, such as fatigue, heat, and humidity, into account. It was formerly on a scale of 6 to 20, and is now on a scale of 1 to 10 (1 being at rest, 10 being absolute maximum). Most people should exercise between a 4 (somewhat strong) and a 5 or 6 (strong).

Carbohydrate - contain carbon, hydrogen, and oxygen. This important macronutrient has four calories per gram, and is the body's preferred fuel source. Carbohydrates (preferably natural and complex) should account for 55-65% (although some experts say 45%) of caloric intake.

Carbohydrates with a high glycemic index (which very often corresponds to white foods, such as sugar, potatoes, white flour, pasta, and rice) can destabilize blood sugar in some people, resulting in insulin spikes, fatigue, hunger, and eventual overeating. In general, foods with complex carbohydrates (such as whole grains, fruits and vegetables) have a lower glycemic index and more nutritional value per calorie, making them smarter food choices.

Sports performance requires carbohydrate. Anaerobic (fast) activity uses ATP and sugar stored in the muscles, and moderate- to high-intensity aerobic exercise, which are the most efficient ways to burn fat, also require significant carbohydrate to meet energy needs. Long sessions of endurance exercise (greater than 60-90 minutes) often deplete muscle and liver glycogen, so carbohydrate feeding (such as sports drinks) might be necessary.

Diet - food habitually eaten (in the sense that the diet of a koala bear is eucalyptus leaves). Commonly used to describe a reduction diet (a diet designed for weight loss).

Fat, dietary - an essential macronutrient which carry essential fat-soluble vitamins and are involved in many functions. Fat contains 9 calories per gram, compared to carbohydrates and protein which each contain 4 calories per gram.

Fiber, dietary - an indigestible carbohydrate; recommended intake is 25g/day for young people, 38g/day for the rest of us.

Glycemic Index - the rate at which a carbohydrate raises blood glucose, which in turn affects the rate at which insulin is released. The glycemic index of many foods can be found in tables; however, the actual effect on the body depends on whether the food is consumed alone or mixed with other foods.

Hypertrophy - an increase in the number and size of myfibrils in the muscle, resulting in increased muscle size, achieved by high volumes of moderate resistance exercises. PLEASE NOTE: Many women miss out on the considerable benefits of using heavier weights for fear of “getting big”. The potential for hypertrophy is very limited in women due to lower testosterone levels.

Protein, dietary - amino acids linked by peptide bonds. Protein should account for 10-35% of total caloric intake for an adult.

Proteins are needed for functions such as tissue repair, and hormone and enzyme synthesis. Extra protein can be used in other ways; however, in order to do this the body first deaminates the protein and then converts the carbon skeleton into either glucose or ketones. Excess of this will be stored as fat. The amines that were removed produce ammonia, which must be processed by the liver and kidneys.

Many high-protein foods also contain high levels of saturated fat and cholesterol. Consuming excess protein increases urinary calcium levels, although that does not prove that that calcium was leached from the bones. Processing protein requires seven times more water than processing carbohydrates or fat, so dehydration is also a danger, particularly during athletic performance.

Registered Dietitian (RD) - also spelled “dietician”. An expert with extensive education and training approved by the Commission on Accreditations for Dietetics Education, including a degree, supervised program often combining graduate study, and a national exam.

Resistance or Strength Training - An important component of integrated fitness training. Resistance exercise involves moving against resistance provided by body weight, elastic bands or tubes, or weights of some kind. It can increase muscular strength, endurance, and/or size. It can also increase tensile strength of connective tissues such as tendons and ligaments and maintain or increase bone mass, which makes it very important for seniors.

Resting Heart Rate (RHR) - Heart rate when an individual is calm and still. Normal resting heart rates range from 60-100 beats per minute (bpm); average for a woman is 75 bpm, and average for a man is 70 bpm. A lower resting heart rate is a somewhat good indication of good cardiorespiratory condition.

Spot Reduction - the belief that fat reduction can be targeted by exercising particular areas of the body (for example, sit-ups or crunches to reduce belly fat). Most evidence points to the contrary, so I’ll believe it when I see significant results from a real study. In the meantime, I recommend a strategy of sensibly reducing overall body fat and toning the muscles underneath “problem areas” to improve appearance.

Target Heart Rate (THR) - A heart rate which (in theory) corresponds to an appropriate level of exertion. Some exercisers choose to regulate the intensity of their workouts by monitoring their heart rate and adjusting intensity accordingly.

Thermic Effect of Food (TEF) - energy required for digestion processes (moving food through the tract, transporting nutrients, etc.) Some foods require more energy than others to digest.

Toning - “muscle tone” is technically the passive ongoing tension in the muscle, which helps it do its part to stabilize the body, resist sudden stretch that could lead to tearing, and be prepared to contract further. In fitness, “toning” is a type of resistance training that promotes anaerobic endurance, firmness, and shape, but not bulk. Although it also implies “leanness”, burning fat requires aerobic exercise as distinct from resistance exercise alone.