FDA (Food & Drug Administration) - It is the US federal agency responsible for the regulation of pharmaceuticals (drugs) and food products

Jog - A slow or very easy run. Often considered an insulting term by serious runners who just call it an easy run.

Race walk - A specific, speedy walking technique that must follow rules and is judged (when performed in competitions). An Olympic sport since 1908.

Heart rate calculations - Standard formula is 220 - (your age) for men, 226 - (your age) for women. Error is 10-15 beats either way since heart rate maximums are genetically determined.

Recovery heart rate - see Heart rate, recovery

Vitamins - organic, essential nutrients required in small amounts and sometimes harmful in excessive amounts.

Intervals - Exercise that alternates high intensity ("work") with easy or light intensity ("recovery"). Used by performance athletes for speed and endurance.

Body fat - What is left when you subtract muscles (body lean),water, bones and vital organs. Usually expressed in a percent.

Fartlek - Swedish for "speed play", a type of loosely structured interval training for runners, cyclists, and in-line skaters. It combines anaerobic segments with aerobic ones. Said to build strength and speed. (Also relieves boredom)

Lactic acid (lactate) - a byproduct of anaerobic (or high-intensity) exercise that collects in the muscles and causes soreness, stiffness and fatigue

Maximum heart rate - see Heart rate, maximum

Plateau (weight) - reaching a level or period of stability. Dieters can plateau when they have lost enough weight that their new, lower, metabolic needs match their caloric intake

Static stretch - a simple muscle stretch that goes just to the point of gentle tension and is held steadily for several seconds without moving or bouncing

Stretch reflex - a protective, involuntary nerve reaction that causes muscles to contract. Bouncing or overstretching can trigger the reflex in which muscles are trying to protect themselves from damage

Triceps - the muscles on the back of the upper arms that straighten your elbows and allow you to push your arms forward