A class that takes the moves of a kickboxer’s training and choreographs them to music.

The point at which your body switches from using oxygen as its primary source of energy to using stored sugar. When you’re in poor physical shape, you hit your anaerobic threshold while exercising at relatively low levels of exercise.

The larger weights (for power lifting in a weight training program) that include a long bar with weights added to each end. You need to use both hands to lift a barbell.

A method of measuring your body fat in which you lie on your back while a signal travels from an electrode on your foot to an electrode on your hand. The slower the signal, the more fat you have.

A measurement of how open your blood vessels are. Low numbers mean that your heart doesn’t have to work very hard to pump the blood through your blood vessels.

How much of your body is composed of fat and how much is composed of everything else. Your body composition is also called your body-fat percentage.

A way of relating your height and weight to estimate how fat you are. You can use a simple formula to determine your BMI.

A non-aerobic, muscle-toning class, usually focused on core strength.

A domed, flexible apparatus that helps to improve balance and can be used in a step aerobics exercise routine. BOSU is an acronym for Both Sides Utilized.

A term (short for cardiovascular) that is often used interchangeably with aerobic. Aerobic exercise is any repetitive activity that you do long enough and hard enough to challenge your heart and lungs.

Otherwise known as "life energy," this is the life force that pulses through your body and keeps you vital. Blocked chi can cause sickness or unhappiness.

A fast-paced class or exercise routine in which you do one exercise for 30 seconds to 5 minutes and then move on to another exercise at the next station. Combines cardio exercise with strength training.

The abdomen, obliques, lower back, butt, and so on, that form the midsection. Many forms of exercise focus on strengthening the body's core.

A non-aerobic, muscle-toning class, usually focused on core strength.

A method of varying your workouts to take your fitness to the next level by adding new forms of training to your current routine.

A method of measuring your body fat that also determines where the fat is located on your body, a more relevant health indicator.

Smaller weights (for a weight training program) that you can lift with one hand.

The hottest trend in cardio machines, which is part stair-climber, part treadmill, part stationary cycle. Your legs travel in an elongated circular movement, and, on some models, you pump arm poles back and forth for an upper-body workout.

A large plastic ball that is an excellent tool for doing challenging exercises (with or without weights) that require varying forms of strength and control.

A type of interval training program that doesn't use an exact measure of time or distance. You just do your intervals whenever you feel like it. The term Fartlek means "speed play" in Swedish.

A faster and more intense walking technique than casual (lifestyle) walking that burns more calories and helps you lose weight. When you fitness walk, you generally move along at a brisk pace of 3.5 to 4.3 miles an hour, covering a mile in 14 to 17 minutes.

The range of motion or distance you can move a joint through. Stretching is the key to maintaining your flexibility.

Portable weights used in a strength training program.

The traditional type of swimming movement that uses the front crawl.

The number of times your heart beats per minute.

A traditional dance-inspired routine that involves jumping or hopping and moves at a slower pace than low-impact aerobics. High/low combines the two types of routines.

A type of skating in which you wear skates with urethane wheels that enable you to glide, sprint, curve, turn, and spin.

A training technique in which you alternate short, fairly intense spurts of exercise with periods of relatively easy exercise.

A class that takes the moves of a kickboxer’s training and choreographs them to music.

A casual walking technique that is low to moderate intensity and relatively slow paced. Most lifestyle walkers walk an average of 2.5 to 3.5 miles per hour, which means that they walk about 1 mile every 17 to 24 minutes.

A traditional dance-inspired routine in which you always have one foot on the floor — you don’t do any jumping or hopping. High/low combines the two types of routines.

An organized 26.2-mile race for runners and walkers.

The maximum number of times your heart should beat in a minute without dangerously overexerting yourself.

A mental process involving focused attention, or calm awareness, which is also called mindfulness.

A fat-tire outdoors bicycle with upright handlebars that is built to withstand rough terrain.

A home gym contraption that looks like a bunch of health-club weight machines welded to each other.

In a strength training program, the point at which your last repetition with weights is so difficult that you cannot perform another repetition.

Fitted shoe inserts designed by a podiatrist that correct weight distribution along the foot.

A method of organizing a strength training workout program into several periods, each lasting about four weeks. Each phase has a different emphasis.

A form of exercise that emphasizes correct form using your body’s core. Pilates is named after its inventor, Joseph Pilates, who invented the technique for injured dancers.

An inflammation of the tough fibrous band of tissue that runs the length of the bottom of your foot.

The number of times your heart beats per minute.

An element of a T'ai Chi practice that covers many different types of movements that involve using and feeling the body's energy.

A type of stationary bike with a bucket seat that provides back support so that you pedal straight out in front of you.

One complete motion of an exercise, often used in reference to strength training.

An acronym that stands for Rest, Ice, Compression, and Elevation — common treatment methods prescribed for runners with training injuries.

The traditional type of outdoor bicycle with curved handlebars that is built for speed.

A cardiovascular machine that resembles a section of a department-store escalator. A set of stairs rotates in a circle so that you climb continuously, but never getting anywhere.

A cardiovascular machine that increases stamina, upper body endurance, strength, and flexibility by mimicking a rowing motion. Also called a rower.

A group of consecutive repetitions in a strength training program.

A popular group studio cycling program invented by ultra-distance cyclist Johnny G. and licensed by Schwinn, which manufactures the bikes used in these classes.

A cardiovascular machine that has two foot plates you pump up and down to mimic the action of climbing stairs. Also called a stepper.

A cardiovascular machine that comes in two styles: upright bikes and recumbent bikes.

A choreographed routine of stepping up and down on a rectangular, square, or circular platform.

A type of workout that uses any combination of weight machines and free weights (dumbbells and barbells) to build muscle strength.

The number of strides that a runner takes over a certain time period.

Group exercise classes that are taught on stationary bicycles.

An ancient martial art focusing on smooth, slow movements that cultivate inward focus and free energy flow. T'ai Chi is properly pronounced tie-jee.

A range that is between 50 percent and 85 percent of your maximum heart rate that can tell you what heart rate to aim for during a workout.

A popular choice for a cardiovascular machine in a home gym if you enjoy fitness walking and jogging (or running).

The traditional kind of stationary bike, which resembles a regular bicycle.

A workout in which you alternate walking and running. By sprinkling running intervals throughout your walking workout, you can spike up exercise intensity and burn more calories.

Aerobics classes that do traditional workouts in waist- to neck-high water in a swimming pool. The resistance of the water makes the workout feel far more intense, while the water cushions you from the impact.

Stationary equipment mostly found at gyms that are easy to use and help you to safely and quickly advance through a strength-training workout.

A type of exercise in which your skeleton is supporting any sort of weight, as it does when you walk, run, or lift weights.

The “martial art” or traditional self-defense activities practiced with or without weapons (includes T'ai Chi).

The terms for opposites that are opposing yet complementary. A concept used throughout all of T’ai Chi and Qigong.

A series of poses (known as asanas) that you hold from a few seconds to several minutes. The moves — a blend of strength, flexibility, and body-awareness exercises — are intended to promote the union of the mind, body, and spirit.