Glossary

Abduction is an anatomical directional term meaning moving away from the body.

Adduction is an anatomical directional term meaning moving toward the body.

ATP is a molecule that is responsible for storing and releasing energy in the body. Due to this, biologists have coined ATP the "currency of life." ATP is generated in the mitochondria of cells; and it can be produced aerobically and anaerobically. The body stores only a small amount of ATP at any given time, so ATP must be continually regenerated on a cellular level.

The term aerobic refers to the type of energy metabolism carried out by your body in the presence of oxygen. Aerobic metabolism, or aerobic oxidation sustains exercise for longer durations of time. The aerobic system uses stored fats, carbohydrates (glycogen), and proteins as energy sources.

As the intensity level of exercise increases, the body must rely more upon anaerobic metabolism to meet its pressing energy needs.

Keep in mind that the different types of energy systems used by the body to fuel exercise are not mutually exclusive. They all operate during exercise but to differing degrees depending upon the intensity of the exercise.

Aerobic capacity is a term used synonymously with VO2max, or maximal oxygen consumption. These terms refer to the highest rate of oxygen transport and use by your body during maximal physical exertion.

VO2max is expressed through the Fick equation, which multiplies heart rate (HR) by stroke volume (SV) by arteriovenous oxygen difference (a-v O2 difference):

VO2max (mL / kg / min) = HR (beat / min) x SV (mL / beat) x (a-v O2 difference)

VO2max can be expressed in absolute terms as liters per minute (L/min), but is typically expressed relative to body weight so that comparisons among individuals can be made. Relative VO2max is therefore expressed as milliliters per kilogram per minute (mL/kg/min).

The following table shows VO2max norms for men and women (ACSM’s Guidelines for Exercise Testing and Prescription: Seventh Edition 2006, p. 79).

Your aerobic threshold (AeT) corresponds to a "conversational" nose-breathing effort. You should be able to breathe through your nose and hold a back-and-forth conversation with someone running next to you when you’re at or below your AeT; breathing is moderate and not labored. 

In most athletes, the AeT corresponds to the top of Zone 2 if you're using the Friel heart rate zones or Zones 1-2 ("easy to moderate") if you're using the Stryd power zones as a guide. On a Borg 1-10 rating of perceived exertion (RPE) scale, this would be an RPE of 5-6 ("moderate").

Training at or below your aerobic threshold is foundational to building your aerobic endurance during base training, allowing you to better metabolize fat and spare glycogen (stored carbohydrate) as a long duration energy source. Work at or below your AeT during other phases of training still comprises the bulk of your training time.

Muscle or muscles that are primarily responsible for movement around a joint. Also called a "prime mover."

The term anaerobic refers to the type of energy metabolism carried out by your body without oxygen. Anaerobic metabolism, or anaerobic glycolysis is used to meet the body’s energy needs at higher levels of intensity. It uses carbohydrates (glycogen or glucose) to rapidly produce energy for the body.

The end product of anaerobic metabolism is lactate, which requires aerobic metabolism (and hence oxygen) to remove from the bloodstream. Any bout of exercise over a few minutes, therefore, cannot be sustained solely through anaerobic metabolism.

Keep in mind that the different types of energy systems used by the body to fuel exercise are not mutually exclusive. They all operate during exercise but to differing degrees depending upon the intensity of the exercise.

Anaerobic endurance refers to the ability to resist fatigue at very high intensity efforts when arm/leg turnover is rapid. Anaerobic endurance is classified as one of three advanced abilities—the other two being power and muscular endurance—according to the training system espoused by Joe Friel. It is a combination of the two basic abilities of speed skills plus endurance.

Muscle or muscles that act in opposition to the agonist muscle(s).

Oxygenated blood leaves the heart through arteries. As the blood circulates throughout the body, muscles extract some of that oxygen for use in energy production. The a-v O2 difference reflects the difference between the oxygen concentration in the arteries (leaving the heart) and the remaining oxygen concentration in the veins (returning to the heart).

At rest, the a-v O2 difference is typically around 5 milliliters of oxygen per deciliter (5 mL O2 / dL), representing a use coefficient of 25%. At exercise, the a-v O2 difference can increase up to around 15 mL O2 / dL with a use coefficient of 75%. In other words, more oxygen is extracted by working muscles as the intensity level increases.

Base training refers to the phase, or period of training that primarily works the aerobic system to build endurance and prepare the body for the demands of higher intensity training.

Your blood pressure consists of two numbers: systolic blood pressure (SBP) and diastolic blood pressure (DBP). The systolic blood pressure refers to the pressure exerted on the wall of your arteries when the heart contracts. The diastolic blood pressure refers to the arterial pressure during the relaxation phase of the heart’s ventricles.

Typical resting blood pressure is 120 / 80 (that is, 120 mm Hg for systolic pressure and 80 mm Hg for diastolic pressure). Consistent resting blood pressure readings at or above 140 / 90 generally constitute high blood pressure, or hypertension.

BMI is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kilograms per meters squared.

The formula attempts to determine if an individual is underweight, average weight, or overweight, but is not an accurate tool to use for an athlete as it does not take body fat or muscle into consideration.

Cadence refers to the number of revolutions, or cycles per minute. For swimming, cadence refers to the number of swim strokes per minute. For cycling, cadence refers to the number of pedals strokes per minute. For running, cadence refers to the number of foot steps per minute.

Capillaries are the smallest blood vessels in the body. They increase in density based on how much blood supply is needed in a particular area. They are found in the tissues of the human body and transport blood from the arteries to the veins. Due to the thinness of the walls of capillaries, oxygen (O2), carbon dioxide (CO2), waste products and nutrients can pass through the walls.

Cardiac output refers to the volume of blood pumped by the heart each minute. Cardiac output (abbreviated Q with a dot over it, or Q-dot) is calculated by multiplying heart rate (HR) by stroke volume (SV).

Q = HR x SV

During a workout, cardiac drift refers to the natural increase or upward “drift” in heart rate while the overall intensity (e.g., respiration rate, effort level, caloric burn) stays the same.

Carbohydrates consist primarily of sugars and starches, making up one of the three principal types of macro-nutrients used as energy by the body (the other two are protein and fat). Carbohydrates are often classified as simple or complex. The classification depends on the chemical structure of the food, and how rapidly the sugar is digested and absorbed by the body.

The cooldown, or warmdown period involves a transition from the exercise session back to a resting level. It involves low-level activity to clear lactate from the blood while allowing the heart rate, blood pressure, and respiration rate to lower.

Core muscles stabilize and support the pelvis and spine. Core muscles include the rectus abdominis, external obliques, internal obliques, transverse abdominis, erector spinae, hip flexors (psoas) and gluteal muscles.

DOMS refers to muscle soreness that reaches its peak 24-48 hours after exercise has ended. DOMS primarily results from movements that involve eccentric muscle contractions, such as running downhill where your quads do a lot of eccentric movements.

Training duration refers to the amount of time of a training session. The frequency of training sessions plus the duration of those training sessions comprise training volume.

Electrolytes are minerals that break into small electrically charged particles called ions. They are present wherever there’s water in your body. They help regulate the body’s fluids to maintain a healthy blood pH balance and create the electrical impulses essential to all aspects of physical activity – from basic cell function to complex neuromuscular interactions needed for athletic performance. The kidneys work to keep the electrolyte concentrations in the blood constant despite changes in the body. Sodium is one of the many important electrolytes.

Endurance refers to the ability to resist fatigue and delay its onset during prolonged activity. Endurance is classified as one of three basic abilities—the other two being force and speed skills—according to the training systems espoused by Tudor Bompa and Joe Friel, among others.

Fast twitch muscle fibers are often referred to as “Type II” fibers. They are classified into two types: IIA and IIB. The primary characteristic of fast twitch muscle fibers is that they contract with a high degree of force but lack the ability to fire repeatedly without fatigue. Fast twitch fibers are non-oxidative, meaning they do not require oxygen to contract.

Fat is a major energy source for the body during long endurance outings. The primary location for fat storage is adipose tissue (i.e., body fat) within the body. The majority of the adipose tissue that is used for energy is called subcutaneous fat (below the skin). Adipose tissue is comprised of adipocytes, or fat cells. Adipocytes are where triglycerides are stored and synthesized. Fat, along with carbohydrates and protein are known as macro-nutrients.

Flexibility refers to the range of motion around joints.

Force refers to the ability to overcome resistance. Force is classified as one of three basic abilities—the other two being endurance and speed skills—according to the training systems espoused by Tudor Bompa and Joe Friel, among others.

Training frequency refers to the number of training sessions done per week. The frequency of training sessions plus the duration of those training sessions comprise training volume.

Functional strength refers to strength that directly benefits sport-specific movements and activities.

Glucose is a carbohydrate (sugar) that circulates in your bloodstream, acting as an energy source for the body’s cells.

Glycogen is a form of carbohydrate that is stored in the muscles and liver, and can be converted to glucose for energy.

Glycogen depletion refers to low levels of glycogen in the body, often resulting in the loss of energy and extreme fatigue. Glycogen is primarily stored in the liver and the muscles, and gets used during exercise. The body can store around 2,000 calories of glycogen.

Heart rate refers to the number of times your heart beats per minute.

Heart rate training zones are ranges used for exercise prescription. They can be percentages based on, among other things, VO2max, VO2 Reserve, HRmax, HR Reserve, LTHR, among others.

The heart rate training zones primarily used in Alp Fitness training plans is Joe Friel's seven-zone system. Each zone corresponds to a range of percentages of lactate threshold heart rate (LTHR).

Zone 1 – Recovery / Easy effort
Zone 2 – Aerobic / Extensive endurance
Zone 3 – Tempo / Intensive endurance
Zone 4 – Sub-threshold
Zone 5a – Super-threshold
Zone 5b – Aerobic capacity
Zone 5c – Anaerobic capacity / Power

The lactate threshold corresponds to the bottom of Zone 5a; thus zones 1-4 are below the lactate threshold and zones 5a-c are above the lactate threshold.

Keep in mind that heart rate training zones are sport specific. You will have different training zones for running, cycling, swimming, skiing, etc.

Hyperthermia, or overheating, occurs when an individual's body temperature is elevated beyond normal. The person's body produces or absorbs more heat than it dissipates.

Hyponatremia refers to a low sodium concentration in the blood, a type of electrolyte imbalance that often results from overhydration (drinking too much water).

Hypothermia occurs when the core body temperature drops below what is required for normal body functioning. This happens when the body loses heat faster than it can produce heat.

Training intensity refers to the effort put forth during a training session, as measured through effort, exertion, speed, power, etc. Training intensity is one of two key axes around which your training revolves—the other is volume.

In general terms, interval training refers to the use of higher intensity work intervals interspersed with recovery intervals, or rest intervals. The length of the work and recovery intervals can vary depending upon what training effect you are trying to achieve.

Running coach Jack Daniels used the term intervals in a more specific way to refer only to VO2max or race pace intervals of 3-5 minutes in duration. He uses the term reps (repetitions) to refer to work periods of less than 2 minutes in duration at highest intensity.

Lactate is a by-product of your body’s energy production and the lactate threshold (LT) is the point at which blood lactate begins to accumulate in the bloodstream. This occurs when the rate of lactate production increases faster than the rate of removal (clearance).

Workloads above the lactate threshold can only be sustained for up to several minutes before the body must slow down. Workloads right at the lactate threshold can generally be maintained for about an hour or even two. Workloads below the lactate threshold can be maintained much longer.

An important effect of endurance training is to ‘raise your lactate threshold.’ Whereas before training you could run, say, seven minutes per mile while at LT, after training the same pace would represent an intensity level below your LT. This means that you would be able to go faster at a lower level of effort.

Your lactate threshold heart rate (LTHR) is the heart rate that corresponds to your lactate threshold (LT). It is specific to the activity, so you will have a different LTHR for running, cycling, swimming, skiing, etc. An athlete’s LTHR for cycling is typically 5-10 beats lower than that athlete’s LTHR for running, so it is possible to estimate one from the other if sport-specific tests are not available for both.

Mitochondria is an organelle that acts as the 'power plant' of cells by converting the potential energy from food molecules into ATP.

Muscular endurance refers to the ability of muscles to maintain a relatively high force load for a prolonged period of time. Muscular endurance is classified as one of three advanced abilities—the other two being power and anaerobic endurance—according to the training system espoused by Joe Friel. It is a combination of the two basic abilities of force plus endurance.

Myofascial release refers to the reduction of tightness and restrictiveness of the muscles and fascia. Fascia is the web of connective tissue that surrounds all muscles, bones, nerves and blood vessels; it has a large affect on posture and muscle balance. Restricted fascia creates pain and muscle dysfunction, which can be addressed with types of bodywork that provide myofascial release.

The overload principle states that any new training gain requires a greater amount of training stress. It is important to apply the appropriate amount of stress to overload the system without overreaching or overtraining. For sport specific improvements, the overload principle must also be coupled with the principle of specificity.

Overreaching involves the accumulation of an amount of stress that causes a temporary decrease in performance without showing the signs of overtraining. If overreaching continues long enough without adequate recovery, overtraining can result.

Overtraining refers to the accumulation of too much stress (training or other types of stress) that leads to extreme fatigue (physical and mental). Overtraining occurs when overreaching is carried too far without adequate recovery. With overtraining, the athlete has dug him/herself a hole that may take several weeks to get out of. Extreme cases can be season ending. Overtraining is obviously to be avoided and the administration of an appropriate training plan can help the athlete use the overload principle for performance gains without overtraining.

The peak training period is done prior to the athlete’s key race or races of the season. It occurs after base training has laid a strong aerobic foundation, and it involves a reduction in training volume along with an increase in training intensity to allow the athlete to achieve a high level of fitness for optimal performance.

Periodization refers to the structuring of training into phases, or periods—such as a base training phase, build phase, race phase, peak training period and so forth. The first use of periodization in training is associated with Tudor Bompa.

Power refers to the ability to apply maximum force quickly. Force is classified as one of three advanced abilities—the other two being muscular endurance and anaerobic endurance—according to the training system espoused by Joe Friel. It is a combination of the two basic abilities of force plus speed skills.

A PNF stretch consists of a passive stretch followed by an isometric muscle contraction. During PNF stretching, a muscle is repeatedly contracted and relaxed, which triggers the golgi tendon reflex numerous times.

Protein is a molecule composed of one or more chains of amino acids. Protein is necessary for the structure, function, and regulation of the body’s cells, tissues, and organs. Protein, along with carbohydrates and fat are known as macro-nutrients.

The most common RPE scales are the Borg 6-20 and Category-Ratio Scales.

A recovery interval refers to the time between work intervals in interval training. It may involve resting (i.e. a rest interval) or moving at a slower pace to allow some recovery before the next work interval.

Slow twitch muscle fibers are often referred to as “Type 1” muscle fibers. They can contract repeatedly for long periods of time, but with relatively low force. Short twitch fibers rely on oxygen for energy and thus are red due to the many blood vessels. Think of the leg of a chicken with its dark meat vs. the breast of a chicken with its white meat.

The principle of specificity states that training adaptations are specific to the system worked. For example, to improve running performance, one must run rather than swim. It also means that within a given sport, the type of training needs to be geared for the type of racing to be done or performance gains desired.

Speed skills refer to the ability to move efficiently and effectively. Speed skill is classified as one of three basic abilities—the other two being endurance and force—according to the training systems espoused by Tudor Bompa and Joe Friel, among others.

Stroke volume refers to the amount of blood your heart—specifically, your left ventricle—ejects when it contracts.

Tapering refers to a decrease in training volume prior to a key race to rest and sharpen the athlete for competition.

Training zones refer to intensity levels used during exercise. Training zones can be based on heart rate, power, velocity, ratings of perceived exertion or some other measurement of work capacity.

Ventilatory threshold refers to the point at which breathing becomes labored during exercise of increasing intensity. It corresponds closely with lactate threshold (LT).

Until the VT is reached, the workload and respiration rate increase linearly. After the ventilatory threshold is reached, the ventilation rate increases faster than the workload.

VO2max (also known as maximal oxygen consumption, or aerobic capacity) refers to the highest rate of oxygen transport and use by your body during maximal physical exertion.

VO2max is expressed through the Fick equation, which multiplies heart rate (HR) by stroke volume (SV) by arteriovenous oxygen difference (a-v O2 difference):

VO2max (mL / kg / min) = HR (beat / min) x SV (mL / beat) x (a-v O2 difference)

VO2max can be expressed in absolute terms as liters per minute (L/min), but is typically expressed relative to body weight so that comparisons among individuals can be made. Relative VO2max is therefore expressed as milliliters per kilogram per minute (mL/kg/min).

The following table shows VO2max norms for men and women (ACSM’s Guidelines for Exercise Testing and Prescription: Seventh Edition 2006, p. 79).

These are muscle contractions that are controlled by the central nervous system (CNS) and the origin of the contraction is a conscious thought by the brain. An example of this is a hamstring curl.

Training volume refers to the amount of training done per week. The frequency of training sessions plus the duration of those training sessions comprise training volume. Training volume is one of two key axes around which your training revolves—the other is intensity.

The warmdown, or cooldown period involves a transition from the exercise session back to a resting level. It involves low-level activity to clear lactate from the blood while allowing the heart rate, blood pressure, and respiration rate to lower.

The warmup period involves a gradual transition from rest to higher intensity exercise. It involves gradually warming up the body temperature through low-level activity.

A work interval, or workbout refers to the time spent in the target training zone in interval training. Work intervals are interspersed with recovery intervals.