NASM-YES key terms

Public health recommendations stating that children and adolescents aged 6 to 17 should accumulate at least 60 minutes of moderate-to-vigorous physical activity daily, including muscle- and bone-strengthening activities at least three days per week.

Activity intense enough to raise heart rate and breathing, ranging from a moderate effort where talking is possible to a vigorous effort where talking becomes difficult. MVPA is the primary target of youth activity recommendations.

Time spent sitting or lying down while awake with very low energy expenditure, such as screen time or prolonged sitting. It is tracked separately from physical inactivity because it carries independent health risks for youth.

Time spent on televisions, computers, tablets, and phones. Guidelines commonly recommend limiting recreational screen time for youth and replacing it with movement, sleep, and face-to-face interaction.

Total hours of sleep per night, which guidelines specify by age (commonly 9 to 12 hours for school-age children and 8 to 10 hours for teens). Adequate sleep supports recovery, growth, and training adaptation.

Movement that produces ground or body-weight impact and muscle force against bone, such as jumping, hopping, running, and resistance exercise. These activities are recommended at least three days per week for growing skeletons.

The motivation, confidence, physical competence, knowledge, and understanding needed to value and take responsibility for lifelong physical activity. It is a central outcome of quality youth programming.

Basic locomotor, stability, and manipulative patterns such as running, hopping, squatting, throwing, and catching. Competence in these patterns underpins later sport-specific and resistance-training skill.

A framework that sequences training emphasis across developmental stages, from early movement exploration through specialization and performance, matching training demands to the athlete's maturation and readiness.

A developmental window in which a specific capacity, such as coordination or speed, appears especially responsive to training. The concept guides when to emphasize particular qualities in youth programming.

Periods during growth when training a given quality (for example aerobic capacity or strength) may yield a particularly strong response. Coaches use them to time emphasis, not to exclude other training.

Time elapsed since birth. It is easy to record but a poor proxy for biological maturity, so programmers pair it with growth and maturity indicators when grouping youth athletes.

The degree of progress toward the adult state, assessed through indicators such as growth spurt timing, skeletal age, or pubertal stage. Two youth of the same age can differ markedly in maturity.

The point of fastest upward growth during the adolescent growth spurt. It is a key landmark because rapid limb growth can temporarily disrupt coordination and raise injury risk.

The estimated time in years before or after peak height velocity, calculated from measures such as standing and sitting height. It helps coaches match training load to developmental stage rather than age alone.

A temporary decline in coordination and body control during rapid growth, when limb length increases faster than the nervous system recalibrates. It calls for patience, skill reinforcement, and reduced complexity.

Elevated susceptibility to overuse and growth-plate injuries during rapid growth and high-load training. Programming responds with load management, movement variety, and attention to pain reports.

Irritation or inflammation at a growth plate where a tendon attaches, common in active adolescents, such as Osgood-Schlatter at the tibial tuberosity. It typically presents as localized pain with activity.

A condition in which repetitive pulling by a tendon inflames an apophysis, the growth region at a tendon attachment. Management centers on load reduction and gradual return rather than complete rest indefinitely.

The overrepresentation of youth born early in a selection year among elite and selected teams, because they are temporarily older and more mature than peers. Coaches should avoid mistaking maturity for talent.

The process of recognizing youth with potential for high performance. Sound practice weighs current skill, growth trajectory, and coachability, and avoids early exclusion based on transient maturity advantages.

A planned program of exercises in which muscles work against external or body resistance to improve strength, power, and movement quality. Youth programs emphasize technique, light-to-moderate loads, and qualified supervision.

Instructing youth exercise under the direction of a trained professional who understands youth physiology, safety, and instruction methods. Guidelines consistently require it for resistance training and other structured programs.

A coaching principle that prioritizes correct movement execution over load or speed. Youth programs advance resistance only when form is consistent across repetitions and sets.

Systematically increasing training demand over time so the body continues to adapt. In youth, progression is often achieved through added repetitions, sets, or complexity before adding external load.

The total stress placed on an athlete by training, combining volume, intensity, and frequency across sessions. Monitoring and adjusting load is central to keeping youth training productive and safe.

The period and processes through which the body repairs and adapts after training, including sleep, nutrition, and easy days. Youth need adequate recovery because growth itself adds physiological demand.

Changes in how the nervous system recruits and coordinates muscle, producing early strength gains before muscle size changes. These adaptations are prominent in youth and support skill learning.

The process by which the nervous system activates additional motor units to produce more force. Training can improve recruitment, contributing to strength gains in youth without marked muscle enlargement.

The frequency at which the nervous system sends signals to muscle fibers, influencing force output. Improved rate coding helps youth generate force more quickly as they train and mature.

An increase in muscle size from training. In youth, hypertrophy is limited before puberty because circulating anabolic hormones are low, so early strength gains come mainly from neural factors.

The mix and concentration of circulating hormones, notably testosterone and growth hormone, that shape training response. It changes markedly with puberty and helps explain age-related differences in adaptation.

The ability to produce energy without oxygen for short, high-intensity efforts. It is relatively limited in children and develops with maturation, which informs how long and hard youth conditioning bouts should be.

The body's ability to take in and use oxygen during sustained activity. It is trainable in youth and responds to games and interval formats that keep children moving rather than to long steady-state drills.

The difference between maximum and resting heart rate, used to set training intensities. Youth-focused programming often favors simple, play-based intensity monitoring over strict percentage targets.

The body's control of internal temperature through sweating and blood flow. Children sweat less and heat up faster than adults, so youth sessions need frequent water breaks, shade, and adjusted intensity in heat.

Maintaining adequate body water before, during, and after exercise. Youth are encouraged to drink regularly during activity, especially in heat, because thirst cues may lag behind need.

A person's belief in their capability to perform a task successfully. In youth exercise, building self-efficacy through achievable challenges and positive feedback supports adherence and physical literacy.

The internal or external drive that initiates and sustains activity. Youth programs foster intrinsic motivation by emphasizing fun, choice, competence, and social connection rather than punishment or comparison.