TSAC-F flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Motor unit recruitment order

Smaller, lower-threshold motor units are recruited first; as force demand rises, progressively larger high-threshold units are added, so heavy loads are needed to train fast-twitch fibers.

ATP-PC system duration

Stored ATP and phosphocreatine fuel maximal efforts for roughly 10 seconds via creatine kinase; this system dominates sprints, jumps, and near-maximal lifts.

Length-tension relationship

Force production depends on actin-myosin crossbridge overlap; it peaks at resting sarcomere length and falls when the muscle is over-shortened or overstretched.

Force-velocity relationship

Concentric force is greatest at slow shortening speeds and falls as velocity rises; eccentric actions can generate more force than isometric or concentric actions.

Cardiac output equation

Cardiac output equals heart rate multiplied by stroke volume; resting values average about 5 L/min and can exceed 20 L/min during maximal exercise.

Type I muscle fibers

Slow-twitch, highly oxidative fibers with dense capillaries and mitochondria; they produce low force but resist fatigue, supporting posture and endurance work.

Type IIx muscle fibers

Fast-twitch glycolytic fibers with high contraction speed and force but rapid fatigue; they are recruited during maximal and near-maximal efforts.

SAID principle

Specific Adaptation to Imposed Demands: the body adapts to the exact stress applied, so training must replicate the speeds, loads, and movement patterns of the target task.

Two-for-two rule

If a trainee fails to reach the target rep range in two consecutive sessions for a given exercise, reduce the load by roughly 2.5-10% and rebuild.

Rest interval for maximal strength

Loads of 85% 1RM or more require about 2-5 minutes between sets so phosphagen stores recover and subsequent set quality stays high.

Hypertrophy rest interval

Roughly 30 seconds to 1.5 minutes between sets increases metabolic stress and training density, supporting muscle growth with moderate loads.

Plyometric volume guidelines

Per session foot contacts: beginners 80-100, intermediate 120-140, advanced 140-200; depth jumps from boxes above about 48 inches are not recommended.

Taper prescription

Reduce weekly training volume by about 40-60% while keeping intensity and frequency, typically for one to three weeks before a key event.

Load for power training

Velocity-focused power training uses about 30-60% 1RM; strength-power lifts such as cleans and snatches use roughly 75-85% 1RM.

Progressive overload

Systematically increasing load, volume, or density over time so the training stimulus stays above the adaptation threshold and performance continues to improve.

Needs analysis

The first program design step: identifies the metabolic and biomechanical demands of the job or sport, the trainee's testing results, and injury history.

Spotting a barbell bench press

Stand behind the lifter with an alternating grip on the bar, hands close but not touching; assist at the sticking point and never let the bar drop to the chest.

Valsalva maneuver caution

Breath-holding against a closed glottis raises intrathoracic pressure and blood pressure; modify or avoid in trainees with hypertension or cardiovascular disease.

Deadlift bar position

Bar starts over the midfoot with shoulders slightly ahead of it; hips and shoulders rise together and the bar stays in contact with the legs.

Power clean triple extension

Ankles, knees, and hips extend explosively, then the lifter pulls under and catches the bar in a quarter squat with elbows high and chest up.

Squat knee tracking

Knees track over the toes in line with the feet; avoid inward collapse, keep the heels down, and maintain a neutral spine through the full range.

Plyometric landing mechanics

Land softly on the balls of the feet with hips back and knees over toes; depth jumps should absorb force for three to five seconds.

Five-point body contact

Bench press contact points are the head, upper back, and buttocks on the bench plus both feet flat on the floor.

Agility deceleration technique

Lower the center of mass, shorten the stride, widen the base of support, and lean away from the intended cut to brake and redirect quickly.

Hydration deficit threshold

Body mass losses near 2% degrade endurance, power, and cognitive performance; replace fluids and electrolytes during long or hot operations.

Heat acclimation timeline

Seven to fourteen days of progressive heat exposure expands plasma volume, triggers earlier sweating, and lowers core temperature during exertion.

Sleep duration recommendation

Adults need seven to nine hours nightly; chronic short sleep raises injury risk, impairs reaction time, and reduces tactical performance.

Leading firefighter line-of-duty death cause

Cardiovascular events, particularly sudden cardiac death, are the leading cause of on-duty firefighter fatalities, exceeding burns and smoke inhalation.

Acute chronic workload ratio

Divide the past seven days of training load by the average of the past twenty-eight days; ratios above about 1.5 are linked to higher injury rates.

Protein intake for tactical athletes

About 1.4-2.0 grams per kilogram of body mass daily supports recovery, maintenance, and adaptation during heavy tactical training.

PAR-Q purpose

A brief pre-participation screening questionnaire that flags people needing medical clearance before starting or increasing physical activity.

Shift work circadian impact

Night and rotating shifts disrupt circadian rhythms, reducing sleep duration and quality while increasing fatigue, error rates, and metabolic strain.