Exercise Science, Strength and Conditioning, and Endurance Physiology

Weight Releasers

An apparatus with a J-shaped hook placed over a barbell that provides extra weight during the eccentric (lowering) phase of a lift and unhooks at the bottom, allowing explosive concentric execution.

Accommodating Resistance

A training setup using tools such as bands or chains where the resistance increases as the bar ascends and decreases as it descends to match the lifter's mechanical leverage and train power.

Partials

A strength training method that uses a reduced range of motion, such as pulling weights from blocks or benches, commonly utilized in track and field and football line training.

Cardiovascular Exercise Guidelines

A baseline activity recommendation for non-athletes consisting of a minimum of $150\text{ minutes}$ per week (about $20\text{ to }25\text{ minutes}$ daily) and an upper limit of $300\text{ minutes}$ per week ($40\text{ to }50\text{ minutes}$ daily).

Constrained Energy Model

A metabolic model stating that total energy expenditure does not increase linearly with activity; beyond a certain volume of work, total calorie burn plateaus because the body downregulates energy spent on background physiological functions.

Phosphagen System (ATP-PC System)

The primary anaerobic energy pathway for immediate, maximal-intensity activities lasting between $0\text{ and }6\text{ seconds}$ (up to $10\text{ seconds}$), which uses stored adenosine triphosphate and phosphocreatine.

Glycolytic Energy System (Glycolysis)

An intermediate energy pathway that uses glycogen as fuel to supply energy for efforts lasting from approximately $10\text{ seconds to }2\text{ minutes}$, operating either anaerobically (producing lactate) or aerobically (producing pyruvate).

Oxidative Energy System

The slowest yet longest-lasting aerobic energy pathway that requires oxygen $100\%$ of the time, oxidizes fats and carbohydrates via the Krebs cycle and electron transport chain, and produces the most ATP.

$$\text{VO}_2\text{ Max}$$

The maximum amount of oxygen the body can take in and utilize during one minute of intense exercise, mathematically expressed as milliliters of oxygen consumed per kilogram of body weight per minute ($\text{mL}\,\text{O}_2\,\text{kg}^{-1}\,\text{min}^{-1}$).

Lactate Threshold

The point during exercise at which blood lactate begins to accumulate above resting levels because anaerobic glycolysis is producing lactic acid faster than the body can clear it.

Exercise Economy

The quantity of energy required to maintain a given movement velocity or consistent athletic pace, heavily influenced by technique, mechanics, and neuromuscular coordination.

Long Slow Distance (LSD)

A low-intensity endurance training modality performed for continuous, extended durations (e.g., $60\text{ minutes}$ at a walking or light jogging pace) that targets the oxidative energy system.

Tempo Training (Pace Training)

A training session performed at an intensity sitting just below the lactate threshold to condition the body to sustain aerobic glycolysis longer and elevate threshold capacity.

Fartlek Training

A Swedish training method meaning 'speed play' that combines continuous distance running with varied-intensity interval bursts and tempo changes based on natural terrain.

Zone 2 Heart Rate Training

A moderate cardiovascular exercise zone where the body derives its highest relative percentage of energy from fat oxidation.

Rate of Perceived Exertion (RPE)

A subjective scale ranging from $1\text{ to }10$ used to evaluate exercise intensity, where $1$ corresponds to resting baseline and $10$ represents maximal possible exertion.

Bone Mineral Density

The concentration of mineral matter in bone tissue that peaks in the mid-20s and is preserved through chronic resistance exercise to prevent demineralization and fractures.

Compound Exercise

A multi-joint exercise that simultaneously recruits two or more muscle groups, such as the back squat, bench press, or deadlift.

Assistance Exercise

An isolation or single-joint exercise that targets a single muscle group, utilized to correct muscular weaknesses, support rehabilitation, or target aesthetics.

Power

The rate at which work is performed or force is applied over time ($\text{Power} = \frac{\text{Force} \times \text{Displacement}}{\text{Time}}$), which is pattern- and plane-specific in athletic performance.

Eccentric Phase

The lowering or lengthening phase of a muscular contraction where the human body is approximately $20\%\text{ to }30\%$ stronger than in the concentric phase.

Yielding Isometric

An isometric muscle action where an individual attempts to hold a weight in place and resist falling or collapsing under a load.

Overcoming Isometric

An isometric muscle action where an individual exerts maximal force against a completely immovable structure or object, producing tension without joint displacement.

Concentric-Only Training

A lifting method that eliminates the eccentric and isometric phases (such as dropping a barbell at the peak of a clean pull) to develop explosive power while minimizing soreness and time under tension.

Principle of Reversibility

The training truth colloquially summarized as 'use it