Exercise Sciences: Bioenergetics, Neuromuscular, and Biomechanical Foundations
Bioenergetics
The phosphagen system (ATP-PC) supplies ATP for the first ~6 s of all-out effort; fast glycolysis dominates from roughly 10-60 s; oxidative phosphorylation takes over for efforts beyond about 2-3 minutes. Questions usually ask which system is predominant, so anchor your answer to duration rather than to the sport's name. Lactate is a fuel and a gluconeogenic precursor, not the cause of delayed-onset muscle soreness.
Neuromuscular and biomechanical concepts
Motor units are recruited in order of size (Henneman's size principle), so heavy loads bring in high-threshold type II fibers. The force-velocity relationship means concentric force falls as shortening velocity rises, while eccentric actions generate the greatest force at a given load; elastic energy stored in the stretch-shortening cycle explains the jump-enhancing effect of a brief countermovement. The length-tension relationship peaks near resting length, where actin-myosin overlap is optimal.
Adaptation traps
Acute responses (heart rate, lactate, hormone spikes) differ from chronic adaptations (hypertrophy, capillary density, neural efficiency). Early strength gains in untrained lifters are largely neural. Testosterone and growth hormone rise acutely after heavy resistance training, but the size of that response is a weak predictor of hypertrophy, so avoid answers that treat a bigger hormonal spike as a bigger training effect.
Worked example
An athlete squats 100 kg through 0.5 m in 1 s. Work = force x distance = (100 kg x 9.81 m/s^2) x 0.5 m = 490 J; power = 490 J / 1 s = 490 W. Doubling the load or halving the time doubles power output, which is a fast way to eliminate numeric distractors.