Eccentric Resistance Training Review Notes

Eccentric (ECC) muscle actions involve active lengthening against a force.
Skeletal muscle produces more force during ECC than isometric (ISO) or concentric (CON) actions.
ECC training can maximize neuromuscular development, leading to faster, more explosive muscle phenotype.

Supramaximal ECC actions enhance neuromuscular changes.
ECC actions have a greater capacity to produce force with lower metabolic cost.
Titin plays a role in ECC actions, increasing filament stiffness.
Lower EMG activity but larger motor cortex activation during ECC actions.
ECC actions induce a stronger anabolic signal and muscle damage (EIMD).
Repeated exposure attenuates EIMD and DOMS.
ECC-only training at higher intensities increases total and ECC strength.
Fast ECC lengthening velocities and heavier loads lead to greater improvements.
ECC training improves muscle power output.
Adaptations include increased sarcomeres in series, preferential fast twitch fiber hypertrophy, and increased MTU stiffness.

Methods include tempo ECC training, flywheel inertial training (FIT), accentuated ECC loading (AEL), and plyometric training (PT).

Alters time parameters of exercise phases.
Involves increasing the duration of the descending phase to overload the ECC muscle action.
Conflicting evidence on acute and chronic hypertrophy, strength, and power output.
Extending ECC duration requires lowering the absolute load.
May limit ECC force production and total volume.
Higher ratings of perceived exertion and lactate accumulation.

Uses inertial resistance from flywheel unwinding during CON action and rewinding during ECC action.
Resistance depends on mass, radius, and angular acceleration of the flywheel.
Improves muscle mass, maximal voluntary contraction, strength, ECC force production, power output, jump ability, running velocity, and EMG activity.
Versatile and portable.
Intensity is altered by the CON velocity generated.

ECC load exceeds CON load using movements requiring coupled ECC and CON actions.
Weight releasers are used to provide greater loading during ECC phase.
Aims to apply additional stress to muscle and connective tissue while maintaining the CON stimulus.
May transfer well to sport tasks and performance.

Rapid ballistic movements incorporating the stretch-shortening cycle (SSC).
Uses ECC muscle action to enhance subsequent CON muscle action.
Increases force, power output, and RFD.
Overload stimulus is based on the velocity of the ECC phase or rate of loading.
Variations include miometric, ISO–miometric, plyometric–miometric, and “shock” methods.

Examine the duration of residual effects of ECC training and optimal prescription frequency.
Identify the optimal length of the ECC phase in tempo training.
Examine the influence of motor learning and work capacity in FIT.
Determine optimal ECC phase length and set configurations in AEL protocols.