This fascinating study set out to assess whether velocity - specificity would still occur when training
with eccentric muscle actions at a moderate velocity (60 degrees / s).
Voluntary activation is lower during
eccentric muscle actions compared to during concentric muscle actions (Westing et al. 1990; Amiridis et al. 1996; Beltman et al. 2004), although some studies have suggested that this effect is limited to untrained people, and that trained individuals are able to reduce this eccentric - specific deficit (Amiridis et al. 1996).
However, no training studies have yet measured whether voluntary activation can be preferentially increased
in eccentric muscle actions after eccentric training (compared to in concentric muscle actions).
Sprint sports such as soccer, rugby, and lacrosse require a high volume of energy turnover and
eccentric muscle actions resulting in metabolic and mechanically induced stress.
Secondly, the bench press can be classified according to the variation, including various grip widths, concentric
vs. eccentric muscle actions, and pressing angles depending on the angle of the bench relative to the floor.
In contrast, they found no difference in peak bar velocity at all loads except 75 % of 1RM when comparing the bench press throw immediately preceded by a
fast eccentric muscle action and the concentric - only muscle action condition.
Since strength is specific, then: strength training
with eccentric muscle actions or accentuated eccentric loading for the knee flexors (and possibly the knee extensors) should lead to superior gains in sprinting performance compared to strength training with similar absolute load in eccentric and concentric phases.
Some studies have indicated that electroencephalography (EEG)- derived movement - related cortical potentials (MRCPs) are greater
during eccentric muscle actions than in concentric contractions (Fang et al. 2001; 2004).
This suggests that
eccentric muscle actions are much harder to control, and that eccentric training could bring about quick improvements in motor learning for such movements, which might then produce large gains in eccentric - specific strength.
Electromyography has limitations, but a consistent finding is that EMG amplitudes are typically lower during
eccentric muscle actions than in concentric muscle actions (Douglas et al. 2016b).
Eccentric Muscle Action — The muscle lengthens as it resists weight.
In contrast, they reported greater triceps brachii muscle activity in
the eccentric muscle action of unsuccessful lifts compared with successful attempts.
Assessing the effect of bench press muscle action and region, Newton et al. (1997) found that a greater concentric average velocity was achieved at all loads between 15 — 90 % of 1RM during the bench press throw when preceded by
the eccentric muscle action compared to the concentric - only muscle action.
It therefore showed that the aspects of an exercise that determine transfer to sport are not limited to the movement pattern, but include other factors such as the muscle group being trained (the hamstrings are key to sprinting ability), and the mode of the contraction (
eccentric muscle actions are very important during sprinting).
The researchers suggested that these findings imply that hip flexor length affects gluteus maximus and hamstrings EMG amplitudes during squatting motions, at least during
eccentric muscle actions.