Firstly, they have made it clear that heavy loads are also superior in young adult subjects with strength training experience (Schoenfeld et al. 2015; Mangine et al. 2015; Morton et al. 2016), showing that training status does not affect the extent to which there is
specificity of strength gains on the strength - endurance continuum.
Some studies have often reported no external load type
specificity of strength gains, although these are primarily limited to those reporting on programs of single - joint knee extension exercises (Manning et al. 1990; Hunter & Culpepper, 1995; Remaud et al. 2010) or programs of combined single - joint and multi-joint leg extension exercises (Walker et al. 2013).
So although there might be small differences in regional hypertrophy between concentric and eccentric training (because of the differences in the muscle architecture adaptations), it is still unclear whether this phenomenon is responsible for
the specificity of strength gains after eccentric training.
Ultimately, what we can say is that since changes in tendon stiffness do not seem to differ between concentric and eccentric training, that changes in tendon stiffness are probably not responsible for
the specificity of strength gains after eccentric training.
Not exact matches
Following the principle
of specificity, we might expect to see the largest
gains in
strength when we test force production at the same movement speed as we use in training.
If the principle
of specificity applies to velocity, then when we train using a fast speed, we should see the greatest
gains in
strength when we test
strength at a high velocity, and the smallest
gains in
strength when we test at a low velocity.
If this is the case, we should find that the main causes
of specificity in
strength gains after training with different types
of external load are regional hypertrophy and joint angle - specific changes in neural drive (especially at end range
of motion).
Moreover, since there is evidence
of specificity in
strength gains with regard to muscle action, eccentric training is often (but not always) used to improve eccentric
strength.
One interesting feature
of stability -
specificity is that the
strength gains are highly specific to the exact movement pattern used in training.