The two loading protocols produced
similar fiber type shifts, but the high external load protocol produced much greater hypertrophy.
However, it is likely that such fiber type characteristics are not caused by shifts between type I and type II muscle fibers, as aerobic exercise and strength training produce very
similar fiber type changes (Farup et al. 2014).
Not exact matches
The results showed a
similar hypertrophy of
type I
fibers between the groups after nine weeks of training, but the group who performed slower on the concentric part had greater increases in
type II
fiber than the group who performed slower on the eccentric part.
With the lower body, women can do the same number of reps as men at a given percentage of their 1RM [one - rep max], since we have a
similar distribution of
type I and
type II muscle
fibers there.
In Mitchell et al. (2012), the group training with 30 % of 1RM increased
type I muscle
fiber area by nearly twice as much as
type II muscle
fiber area, while the group training with 80 % of 1RM increased both
type I and
type II muscle
fiber areas by a
similar amount.
Although it is not well - known, muscle
fibers of different
types (I, IIA and IIX) display very
similar force producing abilities, but very different contraction velocities.
There are some indications that
similar programs can lead to a shift within the sub-types of
type II muscle
fibers, from
type IIX to
type IIA muscle
fibers, as measured by muscle
fiber type proportion.
Similarly, in Campos et al. (2002), increases in
type I
fiber area were
similar to the increases in
type IIA and
type IIX area in the 20 — 28RM group.
Strength training in untrained subjects causes a shift in muscle
fiber proportion from
type IIX to
type IIA muscle
fiber type, and may also produce
similar effects in trained individuals.
Although all
fiber types have a
similar single
fiber force,
type II muscle
fibers display a much faster shortening velocity than
type I muscle
fibers.
The relative CSA reflects the size of each group of
fibers in the sample relative to the others, and this typically involves a
similar shift to the proportion, with
type IIX
fiber area decreasing, and
type IIA
fiber area increasing.
In the literature, it is traditionally (albeit tacitly) assumed that the mechanisms are in some way loosely connected, and that
similar mechanical loading of a muscle
fiber will lead to both hypertrophy and a
fiber type shift (mainly from hybrid or
type IIX
fiber types to
type IIA
fiber type).
This diet is
similar to the Atkins Diet, and we do not recommend these
types of diets because of the many health risks associated with consuming high amounts of protein and fat and low amounts of carbohydrates and
fiber.
The other study used a
similar protocol, but the researchers did actually take muscle biopsies to get an accurate measure of
fiber type breakdown.
However, in this study, heavy training and light training both caused
similar amounts of
Type 1
fiber growth, and in this study, light training to failure didn't cause any
Type 1
fiber growth at all, while heavier training did.