The performance of resistance exercise in these repetition ranges will
strain the neuromuscular system and target different energy systems
in several ways, which may significantly impact the degree of the
hypertrophic response [4].
The extent of muscular strength and hypertrophic gains following
resistance training are universally thought to be dependent on the
intensity of exercise, with an intensity of ‘65% 1RM considered to be
sufficient to promote substantial muscular hypertrophy [9]. As a result,
the use of moderate to low repetition ranges has typically been proven
to elicit greater increases in muscle hypertrophy compared to high
repetitions [10]. Although, there is a recent body of literature proposing
that resistance exercise combined with BFR can promote significant
increases in muscle hypertrophy with exercise intensities as low as
20% 1RM [11]. While it still remains inconclusive as to whether the use
of low, moderate or high repetitions to induce the greatest
hypertrophic response, there is a prevailing body of evidence
suggesting that resistance exercise at a moderate range (6-12 reps) is
optimal for the production of muscle hypertrophy [12-14]. There are
several factors that are associated with the use of moderate repetitions
promoting the greatest anabolic response; these primarily include
metabolic stress, increase fibre recruitment and systemic hormonal
production. These factors will be further discussed in greater detail in
this literature review.
Volume
Exercise volume can be defined as the product of total sets, repetitions
and load complete in a training session. With respect to gains in
muscle hypertrophy, multiple-set, higher-volume protocols have
consistently proven to be far superior compared to lower-volume,
single set protocols [15, 16]. While it is not entirely clear as to why
higher-volume workloads is superior in promoting muscular
hypertrophy, it is suggested that a combination of several factors such
as greater total mechanical tension, metabolic stress and muscle
damage are implicated [4]. High-volume (body-building) type schemes,
have demonstrated to produce significant glycolytic activity which has
been shown to maximise the acute anabolic hormonal response to a
greater extent than low-volume (strength based) schemes [17, 18].
The increase in metabolic stress has been associated with the
augmentation of anabolic hormones such as growth hormone (GH) and
testosterone, therefore increasing the potential for downstream cellular
interactions to create a hypertrophic effect on muscle tissue [19].
Exercise selection
There is evidence to support that the selection of exercise may play a
role in maximising the hypertrophic response. Programs that primarily
incorporate multi-joint exercises tend to recruit greater amounts of
muscle mass, which has an impact on the anabolic hormonal response
to resistance training [4, 20]. It has been demonstrated that the
magnitude in the elevation of anabolic hormones post-exercise is
associated with the degree of muscle mass involved, with multi-joint
