Elite Physique The New Science of Building a Better Body

210 Elite Physique
Mechanical tension
Muscle damage
Metabolic stress
FIGURE 8.1 Three mechanisms of hypertrophy.
E8315/Waterbury/F08.01/670309/mh-R1
to failure. Metabolic stress occurs when a lighter load is taken to failure (or close
to it) or when the rest periods are incomplete. Importantly, the three aforementioned
mechanisms are not mutually exclusive. They can occur at the same time,
which you will see in the programming in this chapter. More detail about the
three mechanisms is as follows:
• Mechanical tension: There are two types of tension generated in your muscles
during resistance training. One is active tension, which occurs when muscle
is shortening (i.e., concentric action). The other is passive tension, which
occurs when muscle is lengthening (i.e., eccentric action). The combination
of these “force” and “stretch” tensions appears to have a compounding
effect on hypertrophy (Hornberger and Chien 2006).
• Application: Train with heavy loads (i.e., three to five repetitions per set).
• Muscle damage: Resistance training with sufficient volume or intensity creates
microtears within the trained muscles. This microtrauma causes various
growth factors to release in order to help your muscles grow (Vierck et al.
2000).
• Application: Perform a high volume of work with heavy loads (e.g., 8 to 10
sets of three to five repetitions), or push one or more of your sets close to
failure or to failure when the load is submaximal.
• Metabolic stress: When you perform a set of high repetitions to failure, or
perform multiple sets of the same exercise with minimal rest, you feel a burn
in your muscles. This stress is due to a buildup of metabolites, most notably
hydrogen ions (H+), which are associated with high acidity (Takada et al.
2012). A lack of oxygen (i.e., muscle hypoxia) is another potential stressor; it
can be induced either by performing a set of high repetitions (e.g., 30) with
a fast tempo to failure or by applying a cuff that restricts blood flow to the
working muscles. Blood flow restriction has been shown to be promising
for hypertrophy; however, it’s often impractical for the typical gym-goer
(Patterson 2019).
• Application: Perform sets of the same exercise with incomplete rest periods,
or take your sets to momentary muscular failure.
A note about momentary muscular failure: Limit training to momentary
muscular failure to single-joint and body weight exercises that are performed
for a high number of repetitions (i.e., >13). Training to failure over the course of