So far a primer has been offered (see here) for the basic concepts being discussed in terms of periodization, as has phase one of a periodized program (see here), at least insofar as you would be able to piece together your own program from these concepts.
Firstly let’s define what hypertrophy might mean:
One of the most visible signs of adaptation is the increase in muscle size – hypertrophy. This phenomenon is due to an increase in cross-sectional area of individual muscle fibers. A reduction of size, resulting from inactivity, is referred to as atrophy. (Bompa et al, 2003, p.10)
More specifically the authors state there are two types of hypertrophy that strength trainers and bodybyuilders experience; short-term hypertrophy and long-term hypertrophy. To Bompa et al short-term hypertrophy refers to what is generally known as “the pump”, that is the fluid accumulation (edema) in the muscles that lasts a few hours after training. After one trains with heavy weights, states Bompa water is flushed into the intracellular spaces of the muscle making it look larger, after a few hours the water returns to the blood and the pump dissipates, this is one reason why muscle strength is not always proportional to muscle size. To the authors, long-term hypertrophy occurs when structural changes occur at the muscle level, via an increase in size (or number?) of those filaments. People with larger fibers will appear to be more muscular, and stronger than those with fewer fibers, with the number of fibers generally being determined by genetic factors, and remains relatively constant (the authors refer to the theory of “hyperplasia”, which states that muscle fibers can, under heavy loads, split and create new fibers, but at the time of this book this has only been demonstrated in animal research, and has not carried over to humans).
Not all the factors involved in hypertrophy are fully understood, and there have been many theories offered to explain it, three will be touched on today; (1) ATP deficiency theory, (2) the role of testosterone, and (3) ST to FT fiber conversion, but the actual answer may rely on all, or none.
(1) Many believe that hypertrophy occurs by a disturbance in the consumption and remanufacturing of ATP (adenosine triphosphate):
During and immediately after a heavy-load training session, protein content in the working muscles is very low, if not exhausted, due to ATP depletion. As the athletes recover between training sessions, their bodies replace the protein in the working muscles; but the protein content in the end exceeds the initial levels, increasing the size of the muscle fibers. A protein-rich diet will make this effect especially pronounced. (Bompa et al, 2003, p.10-11)
(2) This theory focuses on the role of the male sex hormone testosterone (which the authors note is a serum androgen, a substance that has masculinizing properties, p. 11):
Although there are no physiological differences between the muscle of men and women, male athletes usually have larger and stronger muscles. The difference is attributed to testosterone content, which is approximately ten times greater for men than for women. While testosterone seems to promote muscle growth there is no scientific proof to indicate it is the sole determinant of muscle size. (Bompa et al, 2003, p.11)
(3) Finally, although it is mostly speculation, there is some research to suggest that the percentage of slow-twitch fibers decreases due to heavy strength training, and fast-twitch fibers increase:
Studies on this theory have been largely inconclusive, since the research is typically conducted on subjects who are not serious strength trainers or bodybuilders. (Bompa et al, 2003, p.11)
In regards to their periodized model for their Hypertrophy phase (hereafter “H”), the authors recommend two six-week hypertrophy phases (H1 and H2) to allow for sufficient time for muscle development, separated by a one week transition (hereafter “T”) phase (of which will be elaborated on in the final installment in this series) in which volume and intensity will be reduced to allow for recovery. Before I delve into the authors H phase, let’s see what the scope of such a phase is:
Increase muscle size to the desired level by constantly taxing ATP/CP stores.
Refine all muscle groups of the body.
Improve the proportions among all the muscles of the body, especially between the arms and legs, back and chest, leg flexors and extensors. (Bompa et al, 2003, p.204)
Now we can begin with what a H phase might look like.
Bompa et al state that the length of the H phase is dependent on several factors, including the athlete’s classification, training background, specific body goals (they delineate between size, density or definition) and the type of periodization being followed. I might, for example, when programming for my clients, give them an AA phase of four to six weeks, followed by one four week H phase then on to a Max Strength (hereafter “MxS”) phase, finishing with a muscle definition (hereafter “MD) phase, this would encapsulate one block of training. The authors state that at least one H phase is needed (preferably two) to gain significant amounts of muscle mass, using the methods the athlete most desires, with a special attention being paid to rest intervals (hereafter “RI”), such being that fatigue is reached both at the end of the set, and at the end of the workout.
Training Method for H Phase
During a H phase you will be lifting submaximal weights in order to create as much tension on the muscle fiber as possible, bring it to exhaustion without creating maximum tension in said fibers. Different fiber types will fatigue as others take over during submaximal exhaustion thereby stimulating growth of as many fibers as possible. In order to gain optimal training results, the trainee will need to perform many repetitions during each set, striving for local muscle exhaustion (complete failure, which does not allow them to perform another repetition, even if maximal force is exerted). The authors state that if exhaustion is not reached not all the fibers will be recruited and muscle development will suffer:
The key element in hypertrophy training is the cumulative effect of exhaustion over the total number of sets, not just exhaustion per set. This cumulative exhaustion stimulates chemical reactions and protein metabolism responsible for optimal muscle hypertrophy. (Bompa et al, 2003, p.204)
Training in this phase should be designed to deplete fuels used specifically by the anaerobic system (ATP/PC stores), thereby threatening the energy used for the working muscles. This can be achieved by manipulating RIs (30-45 seconds if you’re doing straight sets, I might personal advocate, supersets, trisets, and giantsets). When forcing the body to work harder with less time to recover energy stores are forced to adapt (increase effectiveness and storage space), which in turn causes muscle to adapt by increasing in size.
Program Design for the H Phase
Similar to the AA phase the authors suggest some 1RM testing in the first week as this is the lowest point in the loading pattern for this phase (you’ll recall the authors advocate a step-type loading progression). Below is a picture of the basic program template for their H phase, you can use this coupled with programs I have offered in my previous post (and here) to guide your program design.
I’ve also included below an example entry level program they provide on pagses 216-219.Recreational program:
3 week program:
Bompa, T.O., Pasquale, M.D., Conrnacchia, L.J. (2003). Serious Strength Training (Second Edition). Champaign, IL. Human Kinetics.