The document discusses hypertrophy training and its relationship with athletic performance, outlining the importance of muscle cross-sectional area (CSA), maximum strength development, and the role of various training methods in promoting muscle hypertrophy. It details mechanisms of hypertrophy including mechanical tension, metabolic stress, and muscle damage, and emphasizes factors like training volume, frequency, and nutrition required to maximize muscle growth. Various training techniques such as drop sets, forced repetitions, and the significance of protein and carbohydrate intake are also highlighted for achieving optimal hypertrophic responses.

1. Hypertrophy training
“24th Strength & Conditioning Coaching
Course”
Lecturer: Mahdi Cheraghi
National Olympic Academy of IRAN
August 2018

2. Relationship with Performance
• For maximizing Power development
The first step in power development deals with developing a larger muscle
CSA and a higher work capacity
• higher volume of exercise with an intensity of ≥ 60% of the 1 RM
representing a threshold for optimum CSA gains
• loads as high as 80% 1 RM may be optimal for markedly increasing the
Type II/Type I CSA ratio.
The second step in this process would be the emphasis of basic strength
training
• among relatively weak athletes, increasing maximum strength can
improve RFD and power as much or more than high velocity or power
training
The final step, after achieving a reasonable strength level, deals with
prioritizing power-oriented training

3. Hypertrophy and athletic Performance
• Strength development: Although neurological factors primarily contribute
to the development of force, structural adaptations after long-term
strength training may also influence force generation capacity
• cross-sectional area of the limbs has been associated with both horizontal
and vertical power production in elite athletes
• During the rehabilitation process, muscle atrophy is a key concern,
secondary to unloading
• Greater rate of hypertrophy of Type II muscle fibres compared to Type I
fibres after resistance training

4. Parallel and In-Series (Serial) Hypertrophy

5. Parallel and In-Series (Serial) Hypertrophy
Parallel sarcomeres
• Concentric training
-increases in muscle thickness and pennation angles following heavy strength
training
-favorable when it comes to producing greater overall magnitudes of force
- exercise consisting “slow” concentric-only contractions leads to a serial decrease in
sarcomere length
Serial sarcomeres
• Eccentric training, plyometrics and high velocity power exercises
- induce greater fascicle length (new functional length)
-greater shortening velocity; may increase the overall shortening velocity of the
muscle, likely leading to greater increases in power output
-training with relatively high velocity muscle actions and lighter loads (<60% 1RM)
may produce increases in fascicle length with no changes in pennation angle
-increases in fascicle length following resistance training were strongly correlated
with sprint times.

6. non-uniform hypertrophy
• quadriceps muscles of track and field sprinters may hypertrophy more
proximally than track cyclists due to the lower limb mechanics required

7. Muscle Hypertrophy
• Myofibrillar /contractile/functional hypertrophy
-heavy-load, low repetitions
• Sarcoplasmic /non-functional Hypertrophy
-lighter-load, higher repetitions promote greater accumulation of sarcoplasmic fractions
-enhances muscle bulk without concomitantly increasing strength
• bodybuilders tend to display higher amounts of fibrous endomysial connective tissue as well as a greater
glycogen content compared to powerlifters
• bodybuilders display double the glycogen content of those who do not participate in regular exercise
• Resistance training–induced increases in myofibrillar hypertrophy occur in parallel with those of
noncontractile elements
• the often-cited opinion that bodybuilding-style training leads to nonfunctional hypertrophic adaptations is
misguided.

8. Mechanisms of Hypertrophy
• three primary mechanisms:
• mechanical tension,
• metabolic stress,
• muscle damage

9. mechanical tension:
• Mechanical tension may be the most important factor in training induced Muscle
hypertrophy
• Mechanosensors are sensitive to both the magnitude and the duration of loading, and these
stimuli can directly mediate intracellular signaling to bring about hypertrophic adaptations.

10. Mechanical tension
Signaling Pathways
• PI3K/Akt Pathway:
-a master network for regulating skeletal muscle growth
- mTOR (mammalian target of rapamycin) signaling critical to hypertrophic adaptations
induced by mechanical loading
-primary target of mTOR is p70S6K , which plays an important role in the initiation of mRNA
translation
• MAPK Pathways
• Calcium-Dependent Pathways
• Phosphatidic Acid Pathway
• AMPK Pathway:
-stimulated by an increase in the AMP/ATP ratio
-conditions that elicit substantial intracellular energy stress—including exercise
-AMPK suppresses energy-intensive anabolic processes such as protein synthesis and
amplifies catabolic processes including protein breakdown

12. Metabolic Stress
• metabolic stress is an exercise-induced accumulation of metabolites:
lactate, inorganic phosphate, and H+
• relies heavily on anaerobic glycolysis (15 to 120 sec)
• persistent compression of circulatory flow (occlusion) throughout a longer-duration set results in acute hypoxia
(heightening metabolite buildup)
Myokine Production
• metabolic stress may influence muscle growth by downregulating local catabolic factors
• difficult to formulate conclusions
Cell Swelling (an increase in intracellular hydration)
• increase in the hydration status of a cell concomitantly increases protein synthesis and decreases protein
breakdown.
• cellular hydration causes pressure against the cytoskeleton and cell membrane which stimulates anabolic signaling
• swelling of myofibers may trigger the proliferation of satellite cells and promote their fusion to the affected fibers
• Cell swelling is thought to be heightened by resistance training that generates high amounts of lactic acid via the
osmolytic properties of lactate
• Fast-twitch fibers are thought to be especially sensitive to osmotic changes, presumably because they contain a
high concentration of aquaporin-4 (AQP4) water transport channels
• Systemic Hormone Production:
• post-exercise GH spike mediated by heightened accumulation of lactate or H+
• GH is known to potentiate IGF-1 secretion
• If there is such an effect, it would seem to be of small consequence

13. Muscle Damage
EIMD (exercise-induced muscle damage)
• tears in the sarcolemma, basal lamina, and supportive connective tissue, as well as injury to
contractile elements and the cytoskeleton
• Although concentric and isometric exercise can bring about EIMD, eccentric actions have by far the
greatest impact on its manifestation
• Eccentrically induced EIMD is more prevalent in fast-twitch than in slow-twitch fibers
• EIMD decreases when a person performs the same exercise consistently, a phenomenon commonly
known as the repeated bout effect (RBE)
• upper-extremity muscles have a greater predisposition to EIMD than the leg muscles suggests a
protective benefit in muscles that are frequently used during everyday activities
• excessive damage has a negative effect on muscle development
• Inflammatory Processes: damaging exercise promotes an anabolic stimulus
• Satellite Cell Activity: mechanical stimuli alone can instigate satellite cell proliferation and
differentiation even without appreciable damage to skeletal muscle
• IGF-1 Production : the association between EIMD and IGF-1 upregulation has not been universally
confirmed in the literature
• NSAIDs: (mostly chronic usage) blunt the inflammatory response and hence moderate the extent of
cell swelling, impairs the increase in muscle protein synthesis normally associated with resistance
exercise

14. Volume
• volume load=sets × repetitions × load
• clear dose–response relationship between volume and hypertrophy
• Multiset protocols favoring high volumes of resistance training optimize the
hypertrophic response
• Novices (less experienced): multiset routines totaling 40 to 70 repetitions per
muscle group per session
• More advanced lifters seem to require greater volumes to maximize muscle
protein accretion, perhaps double that of untrained people.

15. Frequency
• A survey of competitive male bodybuilders:
-more than 2/3 trained each muscle group only once per week
-none reported working a muscle group more than twice weekly
• at least 48 to 72 hours of rest between workouts for the same muscle group to ensure
adequate repair, recovery, and adaptation (because of myogenic responses (48 h) and
elevated total RNA (72 h)).
• Split-body routine vs whole body: greater recovery afforded between sessions
• Important: higher training frequencies may be more beneficial for trained individuals in
stimulating greater muscle hypertrophy Because
-trained individuals adapt to resistance training in the long term by reducing the muscle
protein synthesis response
-distributing training volume across a higher frequency has the potential to increase the
total time spent in a positive protein balance by an athlete
• double-split routine: conflicting results!

16. Frequency
• split-body routine(Examples)

17. Frequency
• 10 competitive male bodybuilders
• 4 times/week vs 6 times/week
• 90 min session vs 60 min
• 4 sets in a pyramid fashion (12-, 10-, 8-, and 6RMs)
• Volume was equated
• each muscle group was trained twice weekly
• After 4 weeks,
• similar increases in fat-free mass

18. Load
• repetition ranges are classified as heavy (1- to 5RM), medium (6- to 12RM), and
light (15+RM)
• High intensities of load (>85% of 1RM), short duration of (<15 seconds), primarily
ATP-PC system and little contribution occurs from fast glycolysis: high levels of
mechanical tension but metabolite accumulation is relatively low
• light-load training with sets of ≥15 repetitions generally last 45 seconds or more
(majority of energy from the fast glycolytic system),generates a significant muscle
pump but are insufficient to recruit the highest-threshold motor units
• hypertrophy range: medium-repetition range (6- to 12RM), sets generally last
• between 20 and 40 seconds, which may provide an optimal combination of
mechanical tension and metabolic stress.
• if the goal is to promote hypertrophy to maximize strength, there appears little
reason to employ loads less than approximately 70% of 1RM.
• Important: High load training (>65% 1RM) (with superior strength adaptations) to
be more effective than low-load training (<60% 1RM) (useful for injury
rehabilitation and older adults) for increasing skeletal muscle mass

19. TRAINING TO MOMENTARY MUSCULAR
FAILURE
• it is hypothesized:
-that maximal motor unit recruitment is achieved resulting in the fatigue
of a greater number of muscle fibers, in turn leading to a greater
hypertrophic response
-training to failure is associated with progressive increases in both the
perception of effort and muscle activation levels (EMG)
• Note: complete concentric failure was not required to achieve full muscle
activation using EMG analysis, with a plateau occurring during the final 3–
5 repetitions with a 15RM load
• may produce symptoms of overtraining and subsequent threats to the
anabolic status of athletes
• Should be exposed strategically (periodized) in training
Example: an initial cycle in which all sets are stopped 1 repetition or 2 short
of failure, second cycle by taking the last set of each exercise to failure,
and then culminating in a brief cycle in which the majority of sets are
carried out to failure.

20. training to Failure?!
• training to failure likely stimulates the recruitment of high threshold motor
unit
• Equal hypertrophic adaptations (but not similar strength gains) response
following low (25-30%) compared to high (≥70 %) training loads performed to
failure.
• due to fiber-specific hypertrophy:
-greater increases in type II fiber size from high load training to failure
- greater increases in type I fiber size from low load training to failure
• greater motor unit activation with high loads
• Training status:
- trained participants responded more favorably to non-failure compared to
failure training (~14% and ~12% respectively).
- regular failure training may be too demanding for strength athletes
- untrained participants, the similar increases in muscular strength for failure
versus non-failure training (~34% increase for both groups)
• should be used sparingly in order to limit the risks of injuries and overtraining

21. EXERCISE ORDER
• muscles trained and fatigued in the early stages of a training session will
accumulate higher training volumes and therefore adapt to a greater
extent
• Prefatiguing (pre-exhaustion) a muscle with a single-joint exercise has
been shown to decrease the recruitment of the muscle during a multijoint
exercise with an increased recruitment of the synergistic muscles during
the compound movement
• But activating a muscle with a single-joint exercise but not to the point of
fatigue may increase its activation in the subsequent multijoint exercise

22. Repetition Duration (Tempo)
• little difference in muscle hypertrophy when training with isotonic
repetition durations ranging from 0.5 to 6 seconds to muscular failure
• Concentric and eccentric tempos of 1 to 3 seconds can be considered
viable options
• training at very slow volitional durations (>10 seconds per repetition)
appears to produce inferior increases in muscle growth

23. Range of Motion
• Knee extension:
-vastus lateralis is maximally activated during the first 60° of (ROM)
-vastus medialis is maximally activated during the final 60° of ROM
• arm curl:
-short head appears to be more active in the latter phase of the
movement (greater elbow flexion)
-the long head is more active in the early phase
• Deep Squat: deep squats (0 to 120° of knee flexion) promoted increases in
cross-sectional area across the entire frontal thigh musculature
• shallow squats: (0 to 60° of knee flexion) elicited significant growth only in
the two most proximal sites
• overall change in cross-sectional area was greater at all measured sites in
the deep squat group

24. Accumulation methods
• Drop sets
• Forced repetitions
• Pre-exhaustion
“High training volume is a key determinant in stimulating muscle
hypertrophy”.

25. Drop sets
-one of the most popular methods for prolonging time
under tension
• After reaching a point of MMF, reducing the load in
order to increase the work completed and extend the
set duration, resulting in greater fatigue
• As high levels of fatigue correspond with metabolic
stress and local ischaemia
• both lower and higher threshold motor units will be
recruited to maintain force output for the duration of
the set
• fatigue will occur across a wider spectrum of motor
units when compared to traditional sets,

26. Drop sets
• Example For hypertrophy
• at times of the year where maximal strength is the focus and muscle mass is to be
maintained, incorporating a drop set or forced repetitions at the end of a strength
routine may allow for a hypertrophy stimulus to be present, without excessive
time being required

27. Forced repetitions
• a higher level of fatigue after momentary fatigue
• may allow for increases in training density via the addition of training
volume per unit of time
• employing forced repetitions when a time restriction exists in the planning
• same spotter should be used across the training block

28. Pre-exhaustion
• fatiguing a muscle (target) with a single joint exercise before a
multi-joint movement has the potential to increase the level fatigue
• may be used to manipulate the organisation of muscle activation
strategies
• reduced activation of the fatigued muscle and increased
recruitment of synergistic prime movers.
- pec deck or dumbbell flyes exercises to pre-exhaust the
pectoralis major prior to bench press; more triceps activation and
less pectoralis!!
• by not taking the target muscle to MMF, coaches may increase the
activation of potentially inefficient muscles during compound
exercises
•

29. Intensification methods
• Cluster sets
• Partial range of movements exercises
• Eccentric training

30. Cluster set
• short intraset rest periods of 5-15 seconds
during hypertrophy phases
• Longer intraset rest periods of 30-45 seconds
for training maximal strength
• training density will decrease in order to
account for the additional intraset rest periods
• other methods may be more time-efficient
• Less metabolic stress

31. Eccentric training
• 2/1 TECHNIQUE
• TWO-MOVEMENT TECHNIQUE
• SLOW/SUPERSLOW
• NEGATIVE (SUPRAMAX)

33. nutrient
• “muscle full” concept: that muscle protein synthesis becomes
unresponsive to any further increases in intake once the saturable
level is reached.
• Eating Frequency for Hypertrophy:
• anabolic effect of a protein-rich meal lasts approximately 5
• to 6 hours.
• young people should consume three meals, spread throughout the
day, containing at least 10 g of EAAs.
• the body remains in anabolism over the course of the day and takes
full
• Getting advantage of the >24-hour sensitizing effect of resistance
training
• Elderly people may require up to double this amount.

34. nutrient
• to maximize hypertrophy should consume at least 1.7g/kg/day of
protein.
• high-quality protein (at a dose of ~0.4 to 0.5 g/kg of lean body
mass) both pre- and postexercise within about 4 to 6 hours of each
other depending on meal size.
• Carbohydrate intake should be at least 3 g/kg/day to ensure that
glycogen stores are fully stocked.
• Those who perform 2-a-day (morning and evening workouts in the
same day) should consume carbohydrate (at a dose of ~1.0 to 1.5
g/kg of lean body mass) within 1 hour postworkout.
• At least three meals consisting of a minimum of 25 g of high-quality
protein should be consumed every 5 to 6 hours to maximize
anabolism

36. “Thank you”
National Olympic & Paralympic Academy
Sports Biomechanics center
Lecturer: Mahdi Cheraghi
Email: mahdicheraghi26@gmail.com