Hypertrophy Flashcards
•To be able to define what hypertrophy is. • To explore the physiological components associated with hypertrophy. • To identify the key training variables associated with hypertrophy training. • To design and implement a safe and effective training programme devised to drive a hypertrophic-based adaptation
What is hypertrophy?
Increase in the number of size or cell in a tissue
Contractile hypertrophy can occur by…
↑ Increase sarcomeres in series or in parallel
What happens during hypertrophy?
Contractile elements enlarge
What happens during hyperplasia?
Number of fibers within muscle increases
Why do we need hypertrophy in contact sports?
For protection
To increase Impact forces
What is the Pennation Angle
angle of the muscle fibers within the muscle with respect to the angle of force generation, also known as the line of pull.
What is the degree of the Pennation Angle?
0º
Fusiform
End to end
Unipennate
Muscle fibers are oriented at one fiber angle to the force-generating axis
All on the same side of a tendon
Varies from 0º - 30º
Bipennate
Muscles that have fibers on two sides of a tendon
Multipennate
Fibers that are oriented at multiple angles along the force-generating axis
Three mechanisms to attribute hypertrophy?
– Mechanical loading: Increased muscle tension
– Metabolic stress: Intramuscular energy depletion
– Muscle damage: Muscle fibre damage
Mechanical & metabolic stresses cause growth signalling due to 3 different types of responses:
Muscle Contractions
Hormone Response
Immune Response
ALL 3 RESPONSES QWORK TOGETHER TO PROMOTE MUSCHLE GROWTH
Exercise induced muscle hypertrophy facilitates 2 main “signalling pathways”
Protein Kinase pathway
Calcium Dependant pathway
Protein Kinase pathway
Particularly sensitive to eccentric exercise (DOMS)
– Specific proteins linked to a rapid rise in cell proliferation/repair
Calcium Dependant pathway
CDP’s linked to hypertrophy of ALL fiber types
– A lack of CDP’s shown to prevent muscle growth even if overload occurs
Muscle damage
• Muscle fiber damage = by-product of resistance training & mechanical
loading/stress
- Inflammatory response
- Upregulation of muscle protein synthesis
Muscle signalling
The primary driver of muscle hypertrophy in strength athletes is anincreased stimulation of myofibrillar protein synthesis .
Muscle Protein Synthesis > Muscle Protein Breakdown
Hormones signal and promote growth by:
Growth Hormone (GH)
– Testosterone (TST)
– Insulin-like Growth Factor (IGF)
Immune Response
•Mechanical stress à micro-trauma
• Immediate response from cytokines
– (umbrella term: cell signalling proteins)
• Neutrophil & Macrophage production:
– Neutrophil – circulating cells that are recruited by the blood to sites of inflammation
during acute bouts of exercise e.g: Resistance training
– Macrophage – found resting in the tissue. Once activated, they can secrete both
pro/anti-inflammatory cytokines
Optimal stimulus for hypertrophy is?
Session per muscle group per week?
2-3 sessions per muscle group per
week
4-6 training sessions per week
• Alternatively 2 sessions per day of 30-45 mins
• Helps counteract catabolism if diet is correct
Loading Parameters for Hypertrophy
Intensity 60-80% 1RM (up to 100%?)
Reps 8-12 RM
Sets 3-6
Rest Intervals 30-90 secs
Concentric Tempo 1-10 secs
Eccentric Tempo 4-10 secs
Total Set duration 20-70 secs
No of Ex’s per workout 3-6
No of Sets per workout 9-24
Example Program – Legs
Lift/Exercise | Sets | Repetitions | Load | Rest
Back Squat 3 10 70% 1RM 60 seconds
Deadlift 3 10 70% 1RM 60 seconds
Split Squat 3 8 each leg 70% 1RM 60 seconds
Romanian Deadlift 3 10 70% 1RM 60 seconds
Leg Press 3 10 70% 1RM 60 seconds
Calf Raises 3 10 70% 1RM 60 seconds
