Muscle hypertrophy is defined as an increase in the size of a muscle through an increase in the size of its component cells. There are two main types of hypertrophy: myofibrillar hypertrophy and sarcoplasmic hypertrophy. Myofibrillar hypertrophy increases muscle strength through adding more actins and myosin contractile proteins, while sarcoplasmic hypertrophy increases muscle size through added sarcoplasmic fluid but does not increase strength. Causes of hypertrophy include microtrauma to muscles from exercise, adequate muscular nutrition and protein intake, recruitment of more muscle fibers, genetic responses, and factors like age, gender, and levels of hormones like testosterone and growth hormone.

1. MUSCLE HYPERTROPHY
RAJINEESHWARAN G
1st - M.Sc
Exercise Physiology & Nutrition

2. DEFINITION
● Muscle hypertrophy is difined as, A
increase in the size of a muscle through
an increase a size of its component cells.
● Depending on the type training, the
hypertrophy can occur through
increased sarcoplasmic volume or
increased contractile proteins.

3. Types of hypertrophy
● Myofibrillar
● Sarcoplasmic

4. Myofibrillar
● Actins and myosin contractile proteins increase in
number and add to muscle strength as well as a small
increase in the size of the muscle.
● Myofibrillar hypertrophy is charecteristic of
“Powerlifters”.
● Denser and stronger muscles.

5. Sarcoplasmic
● The volume of sarcoplasmic fluid in the muscle cells
increases with no accompanying increase a muscular
strength.
● Sarcoplasmic hypertrophy is charecteristic of the
muscles of certain “Bodybuilders”.
● Bloted, soft and useless muscles.

6. Myofibrillar Sarcoplasmic

7. Causes of hypertrophy
● Age
● Microtrauma
● Muscle recruitment
● Muscular nutrition
● No of mitochondria
● Myoglobin protein
● Gender
● Contraction in contractile proteins
● Genetic responses

8. Microtrauma
● More the microtrauma more the increase in the size of
the muscle.
● It is the small injury in the muscle fibres.

9. Age
● Healing of microtrauma decreases
● Immunization process becomes slow
● Other co-operative systems becomes week

10. Muscle recruitment
● It may also be trimed as the neural recruitment.
● More the muscles are co-ordinated with the nervous
system more the will involve in the exercise which will
increase their size.

11. Muscular nutrition
● Protein in diet dominates the
hypertrophy as protein increases
the size o the muscle as it
fullfills the demand of the extra
protein in the muscle cells.

12. No.of mitochondria
● Mitochondria traps the ATP in the cells.
● More the mitochondria in the cells then
there will be more energy to serve the
active muscle cells so the sufficient
amount of ATP promote the
hypertrophy.

13. Myoglobin protein
● Myoglobin is a protein protein present
in the muscle which traps the
nutrition from the blood so . If there
is adiquate amount of protein the
there will be more of energy available
for the cell to increase their size.

14. Gender
● Males are tends to have more
hypertrophy then female because of
following reasons :
○ No of muscle fibres
○ Size of muscle fibres
○ Growth hormone

15. Growth hormone
● Males have dominance of the growth
hormone which promotes the
hypertrophy.
● Like Testosterone , Adranaline

16. Contraction in contractile proteins
● Only a high contraction in the
muscle fibres can promote
hypertrophy.

17. Genetic responses
● It is a still a controversial issue
and it's steps are not yet clear.
● In hypertrophy of the muscles
sone of the family the genes are
activated like C-FOS , C-JUN
and MYC.

18. Thankyou 😉