The Biology of Muscle Growth

The sheer number of articles, opinions, magazines andbut rather the size increases. As you work out, your
experts on fitness and muscle growth makes themuscles are subjected to microtrauma, where small
field of weight lifting appear more like the practice oftears appear in the muscle tissue. These tears signal
medicine in the 16th century than a concrete science.what are called the 'satellite cells' on the surface of
Every day new theories, approaches and miracleyour muscle to activate and multiply and go to the
workouts appear, contradicting each other anddamaged sites where they fuse with the existing
proclaiming that they have the truth, and that bymuscle fiber, helping them regenerate.
following their advice you will achieve the body ofWhile the satellite cells are multiplying and fusing with
your dreams. Clearly, some of them are on the rightthe damaged areas, your immune system kicks in
track and some are not, but how to tell thewith a complex series of reactions that ultimately
difference between them all? The answer lies inlead to inflammation meant to contain and repair the
understanding the basics of the biological process ofdamage as well as clean up the area of waste
muscle growth. Once you know some key principles,products. This process if key not only to the health
you will be better equipped to evaluate whether aof the muscle, but its growth, as numerous
new exercise routine is based on sound physicalhormones and cytokines are released which stimulate
principles-or completely bogus.muscle hypertrophy. Among these are hormones like
The most basic principle to understand is that yourinsulin-like growth factor (IGF), fibroblast growth
muscles adapt to whatever stress they arefactor (FGF) and hepatocyte growth factor (HGF).
subjected to. If you spend all day on the couch, thenGrowth hormone (GH) is also released, and is key to
you will be in possession of a fine set of musclespromoting satellite cell division and the release of IGF.
equipped for couch sitting. If you jog forty minutesWhat is important to understand is that this entire
each day, than your body will adapt to that. If youprocess (microtrauma resulting in the complex
always follow the same number of reps and sets andinteraction of satellite cells, the immune system,
routine when weight lifting, then your body will adaptgrowth factors and hormones) is dependent not only
to that too. And once you've adapted, your systemon exercise, but also receiving the appropriate
will stop growing, and simply rest at this new plateau,amount of rest and nutrition to optimize the healing
having achieved the bare minimum required toprocess. Muscular hypertrophy occurs when the
function at that level. Therefore the basic idea is thatmuscle heals itself, not when you are working out.
if you want growth, you need to continuouslyFurthermore, your muscles will only adapt as much as
overload your system.they need to, resulting in a 'plateau' effect if you
The result of progressively overloading your musclesdon't change things up and challenge them in new
is called muscular hypertrophy, and that is theways. This is why it is a good idea to switch up your
increase in muscle mass and cross-sectional area.exercise routines like they do in P90X, and always
Note that the number of muscle cells does notkeep your body guessing as to what comes next.
increase ( a phenomenon called muscular hyperplasia),