There are a hundred variations on this question.
Usually it's prefaced with 'I do cardio
3 times a week' or 'I do intense martial
arts training' or 'I'm just getting
started... so how often should I train?' The greatest single pitfall that bodybuilders and
other athletes fall into is accepting a flat, cookie
cutter answer to this question.
And I can hear that
awful standard no-brainer answer now... "You
should train three times a week." Bull. If you
want to distinguish yourself as a thinker amid a herd
of obedient sheep, read on.
The frequency that you, and everybody else, should
train with is variable. Not fixed. When you lift weights
as a means to develop more muscle the intensity of
your workouts has to progress upward. If it remains
at the same intensity there is no reason for new muscle
to grow. Show me a guy who has been lifting three
days a week for a year and I'll show you a guy
who hasn't changed his physique whatsoever for
at least ten months.
If you want to train efficiently and effectively
you have to understand the relationship between the
ever-increasing intensity of your workouts and the
ever-decreasing frequency of those workouts. As an
example, when a person is just starting out, he could,
indeed, train three times per week performing bench
presses and leg press of, say, 150 pounds and 350
pounds. But he should only lift those weights during
one workout.
On his second workout he might be hoisting
165 and 375 on those two lifts. On his third workout
they should increase again. (Or, if he just can't
get more weight off the pins, he should be increasing
the number of reps he performs. Something must increase.)
But soon a Monday will arrive where he either doesn't
feel like going to the gym (a sign of overtraining)
or he'll discover that he can't even lift
the weights he did last time. He's gotten weaker!
When this happens to most bodybuilders they decide
to 'try harder' in the form of more frequent
workouts, or switching to a new 'system'
or they head to the supplement store to buy something
that promises new muscle from a can. But all they
really need to do is adjust the frequency of their
training... allow more time for full recovery by
training twice per week for a few weeks. When the
problem shows up again they need to train once per
week or once every ten days... and so on.
Maybe your proverbial Monday arrived a long time
ago and you haven't seen changes in your physique
ever since. If so, do this: Take two weeks off of
all weight lifting. (No, you won't wither up.
I work with advanced trainees who train once every
six weeks.) When you return to the gym make sure to
increase the weight on every lift you perform. Then
cut your training frequency in half and try to get
increases every trip to the gym. So if you've
been training once every three days, change it to
once every six days. As soon as your intensity goes
up you'll feel that new muscle growing and soon
see the changes you've been wanting.