Before we can answer the question, “how often should you train a muscle,” a few factors need to be considered.
What is optimal for a beginner would be detrimental for an advanced lifter.
When you’re a newbie, progressive overload and frequency are two of the most important factors in building muscle.
The more frequently you can train a muscle, while stimulating strength gains and without exceeding your capacity to recover, the more muscle you’ll build.
This is no different than any other physical quality that you would like to improve in life.
Want to become a better hitter? Go to the batting cage more frequently.
Want to become a better shooter? Get on the hardwood and knock down 100+ jumpers every day.
Whenever you want to get better at something the answer is always to do it more often.
So if you are new to strength training you should train more frequently.
Like the ability to hit a fastball, strength development is a skill.
You have to teach your muscles and your central nervous system to work in synchronicity so that you can contract harder during a set.
By contracting harder and producing more tension you’ll get stronger and be able to lift heavier weights. When you can lift heavier weights you’ll get bigger (as long as you’re following a proper muscle building diet).
It’s a simple formula that is often overlooked.
All that being said, beginners will get their best results training each muscle group three times per week. Three full body workouts is a standard that has stood the test of time. It always works.
But it only lasts so long.
When you advance beyond your first year or two you can and should split the workouts up into upper body and lower body days. Intermediates get great results training each muscle group twice per week.
That schedule will take you through your next few years of training. And truthfully, you might want to stick with that forever. A lot of the biggest, strongest lifters in the world do.
I love an upper/lower/upper split for almost everyone. Then I add in one hard conditioning workout on the weekend. That qualifies as your second lower body workout. Or I may add in some easy bodyweight based lower body stuff you could do at home in 20 minutes with no equipment.
But everyone is different and some might tend to break down sooner than others.
The stronger you get the more demand you place on your body. That’s because your nervous system is capable of recruiting more muscle fibers and making your muscles contract harder. It’s also because the greater weights being lifted (with more intensity) take more out of your entire system.
The increased loads also take a toll on your joints and spine. So you might need to start to take more rest between muscle groups or movement patterns as you get more advanced.
As a more experienced lifter, with more than 3-5 years of proper training under your belt (especially those of you over 40), you may have to reduce your frequency even more. For guys at this advanced level of strength and development, training a body part once every 5-7 days is can be very beneficial.
That means you could spread your upper and lower body days out over the course of nine days instead of seven. So one week you do lower body twice and upper body once. The following week you do upper body twice and lower body once.
Here’s how that looks over the course of two weeks:
Monday- Upper Body
Wednesday- Lower Body
Friday- Upper Body
Monday- Lower Body
Wednesday- Upper Body
Friday- Lower Body
Another option is to do a push, pull, lower split. Many big, strong guys are able to train this way with relatively few injuries well into their golden years.
To hit four hard strength training days per week everything has to be really dialed in. You have to manage stress properly, sleep a lot and eat well. If you don’t have all that perfected I’d stick with three training days per week.
To sum it up and simplify here is what I recommend for most guys (keeping strength training at three days per week, plus 1-2 hard conditioning days):
Advanced/older guys– Push/pull/lower
And that’s a wrap.
For fully detailed training plans at every level check out The Renegade Strength Club.