Unbeknownst to the average person looking to build significant muscle mass, muscle recovery time is one of the three most important factors in muscle growth, setting aside training and diet for a moment.
Even if you’re training correctly using proper form, increasing the weight and resistance at each workout, without adequate time given for muscle recovery then your efforts in the gym will be fruitless.
You probably know people who hit the gym every day, and if they aren’t using illegal substances that damages (and enlarges) their internal organs, then you also know that they aren’t growing whatsoever, despite the hard effort and time spent lifting iron.
Bodybuilding often appears counter-intuitive until you learn the science behind the bulk. Generally most people assume that the more time spent lifting weights and the more often you do it, the more muscle growth they will see. This is a widely held belief amongst those outside of bodybuilding.
Damaged muscle fibres require time to recover after each workout, else they cannot repair and re-build in numbers, which equates to more strength and size. Providing sufficient recovery time is incorporated in to your program and your diet is feeding the nutrients your body requires, then muscle growth will happen. People need to understand that they will be doing their bodies a favour by leaving their muscles alone. Training every day will not get the results you desire. Alternating between workouts and rest days will.
I advocate a beginner trains 3 major muscle groups per week, allowing a full 6 days in-between working each group, splitting the program in to Monday, Wednesday and Friday, for example. This means you could train your legs on Monday, and not touch them again until the following Monday, allowing 6 days of recovery time.
As time goes on and the resistance (more weight) you add at each workout becomes less, you can reduce your recovery time down to 3 days, or 72 hours. This is because your muscles require less time to build new muscle that can handle the slightly heavier load. As a beginner your muscles will be heavily taxed and require an entire week to recovery and rebuild.
The good news is that as a beginner, this is where you will see the best growth – you will grow far quicker resting your muscles for 6 days than someone a year in to their training whose recovery time is only 3 days.