The Frequency Factor
Frequency, or how often you train, is king. It's true for hypertrophy and even more true for strength. Researchers have found that training a muscle at a higher frequency is superior than a lower frequency. Hit each muscle a minimum of twice per week for maximum growth.
Keep in mind that some muscles can be significantly hit even when they're not the main focus of an exercise. The pecs will get trained by the close-grip bench press even if it primarily hits the triceps. So this doesn't mean that all muscles should be trained three times a week, but that they should at least be stimulated to some degree two or three days a week for maximum growth. Here's a sample:
- Monday: Pecs, upper back
- Tuesday: Lower body, quad dominant
- Wednesday: Off
- Thursday: Shoulders, biceps, triceps
- Friday: Off
- Saturday: Back, lower body (posterior chain dominant)
- Sunday: Off
With this split every muscle gets hit twice per week and the biceps get hit three times when you count the secondary stimulation they get on back days.
Look at the training frequency of elite lifters and athletes. Most train 4 or 5 days a week, with the exception of Olympic lifters whose sport requires more frequent skill practice. If these people – who have superior genetics and are in their prime – find that they're progressing optimally from 4-5 training days per week, what gives us the impression we can handle more?
Training 5 days per week or more is best used temporarily as an overreaching phase a couple weeks before a vacation, or for those with a non-stressful life. But someone who's under a lot of psychological stress or someone working a physical job should stick to 4 training days per week.
An intelligent training split can get you hitting every muscle group to some extent twice a week with just four weekly sessions. It would be possible to do so in three weekly sessions, but the daily workload might be too high, leading to a lower quality of work toward the end of the workouts.
They're important to maximize muscle growth, optimization of the glycogen stores, and neural recovery: all necessary for optimal workout performance which is necessary for muscle growth. A healthy immune and hormonal system requires rest days. The rest days and training schedule I recommend is:
- 2 days on
- 1 off
- 1 on
- 1 off
- 1 on
- 1 off