What is Most Effective for Muscle Growth: Split Training or Full Body Workout?

Increasing muscle mass and strength are important training goals for many people. Not only for cosmetic reasons but for health reasons as well, people seek to increase their muscle mass. A much used method to increase muscle mass more effectively, a process also known as hypertrophy, is using a split training program. In a split training program only a few muscle groups are trained every workout. This allows more exercises per muscle group which increases the training stimulus to the muscle compared with performing just one exercise per muscle group.

Unfortunately there has been little research comparing split training with a comparable full body workout up until now. However the following advantages and disadvantages are theoretically supported.

Advantages Split Training in comparison with Full Body Workout

-A stronger and more complete training stimulus per muscle group. As a result of combining multiple exercises in one training session, a larger part of the muscle is targeted which results in a larger number of muscle fibers that need to adapt.

-It allows for a higher training frequency. When the increase in muscle mass from a Full Body workout performed 3 times a week is not sufficient, it is a bad idea to perform this workout 4 times a week or more. This will not allow the muscle to recuperate and increase its’ size. A split training regimen, if designed properly, even allows daily training. While muscle groups that have been trained in a previous workout are allowed to recover.

Disadvantages compared in comparison with Full Body Workout

-It is less suitable for beginners. The training intensity is often too high for relatively untrained muscles. Moreover, most beginners will have a hard time reaching the necessary training intensity at all, since they still have to learn to activate their muscles to a larger extent. When they can’t reach the necessary training intensity, split training often offers few advantages.

-It requires a higher training frequency to train all muscle groups regularly. Ideally muscles are trained when they are fully recuperated and adapted to the previous training stimulus. For optimal results it is recommended to train every muscle group two times a week. When a split training is performed two times a week, the muscle will have recovered by the time it is trained again, but the training adaptations will probably have disappeared as well.

-Smaller increases in growth hormone and testosterone production. The increase in hormone production is strongly dependent on the amount of muscle mass that is active during training. Since split training targets a few muscle groups each training, the hormonal response on training is smaller. Recent studies have shown that this hormonal response is not a requirement of muscle growth. However, it is likely that growth hormone production has other beneficial effects, such as stimulating fat metabolism. A full body workout is probably more effective in this aspect.

Conclusion:

Using a split training regimen has both advantages and disadvantages. Moreover, no studies comparing both split training and full body workouts have been performed. However a split training allows for a higher training frequency and a more complete workout for each muscle group, while other muscle groups are allowed to recover.

References:

-Kraemer, W.J., Ratamess, N.A. Fundamentals of Resistance Training: Progression and Exercise Prescription. Medicine & Science in Sports & Exercise 2004, 36, 4, 674-688.

-Wescott, W.L. How Often Should Clients Perform Strength Training? ACSM’s Certified News 2010, 20, 2, 10-11.