When designing a resistance training program aimed at maximizing hypertrophy, the question of whether to use split training or full body workouts is one of the most hotly debated. Each method has its proponents and advantages, but the key consideration for most individuals is simple: which builds muscle faster?
In this article, we break down the science behind both training modalities, examine the research comparing them, and help determine which approach may be more effective for maximizing muscular development.
Understanding Split Training and Full Body Workouts
What is Split Training?
Split training involves dividing the body into separate muscle groups and training each group on different days. Common splits include upper/lower body splits, push/pull/legs, or even more targeted body-part splits like chest on Monday, back on Tuesday, legs on Wednesday, and so forth. This allows for higher training volume and intensity per muscle group per session.
What is a Full Body Workout?
Full body training involves working all major muscle groups in a single session, typically performed three times per week. These workouts are generally characterized by compound movements such as squats, deadlifts, presses, and pulls that engage multiple muscle groups at once.
Frequency and Muscle Growth
Training Frequency’s Role in Hypertrophy
Muscle protein synthesis (MPS), the process by which the body repairs and builds muscle tissue, is elevated for approximately 24–48 hours following resistance training (MacDougall et al., 1995; Damas et al., 2016). Given this window, stimulating a muscle more frequently may lead to a greater overall accumulation of MPS throughout the week, potentially leading to faster muscle growth.
A meta-analysis by Schoenfeld et al. (2016) found that training each muscle group at least twice per week resulted in significantly greater hypertrophy compared to once per week. This finding favors full body workouts or higher-frequency splits over traditional bro splits where muscles may only be trained once per week.
Training Volume and Intensity
Volume is Key
Training volume, defined as sets x reps x load, is one of the most critical variables for hypertrophy (Schoenfeld et al., 2017). A study by Radaelli et al. (2015) demonstrated that higher weekly volume led to greater increases in muscle cross-sectional area.
Split training allows for more volume per muscle group per session, potentially leading to greater per-session stimulus. However, excessively high volume in a single session can result in diminishing returns due to fatigue, impacting performance and recovery (Spiering et al., 2008).
Intensity and Load Distribution
Full body workouts often limit the volume per muscle group due to time constraints but allow for higher frequency. This creates a more even distribution of training stress and may be more sustainable for long-term progression. Split routines may offer better conditions for targeting specific muscles with higher loads and intensity in a given session.
Recovery and Adaptation
Recovery is a major factor in hypertrophy. Training a muscle too frequently without adequate recovery can impair performance and growth. Conversely, waiting too long between sessions (as with once-per-week bro splits) can reduce the frequency of hypertrophic stimuli (Schoenfeld, 2010).
Research by Bickel et al. (2011) suggests that older individuals especially benefit from more frequent stimulation due to slower recovery and reduced anabolic signaling. Full body training may thus offer advantages for both novice lifters and aging populations by maintaining consistent stimulation.
Hormonal Responses and Muscle Growth
Although transient hormonal increases (e.g., testosterone, growth hormone) have been thought to drive hypertrophy, more recent evidence suggests these spikes do not directly correlate with muscle growth (West & Phillips, 2012). Nevertheless, full body training often elicits a larger acute hormonal response due to the greater overall stress imposed during each session (McCaulley et al., 2009).
This systemic stress may be beneficial for novice trainees by stimulating whole-body adaptation. However, the importance of local muscle-specific tension and mechanical overload remains the primary driver of hypertrophy, not transient hormonal changes.
Practical Application and Program Adherence
Time Constraints and Efficiency
Full body workouts are generally more time-efficient and better suited to those who can train only 2–3 times per week. Split routines are more appropriate for individuals with more time and the ability to train 5–7 days per week.
Adherence and Enjoyment
Sustainability is a key determinant of long-term progress. A program that aligns with the trainee’s schedule, preferences, and recovery capacity is more likely to be followed consistently. Research has shown that enjoyment and autonomy are strongly linked to adherence and long-term success (Teixeira et al., 2012).
Experience Level and Training Background
Beginners typically benefit more from full body routines due to their lower strength levels, faster recovery, and need for frequent practice of compound movements. A study by Candow & Burke (2007) found that untrained subjects experienced greater strength gains with full body training.
Advanced trainees may require higher training volumes and more isolation work to continue progressing, which split routines accommodate more effectively. This doesn’t imply that full body training is ineffective for advanced lifters, but managing fatigue and volume becomes more complex.
Summary of Research Findings
- Frequency matters: Training a muscle more than once per week promotes greater hypertrophy (Schoenfeld et al., 2016).
- Volume is crucial: Total weekly volume is a primary driver of hypertrophy (Schoenfeld et al., 2017).
- Full body training offers higher frequency and systemic stress, benefiting beginners and those with limited training time.
- Split training allows higher volume per session and more targeted work, suiting advanced trainees with more recovery capacity.
- Adherence to the chosen program significantly influences results.
Conclusion
So, which builds muscle faster? The answer depends on the individual’s training age, schedule, and goals. For beginners and intermediates, full body training performed 3 times per week provides optimal frequency, efficient use of time, and consistent stimulus for hypertrophy. For advanced lifters, split routines may allow for higher per-muscle volume and focused progression. Ultimately, the most effective program is the one that maximizes weekly volume and frequency while allowing for adequate recovery and long-term adherence.
Key Takeaways Table
References
Bickel, C. S., Cross, J. M., & Bamman, M. M. (2011). Exercise dosing to retain resistance training adaptations in young and older adults. Medicine and Science in Sports and Exercise, 43(7), 1177-1187.
Candow, D. G., & Burke, D. G. (2007). Effect of short-term equal-volume resistance training with different workout frequency on muscle mass and strength in untrained men and women. Journal of Strength and Conditioning Research, 21(1), 204-207.
Damas, F., Phillips, S. M., Libardi, C. A., Vechin, F. C., Lixandrão, M. E., Jannig, P. R., … & Ugrinowitsch, C. (2016). Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage. Journal of Physiology, 594(18), 5209-5222.
MacDougall, J. D., Gibala, M. J., Tarnopolsky, M. A., MacDonald, J. R., Interisano, S. A., & Yarasheski, K. E. (1995). The time course for elevated muscle protein synthesis following heavy resistance exercise. Canadian Journal of Applied Physiology, 20(4), 480-486.
McCaulley, G. O., McBride, J. M., Cormie, P., Hudson, M. B., Nuzzo, J. L., Quindry, J. C., & Travis Triplett, N. (2009). Acute hormonal and neuromuscular responses to hypertrophy, strength and power type resistance exercise. European Journal of Applied Physiology, 105(5), 695-704.
Radaelli, R., Fleck, S. J., Leite, T., Leite, R. D., Pinto, R. S., Fernandes, L., & Simão, R. (2015). Dose-response of 1, 3, and 5 sets of resistance exercise on strength, local muscular endurance, and hypertrophy. Journal of Strength and Conditioning Research, 29(5), 1349-1358.
Schoenfeld, B. J. (2010). The mechanisms of muscle hypertrophy and their application to resistance training. Journal of Strength and Conditioning Research, 24(10), 2857-2872.
Schoenfeld, B. J., Ogborn, D., & Krieger, J. W. (2016). Effects of resistance training frequency on measures of muscle hypertrophy: A systematic review and meta-analysis. Sports Medicine, 46(11), 1689-1697.
Schoenfeld, B. J., Ogborn, D., & Krieger, J. W. (2017). Dose-response relationship between weekly resistance training volume and increases in muscle mass: A systematic review and meta-analysis. Journal of Sports Sciences, 35(11), 1073-1082.
Spiering, B. A., Kraemer, W. J., Anderson, J. M., Armstrong, L. E., Nindl, B. C., Volek, J. S., & Maresh, C. M. (2008). Resistance exercise biology: Manipulation of resistance exercise programme variables determines the responses of cellular and molecular signaling pathways. Sports Medicine, 38(7), 527-540.
Teixeira, P. J., Carraca, E. V., Markland, D., Silva, M. N., & Ryan, R. M. (2012). Exercise, physical activity, and self-determination theory: A systematic review. International Journal of Behavioral Nutrition and Physical Activity, 9(1), 78.
West, D. W., & Phillips, S. M. (2012). Anabolic processes in human skeletal muscle: Restoring the identities of growth hormone and testosterone. Physiology, 27(4), 233-241.
