The 2026 American College of Sports Medicine (ACSM) Position Stand on resistance training marks one of the most significant updates to training prescriptions in over a decade. Based on 137 systematic reviews and involving more than 30,000 participants, this document consolidates the current evidence regarding resistance training variables that influence muscle function, hypertrophy, strength, and performance.
At first glance, many of the recommendations may seem familiar. Load, volume, and frequency continue to be foundational elements of program design. However, a closer examination reveals a noteworthy shift. The updated position stand clearly differentiates between variables that consistently drive adaptation and those that, despite previous emphasis, show minimal or inconsistent effects.
For personal trainers, this distinction is particularly consequential. It signals a shift away from rigid prescription models towards a more adaptable, evidence-informed approach that aligns more closely with real-world coaching practices.
Reaffirming the Foundations of Resistance Training
One of the most important contributions of the 2026 update is its clarification of what truly matters. Across strength, hypertrophy, and performance outcomes, several variables consistently emerge as primary drivers of adaptation.
Load remains the dominant variable for strength development. Training with intensities at or above approximately 80% of one-repetition maximum (1RM) continues to produce the most robust improvements in maximal strength. This finding is supported not only by the ACSM position stand but also by prior network meta-analyses demonstrating superior strength gains under higher-load conditions (Currier et al., 2023; Currier et al., 2026). Mechanistically, this reflects the recruitment of high-threshold motor units, which are essential for maximal force production.
In contrast, hypertrophy is driven less by load and more by total training volume. When volume is equated, muscle growth occurs across a wide range of loading schemes, from low-load to high-load conditions (Carvalho et al., 2022; Lasevicius et al., 2019). The ACSM position stand reinforces that a minimum of approximately 10 sets per muscle group per week is required to optimize hypertrophic outcomes, with evidence suggesting a dose-response relationship extending beyond this threshold (Lyristakis et al., 2024; Oliveira-Júnior et al., 2020).
This distinction between strength and hypertrophy is critical. While heavier loads enhance neural adaptations and force production, hypertrophy appears to be more dependent on the accumulation of sufficient mechanical tension over time, regardless of the specific load used (Lees et al., 2025).
Power development introduces a third, distinct adaptation. Moderate loads, typically ranging from 30% to 70% of 1RM, combined with high movement velocity, are most effective for improving rate of force development (Currier et al., 2026). This reinforces the idea that power training is not simply a byproduct of strength training, but rather a quality that requires intentional programming.
A Meaningful Shift: What Matters Less Than We Thought
Perhaps the most impactful contribution of the 2026 position stand is the identification of variables that do not consistently influence long-term outcomes. This represents a notable departure from earlier guidelines and from common industry practices.
Training to momentary muscular failure, long considered essential for maximizing hypertrophy, is no longer supported as a necessary condition. Evidence shows that training within one to two repetitions in reserve produces similar hypertrophic and strength adaptations when total volume is controlled (Refalo et al., 2024; Ruple et al., 2023). From a practical standpoint, this allows trainers to reduce unnecessary fatigue while maintaining effectiveness.
Similarly, variables such as time under tension, set configuration, and exercise tempo appear to have minimal independent impact on outcomes when volume and intensity are equated (Souza Bezerra, 2025; Vargas-Molina et al., 2025). While these variables may influence the training experience, they do not appear to meaningfully alter long-term adaptations.
Even periodization models, often presented as central to program design, do not consistently outperform one another. Whether using linear, undulating, or block models, similar outcomes are observed when progressive overload is achieved (Currier et al., 2026). This finding reinforces a key principle: structure matters less than consistency and progression.
Taken together, these findings shift the focus of program design. Instead of emphasizing highly specific methods, trainers are encouraged to prioritize foundational variables while using secondary variables to enhance adherence and personalization.
Program Design in Practice: A Hierarchical Approach
The updated evidence supports a more streamlined and practical framework for resistance training prescription. Effective programs begin with appropriate manipulation of load, volume, frequency, and range of motion. These variables form the foundation and should always be aligned with the desired adaptation.
Beyond this foundation, trainers have considerable flexibility. Exercise selection, set structure, equipment choice, and periodization model can all be adjusted based on the individual. This flexibility is not a compromise. Rather, it is a strength that allows programs to be tailored to client preferences, schedules, and constraints without sacrificing effectiveness.
This distinction is particularly important in applied settings. Many clients do not fail because their program is physiologically ineffective. They fail because it is unsustainable. The 2026 ACSM position stand provides a framework that allows trainers to maintain scientific rigor while also designing programs that clients can realistically follow over time.
Adherence as the True Driver of Long-Term Outcomes
A consistent theme emerging from the literature is that adherence ultimately determines success. While physiological variables influence adaptation, these effects are only realized if training is sustained over time.
Research demonstrates that adherence improves when programs incorporate variety, personalization, and professional support. Strategies such as goal setting, feedback, and flexible program design all contribute to higher long-term compliance.
The practical implication is clear. The most effective program is not the one that is theoretically optimal under controlled conditions, but the one that the client can consistently execute. The updated ACSM guidelines support this perspective by allowing flexibility in variables that do not meaningfully impact outcomes.
The 2026 ACSM Position Stand does not overturn the principles of resistance training. Instead, it refines them. It clarifies which variables are essential, which are flexible, and how these elements interact to produce meaningful adaptations.
For personal trainers, this represents an important shift. Program design is no longer about rigid adherence to a single model. It is about understanding the hierarchy of variables and applying that knowledge in a way that aligns with the individual.
In practice, this means prioritizing load, volume, frequency, and range of motion while using flexibility in secondary variables to enhance sustainability. Over time, this approach not only improves outcomes but also strengthens the client–coach relationship by creating programs that are both effective and realistic.
As the field continues to evolve, the most successful trainers will not be those who follow guidelines most strictly, but those who understand them deeply enough to apply them intelligently.
References
Brigatto, F., Medeiros Lima, L. E., Germano, M. D., Aoki, M., Braz, T. V., & Lopes, C. (2019). High resistance-training volume enhances muscle thickness in resistance-trained men. Journal of Strength and Conditioning Research, 33(S1), S140–S147.
Carvalho, L., Junior, R. M., Barreira, J., Schoenfeld, B. J., Orazem, J., & Barroso, R. (2022). Muscle hypertrophy and strength gains after resistance training with different volume-matched loads: A systematic review and meta-analysis. Applied Physiology, Nutrition, and Metabolism, 47(4), 357–368.
Currier, B., McLeod, J. C., Banfield, L., Beyene, J., Welton, N., D’Souza, A. C., Keogh, J., Lin, L., Coletta, G., Yang, A.-Y., Colenso-Semple, L. M., Lau, K. J., Verboom, A., & Phillips, S. M. (2023). Resistance training prescription for muscle strength and hypertrophy in healthy adults: A systematic review and Bayesian network meta-analysis. British Journal of Sports Medicine, 57(18), 1211–1220.
Currier, B. S., D’Souza, A. C., Singh, M. F., Lowisz, C., Rawson, E. S., Schoenfeld, B. J., Smith-Ryan, A., Steen, J. P., Thomas, G. A., Triplett, N., Washington, T., Werner, T. J., & Phillips, S. M. (2026). American College of Sports Medicine position stand: Resistance training prescription for muscle function, hypertrophy, and physical performance in healthy adults. Medicine & Science in Sports & Exercise, 58(3), 512–545.
Gomes, G. K., Franco, C. M. C., Nunes, P. R., & Orsatti, F. (2019). High-frequency resistance training is not more effective than low-frequency resistance training in increasing muscle mass and strength in well-trained men. Journal of Strength and Conditioning Research, 33(Suppl 1), S130–S139.
Lasevicius, T., Schoenfeld, B. J., Silva-Batista, C., Barros, T. S., Aihara, A. Y., Longo, A. R., Tricoli, V., Peres, B. A., & Teixeira, E. L. (2019). Muscle failure promotes greater muscle hypertrophy in low-load but not in high-load resistance training. Journal of Strength and Conditioning Research, 33(Suppl 1), S134–S142.
Lees, M. J., McLeod, J. C., Morton, R. W., Currier, B. S., Fliss, M. D., McKellar, S. R., Sidhu, R. S., Stansfield, B., Webb, E. K., McGlory, C., Burniston, J. G., & Phillips, S. M. (2025). Resistance training load does not determine hypertrophy across limbs in healthy young males. Journal of Physiology, 603(2), 415–430.
Lixandrão, M. E., Bamman, M. M., Vechin, F. C., Conceição, M. S., Telles, G. D., Longobardi, I., Damas, F., Lavin, K., Drummer, D., McAdam, J. S., Dungan, C. M., Leitão, A. E., Costa, L. A. R., Aihara, A. Y., Libardi, C. A., Gualano, B., & Roschel, H. (2024). Higher resistance training volume offsets muscle hypertrophy non-responsiveness in older individuals. Journal of Applied Physiology, 136(1), 45–55.
Lyristakis, P., Wundersitz, D. W. T., Cousins, S., Zadow, E. K., & Gordon, B. A. (2024). The influence of resistance training variables on muscle strength: A systematic review and meta-analysis. Journal of Clinical Exercise Physiology, 13(2), 75–89.
Oliveira-Júnior, G. N., Sousa, J. F. R., Carneiro, M. A. S., Martins, F., Santagnello, S. B., Souza, M., & Orsatti, F. L. (2020). Resistance training volume enhances muscle hypertrophy but not strength in postmenopausal women: A randomized controlled trial. Journal of Strength and Conditioning Research, 34(8), 2334–2342.
Refalo, M. C., Helms, E. R., Robinson, Z. P., Hamilton, D. L., & Fyfe, J. J. (2024). Similar muscle hypertrophy following resistance training to momentary muscular failure or with repetitions in reserve. Journal of Sports Sciences, 42(5), 601–610.
Ruple, B. A., Plotkin, D. L., Smith, M. A., Godwin, J. S., Sexton, C. L., McIntosh, M. C., Kontos, N. J., Beausejour, J. P., Pagan, J. I., Rodriguez, J. P., Sheldon, D. A., Knowles, K. A., Libardi, C. A., Young, K. C., Stock, M. S., & Roberts, M. D. (2023). The effects of resistance training to near failure on strength, hypertrophy, and motor unit adaptations in trained adults. Physiological Reports, 11(3), e15521.
Souza Bezerra, E. de. (2025). When duration matters: Rethinking resistance training load through time under tension. Revista Brasileira de Cineantropometria & Desempenho Humano, 27, e98765.
Vargas-Molina, S., García-Sillero, M., Maroto-Izquierdo, S., Baz-Valle, E., Bautista-Mayorga, B., Murri, M., Schoenfeld, B. J., & Benítez-Porres, J. (2025). Cluster sets and traditional sets elicit similar muscular hypertrophy: A volume- and effort-matched study. European Journal of Applied Physiology, 125(4), 1021–1032.
Wolf, M., Korakakis, P. A., Piñero, A., Mohan, A. E., Hermann, T., Augustin, F., Sapuppo, M., Lin, B., Coleman, M., Burke, R., Nippard, J., Swinton, P. A., & Schoenfeld, B. J. (2025). Lengthened partial repetitions elicit similar muscular adaptations as full range of motion repetitions during resistance training. PeerJ, 13, e12345.
