Minimum-Effective Resistance Training Doses

INTRODUCTION — NOT ENOUGH PEOPLE LIFTResistance training (RT) is reported to stimulate a variety of muscular adaptations such as endurance, hypertrophy, power, and strength (1). In addition, RT confers a myriad of health benefits that include reduced risk for chronic diseases (e.g., type 2 diabetes) and staving off negative consequences of aging (e.g., sarcopenia) (2). Despite these positive effects, most people are reluctant to partake in RT. Specifically, only ~20% of adults satisfy basic recommendations for RT — performing muscle-strengthening activity 2 days per week (3). There are many perceived barriers to participating in RT, but “uncertainty of how to properly use equipment” and “lack of time” are commonly reported (3). Thus, it is critical for exercise professionals to reinforce proper form when their clients perform RT, as well as inform them about the health and fitness benefits of RT. In addition, to help people save time in the gym, it is noteworthy that exercise professionals and researchers have recently explored the minimum-effective dose for RT (4). In this column, we will define “minimum-effective dose” as the lowest volume of RT that stimulates significant muscular adaptations (3,4). BIRD’S EYE VIEW — WHAT IS KNOWN ABOUT MINIMUM-EFFECTIVE DOSES? Based on the history of RT research and application, it seems like most people are focused on optimal training doses — what is the best prescription for volume, load, movement velocity, etc. Of course, this is understandable, because exercise professionals and their clientele are likely interested in maximizing returns (e.g., muscle hypertrophy) on their training investment. Given that ~80% of adults do not meet RT recommendations, a focus of research has emerged to identify the minimum-effective dose of RT for stimulating hypertrophy and strength (3,4). For example, three recent reviews (3–5) and one recent meta-analysis (6) have explored this issue, and exercise professionals are encouraged to read these additional resources to accompany this column. To streamline this column, we will discuss one review that focused on skeletal muscle hypertrophy (4) and another that focused on muscular strength (6). First, in a narrative review, Iversen et al. (4) established that the minimum-effective dose for stimulating skeletal muscle hypertrophy is 4 working sets, performed close to momentary failure, per muscle group per week. For more context, these 4 working sets should be executed with external loads that correspond with 6 to 15 repetitions per set. Second, in a meta-analysis, Androulakis-Korakakis et al. (6) identified that upper-body (e.g., bench press) and lower-body (e.g., back squat) strength can be increased with 2 to 3 working sets dedicated to a particular exercise per week. Further, these 2 to 3 working sets should be completed close to momentary failure with external loads that correspond with 70% to 85% 1 RM and 6 to 12 repetitions per set. To summarize, the minimum-effective dose for skeletal muscle hypertrophy may be 4 sets of 6 to 15 repetitions per muscle group per week (4), and the minimum-effective dose for strength may be 2 to 3 sets of 6 to 12 repetitions per exercise per week (6). Of course, these recommendations may not be perfect for every client, but they can provide exercise professionals with a minimum-effective dose baseline from which to build.Sidebar 1. Explaining the Repetitions in Reserve (RIR) Scale Quantifying set end point – which is generally described as proximity to momentary failure – is perhaps the most difficult RT variable to account for during a training session. If considered as a dichotomy, momentary failure (i.e., the point at which the lifter would fail to complete the concentric phase of the final repetition) is easier to determine than set end points that are considered “nonfailure” because the latter has such high variability. To address this issue, recent research in the set-end-point literature has developed the RIR scale to help exercise professionals determine proximity to momentary failure during RT sets. For instance, an RIR of 3 indicates that the lifter perceived themselves to be ~3 repetitions shy of momentary failure while an RIR of 1 would indicate being ~1 repetition shy of momentary failure. These examples are pertinent because recent studies have demonstrated that sets terminated with an RIR of 1 to 3 led to similar hypertrophy and strength as those completed to momentary failure. In summary, exercise professionals can apply the RIR scale to help control the intensity of effort during RT sessions.SINGLE-SET TRAINING — STRENGTHS AND WEAKNESSES In a manuscript focused on muscular strength, Nuzzo et al. (3) reviewed several low-volume, time-saving RT protocols including exercise snacks, practicing the test, and single-set training (SST). The rest of this column will focus on the latter technique. Single-set training is defined as performing one working set per exercise, which typically involves several exercises per session (7). An advantage of SST is that it stimulates positive adaptations, like hypertrophy and strength, with considerably short training sessions (e.g., 15 to 20 min) (8,9). These programs have proven effective in a variety of populations including young, trained lifters (8); young, untrained lifters (9); and older, healthy lifters (10). However, a potential disadvantage of SST is because the training volume is so low (i.e., one working set), it may require trainees to perform each set to momentary failure, or very close to it. Perhaps intuitively, training to momentary failure leads to significantly greater neuromuscular fatigue, perceived discomfort, and soreness when compared to nonfailure training (11). This information should be carefully considered by exercise professionals, because perceived discomfort and fear of injury/pain also are commonly cited as barriers to consistently performing RT, particularly in older adults (12). Thus, the execution of SST programs can be considered a conundrum — they address one barrier to RT, lack of time, while perpetuating another barrier to RT, perceived discomfort, pain, and soreness, because trainees perform each set to momentary failure. Although SST sessions are low volume, people with less training experience may still experience delayed onset muscle soreness (DOMS) due to the novelty of the resistance or physical stress imposed during a specific movement pattern. In a perfect world, people could perform SST programs without having to put forth maximal effort during every set, which could mitigate perceived discomfort, pain, and DOMS. Thankfully, results from a brand-new study by Hermann et al. (7) can help exercise professionals strike a balance between saving time in the gym without inflicting unnecessary strain on their clientele. We will discuss this study in the following section. BRAND-NEW RESEARCH — HERMANN ET AL., 2025 With a randomized-controlled trial, Hermann et al. (7) assigned a sample of young, healthy, resistance-trained subjects to train to momentary failure (FAIL) or to an estimation of two repetitions in reserve (2-RIR; Sidebar 1). Both groups partook in a total-body, SST program 2 days per week for 8 weeks, and a thorough description of the RT intervention can be found in Sidebar 2. Results indicated that both groups increased the muscle thickness of their biceps, quadriceps, and triceps, but FAIL may have been more effective for mid-quadriceps and triceps. Further, both groups significantly improved their lower- and upper-body strength, as well as their lower-body muscular endurance, with no differences detected between FAIL and 2-RIR. Lower-body power also was assessed via counter-movement jump height, and data revealed that both groups improved, but FAIL (+6%) may have been more effective than 2-RIR (+1.4%). In short, the study by Hermann et al. (2025) demonstrated that SST performed to FAIL and 2-RIR were both effective for stimulating muscular endurance, hypertrophy, power, and strength, but FAIL was potentially superior for hypertrophy and power. Perhaps most interestingly, these data were collected in a sample of lifters with an average training age of 4.4 years, suggesting that both low-volume approaches are still effective for people with considerable RT experience. This study helps answer the ominous “how low can you go” question with a clear, practical answer — SST across nine total-body exercises, twice weekly, with a set end point of 2-RIR (7). Several recommendations for practical application will be discussed at the end of this column.Sidebar 2. A Description of the Resistance Training (RT) Program Applied by Hermann et al. (7). - Volume: 1 working set per exercise. - Frequency: 2 days per week; total-body sessions. - Relative Intensity: external loads that corresponded with 8 to 12 repetitions per set. - Rest Intervals: 2 minutes between exercises. - Repetition Tempo: 2-second eccentric, 1-second concentric. - Exercises: lat pulldown, seated cable row, machine shoulder press, machine chest press, cable triceps pushdown, dumbbell biceps curl, smith-machine squat, leg press, and knee extension. - Set end point: momentary failure or 2 repetitions in reserve (i.e., nonfailure). Sidebar 3. A Training Template for a Total-body Single-Set Training Session. - Template Examples of Exercises 1. Total-body power 1. Medicine ball squat + chest pass 2. Knee dominant 2. Safety-bar squat 3. Upper pull 3. Seated cable row 4. Hip dominant 4. Romanian deadlift 5. Upper push 5. Dumbbell incline press 6. Single leg 6. Step-back lunges 7. Upper auxiliary 7. Band pull apart 8. Lower auxiliary 8. Calf raises 9. Core/Trunk 9. Pallof press isometric SUMMARY POINTS RT is a powerful intervention to improve fitness and health, but most people do not participate in RT programs. Thanks to a bevy of recent reviews, the minimum-effective dose for stimulating muscular adaptations is much lower than previously believed — 4 working sets per muscle group per week for hypertrophy and 2 to 3 working sets for strength. Single-set training is a simple application of minimum-effective dose RT that only requires 15 to 20 minutes in the gym per session. However, to date, the effectiveness of SST programs has only been observed when sets are performed to momentary failure, which may lead to undue physiological strain that prevents people from participating altogether. Fortunately, brand-new data from Hermann et al. (7) demonstrated that SST can be effective whether sets are completed to momentary failure or approximately two repetitions shy of momentary failure. This information can help exercise professionals better serve clients who are apprehensive about the stress imposed by RT, short on time, or both. Single-set training also may be perceived as an effective tool to apply to higher-trained lifters who wish to take a break from high-volume training while improving/maintaining their fitness. However, for lifters with more RT experience, it is worth noting that they will likely need multiple-set programs to achieve their desired fitness outcomes.Sidebar 4. An Example of Spreading Single-set Training Over a Week - Monday – Upper Push Wednesday – Upper Pull Friday – Lower Body 1. Bench press 1. Inverted row 1. Goblet squat 2. Incline press 2. Lat pulldown 2. Kettlebell deadlift 3. Push press 3. Cable row 3. Step ups 4. Pushups 4. Face pull 4. Hip thrust 5. Dumbbell raise 5. Band pull apart 5. Knee flexion 6. Dumbbell kick back 6. Hammer curl 6. Knee extension 7. Triceps push down 7. Preacher curl 7. Calf raises Message from Column Editor Zachary Mang, Ph.D. Since 2015, I have been immersed in the resistance training literature and have published studies on a variety of topics including circuit training, pyramid training, repetition tempo, and superset training. Better yet, my consumption of, and contributions to, the resistance training literature have always been coupled with its immediate application to the athletes and clients I worked with every day. This dichotomy in my professional career reflects the primary purpose of this column – to unpack exciting new topics in the resistance training literature while providing strategies to make the findings actionable for exercise professionals. Readers of this column should expect to learn the science behind a variety of resistance training techniques and to be equipped with practical application tips that can be used immediately with their clientele. This is an exciting opportunity for both of us, and I offer a humble and preemptive “thank you” to the reader for following along.PRACTICAL APPLICATION When to use SST. These programs are a great fit for people with lower fitness levels and/or lesser experience with RT who are easing into their training plan. On the other hand, SST can be applied to people with higher fitness levels and previous experience with RT who are taking a break from higher-volume training to facilitate recovery. It also may be applied to athletes as an in-season periodization strategy when RT volume is low and sport-practice volume is high. Last, SST can be more broadly applied to people of any fitness level or background who are short on time but still want to increase or maintain their muscular fitness. Structure of the session. The majority of SST studies have applied total-body sessions that target every major muscle group 2 to 3 days per week. This is a simple strategy to use, and a template for doing so is displayed in Sidebar 3. Alternatively, exercise professionals can split days dedicated to muscle groups (e.g., upper/lower or push/pull/legs), which would involve performing single sets across many exercises that target the same musculature (Sidebar 4). Load, effort, and rest. To satisfy the minimum-effective dose for hypertrophy and strength, select external loads that lead to 6 to 12 repetitions completed per set. These sets can be completed to momentary failure or approximately two repetitions shy of momentary failure. Every client is different, and their capacity to recover will vary based on age, sex, and training history, but allowing ~2 minutes of rest between exercises/sets should suffice. Alternatives to SST. Even if a client does not want to perform an SST program, exercise professionals should design training weeks that at least satisfy the minimum-effective dose for hypertrophy and strength. As discussed in this column, this can be accomplished with 4 working sets per muscle group for the former and 2 to 3 working sets per exercise of interest for the latter. These should be treated as the lowest effective training volumes that should be systematically increased as clients adapt or simply have more time to train.