This article is a sub-topic of a comprehensive research review:

• Endurance Training: Evidence-based Model

Strength Endurance Adaptations Are Specific

It would not be entirely inaccurate to argue that “strength endurance” is not a distinct training goal. Although certain physiological adaptations can increase fatigue resistance and the ability to sustain force production, evidence suggests that endurance adaptations are load-specific and velocity-specific, and potentially exercise-specific. “Strength endurance” is often defined as the ability to lift submaximal loads for more repetitions. However, due to the specificity of adaptation, it cannot be narrowly defined as simply performing lighter loads for more repetitions. A more accurate definition may consider “strength” and “endurance” as points on a continuum of shared acute variables, adjusted to match the client’s goal.

Practically, if the goal is to perform more repetitions with a heavy load, training must include attempts to increase repetitions at that load. Additionally, increasing maximal strength can contribute to endurance, but optimizing performance with lighter loads requires dedicating some training time to improving repetition performance with those lighter loads. For example, if the goal is to increase bench press performance from 7 reps per set at 225 lb to 12 reps per set at 225 lb, performing sets of 155 lb for 15 to 20 repetitions is unlikely to result in significant improvements at 225 lb. Conversely, if the goal is to perform 155 lb for 20 reps per set, training primarily with 7 to 10 reps per set at 225 lb is also unlikely to yield optimal outcomes. The same logic applies to repetition tempo, contraction velocity, and, potentially, the exercise selected.

Repetition Range and Aerobic Performance

The available research also suggests that the repetition range has little influence on the aerobic benefits derived from resistance training. Studies comparing heavier-load, lower-repetition training to lighter-load, higher-repetition training suggest that both approaches may similarly improve aerobic outcomes, including peak oxygen uptake, work capacity, and time to exhaustion. These findings should temper the assumption that aerobic endurance athletes require a dedicated, high-repetition “strength endurance” phase to achieve the full conditioning benefits of resistance training.

This does not mean higher repetition work is never appropriate. There may still be practical reasons to use it, including tolerance, joint comfort, total volume management, or sport-specific demands. However, the evidence does not appear to support the belief that lighter loads and higher repetition resistance training are uniquely superior for improving aerobic endurance.

Strength Endurance is Load and Velocity Specific

As noted above, the research suggests that endurance is likely load-specific. When endurance is tested with lighter loads, lighter load training tends to produce the greatest improvements. When endurance is tested with heavier loads, heavier load training tends to produce better outcomes. This point is easy to miss because “endurance” sounds like a general adaptation. In practice, it is better understood as the capacity to sustain performance under a particular set of conditions.

Strength endurance improvements may also be specific to repetition tempo and contraction velocity. Research suggests that slower training may improve strength across a broader range of velocities, and slower tempos that increase time under tension may result in larger improvements in endurance. However, faster repetition tempos, for example, maximum velocity concentric contractions, appear to produce more velocity-specific adaptations, including improved peak velocity.

When these points are considered together, it cannot be suggested that there is one ideal set of acute variable ranges that is “best” for strength endurance. Further, a generic “endurance block” may not be specific enough to be ideal for many intermediate and advanced exercisers. Instead, strength endurance training should likely be viewed as a modification of strength training variables that emphasizes the type of endurance most relevant to the individual’s goals.

Why Drop Sets Complicate the Need for Endurance Days

• Definition - Drops Sets : Performing a set with repetitions-to-failure, followed by an immediate reduction in load and a continuation (without rest) of repetitions-to-failure, and potentially 1 or 2 more decreases in load ("drops") with repetitions-to-failure.

Drop sets may further reduce the need for separate endurance-focused work. A drop set starts with a relatively heavy load, then reduces the load and continues for additional repetitions. Practically, this combines heavy loads and lighter loads, potentially attaining both maximum strength and endurance benefits. Several studies suggest that drop-set protocols may improve endurance as well as, or better than, conventional set structures. This is particularly relevant for advanced exercisers who already tolerate multiple hard sets per muscle group and would benefit from efficient ways to increase training density. And, for advanced exercisers , this may provide a more efficient strategy for incorporating strength and endurance goals.

This should not be interpreted as a recommendation to replace conventional programming with drop sets. Rather, drop sets may be best viewed as a progression, one that can increase endurance while preserving exposure to heavier loads. For many advanced clients, that may be enough to reduce the value of standalone endurance training..

Why “Endurance Phases” May Be Overemphasized

Because endurance is likely to be specific to the demands imposed, dedicating an entire training phase to “endurance work” may warrant reconsideration. This does not mean that lighter loads, higher repetitions, or slower tempos have no role. However, an endurance phase built around lighter loads and higher repetitions is not guaranteed to elicit adaptations specific to the exerciser’s needs. Acute variables should be selected because they match a clearly defined performance outcome.

Because of the issues discussed in this article, the evidence-based endurance training model is not entirely distinct from the evidence-based strength training model . In many cases, they overlap substantially. The difference is not that one model builds strength and the other builds endurance. The difference is that the variables are adjusted to emphasize a specific outcome along a shared continuum. Coaches, clinicians, and exercisers should stop thinking of endurance in resistance training as a single adaptation. Instead, they should ask more precise questions:

How many repetitions, or how much time under tension, is the goal?

• At what load?
• At what velocity?
• During which movement pattern or exercise?

Once those questions are answered, the acute variables can be adjusted accordingly. If the goal is more repetitions with a heavy load, then heavy-load training close to failure is likely appropriate. If the goal is more repetitions with a lighter load, then lighter load sets should be included. If the goal includes sustaining output with slower contractions or longer time under tension, then tempo should reflect that demand.

In summary, “endurance training” may warrant deprioritization as a broad, standalone category within resistance training. This is not because endurance adaptations are unimportant, but because they appear to be more specific and more context-dependent than traditional models imply. Rather than separating strength and endurance into rigid boxes, it may be more accurate to view them as overlapping outcomes shaped by shared acute variables. The better approach is not to train for a label, but to train for the exact performance demand the client hopes to improve.

Summary of Relevant Research Findings

• Strength endurance and aerobic performance: Repetition range appears to have minimal influence on the aerobic benefits derived from strength training.
• Load specificity: Endurance is likely load-specific. When endurance is assessed using repetitions to failure with light loads, lighter load training and higher repetitions typically produce the greatest improvements. Conversely, when the goal is more repetitions with heavy loads, training to failure per set is likely the better approach.
• Velocity specificity: Slower velocities may improve strength across a wider range of velocities, slower tempos that increase time under tension may yield greater improvements in endurance, and faster tempos, such as maximum velocity concentric contractions, may yield greater improvements in peak velocity.
• Drop sets: Drop sets may be an appropriate progression for advanced exercisers who benefit from higher training volumes, for example, individuals already performing three or more conventional sets per muscle group. Drop sets have been shown to increase endurance, potentially to a greater extent than traditional set configurations. For many individuals, performing drop sets regularly may reduce the need for separate endurance-focused work.

Caption: Muscular endurance training is load specific

Review of Selected Relevant Studies

Strength Endurance and Aerobic Performance

Studies investigating the effect of strength endurance training on aerobic endurance activity suggest rep range may not be a significant factor. Netreba et al. compared 18 resistance-trained males. Participants were randomly assigned to a conventional training group (age: 20 ± 4 years) and a continuous tension group (age: 21 ± 4 years), for 8 weeks, 3 sessions/week. The conventional training group performed leg extensions for 7 sets/exercise on Mondays and 3 sets/exercise on Wednesdays and Fridays; all sets for 6-10 reps-to-failure/set, using 80-85% of 1-RM loads, with very long (10 min) rest between sets. The continuous tension group performed leg extensions with continuous tension (but reduced the ROM by 15% less than conventional training) for 4 series of 3 sets/exercise on Mondays, and 1 set of reps-to-failure/set on Wednesdays and Fridays; using 50% of 1-RM loads, using 30 sec rest between sets, and very long (10 min) rest. Both groups performed the same lower-body routine (including hip extensions, leg extensions, and leg curls). Outcome measures included total work, hip extension, knee extension, and knee flexion 1-RM strength at angular velocities of 30, 180, and 300 degrees/sec, knee extension endurance (45 sec maximal isometric test), peak power, average aerobic threshold, and VO2 max. The findings demonstrated that total work was significantly higher for the conventional training group. Hip extension 1-RM strength at all angular velocities increased significantly more for the conventional training group when compared to baseline; further, knee extension 1-RM strength increased significantly more for the conventional training group at 180 degrees. Conventional and continuous tension groups exhibited similar increases in 1-RM strength during knee extensions at 300 degrees of knee flexion at all angular velocities. Additionally, Knee extension strength endurance decreased significantly more in the conventional training group than at baseline. Peak power, anaerobic threshold, and VO2 max were similar for both groups (1). An RCT by Jackson et al. compared 23 high-level cyclists. Participants were randomly assigned to a control group (age: 27 ± 10 years), a high resistance/low repetition group (age: 31 ± 10 years), or a low resistance/high repetition group (age: 32 ± 9 years), for 10 weeks, 3 sessions/week. All groups performed a periodized cycling program. Additionally, all participants performed a "graded incremental lactate profile test" on a cycle ergometer and leg press 1-RM strength testing as a baseline. The control group performed no additional activity. The high resistance group performed 4 sets of 4 reps/set, using 85% of 1-RM loads. The high repetition group performed 2 sets of 20 reps/set, using 50% of 1-RM loads. Both exercise groups performed a lower body routine (including barbell squats, machine leg curls, machine leg press, and Smith machine single leg step-ups); additionally, the exercise groups performed an abdominal routine (including abdominal crunches and back hyperextensions for 1 set of 20 reps/exercise; planks and side planks for 1 set of 30 sec/exercise). Outcome measures included leg press 1-RM strength, post-exercise serum lactate concentrations, peak power, and peak VO2. The findings demonstrated 1-RM strength of the leg press increased significantly more for the high resistance group when compared to the high repetition and control groups. Post-exercise serum lactate concentrations increased significantly and similarly across all groups. Peak power, VO2, and peak VO2 were similar for all groups (2). An RCT by Vincent et al. compared 62 males and females (age: 71 ± 4.7 years) with no history of orthopedic or cardiovascular conditions. Participants were randomly assigned to a control group, a low-intensity exercise group, or a high-intensity exercise group for 24 weeks, 3 sessions/week. All participants performed 1-RM strength testing of the lower and upper body (including leg press, leg extension, chest press, seated row, overhead press, triceps dips, biceps curls), VO2 max testing, and treadmill time-to-exhaustion as a baseline. The control group performed no activity. The low-intensity exercise group performed 1 set of 13 reps/set, using 50% of 1-RM loads. The high-intensity exercise group performed 1 set of 8 reps/set, using 80% of 1-RM loads. The exercise groups performed a total-body routine (including abdominal crunches, leg press, leg extensions, leg curls, calf raises, seated rows, overhead press, biceps curls, seated dips, leg abduction, leg adduction, and back extensions). Outcome measures included changes in 1-RM strength, peak VO2 max, and treadmill time to exhaustion. The findings demonstrated that 1-RM strength of lower- and upper-body exercises increased significantly, and similarly, for both the low-intensity and high-intensity groups, compared to baseline. 1-RM strength did not change for the control group. Peak VO2 max increased significantly, and similarly for the low-intensity and high-intensity groups, compared to baseline. Peak VO2 max did not change for the control group. Time to exhaustion was significantly increased in both the low-intensity and high-intensity groups, but not the control group, when compared to baseline (3). In summary, rep range likely has little effect on the benefits attained from strength training for improving aerobic performance.

Strength Endurance is Load Specific

Studies suggest that improving strength endurance may be specific to training load. Mitchell et al. compared 18 novice male exercisers (age: 21 ± 1 years) with each limb randomly assigned to 2 of 3 protocols for 10 weeks: 30% of 1 RM load for 3 sets and reps to failure/set, 80% of 1 RM load for 1 set and reps to failure/set, or 80% of 1 RM load for 3 sets and reps to failure/set. The findings demonstrated that all protocols resulted in significant increases in isometric knee extension strength; however, both 80% of 1 RM load protocols resulted in significantly larger increases in knee extension 1 RM strength, and only the 30% of 1 RM load protocol resulted in significant increases in endurance at 30% of 1 RM load (4). De Vos et al. compared 112 novice participants (age: 69 ± 6 years) randomly assigned to 1 of 4 groups: a control (no exercise) group, or groups performing 20%, 50%, or 80% of 1 RM loads. Participants completed a full body program with pneumatic machines (leg presses, seated chest press, knee extensions, rows, and leg curls) for 8-12 weeks, 2x/week, 2-3 sets/exercise, short (10-15 sec) rest between reps, and a moderate (3:0:MaxV) rep tempo. Note that participants "alternated exercises after each set," but the study did not provide specifics. Results demonstrated that when compared to pre-intervention values, all intervention groups exhibited similar average increases in peak torque and peak power, the 80% of 1RM load group exhibited the largest increase in 1 RM strength for most exercises, followed by the 50% group, and then the 20% group. Interestingly, results demonstrated that the 80% of 1 RM load group exhibited the largest increases in endurance, and the 50% and 20% groups exhibited less improvement in strength endurance. This is likely due to endurance being assessed with as many reps as possible with 90% of pre-intervention 1 RM load (5). Stone et al. compared 50 novice female exercisers (age: 23.1 ± 3.5 years) randomly assigned to a 6-8 RM load, 15-20 RM load, or a 30-40 RM load group. Participants completed a full body program (bench press, squats, triceps press-downs, bicep curls, and lat pulldowns) for 9 weeks, 3x/week, with reps to failure/set, and a moderate (2-3 min) rest between sets. The 6-8 RM group performed 3 sets/exercise; the 15-20 RM group performed 2 sets/exercise; and the 30-40 RM group completed 1 set/exercise. Results demonstrated that the 6-8 RM load group exhibited significantly larger increases in bench press 1RM strength and squat 1 RM strength, followed by the 15-20 RM group, and 30-40 RM group; however, the difference between groups was only statistically significant between the 6-8 RM load group and 30-40 RM load group. Additionally, although all groups exhibited statistically significant and similar improvements in absolute endurance strength, the 6-8 RM load group and 15-20 RM load groups exhibited a trend toward larger improvements in bench press absolute endurance (40 reps/minute to failure with a bench press load of 15.9 kg), and the 30-40 RM load group exhibited a trend toward larger increases in squat absolute endurance (40 reps/minute to failure with a squat load of 25 kg). Interestingly, all groups exhibited statistically significant and similar improvements in relative strength endurance (45% of pre-intervention bench press 1 RM load, and 55% of pre-intervention squat 1 RM load); however, it was the 6-8 RM load group and 30-40 RM load groups that exhibited trends toward the largest improvements (6). In summary, these studies suggest that if an increase in strength endurance is tested with light loads, then performing reps-to-failure/set with lighter loads will result in larger improvements; however, if strength endurance is tested with significantly heavier loads, then training with heavier loads will result in larger improvements.

Caption: Muscular endurance may be exercise specific

Strength Endurance is Velocity Specific

There is evidence that tempo may be correlated with velocity-specific improvements in strength. Peterson et al. compared 30 male varsity athletes performing a slower tempo (1.05 rad/second) or a faster tempo (3.14 rad/second) during a resistance training program including 6 hydraulic machines for 6 weeks, 3x/week, completing either 2 sets (weeks 1-2) or 3 sets (weeks 3-6) in a circuit, with 2 bouts of 20 sec. with maximal exertion/set. The findings suggested that the slower tempo group exhibited strength gains across all tested velocities, whereas the faster tempo group exhibited strength gains only at higher velocities (7). Young et al. compared 18 experienced male subjects performing a slow eccentric tempo and a maxV concentric tempo, or a slow eccentric and a slow concentric tempo, during a routine of half-squats for 7.5 weeks, 3x/week, 4 sets/session, long (3 min.) rest between sets, 8-12 reps/set, with 8-12 RM load. The findings suggest that improvements in muscle CSA were similar across groups; however, maximal isometric strength improved more in the slower-rep group, and maximal rep velocity improved more in the maxV contraction group (8). Rana et al. compared 24 healthy adult females, split into 4 groups including 1 control group performing no exercise, a traditional strength training protocol of 6-10 RM/set (until failure) and a moderate tempo (1-2:0:1-2), a high rep training protocol of 20-30 RM/set and a moderate tempo (1-2:0:1-2), and a very slow velocity training protocol of 6-10 RM/set (until failure) with a very slow tempo (4:0:10). Each protocol was performed during a lower-body resistance training routine (leg press, back squats, and knee extensions) for 6 weeks, 3 sets/exercise, with 3-5 min. rest between sets. The findings indicated that 6-10 reps/set and a moderate tempo (1-2:0:1-2) yielded the largest improvements in strength, and the higher-rep and slower-tempo groups exhibited similar improvements in muscle endurance (9). These studies demonstrate that slower velocities may improve strength across a wider range of velocities, slower tempos that result in more time under tension may yield greater improvements in endurance, and faster tempos (maxV) may yield greater improvements in peak velocity.

Strength Endurance and Drop Sets

Several studies compared strength improvements following conventional and drop-set protocols. Singh et al. compared 30 male experienced exercisers (age: 21.88 ± 2.22 years) with no history of spine injury or joint pathology (i.e., hypermobility, instability, or pain). Participants were randomly assigned to a conventional set group or a drop-set group for 6 weeks, 3 sessions/week, for a total of 18 sessions. The conventional set group performed 8-12 reps/set, with 85% of 1 RM load, and long (3 min) rest between sets. The drop-set group performed reps to failure/set, with 85/65/45% of 1 RM load/set, and minimal rest between sets. All participants completed quarter deadlifts for 3 sets/session. The findings demonstrated that the drop-set group exhibited larger increases in 1 RM strength and back extension endurance (Biering Sorenson Test) (10). Fink et al. compared 16 male exercisers with less than 1 year of resistance training experience (age: 22.8 ± 3.9 years). Participants were randomly assigned to a conventional set group or drop-set group for 6 weeks. The conventional set group performed 3 sets/exercise, 12 RM loads, and a moderate (1.5 min) rest between sets. The drop-set group performed 1 conventional set/exercise with 12 RM loads, and then 2 drop-sets with a 20% decrease in load/drop-set, and minimal rest between sets. All participants performed triceps press-downs, reps to failure/set, and a moderate (2:0:1) rep tempo. The findings demonstrated that both groups exhibited similar total exercise volume/session (load × reps); however, the drop-set group exhibited a significant reduction in session length. Further, both groups exhibited significant and similar increases in triceps press-down 12 RM strength (11). An RCT by Fisher et al. compared 36 healthy, experienced male and female exercisers (control group age: 34 ± 12 years; 1 drop-set group age: 38 ± 7 years; 2 drop-set group age: 37 ± 13 years). Participants were randomly assigned to a 1 conventional set group, 1 set with 1 drop set group, or 1 set with 2 drop sets group for 12 weeks, 2 sessions/week, for a total of 24 sessions. The control group performed 1 set/exercise, 8-12 reps/set. The 1-drop-set group performed 1 conventional set/exercise, 8-12 reps to failure, and then 1-drop-set/exercise, with a 30% decrease in load and minimal rest between the conventional set and drop-set. The 2-drop-set group performed 1 conventional set/exercise, 4 reps to failure, and then 2 drop sets/exercise, each drop-set with a 20% decrease in load, with minimal rest between conventional sets and drop sets. Participants performed a full body program (chest press, leg press, lat pulldowns, overhead press, adduction machine, abduction machine, crunches, back extensions, pec flys, pullovers, knee extensions, dips, bicep curls, calf raises, hamstring curls, and abdominal rotations), with a slow (4:0:2) rep tempo. Note that the drop-set groups only performed drop-sets for chest press, leg press, and lat pulldowns. The findings demonstrated that the conventional set and drop-set groups exhibited significant and similar increases in chest press, leg press, and lat pulldown endurance (number of reps to failure with 8-12 RM load established before the intervention). However, the control group and 2 drop-set group exhibited a trend towards larger increases in chest press endurance when compared to the 1 drop-set group (12). Fasihiyan et al. compared 27 male experienced exercisers (age: approximately 26 ± 8 years) with no history of medical issues that would affect muscle biology or imply exercise is contraindicated. Participants were randomly assigned to a conventional set, single-drop set, or multi-drop set group for 8 weeks, 3 sessions/week, for a total of 24 sessions. The conventional set group performed 4 sets/exercise, 10 reps/set, 75% of 1 RM load/set, and moderate (1.5 min) rest between sets. The single-drop group performed 1 set with reps-to-failure/set with 80% of 1 RM loads, followed immediately by 1 drop with reps-to-failure/set with 45% of 1 RM loads. The multi-drop group performed 1 set with reps-to-failure/set with 80% of 1 RM loads, immediately followed by 3 drops with reps-to-failure/set with 65/50/35% of 1 RM loads/set. All participants performed bench press and leg press, with long (3 min) rest between exercises and a moderate (1:1:1:1) rep tempo. The findings demonstrated that all groups exhibited significant and similar increases in knee extension isometric strength and bench press 1 RM strength. However, both drop-set groups exhibited similar increases in leg press 1 RM strength, which was significantly greater than that of the conventional set group. Additionally, the multi-drop group exhibited a trend towards larger increases in leg press endurance (reps to failure with 40% of 1 RM load) than the single drop-set group, and both drop-set groups exhibited significantly larger increases compared to the conventional set group. The multi-drop group also exhibited the largest increases in bench press endurance (reps to failure with 40% of 1 RM load), with the single-drop and conventional set groups exhibiting similar increases (13). In summary, these studies imply that drop-set protocols result in significantly greater increases in strength and endurance compared to conventional set protocols. Further, 1 drop-set may be as effective, or more effective than 3-4 conventional sets. Last, more "drops" likely result in larger improvements than a single "drop."

© 2026 Brent Brookbush (B2C Fitness, LLC d.b.a. Brookbush Institute)

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