Strength

Strength is the ability to produce force or torque against an external resistance.

In exercise science and resistance training, the term “strength” most often refers to maximum strength (maximal voluntary force production), commonly assessed as 1-repetition maximum (1-RM) strength, maximal isometric force, or peak torque in a specific movement pattern.

Although strength is often discussed as a general quality, performance is highly task-specific, including the movement pattern, joint angles, contraction type, range of motion, and contraction velocity. For this reason, “strength” should generally be interpreted as the maximum force (or torque) that can be expressed under a specific set of conditions, rather than a single global ability that transfers equally across all exercises and speeds.

Semantic Clarification

Strength vs. muscular endurance (strength endurance)

• Strength: Maximal force or torque production, typically measured by repetition maximum (1-RM), maximal isometric strength, or peak torque.
• Muscular endurance (strength endurance): The ability to sustain force production or perform repeated contractions against a given load over time. Strength contributes to muscular endurance by reducing the relative intensity of submaximal loads, but muscular endurance adaptations remain strongly task-specific and often benefit from goal-specific repeated-effort practice.

Maximum strength vs. power

• Maximum strength: The highest force or torque that can be produced, regardless of how long it takes to produce it.
• Power: The rate of doing work (force × velocity), often described as “explosive strength.” Strength and power are related, but power depends more strongly on movement velocity and the ability to express force quickly.

Absolute strength vs. relative strength

• Absolute strength: The total force output regardless of body mass (for example, a 1-RM load).
• Relative strength: Strength expressed relative to body mass (for example, 1-RM divided by body weight). Relative strength is often more relevant for sport tasks that involve moving one’s own body.

Dynamic strength vs. isometric strength

• Dynamic strength: Force production during movement (for example, a 1-RM squat).
• Isometric strength: Force production without joint motion (for example, maximal force during an isometric mid-thigh pull). Strength is specific to the contraction type and testing position.

Frequently Asked Questions (FAQs)

What is strength training?

• Strength training is resistance training designed to increase force production, commonly measured by outcomes such as 1-RM strength, peak torque, or isometric force. In practice, strength training emphasizes stable, loadable exercises, progressive overload, and sufficient rest and recovery to repeat high-quality efforts over weeks and months.

What is the best rep range for strength?

• For most experienced lifters, strength gains are most consistently optimized by prioritizing heavier sets, commonly in the 3–8 RM/set range, supported by some moderate-load work (8–12 RM/set) to maintain volume and practice. Novice lifters often do very well starting in moderate ranges, then progressing toward heavier loading as technique and tolerance improve.

Do you have to lift heavy to get strong?

• To maximize long-term strength, most individuals benefit from some exposure to heavier loads because strength is specific to the loads and skills you practice. However, beginners can make large strength gains with moderate loads early on, especially while learning technique, improving coordination, and building consistency.

What is progressive overload for strength?

• Progressive overload is a systematic increase in training demand over time, commonly achieved by increasing load, reps within a target rep range, or sets, or by improving execution at the same load. A practical rule is: increase load when you exceed the top of your rep range with good form, and reduce load when you cannot meet the minimum reps with good form.

Is a 5×5 program best for strength?

• 5×5 can be effective, especially for intermediate and advanced lifters, because it provides repeated practice with heavy loads and sufficient work to drive progression. However, it is not inherently “best.” Outcomes depend more on appropriate loads, autoregulation of progressions, recovery, and long-term programming that prevents stagnation.

How long does it take to see strength gains?

• Many people notice measurable strength gains within a few weeks, often driven by improved skill and early neural adaptations, with more visible sustained progress accumulating over 8–12 weeks of consistent training. As training experience increases, improvements become more dependent on precise programming, recovery, and long-term consistency.

How many sets should I do for strength?

• There is no single perfect number, but the research trend is an upper limit per session for most lifters. For novices, start low (often 1 set per upper-body muscle group and 2 sets per lower-body muscle group during the initial 6 to 12 weeks), then progress toward 3 to 4 high-quality sets per muscle group per session as tolerance improves. For those optimizing strength, you generally should not exceed 5 to 6 sets per muscle group per session, because adding beyond 3 to 4 sets tends to produce only small additional improvements, and more sets often become “fatigued sets” that are lower quality.

How long should I rest between sets for strength?

Rest should be determined by how many sets you are doing per exercise (volume), not by the training goal or load. A simple rule recommended based on a systematic research review by the Brookbush Institute is:

• 2 sets per exercise: ~2 minutes
• 3 sets per exercise: ~3 minutes
• 4 or more sets per exercise: 3+ minutes, and in some cases 4+ minutes

This approach is meant to preserve repetition quality and total volume across sets.

Should you train to failure to build strength?

For maximal strength, the Brookbush Institute’s evidence-based position is that reps-to-failure per set is recommended for optimal improvements in maximal strength, but it is not always the most influential variable. Training volume and load can matter more, and a single set to failure is less effective than multiple sets not to failure when total volume is higher.

A practical compromise is:

• Use reps-to-failure for most sets, or at least the last set of an exercise, especially when strength is the primary goal.
• If you need to preserve force production, rep velocity, and recovery (common in athletes training at high frequency), use 1 to 2 reps in reserve on earlier sets and add one additional set to maintain volume.

Brookbush Institute’s Strength Training Model: Comprehensively Evidence-based and Outcome-driven

1. Tempo:
   • Training: 1-2 seconds eccentric: 0-2 seconds isometric: maximum velocity or longer concentric (1-2: 0-2: MaxV+)
   • Heaviest Lifts and Lifting Practice: As fast as can be controlled
2. Reps-to-Failure/set: Perform reps-to-failure/set for most sets, or at least the last set, which likely results in larger increases in strength and hypertrophy long-term. However, during heavy strength training days (3-8 RM loads), there may be a benefit to performing reps-in-reserve/set to maintain force production and power. Reps-in-reserve/set should likely be combined with an additional set, performing the last set-to-failure, and for advanced exercisers, performing a drop-set on the last set.
3. Reps and Load:
   • Experienced Lifters:
     • Heavy: 3 - 8 RM/set (80 - 95% of 1-RM)
     • Moderate: 8 - 12 RM/set (70 - 80% of 1-RM)
     • Lighter loads may be added if a reduction in intensity is warranted due to over-training, injury, additional recovery needs, or learning a new exercise or technique (Light 12 - 25 RM/set (50 - 70% of 1-RM).
   • Novice and Post-Menopausal Females:
     • Moderate: 8 - 12 RM/set (70 - 80% of 1-RM)
     • Progress to heavier loads gradually
     • Lighter loads may be added if a reduction in intensity is warranted due to over-training, injury, additional recovery needs, or learning a new exercise or technique (Light 12 - 25 RM/set (50 - 70% of 1-RM).
   • Avoid: Very Heavy: 1-2 RM/set (95 - 100% of 1-RM), except for practicing for competition.
   • Avoid: Very Light: 25 or more RM/set (≤50% of 1-RM).
4. Range of Motion (ROM): Exercise should be performed with the largest ROM that can be performed without pain and with good form (That is, form that is free from signs correlated with dysfunction, injury, or pain). However, increasing load to improve strength and hypertrophy is likely to be beneficial, even if it results in a temporary reduction in exercise ROM.
5. Rest Between Sets and Circuits: Moderate (2 min) to long (3 min) rest between sets for similar muscle groups, or circuit training with short (30-60 sec) rest between exercises
6. Set strategies:
   • Pyramid sets are not recommended.
   • Agonist/antagonist supersets or circuit training are recommended to increase workout efficiency.
   • Drop sets are recommended as a progression for advanced exercisers who can benefit from higher exercise volumes (currently performing 3 or more conventional sets/muscle group). During heavy training sessions (3-8 RM loads/set), it is likely optimal to perform drop sets only on the final set. This allows maintenance of force production and reps/set during initial sets, whereas performing a drop set on the last set preserves training volume, which may be beneficial for long-term adaptation and strength gains.
7. Sets/Muscle Group/Session: A progressive increase from 1-5 sets/muscle group/session
   1. Novice Exercisers (6-12 weeks): 1 - 2 sets/upper body muscle group, 2-3 sets/lower body muscle group
   2. Experienced Exercisers: 2-5 sets
   3. Supersets and Drop-sets: 1-4 sets
8. Training Frequency:
   • General recommendation: 1.5 - 3 sessions/muscle group/week and 2-5 days rest between sessions
     • Starting a new routine: 3 sessions/muscle group/2 weeks and 3 - 7 days rest between sessions. Alternatively, consider scheduling "de-loading weeks" after the first session of a new routine (not the last session of a routine).
     • Initial Training Period (8-12 weeks): 1 - 3 sessions/muscle group/week
     • Maintenance: 1-2 sessions/muscle group/week
     • High-volume (Advanced) Training: 4 or more resistance-training sessions/week require split routines.
9. Recommended Training Splits:
   • 1 - 2 days/week = total body
   • 3 days/week = total body or upper/lower split
   • 4 days/week = upper/lower split
   • 5 - 6 days a week (not recommended for resistance training) = Upper/lower/recovery split or Push/Pull/Legs
10. Periodization for Hypertrophy
    • Maximize exposure to goal-specific acute variables: Most time spent with moderate loads, followed by heavy loads, with some lighter load training when necessary to reduce intensity or introduce a new stimulus. Note that drop sets may reduce the need for light-load/high-rep training.
    • Load adjustments: Auto-regulated, frequent, adaptive intra-session or session-to-session load adjustments. Increase load when more reps than the upper limit of the rep range can be performed, and decrease load if the lower limit of the rep range can not be performed.
    • Novice Exercisers: Periodization will not result in better outcomes for at least the initial 12 weeks. Perform moderate loads and reps/set with auto-regulated load adjustments.
    • Experienced Exercisers: True linear periodization with daily undulation is likely the most effective strategy. Although block periodization is unlikely to result in additional benefits, it can be helpful to organize a training program into phases and then blend those phases with a linear progression of loads.
      • Recommended progression of periodization strategies.
        • Goal: Optimize force production and strength, while maintaining volume to improve hypertrophy and strength outcomes.
          • True linear periodization (frequent, auto-regulated load adjustments), with moderate loads
          • True linear periodization (frequent, auto-regulated load adjustments), progressing from moderate to heavy loads
          • True linear periodization with daily undulation, including heavy days, moderate load/hypertrophy days, and intermittent periods incorporating light load days (frequent, auto-regulated load adjustments).
          • True linear periodization with daily undulation, including heavy days and moderate load/hypertrophy days with a drop set on the last set of each exercise, and intermittent periods incorporating light load days (frequent, auto-regulated load adjustments).
          • True linear periodization with daily undulation, including heavy days with a drop set on the last set of each exercise, moderate load/hypertrophy days with strength/stability drop sets to improve "stability strength," and intermittent periods incorporating light load days (frequent, auto-regulated load adjustments).
11. Exercise Selection: Moderately stable exercise and progressions that can be performed with sufficient loads, and periodic change (e.g., 1 time/4-12 weeks) in exercise selection as set performance goals are reached.
12. Exercise Order:
    • Start with your most important exercises
    • Start with large muscle groups and multi-joint movements
    • When priorities are equal, perform upper-body exercises before lower-body exercises
    • Program back exercises before chest when both are trained in the same routine
    • Perform strength training before aerobic training
    • To optimize performance on a key lift, avoid training similar muscles in the same session

Additional Courses

• Hypertrophy Training: Evidence-based Model
• Strength Training: Evidence-based Model
• Endurance Training: Evidence-based Model

Additional Articles:

• Should You Perform Sets to Failure
• Is 3 Sets Per Muscle Group the Upper Limit
• Optimal rest between sets is not determined by goal or load

Additional Glossary Terms

• Muscular Endurance
• Hypertophy