How to Build Strength, Muscle Size and Endurance: Essential Training Principles

Getting stronger, building muscle and improving endurance are related goals, but they are not the same goal. The exercises can look remarkably similar. What changes the outcome is how you perform them: the load, repetitions, sets, rest intervals, frequency and intention you bring to the work.

That distinction is central to Dr. Andy Galpin’s approach to exercise. You can get stronger without adding much muscle size. You can train for muscle growth across a surprisingly broad range of repetitions. And you can make an otherwise sound program less effective by chasing soreness or rushing through work that requires recovery.

The useful starting point is not “Which exercise is best?” It is “What adaptation am I trying to create?” From there, the programming becomes much clearer.

Table of Contents

• The Nine Adaptations You Can Train
• Progressive Overload: Give the Body a Reason to Adapt
• Choose Exercises You Can Perform Well
• How to Train for Strength
• How to Train for Muscle Growth
• Soreness Is Not a Workout Score
• The Three-to-Five Framework for Strength and Power
• Mental Focus Changes the Quality of Training
• How to Engage a Muscle You Struggle to Feel
• Breathing During Resistance Training
• Finish With Three to Five Minutes of Downregulation
• Build the Program Around the Adaptation

The Nine Adaptations You Can Train

Exercise is not one stimulus that produces one general improvement called fitness. Galpin describes nine broad adaptations, each with a different emphasis:

1. Skill: Improving how you execute a movement, whether that is a golf swing, squat or running stride.
2. Speed: Moving as fast as possible.
3. Power: Producing force quickly. A practical way to think about power is force multiplied by movement velocity.
4. Strength: Increasing the amount of force you can produce.
5. Hypertrophy: Increasing muscle size.
6. Muscular endurance: Sustaining repeated muscular efforts, such as performing as many push-ups as possible in one minute.
7. Anaerobic power: Producing a large amount of work over roughly 30 seconds to two minutes.
8. Maximal aerobic capacity, or VO2 max: Supporting very demanding efforts in the approximate range of three to 12 minutes. This involves more than simply reaching a high heart rate.
9. Long-duration endurance: Sustaining continuous work for 30 minutes or longer, with the emphasis on how long you can continue.

These categories overlap. Strength can support power, and resistance training can produce both strength and muscle growth. But overlap does not make the adaptations interchangeable. Some training priorities also compete with others, so a program should reflect what matters most to you.

Progressive Overload: Give the Body a Reason to Adapt

Physiological adaptation occurs in response to stress. If you repeat exactly the same workout indefinitely, it may help maintain your current capacity, but it provides progressively less reason for further improvement.

Progressive overload means advancing the training demand over time. Adding weight is one option, not the only option. You can also increase repetitions, train more frequently or progress toward a more complex movement.

For example, moving from a machine leg extension toward a squat changes the demands of the exercise, even before you change the sets or repetitions. For a beginner, learning to control that more involved movement can be an appropriate progression. The priority is first to move well and develop tolerance to training, rather than immediately pursuing heavy loads.

This principle also appears in the American College of Sports Medicine’s position stand on progression in resistance training: training must evolve with the individual’s capacity and goals.

The Six Variables You Can Modify

Galpin organizes exercise programming around six modifiable variables:

• Exercise choice: Which movements you perform.
• Intensity: How much load or physiological demand you use relative to your maximum.
• Volume: How many sets and repetitions you complete.
• Rest intervals: How long you recover between sets.
• Progression: How the demands change over time.
• Frequency: How often you train a movement or muscle group.

In this context, intensity does not mean how exhausting the session feels. For resistance training, it usually refers to a percentage of your one-repetition maximum, or 1RM: the maximum load you can lift once. A squat at 75% intensity means approximately 75% of that maximum. In cardiovascular training, intensity might instead refer to a percentage of maximum heart rate or VO2 max.

A simple way to count repetition volume is sets multiplied by repetitions. Three sets of 10 gives you 30 repetitions; five sets of five gives you 25. For hypertrophy programming, weekly working sets per muscle group are another especially useful measure.

The important point is that an exercise name does not determine the adaptation. A bench press can emphasize strength, muscle growth or muscular endurance depending on how you manipulate these variables.

Choose Exercises You Can Perform Well

A useful default is to move every joint through its available full range of motion over the course of your training week. Larger ranges of motion generally support strength and hypertrophy, but range of motion is not permission to abandon good positioning.

If reaching a particular depth requires you to compromise your back position, the solution is not to force the depth. The objective is a controlled, appropriate range for your body and the exercise.

Confidence and stability matter, too. Someone who has never performed a snatch should not begin by trying to express maximum strength through that lift. A stable machine exercise may be a much better way to produce force safely while developing experience.

A Simple Full-Body Exercise Framework

For a reasonably balanced session, select movements from four categories:

• Upper-body press: Pushing a resistance away from you, such as a bench press.
• Upper-body pull: Pulling a resistance toward you, such as a row or pull-up.
• Lower-body hinge: A hip-hinging movement, such as a deadlift.
• Lower-body press: A movement such as a squat.

Across the week, include both horizontal and vertical upper-body movements. Horizontal pressing and rowing challenge different movement directions from overhead pressing and vertical pulling. You do not need every variation in every workout, but the overall program should have balance.

How to Train for Strength

Strength training asks the neuromuscular system to produce high force. Lower-force efforts generally recruit lower-threshold motor units first. As force demands increase, higher-threshold units become involved.

This matters beyond athletic performance. The preferential loss of fast-twitch muscle fibers with aging is one reason maintaining high-force capacity is so important.

The practical implication is straightforward: to emphasize strength, impose a meaningful demand for force, not simply a demand for more repetitions.

Load, Repetitions and Working Sets

Galpin’s general guidelines for strength-focused work are:

• Load: Often around 85% of 1RM or higher, although loads around 75% can also be productive depending on training status.
• Repetitions: Typically five or fewer per set.
• Working sets: Around three per exercise can be enough, with the appropriate amount depending on your fitness and experience.
• Rest: Usually two to four minutes before repeating the same exercise.

These variables fit together. A genuinely heavy load limits how many repetitions you can perform. You cannot perform 12 repetitions at a true 95% of your one-repetition maximum. If you can, the load was not actually 95%.

Warm Up Before the Heavy Work

Working sets are not warm-up sets. Do not walk into the gym and immediately load 85% of your maximum.

One example Galpin gives is to build through approximately 10 repetitions at 50%, eight at 60%, another set around 70%, and then a lower-repetition set around 75% before the working sets. The exact sequence is less important than the principle: progressively increase the load while preparing for the heavier work.

Rest Long Enough to Preserve the Signal

For strength, high force is the central training signal. If short rest intervals create so much fatigue that you must substantially lower the load, you have changed the workout’s emphasis.

That does not mean you must remain idle between sets. You can alternate exercises that involve different muscle groups, allowing one area to recover while another works. This is a form of supersetting.

There can be a small tradeoff in maximal strength development compared with fully separated work. For a competitive lifter pursuing a record, that tradeoff matters. For someone trying to train effectively within a limited schedule, the time savings may be well worth it.

How Often Should You Train for Strength?

Training each muscle group about twice per week is a useful, effective starting point. Three exposures can also work well.

Strength, speed and power work can sometimes be practiced much more frequently, even daily, when the workload and fatigue are managed appropriately. That is a possibility, not a requirement to train the same muscle heavily every day.

How to Train for Muscle Growth

For hypertrophy, the emphasis shifts toward accumulating enough challenging work and recovering from it. Whereas strength programming prioritizes high force, hypertrophy programming places greater emphasis on sufficient hard-set volume.

A Broad Repetition Range Can Work

Muscle growth can occur across roughly five to 30 repetitions per set. The key condition is that the sets must be sufficiently challenging, approaching muscular failure.

That does not mean every set must end with a training partner pulling a barbell off your chest. Galpin distinguishes getting close to the limit from pursuing extreme failure. The objective is to challenge the muscle, not create an unnecessarily hazardous finish.

This broad effective range gives you flexibility. You do not have to perform three sets of 10 forever. Changing repetition ranges can make training more engaging while keeping the work aligned with muscle growth.

Nor is there a sharp physiological boundary between strength and hypertrophy. Sets of five or eight can contribute to both. The emphasis changes gradually rather than switching on at one repetition count and off at another.

Weekly Volume Matters More Than a Perfect Split

Galpin offers approximately 10 working sets per muscle group per week as a useful lower-end target for hypertrophy programming. Depending on the person, 15 to 20 may be appropriate, and some well-trained individuals may use 20 to 25.

These are programming guideposts, not instructions to begin at the highest number.

Consider three shoulder sessions with three working sets each. That produces nine weekly sets. If your target is substantially higher, trying to fit all of the work into one session becomes difficult.

This is a major reason to distribute training across the week. Frequency helps you accumulate quality volume rather than merely survive a very large workout.

Recovery Determines When to Train Again

For muscle growth, Galpin suggests allowing roughly 48 to 72 hours between demanding sessions for the same muscle group, adjusted to individual recovery. Shoulders trained on Monday might be ready again on Wednesday or Thursday, rather than Tuesday.

The underlying processes occur on different timelines. Some exercise-triggered signals begin within seconds. Gene-related responses unfold over hours, while muscle protein synthesis can remain elevated over the following day or two. The practical goal is to provide a useful stimulus, support recovery and then repeat the stimulus when you can again perform quality work.

What if your schedule requires five or six days between sessions for a muscle group? You have not automatically lost the muscle you built. It is better to think of that as potentially missing an additional opportunity to stimulate growth. Different frequencies can work when total weekly volume is comparable, but fewer sessions require more work in each session.

What About Tension, Metabolic Stress and Muscle Damage?

Galpin discusses mechanical tension, metabolic stress and muscle damage as commonly proposed contributors to hypertrophy. Heavy resistance supplies substantial mechanical tension. Higher-repetition work can create pronounced metabolic stress, including the familiar burning sensation.

The precise role of metabolic stress remains an area of scientific debate. More importantly, muscle damage is not a goal to maximize. You do not need to pursue every possible mechanism in every session, and more damage does not mean more growth.

Soreness Is Not a Workout Score

Soreness is a poor way to judge whether a workout was productive. That applies to beginners and experienced athletes alike.

Some mild soreness may be compatible with training. But if your glutes are so sore that sitting down is an ordeal, you may have created a problem rather than a better stimulus. Missing subsequent workouts can reduce the total amount of productive training you accomplish over a month.

For hypertrophy, Galpin offers soreness below roughly three out of 10 as one practical sign that training the area again may be reasonable. It is a rough check, not a complete assessment of recovery.

The larger rule is to protect consistency. Especially early on, err toward a little less soreness rather than a little more. A workout should challenge you without making the next useful workout impossible.

The Three-to-Five Framework for Strength and Power

For a memorable programming framework, Galpin uses the “three-to-five” concept:

• Choose three to five exercises.
• Perform three to five repetitions per set.
• Complete three to five sets.
• Allow three to five minutes of rest between efforts for the same exercise.
• Train three to five times per week, distributing the work appropriately.

The lower end can accommodate shorter sessions or days when you have less capacity. The upper end represents substantially more work and is not a default prescription for everyone. The point is to keep the program adaptable without losing its strength or power emphasis.

Change the Load to Change the Emphasis

The main distinction between strength and power within this framework is intensity:

• For strength: Emphasize heavier loads, often around 85% of 1RM or more.
• For power: Use lighter loads, broadly around 40% to 70% of 1RM, so you can emphasize movement velocity.

Getting stronger can help power, but power also requires the ability to express force quickly. The lighter loading is not an invitation to move casually. The intention is to accelerate.

Mental Focus Changes the Quality of Training

The nervous system does more than activate muscles. Your intention during a repetition can influence the adaptation you get from it.

For strength and power, intending to move the resistance quickly can produce a different outcome from merely doing enough to complete the lift. Galpin points to research in which the intent to accelerate mattered even when the resulting movement velocity was similar.

A heavy bar may move slowly. You can still be trying to move it quickly while maintaining control and position.

For hypertrophy, the focus can shift toward the target muscle. Early research on the mind-muscle connection suggests that deliberately concentrating on contraction may improve growth compared with completing the same work without that focus.

A useful distinction is:

• Strength and power: Focus on producing force and moving the load with intent.
• Hypertrophy: Focus on challenging and contracting the intended muscle.

Both require sound technique. Neither means abandoning form to pursue a sensation.

I find the broader lesson especially useful: a shorter session of deliberate, high-quality work can be more valuable than a longer session spent mentally elsewhere. Sometimes the productive adjustment is not adding another exercise. It is taking a moment to get your attention into the work.

How to Engage a Muscle You Struggle to Feel

If a particular muscle never seems to contribute as intended, start with awareness and execution rather than assuming you need an entirely different exercise.

A simple tactile cue can help. During a row or pulldown, a coach might touch the lat and cue you to contract that area. The cue directs attention toward the intended muscle.

Break the Movement Down With Controlled Eccentrics

The eccentric phase is the lowering portion of a movement. Emphasizing it can simplify a difficult exercise and create more opportunity to practice control.

For a pull-up, that might look like this:

1. Use a box to reach the top position without first pulling yourself up.
2. Lower yourself under control while focusing on the intended muscles.
3. Repeat the controlled lowering work within your current capacity.
4. Gradually integrate the lifting, lowering and holding portions of the movement.

This process may take weeks or months. Eccentric work can contribute to both strength and hypertrophy while helping you learn the movement.

You may notice soreness in a muscle you previously struggled to feel. That can offer a clue that the exercise reached the area, but it is still not the objective. Keep the emphasis on controlled execution and gradual progression.

Breathing During Resistance Training

Breathing strategy depends on the exercise, load and number of repetitions. A useful general pattern is to inhale and brace before the lowering phase, maintain that brace through the more vulnerable portion of the movement, and exhale during the lifting phase.

On a bench press, for example, that could mean:

1. Inhale and establish your brace.
2. Lower the bar under control.
3. Begin pressing while maintaining stability.
4. Exhale during the latter portion of the press, then reset.

A single repetition is different from a longer set. As repetitions accumulate, you need a repeatable way to breathe and restore your brace. Some lifters reset each repetition; others use a rhythm across several repetitions. A squat and a deadlift also create different opportunities to pause and reset.

The important point is not to force one breathing pattern onto every exercise. It is to coordinate breathing with stable, controlled movement rather than leave it entirely unplanned.

Finish With Three to Five Minutes of Downregulation

One of the most useful practices discussed with Galpin costs almost no time: deliberately shift out of the workout’s heightened state before moving into the rest of your day.

Instead of finishing a hard session and immediately opening email, spend three to five minutes doing something that calms you. Breath control is a simple option, with nasal breathing where comfortable.

Two Simple Breathing Options

• Longer-exhale breathing: Inhale for about four seconds, then exhale for about eight seconds.
• Box breathing: Inhale, hold, exhale and hold again for equal durations, such as four seconds per phase.

The specific method can vary. The objective is to provide a clear transition away from exertion.

When I introduced five minutes of post-workout downregulation on Galpin’s recommendation, I noticed better recovery between workouts and less of the energy dip I had experienced several hours after hard training. That is a personal observation, not a guarantee that everyone will respond identically, but it made the practice particularly compelling to me.

If five minutes is not realistic, use three. The same principle can extend beyond exercise: even one minute of deliberate calming after an intense work period or difficult interaction can create a useful transition.

Build the Program Around the Adaptation

The central lesson is that training outcomes are not determined by exercise selection alone. They emerge from how you combine load, volume, rest, progression, frequency and execution.

For strength, preserve high-force work. For muscle growth, accumulate enough challenging sets and allow recovery. For power, pair appropriate loading with the intent to move quickly. Across all of them, prioritize sound movement, attention and consistency over exhaustion for its own sake.

You do not need to make every workout more complicated. You need to know what the workout is meant to accomplish, then give your body a clear, repeatable reason to adapt.