• Introduction
  • The basics of acute training variables
  • Choice of exercises
  • Order of exercises
  • Load
  • Volume
  • Rest
  • Type of muscle action
  • Repetition velocity
  • Frequency
  • Final thoughts
  • Bibliography
  • Assistance exercises: movements that support the function of the prime movers, and mainly focus on one muscle group at a time (e.g. leg extension).
  • Bilateral exercises: movement executed evenly and simultaneously by both limbs.
  • Compound exercise: a movement utilizing more than one muscle group at a time.
  • Concentric muscle action: muscle shortens and generates movement.
  • Eccentric muscle action: when external force on a muscle is greater than the force it can produce, resulting in muscle lengthening.
  • Isokinetic muscle action: the muscle contraction remains constant while muscle length changes.
  • Isometric muscle action: when a muscle is activated with no change in muscle length.
  • Electromyography activity: greater motor unit recruitment.
  • Isolated exercise: a movement utilizing one limb at a time.
  • Length-tension relationship: relationship between muscle length and force production. 
  • Post-activation potentiation: a short-term performance improvement due to improved neural activation following a high-intensity stimulus.
  • Prime mover: the major muscle groups responsible for movement.
  • Unilateral exercise: an exercise where movement is performed on one side of the body.

Introduction

A well-rounded training program is a combination of several factors, including the choice and order of exercises, training volume and intensity, as well as recovery time between sets and subsequent exercises. These are more commonly known as acute training variables, because they can be varied within a single workout and thus determine the long-term adaptations of a training program. These training variables also allow individuals to design, track, and evaluate the effectiveness of their current training regimen.

Having a good understanding of different trainable characteristics, and how to manipulate them to create a certain training stimuli, is essential when designing a training program. This process starts with the individual’s goals and needs in mind (e.g. hypertrophy, maximal strength, power, muscular endurance, etc.). From there, the program can be broken down into smaller blocks and separate workouts with a specific training focus. Over time, these exercise decisions determine the progression of a training program.

This post explains the basics of training variables as well as the general recommendations for optimal sequencing. These guidelines are based on the extensive research by The American College of Sports Medicine

The basics of training variables

The manipulation of different acute training variables is essential when designing an exercise program with a specific training stimulus. In the past, the vast majority of literature on resistance training variables has focused on intensity (load) and volume (total number of repetitions). However, more recent studies have put emphasis on several other factors that contribute to strength and hypertrophic gains, as well as the changes in muscle architecture. There are several factors that determine the training stimulus of a workout, including:

  • Exercise selection (compound vs isolated exercises, vertical vs horizontal load)
  • Exercise order (e.g compound exercises before isolated exercises)
  • Type of muscle action (eccentric, concentric, isometric)
  • Volume (repetitions and sets)
  • Rest periods (rest between sets and/or exercises)
  • Load (the % of one-repetition maximum used during a set)
  • Movement velocity (duration of eccentric and concentric phases, time-under-tension)
  • Training frequency (number of training sessions per week, training splits)

The optimal use of the aforementioned training variables depends on the physical adaptations that the individual is looking for. Generally speaking, muscular strength training requires a smaller training volume with heavy resistance to ensure the recruitment of as many fast-twitch muscle fibers as possible, and thus, improving the neural adaptations to resistance training.

Hypertrophy-focused training requires moderate-to-heavy resistance and moderate-to-high training volume. This offers the optimal stimulus for muscle growth. Power training involves explosive ballistic exercises utilizing a moderate resistance with moderate repetitions. This ensures that each exercise is performed with the highest peak velocity as possible. Finally, local muscle endurance training consists of a higher training volume utilizing smaller loads. This allows for increased metabolic demand of the muscles used during exercise, which is integral for local muscle endurance.

Because each of these strength components rely on different mechanisms, it is important to always adjust the training stimulus according to individual needs. Strength training also relies on several fundamental principles; individuality, specificity, overload, progression, adaptation, and reversibility. This means that the body constantly adapts to the stress that it is put under. Thus, training load must be gradually increased to offer a stimulus strong enough to maintain progression. Naturally, all of the training choices must also be done according to the individual’s current level of fitness, as well as personal needs and goals.

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Training Variables


Exercise choiceExercise orderVolumeLoadRestType of muscle actionMovement velocityFrequency

Choice of exercises

Exercises should be chosen according to the specific areas of the body and biomechanical properties that need improvement. Because the body has such a wide range of functional movements, the number of exercises that focus on specific joint angles are nearly endless. Since only the activated muscles benefit from a strength training stimulus, the chosen exercises should stress the muscles and joint angles that support the individual’s personal goals.

Different exercises can be divided into primary exercises and assistance exercises. Primary exercises refer to movements that target the major muscle groups responsible for movement – also known as prime movers (e.g. quadriceps femoris for leg extension, etc.). Assistance exercises are movements that support the function of the prime movers, and mainly focus on one muscle group at a time (e.g. leg extension). Different exercises can also be classified as structural or body part specific movements. Structural exercises involve multiple joints and require on a coordinated action of several muscle groups. Some of these exercises incorporate the entire body (e.g. powerlifting techniques) whereas others simply involve multiple joints or muscles (e.g. bench press, lat pulldown, etc.). Body part specific exercises consist of isolated single-joint movements that focus on a specific muscle group (e.g. bicep curl, leg extension, etc.). These types of movements are especially useful in rehabilitation and reducing muscle imbalances.

Both single and multiple-joint exercises have proven effective in increasing muscular strength of targeted muscle groups. These findings are also consistent across different training modalities (e.g. free weights, machines, etc.) used in training. Multiple-joint exercises (e.g. squats, deadlifts, bench press, etc.) require a coordinated effort of several joints, allowing for more weight to be used, and thus, requiring a more complex neural response. That is why multiple-joint exercises are considered superior in increasing overall strength and power. Single-joint exercises are beginner-friendly and can be used to 1) target specific muscle groups that may not receive a sufficient training stimulus through compound exercises, or 2) train specific muscle groups according to individual goals and needs (weaknesses, muscle imbalances, injury history, etc.). Both multiple- and single-joint exercises can also be altered with different stances, grip placements, and body postures. 

Exercises selection can also be expanded using unilateral (movement is performed on one side of the body) and bilateral (movement executed evenly and simultaneously by both sides of the body) exercises, or performing exercises on an unstable surface. Interestingly, unilateral exercises (e.g. single leg squat, Bulgarian split squat, single leg jump, etc.) have shown improvements in bilateral exercises (back squat, deadlift, countermovement jump, etc.) and vice versa. Additionally, performing single- or multiple-joint exercises on an uneven surface (BOSU balls, soft mats, wobble boards, balance boards, etc.) have shown a greater level of activation on lower torso musculature and other stabilizing muscles in comparison to exercises on a stable surface. However, these exercises also result in significantly lower agonist force production, meaning that less load can be lifted. Together, these aforementioned variations allow for a wide array of exercises and progression strategies for all levels of resistance training.

As a general recommendation, strength and power training should include both unilateral and bilateral exercises with an emphasis on multi-joint movements. The training should otherwise follow the general strength training sequencing guidelines (see: order of exercises). 

Both single and multiple-joint exercises have also proven effective in increasing muscle hypertrophy. However, the complexity of exercises has shown to affect the time required for adaptations to occur. This is due to the fact that multiple-joint exercises require a longer neural adaptive phase (initial learning phase) in comparison to single-joint exercises. Although less is known about exercise order in regards to hypertrophy, it seems that increasing muscle mass follows similar guidelines as muscular strength training. As for local muscle endurance, the sequence of exercises may not be as important as exercise-induced fatigue. This is because the metabolic demand (accumulation of metabolic waste products, substrate depletion) of the exercise plays a key role in the adaptations necessary for improving local muscle endurance (increased mitochondrial and capillary density, fiber type transitions, lactate buffering capacity, etc.). Thus, exercises aiming for local muscle endurance should also follow the same guidelines as strength training. 

Order of exercises

The order of exercises is another important acute training variable, especially when working out with heavier resistance. Therefore, understanding the best organization of exercises is essential when optimizing a resistance training session for muscle mass gains. As a general rule of thumb, targeting large muscle groups first allows for a greater training stimulus to all muscles involved.

Multi-joint exercises generate a significant stabilization of the body, involving several muscles that could not be stimulated by single-joint movements. Studies also show that performance in multiple-joint exercises declines when performed later (after exercises stressing the same muscle groups) as opposed to earlier in the workout. Because these compound exercises (which require more muscle mass and energy for optimal technique and performance) have proven to be effective for increasing strength, it is advised that they are performed early in a workout to maximize their benefits. However, not all muscles receive sufficient stimulation during these exercises because they remain at relatively constant length during their execution. Single-joint exercises can be used to target specific muscles and achieve optimal length-tension relationship (relationship between muscle length and force production) and a greater electromyography activity (greater motor unit recruitment). 

This sequencing ensures that structural exercises are performed without fatigue, allowing for a greater training stimulus for larger muscle groups. In short, targeting large muscle groups induces greater neural, metabolic, endocrine, and circulatory responses. As a general recommendation for all levels of resistance training, workouts should be sequenced according to the following principles;

  • Targeting large muscle groups before small muscle groups.
  • Performing multi-joint exercises before single-joint exercises.
  • Performing intense exercises first, especially when targeting specific muscle groups within a single workout.
  • Performing power-specific exercises (e.g. Olympic lifts and other explosive movements) before basic strength and single-joint assistance exercises.
  • Utilizing various workout splits (e.g. whole body split, push/pull/legs split, upper/lower split, 4-day split, 5-day split, etc.).
  • Targeting weak points or training priorities before other exercises.

Additionally, specific exercises may even amplify the training stimulus of subsequent exercises later in the workout. This phenomenon, known as post-activation potentiation, relies on a short-term performance improvement due to improved neural activation following a high-intensity stimulus. This can be especially useful in power training, because performing high-velocity power exercises before multiple-joint exercises have been shown to improve strength performance later in the workout. However, it is also important to remember that force and power may be reduced if the exercises are performed consecutively. Therefore, it is recommended that explosive total body exercises are performed in the beginning of the workout and sequenced according to complexity. Thus, reducing fatigue in exercises that require as high of a peak velocity as possible.

Although less is known about the effects of exercise order on increasing lean muscle mass, it seems that the general guidelines for strength training apply for muscle hypertrophy. In addition to exercise selection mentioned above, it appears that sequencing may not be as important as the metabolic demands of the exercise when it comes to increasing local muscle endurance. Therefore, it is recommended that unilateral and bilateral single and multi-joint exercises are used with varying sequencing combinations for all levels of training.

Load

Altering the training load can significantly affect the acute metabolic, neural, hormonal, and cardiovascular responses to an exercise bout. This makes resistance one of the most important training variables for hypertrophy, strength, and local muscle endurance development. The optimal training load is based on the individual’s experience and current level of fitness. A well-designed resistance training program often utilizes one or more of the following loading schemes: 1) increasing the load based on a percentage of one-repetition maximum (1 RM) of a specific exercise, 2) increasing the load based on a targeted number of repetitions, or 3) increasing the load within a targeted repetition zone (e.g. 8–12 RM). Each percentage of the 1RM corresponds to a certain number of maximum repetitions, typically categorized as low (<30% 1RM, >20 repetitions), moderate (30–70% 1RM, 11–20 repetitions) and high (>70% 1RM, <11 repetitions) ranges. 

Studies have found that strength can be improved with relatively low training loads among untrained (45-50% of 1RM) and moderately trained individuals utilizing a higher volume (15-25 repetitions). However, meta-analytical data suggests that a higher training load is required for optimal neural adaptation and strength progression, especially among advanced individuals. As a general recommendation for maximizing muscular strength, novice and intermediate individuals should utilize training loads of 60-70% of 1 RM with 8-12 repetitions, whereas advanced individuals should increase training load to 80-100% 1 RM. Additionally, exercises could be increased in load by 2-10% (more for larger muscle groups) when the individual can perform one or two extra repetitions in two consecutive training sessions. Interestingly, studies have also shown that self-selected resistance training loads tend to be lower than what is recommended (e.g. 38–58% of 1 RM). With this in mind, the training intensity needs to be set above the individual’s threshold (based on targeted number of repetitions) for continuous progression among experienced individuals. 

Several resistance training methods with varying loads have shown increases in hypertrophy in novice and untrained individuals. To maximize increases in lean muscle mass, acute training variables can be manipulated to optimize both mechanical and metabolic factors of resistance training (e.g. varying load/volume). Hypertrophy-focused training typically consists of moderate to very high loading, relatively high volume, and short rest periods. This has been shown to induce a greater concentration of testosterone and growth hormone in comparison to high-resistance, low-volume programs with long (~3mins) recovery intervals. Although both mechanical load and total work has been shown to increase muscular strength and hypertrophy, it seems that the total work of traditional resistance training (high load, low repetition, and long rest periods) may not be optimal for increasing lean muscle mass. A combination of hypertrophy and strength training appears to be most effective for advanced hypertrophy training. A general recommendation for novice and intermediate individuals is using a moderate load (70–85% of 1 RM) for 8–12 repetitions per set for 1-3 sets per exercise. For advanced training, it is recommended that a loading range of 70–100% of 1 RM be used for 1–12 repetitions per set for 3-6 sets per exercise. These exercises should also be sequenced in periodized manner (e.g. emphasis on 6–12 RM with less focus on 1–6 RM loading). 

Movement velocity is fundamental training variable in power training (see: repetition velocity). Another key factor to understand is that the intensity at which peak force is produced depends on the type of exercise, the muscles used, and the individual’s strength level. For ballistic exercises (where weight is explosively projected into a flight phase), the peak power ranges from 15-50% (upper body), and 0-60% (lower body) of 1RM, whereas traditional exercises range from 30-70% of 1RM. For Olympic lifts, the peak power is attained at 70-80% of 1RM. It is recommended that a power component is incorporated as a part of a periodized strength training program. These exercises should consist of 1-3 sets per of light to moderate loading (30–60% of 1 RM for upper body exercises, 0–60% of 1 RM for lower body exercises) for 3-6 repetitions. To further enhance power, individuals should incorporate both heavy loads (85–100% of 1 RM) and light to moderate loads (30–60% of 1 RM for upper body exercises, 0–60% of 1 RM for lower body exercises) performed in an explosive manner. These exercises should consist of 3-6 sets of 1-3 repetitions. Thus, developing both the strength and speed components of the power equation.

High volume (>15-25 repetitions per set, multiple sets) training coupled with light loads has been proven the most effective for improving local muscle endurance. However, moderate to heavy loads (paired with short rest intervals) have also shown similar improvements, albeit not as pronounced. As a general recommendation, novice and intermediate training should consist of relatively light loads and high volume (10-15 repetitions) to ensure high metabolic demand. Advanced local muscle endurance training should comprise of various loading strategies, performed for multiple sets (10-25 repetitions) and structured in a periodized manner. The overall emphasis should be on a high overall training volume.

Volume

Training volume refers to the sum of repetitions performed in a workout multiplied by the resistance (kg/lbs) used. This makes training volume a good representation of the duration of which muscles are under stress. Training volume has been proven to have a significant impact on hypertrophic, metabolic, and hormonal responses to resistance training, as well as the subsequent physical adaptations. This is also supported by the fact that when other acute training variables remaining unchanged, increasing training volume also increases time-under-tension, and thus, produces a stronger anabolic stimulus for muscle growth. 

Training volume can be manipulated in several ways; 1) changing the number of exercises in a workout session, or 2) changing the amount of repetitions in a set, or 3) changing the number of sets performed of each exercise. Several meta-analytical studies have shown multiple-set programs lasting between 17-40 weeks to produce greater strength gains in both untrained and trained individuals in comparison to single set programs. To date, no study has shown single-set training to be superior to multiple-set training, although the strength enhancing effect of multiple set programs appear to be more pronounced among moderately trained individuals, whereas novice individuals seem to benefit from both single-set and multi-set programs. These studies concluded that 3-4 sets per exercise produced the greatest strength enhancing stimulus during short and moderate-term training periods. For long-term progression, a moderate increase in training volume is recommended, along with sufficient increase in resistance. The general recommendations for training volume is 1-3 sets for novices, whereas progressing to intermediate and advanced stages requires a systematic manipulation of both training load and volume, whilst ensuring a growing training stimulus over time. Increasing the volume too drastically is not recommended due to risk of overtraining or injury.

Several studies have shown increases in muscle hypertrophy using both single and multiple set programs among novice to intermediate individuals. However, this effect appears to be more pronounced when multi-set exercises are used. Most programs aiming for increased lean muscle mass consist of moderate to very high loading, relatively high volume, and short rest intervals. These are thought to have the greatest metabolic response (increased testosterone, growth hormone, and protein synthesis) for muscle growth in comparison to high-resistance, low-repetition sets utilizing long (3min) rest periods. For optimal muscle growth, several acute training variables (load/volume) should be manipulated to offer a sufficient mechanical and metabolic stimulus, especially among advanced stages of training. Although training volume offers a positive dose-response relationship, more research is needed to identify the level over which hypertrophic adaptations begin to plateau and the risk of overtraining syndrome starts to increase. The general recommended training volume for hypertrophy is 8-12 repetitions per set utilizing moderate loading (70–85% of 1 RM) for 1-3 sets per exercise for novice and intermediate individuals. For advanced individuals, the recommended training volume consist of 1-12 repetitions of high resistance (70–100% of 1 RM) per set for 3-6 sets per exercise, and performed in a periodized manner (emphasis on 6-12 RM, less on 1-6 RM).

For power-specific training, the recommended training volume is 3-6 repetitions per set, repeated for 1-3 times per exercise. More advanced training methods can be divided into two categories; 1) heavy loading (85–100% of 1 RM) for increasing the force component of the power equation, and 2) light to moderate loading (30–60% of 1 RM for upper body exercises, 0–60% of 1 RM for lower body exercises) performed explosively to increase the rate of force development. The aforementioned factors are crucial in order to reach as high of a peak velocity as possible during the lift.

Finally, it seems that high-volume (multiple sets) training produces the greatest enhancements in high-intensity and absolute local muscle endurance. As a general recommendation, novice and intermediate individuals should use relatively light loads and moderate-to-high volume (10-12 repetitions per set). Advanced individuals should incorporate several loading methods to their training, with multiple sets of 10-25 repetitions per exercise. These should also be performed as a part of a periodized training program, leading to a higher volume using lighter intensities.

Rest

The amount of rest between sets and exercises significantly affects metabolic, hormonal, and cardiovascular responses to an acute bout of resistance exercise as well as the performance of subsequent sets and overall training adaptations. The rest period duration significantly affects muscular strength, whereas its effects on muscle hypertrophy are less known. 

Several studies have shown that the number of repetitions performed in a set may be compromised by shorter rest periods (30s-2mins) due to incomplete strength recovery, whereas longer (3-5mins) rest periods seem to produce less adverse effects on overall strength performance. Similarly, most longitudinal studies have shown greater increases strength with long rest periods (2-5mins) than with short (30-40s) rest periods. Thus, the recommended rest period for increasing absolute strength and power is at least 2-3 minutes between sets for multi-joint structural exercises (e.g. squats, deadlifts, cleans, etc.) using near-maximal loads. Long rest periods ensure that each repetition is performed with sufficient quality (e.g. safety reasons and to achieve a high peak velocity during power training) to elicit desired neurological responses. For single-joint and assistance exercises, a shorter rest period of 1-2 minutes may suffice. However, the rest period length depends on the complexity (e.g. longer periods for Olympic lifts etc.) of the exercise as well as the reason for incorporating it into the training program. Thus, not all exercises require the same period of rest. 

To maximize muscle hypertrophy, the recommendation for rest is 1-2 minutes between sets with moderate-to-high intensity and volume. This seems to produce the greatest acute anabolic hormonal response in comparison to programs utilizing long periods of rest and very heavy loads. These acute hormonal responses have been considered even more important for muscle hypertrophy than chronic changes, meaning that hypertrophy can be trained with various rest intervals and training intensities. This also means that training for muscle hypertrophy fundamentally differs from strength or power training because the objective is to produce an anabolic environment. 

For local muscle endurance, the recommended rest duration is 1-2 minutes for high-volume (15-20 repetitions) and <1 minute for moderate-volume (10-15 repetitions) sets. These shorter rest periods are essential because the metabolic demands are an important stimulus to improve local muscle endurance (increased capillary and mitochondrial density, lactate buffering, muscle fiber adaptations, etc.).

Type of muscle action

Resistance training programs consist of mostly dynamic repetitions of concentric (muscle shortening) and eccentric (muscle lengthening) muscle actions, whereas isometric (no change in muscle length) actions play a secondary role in stabilizing active muscles. Eccentric movements produce the greatest amount of force, whilst requiring less motor unit activation, and thus, being less metabolically demanding. Eccentric actions also promote hypertrophic adaptations, albeit also causing greater delayed onset muscle soreness in comparison to concentric actions. The muscular strength improvement in dynamic concentric actions is the greatest when combined with an eccentric muscle action. Eccentric-isokinetic (contraction remains constant while muscle length changes) training has shown greater gains in muscle-specific actions than concentric training.

The manipulation of muscle actions seems to have minimal effects to the overall effectiveness of a training program. However, adding isometric exercises (e.g. functional isometrics, supra-maximal exercises) may be beneficial in specific situations. For example, certain isometric exercises have proven useful in the treatment of lower back pain due to the recruitment of spinal-stabilization (postural) muscles.

It is recommended that novice, intermediate, and advanced individuals include exercises utilizing eccentric, concentric, and isometric muscle actions in their training program.

Repetition velocity

Muscle contraction velocity during dynamic movements has a tremendous impact on metabolic, hypertrophic, and neural responses to resistance training. It is also inversely related to the relative load in maximal muscle contractions. The repetition velocity can be roughly divided into fast (<1s concentric contraction: 1s eccentric contraction), moderate (1:2), slow (5:5), and super slow (10:5-10:10) movements. However, there seems to be variability from one exercise to another.

Slow movement speeds can be categorized in two ways; intentional and unintentional. Intentional slow-velocity contractions utilize submaximal loads and allow for increased control of movement velocity and time-under-tension. Unintentional slow velocity contractions occur when the intensity or fatigue affect the velocity of movement. Studies have shown that intentionally slow movements have significantly lower concentric force production and corresponding neural activation, albeit having a lower rate of energy expenditure. This results in lower peak force, less power, and fewer repetitions in comparison to self-selected velocity with matching intensity, which is based on a continuum where the highest number of repetitions can be performed with high velocities, whereas the number of repetitions decrease proportionally as the velocity decreases. This may be due to reduced motor unit activity of slower movement velocities, which may not provide a sufficient training stimulus for strength progression in trained individuals. If intentional slow repetitions are chosen, a ~30% reduction in load is needed to ensure the same number of repetitions as moderate velocity training.

Moderate and fast velocities have shown greater improvements in performance (volume, work and power output, number of repetitions) in comparison to slow movement velocities. Thus, lifting the load as fast as possible appears to produce the greatest strength gains. The recommendations for movement velocity is slow to moderate for novices, moderate for intermediates, and a variety of slow to fast movement speeds for advanced individuals. However, the chosen velocity should always correspond to the intensity of the exercise, and the general intent should be to maximize the velocity of the concentric muscle action.

As mentioned previously, the intensity at which peak power is attained varies according to the exercise type, what muscle groups are used, and the individual’s strength level (see: training load). Although any intensity can improve power and shift the force-velocity curve to the right, the variability at which peak power is attained means that training methods must be chosen according to the specific needs of the individual and their sport. Fast lifting velocities with submaximal loads are crucial for optimal power development. Thus, any power-related exercise should be performed with maximal acceleration.

The optimal repetition velocity for hypertrophy is yet to be established. It has been suggested that slow and moderate velocities produce a more significant stimulus for muscle growth. However, intentional slow movements require a reduction in training load, resulting in a lower metabolic and lactate response when total training time is equated. Therefore, it appears that hypertrophy can be effectively trained with a variety of movement velocities. The recommended movement velocity for hypertrophy appears to be slow to moderate among untrained and intermediate individuals. Advanced individuals may also utilize fast movement speeds depending on the load, repetitions, and training goals.

Increasing time-under-tension with sufficient loading appears to be optimal for improving local muscle endurance. This is due to the fact that increased fatigue is key to induce the wanted training adaptations of local muscle endurance. The training recommendations for this type of training are; 1) using intentionally slow velocity with moderate number of repetitions (10-15) and 2) using moderate-to-fast velocity with a high number of repetitions (15-25).

Frequency

Training frequency refers to the number of resistance training sessions performed or the number of times a muscle group is trained in a specific timeframe (usually a week). The optimal frequency depends on multiple factors, including volume, intensity, exercise selection, fitness level, the number of incorporated muscle groups, as well as the individual’s ability to recover. Several studies have found that strength gains among untrained individuals were the highest with a training frequency of 3 times per week in comparison to 1 or 2 per week programs. However, a training frequency of 1-2 per weeks seems to be an effective maintenance frequency for individuals regularly participating in resistance training. The aforementioned training frequency seems to work from untrained to intermediate individuals, whereas other training variables (exercises choice, volume, intensity) may have a bigger impact on strength adaptations.

For further development, a training frequency of 3-4 may be optimal depending on the workout split (e.g. 3 per week for whole body split, 4 per week for upper/lower split as long as muscle groups are trained at least twice per week). The optimal training frequency for advanced individuals and elite-level athletes varies greatly. The rationale behind high-frequency training (4-6 sessions per week) is that it allows for better performance in each training session due to scheduled periods of recovery, food intake, and nutrition supplementation. Double split routines (two sessions per day utilizing different muscle groups) have reportedly produced greater increases in muscle cross-sectional area (CSA) and strength in comparison to training once a day.

Power training is traditionally built into a periodized strength training program. Due to their similarities, the frequency for power training follows similar recommendations as strength training; 2-3 times per week for novices (utilizing the entire body), 3-4 times per week for intermediates (full body or a training split), and 4-5 per week for advanced individuals (full body or a training split).

The optimal frequency for muscle hypertrophy depends on training intensity, volume, muscle groups trained, as well as the individual’s level of fitness. Studies have shown that training 2-3 per week can improve hypertrophy among novice and intermediate individuals, whereas higher frequencies (4-6 per week) have been suggested for more advanced men and women. However, higher training frequencies also require careful planning and the utilization of training splits (e.g. upper/lower body split) to ensure that each major muscle group is trained twice per week (e.g. 1-3 muscle groups trained per workout). The optimal frequency for local muscle endurance appears to similar to muscle hypertrophy training. 

Training variables determine both the training stimulus of an exercise and the long-term adaptations of a training program.

Final thoughts

There are several ways to bring variety to a training routine. These include load, volume, rest, exercise choice and order, muscle action, movement velocity, and training frequency. These so-called training variables not only decide the training stimulus of a single workout, but also determine the long-term adaptations of a periodized training program. 

To ensure effective and sustainable progression, training must follow the basic principles of strength training; individuality, specificity, overload, progression, adaptation, and reversibility. In short, the body must be constantly put under more stress that it is accustomed to in order to continue improving in performance. These aforementioned training variables are at the very heart of this process. Thus, it is essential that they are incorporated into a training program in a structured way.

Did you learn anything new about training variables? Let us know in the comments.

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