You need to follow scientific strength training rules if you want to build strength and muscle mass efficiently. The following rules are condensed from the Evidence-based Resistance Training Recommendations of Fisher et al .
Muscular strength is simply defined as the ability to exert force. The body increases muscle mass when increased mass is required to produce greater amounts of force. Strength and muscle grow only if you subject your muscles to ever-increasing demands for force production.
This means you must design your training so that you can gradually increase the force you can exert, which means gradually increasing the amount of resistance you can handle for specified time periods.
This fact leads many people to focus only on increasing the number of repetitions they can perform, or the total amount of weight they can lift in an exercise, at the expense of proper exercise form. This is counterproductive. You can't achieve true progression of resistance without standardizing exercise form. You have to implement the other strength training rules below in order to ensure that you are making genuine progress.
If you want to ensure that you are actually progressing in strength, you need to standardize your exercise form. Here's why:
Let's say you can do 10 full range pull ups with your bodyweight, and each repetition is performed as follows:
You decide to add ten pounds around your waist at your next training session. You perform 4 repetitions. You might think it goes without saying that you have progressed. However, upon analysis, in this session you performed the pull ups as follows:
On this second session, you have increased the resistance, but you have changed your pull up performance in a way that makes each repetition much easier. Therefore, it is unclear whether you have actually progressed or imposed greater demands on your upper back, biceps and forearms.
Proper form is one of the most important strength training rules. It involves performing a full range of motion, easing into and out of the stretched positions, and incorporating brief pauses in the stretched or contracted positions where the exercise is most difficult.
In strength training, you are not using your muscles to do something to the resistance (whether bodyweight or external weights), your are using the resistance to do something to your muscles – namely, stimulate them to grow stronger and larger. Therefore, you must make progression of resistance or difficulty subordinate to maintenance of consistent form.
Performance of any exercise can involve up to three different types of muscle activity:
Exercise form includes repetition duration: how long it takes to perform each repetition or phase of the movement. Research suggests that repetition durations ranging from 0.5 to 8.0 s produce similar muscle growth, but moving deliberately slowly so that repetitions take 10 s or more may be inferior [13, 14].
Generally, and to a point, slower movement allows one to generate greater tension in the active muscles, which is superior for strength and mass development. Here’s how you determine the optimum repetition speed for any movement:
For most exercises that start from the bottom position such as overhead presses and chin ups, start a repetition using only enough force to initiate movement. From there, continue to apply just enough force to maintain the speed of movement without acceleration. Once you reach the top end of the range of motion, pause very briefly - one second or less - and reduce your force production to allow the weight to reverse direction. Now produce just enough force to allow a slow the descent of the load. At the bottom pause briefly to dissipate elastic forces (i.e. no bouncing out of the bottom), then repeat the process for the next repetition.
For most exercises that start from the top position such as dips and squats, start a repetition by smoothly and slowly unlocking the joints to initiate movement, producing sufficient force against the load to maintain a slow descent into the bottom. Once you reach the bottom, most difficult position, pause for 1-2 seconds to dissipate elastic forces. Next, generate just enough force to get the load moving upward with minimal acceleration. At the top pause briefly to allow kinetic energy to dissipate, and then repeat the process for the next repetition.
In the second half of the set, as you fatigue, you can move as fast as possible, but because of fatigue produced by the first half of the set, you will not be able to move quickly.
This method of performance minimizes momentum so makes the muscles work much harder on each repetition. Most importantly, it minimizes the risk of injury due to impact forces caused by sudden acceleration and deceleration.
Harder is better. If you perform exercises this way, generally your repetitions for major upper or lower body movements will be 6 to 10 seconds in duration, although the time will vary from individual to individual due to differences in limb length. Movements with very short strokes such as rise on toes, wrist extension or flexion, or neck extension or flexion will have shorter repetition duration, and movements with longer strokes such as chin ups or deep squats will have longer repetition duration.
Remember this: In training your goal is to make your body work hard in order to stimulate adaptation. Thus, you should make the exercises as difficult as possible by maintaining strict form. Relaxing form to achieve more time under load, more repetitions or more resistance will reduce stimulation and thus hinder true progress. If you thoroughly stimulate the muscles and provide adequate rest and recovery the progression of time under load or resistance will take care of itself.
Effort (sometimes called intensity) refers to the level of effort you put into training, which can range from 0 (no training) to 100 (full effort).
Contrary to common belief, you do not have to use high load, low repetition dynamic training, or short duration (<30 second) isometric training to increase strength. It has been proven that load plays little to no role in strength development provided that training involves exerting maximum efforts.
Muscle hypertrophy is fundamentally driven by motor unit activation. Motor unit activation follows the size principle of muscle physiology.
"The size principle states that when the central nervous system recruits motor units for a specific activity, it begins with the smaller, easily excited motor units and progresses to the larger, more difficult to excite motor units. An increase in force production is a result of the orderly activation of a greater number of motor units (recruitment) and an increase in their frequency of activation (rate coding). Most of the peer-reviewed evidence strongly suggests that there are no functionally meaningful violations of the size principle".
If you train with a moderate or low load up to a point near momentary muscular fatigue (not able to move the resistance),
as you exert muscular tension against the resistance over a period of
time or set of repetitions, motor units are sequentially recruited
starting with low threshold (low force) units and proceeding through
high threshold units as fatigue builds. When you reach momentary
muscular failure, you have recruited all motor units.
that performing resistance training with either low or high loads (high
or low time under load, respectively) provides a similar and sufficient
stimulus for both strength and hypertrophy [3, 4]. In other words, you don't have to use high loads (or high difficulty low-leverage static holds) that would enforce very limited time under load (<30 seconds time under load) in order to develop either dynamic or isometric strength.
A 2017 study demonstrated that the level of effort, not the level of exercise resistance (as a percent of maximum voluntary contraction), determines the results you get from training. Subjects who exerted high effort increased their strength by about 20% in 6 weeks, while those exerted low effort increased their strength by only about 2% in the same time period.
While it is necessary to use a high level of effort to produce optimal results from training, excess effort is a negative factor in training. On the one hand, you must reach a minimum level of effort or intensity to recruit sufficient motor units and stimulate adaptation. On the other hand, if you exert maximum effort and expect to surpass previous performances every session, you may become psychologically averse to training. Further, the higher the intensity of the training stimulus, the more time you need to recover from that training stimulus.
To illustrate, consider the way the body responds to sunlight exposure as a stimulus for tanning. If the sun exposure is too intense (e.g. noon on a Arizona summer day) the skin will burn and it will need many days, maybe a week or more, to recover from the burn and acquire a tan. A more frequent (e.g. daily) and longer exposure to a somewhat milder stimulus (e.g. 9-9:30 AM) will produce a tan more quickly.
Consequently, one must regulate intensity wisely to sustain progress. Some people – perhaps most – will find that training brutally hard (beyond positive failure) is less productive in the long term than training hard enough (just to failure or just short of failure).
You can regulate training effort (intensity) with mindfulness of body responses.
In his book The Way to Live the famed early 20th Century wrestler and strongman George Hackenschmidt made some interesting recommendations along these lines. He wrote:
“If for any kind of work the breath through the nose ceases to be sufficient, one ought to either discontinue the work or restrict the movement until breathing has again become normal.”
This is a way of regulating intensity through mindfulness of breathing difficulty, as done by runners. The idea is to work hard, but not so hard that you are uncomfortably gasping for breath. Of course this does not apply to conditioning training such as sprint intervals.
Hackenschmidt also advised:
“Never on any account continue the exercises until exhaustion sets in and always relax your muscles afterwards.”
Some people think that in this statement Hackenschmidt was expression opposition to training any movement to momentary muscular exhaustion. I don't think so. Here he is saying that one's training sessions should not be so hard and long that you feel systemically exhausted by them.
Again, work hard, even very hard, but don't drive yourself into the ground. Focus on progression of resistance or difficulty of exercise. Remember, your goal is to get progressively stronger, not to have the hardest possible training sessions. You must train hard enough to stimulate changes, but not so hard that you prevent changes.
Always focus on long-term progression of resistance in perfect form. Regulate intensity to achieve progression. If you aren't progressing, your level of effort may be either too low or too high. Find out which it is and fix it.
Volume refers to the amount of exercise you perform. Volume and intensity of effort are always inversely related. The more force you
exert, the less time you can sustain it. You can run hard and fast, or
you can run for a long time, but you can't run hard and fast for a long
time. This is a simple physiological fact.
This means that if you train with a high level of effort, you literally can not tolerate a high volume of exercise. Since a high level of intensity is physiologically required for stimulation of gains in strength and muscle mass, a training routine specifically designed for these purposes must be a low volume routine.
Most resistance trainers calculate volume by the number of sets and repetitions performed. There is a big problem with this.
Suppose in one training session I perform 10 pull ups, each taking 6 seconds to perform. In another training session, I perform 4 sets of 5 repetitions, each taking 3 seconds to perform.
If you account by sets and repetitions, in the second session I performed 20 repetitions, twice the volume of work as in the first session. However, if you account by the actual amount of time spent doing repetitions, the volume of these two sessions is identical:
Session 1: 10 pull ups x 6 seconds each = 60 seconds of actual time under load
Session 2: 4 sets x 5 pull ups x 3 seconds each = 60 seconds of actual time under load
It is the amount of actual time under load that imposes demands on the body's resources. The greater the time under load, the greater the demands on your body.
Many people say that single-set training "doesn't provide enough volume" for some results. However, as illustrated by my example above, a single set can provide as much actual volume of exercise – measured in time under load – as multiple sets.
Some meta-analysis studies have suggested that multiple-set routines are more productive than single-set routines, advocates of single-set training have questioned the validity of the conclusions of these meta-analysis studies due to the high variability in quality and execution of the experimental studies included in the meta-analyses [5, 6]. They point out that the vast majority of studies report little or no difference in strength or hypertrophy outcomes between single set and multiple set routines.
In fact, performing multiple sets of one exercise generally contradicts the goal of providing progressive loading.
Assume that you perform 10 repetitions to failure with 100 pounds on the first set of an exercise. This will drain strength from both the local muscle tissue and the system. As a consequence, if you attempt a second set with the same 100 pounds, you will be unable to perform the same number of repetitions; or, to obtain the same number of repetitions, you will have to reduce the load.
For crude calculation, the first set provides a load of 10 x 100 = 1000 pounds. If on the second set you achieve only 8 repetitions, the load is only 800 pounds, i.e. 20% less than the first set. Hence the second set is NOT progressive, but regressive. The same applies if you reduce the load to 80 pounds to achieve 10 repetitions on the second set. Either way, the second set (of the same exercise) does not apply the basic principle of progressive resistance or overload. Instead, it just drains energy resources, making recovery more difficult.
Thus, there generally exists no reason to perform multiple work sets of the same exercise, if the quality of the first set is adequate. (This does not mean that one should not perform minimal warm-up sets to prepare for the top set when necessary.)
However, this is a general rule. Some muscle groups – those having a high proportion of type I slow twitch endurance tolerant fibers – will perform as well or better on the second set despite taking the first set to momentary muscular failure. These muscles may respond better to multiple sets.
In such cases, it is best to perform multiple exercises, when possible, to avoid redundancy.
For example, commonly the thighs and hips have a high proportion of slow twitch fibers. If this applies, one should run a trial of training with only one set with an appropriate time under tension (90-120 seconds for muscles with a high ratio of slow twitch fibers) to determine the rate of progress with one set. Once the baseline is established, run a trial with two sets, using a second exercise for the second set (e.g. back squats for the first set, split squats or front squats for the second set). If the two set training routine produces significantly better progress without excessive time cost, retain it; if not, one set is "good enough."
However, for some muscles, diverse exercises are limited. The calves (gastrocnemius) tend to have a high proportion of slow twitch fibers. All calf exercises are basically the same: rise on toes. Hence, if one determines that one's calves respond best to two sets per training session, one has little choice but to repeat the same exercise.
Let me illustrate the poor reasoning and research methods used by proponents of multiple set training.
Burd et al showed that a bout of training with 3 sets (per muscle group, not per exercise) produces greater increases in amplitude and duration of increase in muscle protein synthesis than a bout consisting of only one set per muscle group . This suggests that, for any given muscle group, 3 sets of exercise is more anabolic than 1 set and may over time lead to greater muscle hypertrophy.
However, muscle protein synthesis is what medical scientists call a surrogate outcome. I do not care if my muscle protein synthesis is greater after training with 3 sets than after training with 1 set; I do not want temporarily greater increases muscle protein synthesis, I want stronger and larger muscles.
Every set you do does some damage to your muscles and also drains energy reserves. Before building new muscle, the body must repair damage to existing muscle and recover energy stores. Clearly 3 sets will do more damage and drain more energy than 1 set. Therefore, the body must do more repair to recover from 3 sets than 1 set.
Hence, the presence of greater metabolic activity after one session involving three times more work than the other – 3 sets vs. 1 set – is expected, but it is not proof that the greater volume produces better results, only that it increases recovery requirements. Indeed, this is why there exists an inverse relationship between training volume and frequency; the more volume, the more damage done and energy expended, so the more recovery needed, and the less frequency tolerated.
Moreover, individuals will vary markedly in their tolerance for different volumes of exercise. Some individuals may tolerate and gain from 3 sets, while others may actually regress. In short, the fact that doing more exercise results in more recovery processes does not prove that more exercise produces better outcomes, only that doing more exercise increases the amount of repair to existing tissue the body must accomplish after a training session before devoting resources to building new tissue.
For another example of poorly performed research claiming to support performance of multiple sets, Mitchell et al reported finding no statistical difference in hypertrophy response over ten weeks of training with either 1 set or 3 sets of knee extensions using 80% of 1RM load, but also claimed the 3 set condition produced a 7% increase in quadriceps volume while the 1 set condition produced only a 3% increase in volume, suggesting that a higher volume dose may influence quadriceps (vastus lateralis head) gains .
Table 1 of this study reports that in the group trained with 1 set, type I (slow twitch) fiber size increased by ~16%, and type II by ~20%. In the group trained with 3 sets, type I fiber size increased by ~30% and type II by ~18%. Thus, evidently the 1 set condition produced more hypertrophy in the fast twitch fibers, but less in the slow twitch fibers, and the 3 set condition, the opposite.
If so, this presumably showed that the quadriceps' vastus lateralis head may require a greater time under tension for optimum hypertrophy response, which should be no surprise since the vastus lateralis tends to have a higher proportion (~50%) of slow twitch fibers. There is no reason to assume that this result would apply to other muscle groups such as upper body muscles which typically have a lower proportion of type I fibers.
However, the 1-set and 3-set methods produced equal improvements in strength. This being so, since muscle hypertrophy occurs to support strength increases, what can account for a greater hypertrophy response in the 3-set group? Since the supposed increase in "hypertrophy" observed in the 3-set group in this study was not associated with increased strength relative to the 1-set group, and the increased "hypertrophy" observed in the 3-set group occurred only in the endurance tolerant type I fibers, it is logical to conclude that the "hypertrophy" was not the type we are actually aiming for via strength training. In other words, the 3-set training may have produced an endurance adaptation, not a strength adaptation.
Unfortunately, the authors of this study did not control for repetition or set duration. A properly designed strength training program adjusts the set duration to the muscle fiber type of the muscles being trained. An 80% 1RM load certainly enforced a limited set duration in the 1 set group. Perhaps performing 1 set with a 70% 1RM load (therefore a higher time under tension in one set) produces a result equal to or better than 3 shorter sets with 80% 1RM. It is rational to seek a procedure with the lowest cost: benefit ratio but these researchers did not seek the best dose, and appear to have performed the study aiming to prove their bias in favor of 3 sets.
That accusation is further supported another clear flaw with this study, namely the absence of a group training with 2 sets rather than 1 or 3. It is impossible to identify a dose-response relationship if you do not test doses in the smallest possible increments. In this case, after 1 set, the next possible increment is 2 sets. If following a logical procedure, one should determine the effect of a doubled dose (2 sets) before or simultaneous to testing a tripled dose (3 sets). This is the only way to determine whether any threshold dose exists. Perhaps 2 sets produces results equal or better than 3 sets as the latter may actually be overkill.
The researchers did not use a logical procedure so did not produce the most useful information possible. Rational evaluation of a training methodology should include a cost-benefit calculation. We want to find the minimum dose and cost necessary to produce the desired results. Doubling the set dose doubles the energy cost and more than doubles the time cost of training. Tripling the set dose triples the energy cost and more than triples the time cost of training.
It bears repeating that, according to this study, tripling the set dose and more than tripling the time cost of training did not even triple the results, as even they had to admit that in the end there was no difference in strength outcome, and no statistically significant difference in hypertrophy outcome, between the 1-set and 3-set protocols. Hence the apparent difference in hypertrophy outcome between the two protocols may have been the results of a coincidence of investigator bias and chance.
Kumar et al found no difference in muscle protein synthesis activity following either 3 or 6 sets of resistance exercise . This indicates that there probably exists an upper limit to the amplitude and duration of post-training muscle protein synthesis. In other words, the body can only do so much. This is why overtraining occurs. One simply does more damage to the body in one session than the body can repair in the observed time frame.
To repeat, while some muscle groups and individuals may benefit from up to 3 sets per session for some muscle groups, this may not mean you should do multiple sets of multiple exercises for those muscle groups. Rather, you may need to do a TOTAL of 3 sets (not a hard upper limit) for some muscle groups. If deemed beneficial to perform additional sets (beyond 1) for any muscle group, the total number of sets should optimally be distributed over an equal number of different exercises when possible and practical.
For example, the upper back has many muscles with different functions (humerus adduction and extension, scapular retraction, depression and elevation). Hence, if doing more than one exercise set for the upper back in one training session, you benefit most if you choose different exercises addressing different functions or addressing different ranges of motion, e.g. chin ups, rows, and shrugs.
Also consider that although we divide upper body exercises into pushing and pulling types, the fact is that so-called "pushing" exercises involve "pulling" muscles and vice versa. For example, pull ups are often stated to be an exercise for the back and biceps. In fact, pull ups also train the pectorals, shoulders and triceps. Dips are said to be an exercise for the chest, shoulders and triceps. but in fact they also require strong contractions from the latissimus dorsi and biceps. Thus if you do one set of pull ups and one set of dips, you have effectively done two sets for all of the upper body muscles.
Excess volume is a negative factor in that it takes time and energy to perform greater volumes of exercise, which reduces the amount of time and energy you have available for other life activities. It is only rational to limit the amount of exercise you do to the least amount that will provide the desired results. You should start with the absolute minimum in training volume – that being one direct set for each major muscle group – and only increase volume if you determine doing so has a desirable cost:benefit ratio.
A beginner can train all muscles of the body with a very limited program such as follows (repetition ranges are for typical trainees performing repetitions having ~6 second duration):
Each routine should take about half an hour to complete. Alternate these routines three times weekly.
When you reach intermediate strength levels, if progress slows, you may need to simplify the routines and reduce training frequency.
Most of all, I recommend trusting your direct experience in training. Training is not about forcing your body to respond by pushing it as hard as possible, whether that pushing is in extreme efforts (i.e. high intensity techniques) or in added time under load (more volume, more sets). Training is about coaxing your body to respond by giving it just the right combination of intensity and volume, and it is wise to use the minimum doses of both effort and volume necessary to achieve the desired results, because both your energy and your time are limited commodities.
Remember, in the end, the only thing that matters is progression of resistance or difficulty. Since as I have stated volume is a negative factor that consumes your time and energy, add volume to your training only if you find no other way to achieve progress. Many times, you don't need more volume of exercise, you need more rest and recovery, through reduced volume or frequency (rule 5) or better recovery practices (rule 6), or both.
Frequency refers to how often you train. As with volume, frequency is inversely related to effort. The more effort you put into training, the less frequently you can tolerate the effort.
Resistance training research generally indicates that muscle protein synthesis is elevated for about 36 hours after a resistance training session . This suggests that for most beginning and novice trainees, local muscle recovery is generally completed within 48 hours. Thus, the optimal training frequency for most people is no more frequently than once every 48 hours. Assuming each session trains the whole body, this permits a training schedule of thrice weekly on alternating days.
Some people may do better training only twice weekly. In general, as one advances in strength and development, training sessions become more demanding, and one will need to reduce training frequency to sustain progress, such as training each muscle group only once weekly.
I tend to agree with Arthur Jones that it is best to train the whole body in every strength training session. Doing so enables one to train with both maximum frequency and maximum rest time. In reality, it is impossible to train only one part of your body at a time, as your whole body is involved systemically in any training session. Further, especially with gymnastic strength training, it is practically impossible to isolate any muscle group. You might believe that you are only training part of your body in a split routine, but in fact every time you train you impose stress on your whole body.
At least one study has provided evidence that whole body training thrice weekly may produce greater gains in muscle mass than split routines that train each muscle group only twice weekly . A 2016 meta-analysis suggests that training each muscle group at least twice weekly may produce greater increases in muscle mass than training each muscle group only once weekly . Again, these are general rules mostly applicable to beginners through intermediate trainees. As you advance you may need to reduce your frequency in order to recover fully from training sessions.
Full body routines allow you to train the whole body with maximum tolerable frequency while also allowing you maximum rest days. If you use a full body routine three times weekly, you load every body part thrice weekly while allowing yourself 4 days to rest from strength training. If you try to split the body in two, say upper and lower, you will be forced to strength train 6 days in a week to train both upper and lower body 3 times. Since every training session imposes systemic stress, you will be much more likely to overtrain.
Ideally your strength training should be hard enough to require 48-72 hours of rest before you can repeat the effort. Typically you can achieve this by training each exercise very close to momentary muscular failure without including any so-called intensity-enhancing techniques. This translates to strength training two to three times per week for the average person.
Strength training makes demands on your recovery ability. While your potential recovery ability is most likely genetically determined, several factors determine whether you realize your full potential for recovery from intense exercise. To realize your full recovery capacity you can do the following:
To succeed in strength training, you need to incorporate periods of reduced effort into your schedule to allow the body to recover from the intense efforts. On page 181 of Building the Gymnastic Body, Christopher Sommer explains:
"By constantly attempting to improve from workout to workout; more weight, more reps, more volume, more speed, etc. over and extended period of time, the athlete will eventually, usually within an eight week time frame, come up against their [sic] current physical limitation. Continued attempt to try to force the body to blast thru these very real physical limitations are fruitless as the body's schedule of regeneration and adaptation is set and cannot be exceeded.
"All that will be accomplished by continually struggling to exceed these biological limitations are a plethora of over-training issues, among these being: joint pain, muscle strains, lack of energy, decrease in coordination, lack of explosiveness, connective tissue issues and mental fatigue. In addition, continuing to push in the fact of these over-training issues will often result in a short-term injury, which could easily have been resolved through reduced training or rest, becoming a chronic or permanent physical impairment."
The mind has limitless desires, but the body has natural limits. Improvements in your body are accomplished by biochemical reactions that take definite amounts of time. It is impossible to increase the rate at which your body can build muscle, bone, or connective tissue. You can provide the stimulus for change, but you have to allow the body to change at its own rate. As the European proverb goes, you can't push the river.
If you are training properly but not making regular progress, you probably are not getting adequate recovery. You may need to reduce your training frequency from thrice weekly to twice weekly, or from twice weekly to once every 4-5 days, or from once every 4-5 days to once weekly.
1. Fisher J, Steele J, Bruce-Low S, Smith D. Evidence-based resistance training recommendations. Medicina Sportiva 2011;15(3):147-162.
2. Jungblut S. The correct interpretation of the size principle and its practical application to resistance training. Medicina Sportiva 2009;13(4):203-209.
3. Morton RW, Oikawa SY, Wavell CG, et al. Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men. J Appl Physiol 2016;121:129-138.
4. Fisher J, Steele J, Smith D. High- and Low-Load Resistance Training: Interpretation and Practical Application of Current Research Findings. Sports Medicine 2016 Aug 01
5. Fisher J. Beware the Meta-Analysis: Is Multiple Set Training Really Better than Single Set Training for Muscle Hypertrophy? J Ex Physiol (online) 2012 Dec;15(6):23-30.
6. Genil P, Arruda A, Souza D, et al. Is there any practical application of meta-analytical results in strength training? Front Physiol 2017;8:1.
7. Burd, Nicholas A et al. “Resistance Exercise Volume Affects Myofibrillar Protein Synthesis and Anabolic Signalling Molecule Phosphorylation in Young Men.” The Journal of Physiology 588.Pt 16 (2010): 3119–3130. PMC. Web. 2 June 2017.
8. Mitchell, Cameron J. et al. “Resistance Exercise Load Does Not Determine Training-Mediated Hypertrophic Gains in Young Men.” Journal of Applied Physiology 113.1 (2012): 71–77. PMC. Web. 2 June 2017.
9. Kumar, Vinod et al. “Age-Related Differences in the Dose–response Relationship of Muscle Protein Synthesis to Resistance Exercise in Young and Old Men.” The Journal of Physiology 587.Pt 1 (2009): 211–217. PMC. Web. 2 June 2017.
10. MacDougall JD, Gibala MJ, Tanopolski MA, et al. The Time Course for Elevated Muscle Protein Synthesis Following Heavy Resistance Exercise. Can J Appl Physiol 1995;20:480-86.
11. Schoenfeld BJ, Ratamess NA, Peterson MD, Contreras B, Tiryaki-Sonmez G. Influence of Resistance Training Frequency on Muscular Adaptations in Well-Trained Men. J Strength Cond Res. 2015 Jul;29(7):1821-9. doi: 10.1519/JSC.0000000000000970. PubMed PMID: 25932981.
12. Schoenfeld BJ, Ogborn D, Krieger JW. Effects of Resistance Training Frequency on Measures of Muscle Hypertrophy: A Systematic Review and Meta-Analysis. Sports Med. 2016 Nov;46(11):1689-1697. Review. PubMed PMID: 27102172.
13. Schoenfeld BJ, Ogborn DI, Krieger JW. Effect of Repetition Duration During Resistance Training on Muscle Hypertrophy: A Systematic Review and Meta-Analysis. Sports Med 2015 Jan. <https://www.researchgate.net/publication/271533635_Effect_of_Repetition_Duration_During_Resistance_Training_on_Muscle_Hypertrophy_A_Systematic_Review_and_Meta-Analysis>
14. Schilling BK, Falvo MJ, Chiu LZF. Force-velocity, impulse-momentum relationships: Implications for efficacy of purposefully slow resistance training. J Sports Sci and Med 2008;7:299-304.