Periodization is a term that refers to the systematic manipulation of the acute training variables over a long-term period that may range from days to years.

The acute variables include: 1) Exercises used, 2) Exercise order, 3) Weight used/intensity (reps completed), 4) Sets performed, 5) Rest periods taken between sets, and 6) Rep speed/tempo used. The original concept of periodization was developed in the former Eastern Bloc countries back in the late 1950’s/early60’s to optimize athletes’ adaptations to resistance training. More importantly, periodization revolves around the athlete’s competitive calendar, such that they are at their competitive peak for competition.

The basis behind periodization is a concept called the general adaptation syndrome (GAS). GAS describes three stages an organism – such as an athlete – goes through when exposed to a novel stress (Seyle, 1936). These three stages are 1) Alarm, 2) Adaptation, and 3) Exhaustion. As a new stress is placed on the body –lets use heavy training in the 3-5 rep range as an example – the body first goes through an alarm reaction. During this stage the body momentarily gets weaker. But with continued exposure to the stress (i.e. successive workouts), the body enters the stage of adaptation. In this stage, the body super compensates for the stress – such as increasing muscle strength – to better deal with it.

If the body is continually exposed to the same stress for too long a period of time it may enter the stage of exhaustion where its adaptation to the stress may actually decline. This may mean that the strength gains made during the adaptation stage will cease and stagnation may set in. It may even lead to an actual decline in strength. Although this theory is now considered a simplistic take on the body’s response to stress, it does hold true on the surface level and explains the reason periodization is so important for proper adaptation to strength training.

You must expose the muscle to any one training style for just long enough to reap the benefits but avoid a nosedive of those positive adaptations. At this stage, a new training style should be introduced, and the cycle continues. This will prevent stagnation and maximize training adaptations. A simplistic take on periodization is the maxim, “everything works, but nothing works forever”.

The three periodization schemes most commonly used by strength coaches and also the three that are the most extensively researched are known as 1) Linear Periodization (often referred to as classic periodization), 2) Reverse-Linear Periodization, and 3) Undulating Periodization.

While there are many other more obscure periodization schemes out there (pendulum approach, wave loading, step loading, etc…), a discussion covering these three will be more than sufficient to fully understand and utilize periodization. Regardless of the exact plan, periodized strength training programs have been shown through research to be significantly more effective than non-periodized programs for increasing strength, power and athletic performance in both men and women (Kraemer, et al. 2003; Marx, et al., 2001; Rhea and Alderman, 2004; Willoughby, 1993).

Classic (Linear) Periodization

As the name implies this periodization system is the hallmark periodization scheme most associated with the term periodization. It was designed by Russian sport scientist Leonid Matveyev. In its most general form, classic periodization divides a long-term training period called the macrocycle (typically runs 6 months to one year with athletes, but may be up to 4 years in length such as with Olympic athletes) into several phases called mesocycles (usually lasting several weeks to months). Each mesocycle can be further divided into weekly microcycles. See Figure 1 above for a sample paradigm of Mayveyev’s classic linear periodized model. In Figure 1 (above at the top of the page) intensity represents weight used and volume represents sets multiplied by reps. So over time the weight used (intensity) increases while the reps completed per set decrease. Figure 2 below represents the classic linear periodized model in table form.

Phase	Reps	Intensity	Sets	Volume
Hypertrophy	8-12+	Low-Moderate	3-5	Very High
Basic Strength	4-6	Moderate-High	3-5	Moderate-High
Strength and Power	3-5	high	3-5	Low
Peaking	1-3	Very High	1-3	Very Low

Again, as this table shows, the rep ranges decrease with each phase (mesocycle) as the weight used (intensity) increases.

The first phase (mesocycle) is classified as the hypertrophy phase and is categorized as being low to moderate in intensity with rep ranges usually being around 8-12 per set, and sometimes as high as 20 or more reps per sets.

It is considered very high in volume (sets x reps) since rep ranges are so high. For example, the volume is much higher when doing 3 sets x 12 reps (36 reps) per exercise as compared to doing 3 sets x 3 reps (9 reps) per exercise. The goal of this phase is typically to prepare the athlete for the high intensity (heavier) training that is on its way. The muscle hypertrophy they experience from this phase will also enhance the strength and power gains that they will make in the later stages.

*Note: In some periodized programs designed for athletes the hypertrophy phase may be preceded by what is known as a general preparedness (GP) phase. This is especially true if the athlete being trained is a rank beginner or is an athlete who is returning after an off-season where little, if any training took place. This would provide a means to prepare them for the hypertrophy phase with very low intensity and moderate to high volume training.

The second phase of the classic periodization model is usually the strength phase. As the name implies, the major goal during this phase is to maximize muscle strength. This phase is typically moderate to high in intensity and volume with reps being in the 4-6 range and the goal being to build up muscle strength.

Following the strength phase is the third phase, the power phase. It is somewhat similar to the strength phase in that the intensity is high with reps and therefore volume, being low – usually in the 3-5 rep range. Although often, the intensity is rather low while reps are still low to build explosive power. The point of this phase is to start transferring the strength gains the athletes made during the first two phases into more explosive power that serves well for competition.

The final two mesocycles prepare the athlete for their competition.

The peaking phase, is the fourth phase and follows the power phase. It is categorized by very low volume with very high intensity with reps as low as 1-3 reps per set. This phase gets them ready for competition by maximizing strength and power. Following this phase they drop the strength training and follow a period of active rest just before competition. The active rest phase is categorized by activity other than strength training such as swimming, hiking, or sports activities like basketball and tennis. This phase usually lasts for only about one to two weeks before a competition to allow the athletes’ body to recover from all the strenuous training so that they can perform at their best. After competition, this phase may actually continue for several weeks before the periodized training scheme starts over again. For this reason, the active rest phase is often referred to as the transition phase.

Microcycles

With the classic linear periodized model, sticking with the same rep range for a full mesocycle, which may last numerous weeks can have some drawbacks. Some athletes may get bored using the same rep ranges for several weeks. Another issue is the fact that some of the adaptations made in a previous mesocycle may be lost in a later mesocycle. For example, gains in muscle size made during the hypertrophy phase may be lost during the strength and power phases where repetitions performed each set rarely exceed 6 reps. Undulating periodization is one way to remedy the issues of the messocycles (see below). However, using a linear model, whether it be the classic linear scheme or the reverse linear scheme (see below) has merit.

Using microcycles may be an even more effective way of utilizing linear periodized training schemes. The term microcycle refers to weekly changes in the weight used and the reps performed. For example, if following the classic linear model, week 1 might be a muscle endurance microcycle with reps in the 12-15 rep range. Then week 2 might be the hypertrophy microcyle with reps in the 9-11 range, Week 3 continues increasing the weight and decreasing the reps for the strength microcycle with reps in the 6-8 rep range. And then in week 4, which could be the strength and power microcycle, reps drop again down to just 3-5 reps per set. After week 4, the cycle repeats itself with week 5 returning to the muscle endurance microcycle. These microcycles can keep repeating in this order until the athlete is ready for competition, or for a non-competitive strength trainer, the program is over after 12 weeks or so.

See Figure 3 below for a sample linear scheme that uses microcycles. This is very similar to my Micro Muscle (a.k.a. Shortcut To Size) program. Figure 3: This table shows the weight and rep range changes that occur each week in each phase of the Micro Muscle (a.k.a. Shortcut To Size) program.

Week/Microcycle	Weight	Rep Range
1	Light	12-15
2	Moderate	9-11
3	Moderate-heavy	6-8
4	Heavy	3-5

Reverse Linear Periodization

Reverse linear periodization basically takes the linear periodization scheme and runs it backwards. While the goal of the classic linear periodization model is to maximize an athlete’s strength and power, the goal of the reverse linear model is to maximize muscle hypertrophy or endurance strength – depending on the rep range that the program concludes with (8-12 for hypertrophy; about 20-30 for endurance strength). Research supports the concept that the reverse linear periodization scheme is more effective for increasing endurance strength than the classic model (Rhea, et al. 2003). Figure 4: This table shows a sample reverse linear periodized model for muscle hypertrophy.

Phase/Mesocycle	Weight	Rep Range
1: Power Phase	Heavy	2-3
2: Strength Phase	Moderate-Heavy	3-6
3: Hypertrophy Phase	Light-Moderate	8-12

*Each phase may typically last 3-6 weeks.

In essence, the reverse linear model starts with the power phase where intensity is very high with reps low (2-3 reps per set). The peaking phase is usually skipped because the athlete is not preparing for competition where power and strength matter. After the power phase has been followed for several weeks comes the strength phase. The strength phase utilizes moderate to high in intensity with lower reps (3-6 reps per set). The goal of these first two phases is to build the strength and power the athlete will need to optimize mass gains or endurance strength.

Being able to lift heavier weight for the desired number of reps during the hypertrophy phase can result in significant gains in muscle mass as well as muscle endurance. The hypertrophy stage comes last in the program and it involves lower intensity with higher reps (8-12 reps per set). If the goal was to prepare an athlete who needed strength endurance (rower; short distance runner; etc.) the reverse linear program would often involve a fourth mesocycle that lightens the weight again and increases the rep range to 20 reps and above per set.

Undulating Periodization

As the name implies, undulating periodization follows a nonlinear scheme, unlike the classic linear and the reverse linear periodization schemes. Undulating models are gaining popularity in strength rooms due to their convenience and effectiveness. In training athletes many undulating periodization schemes follow a 14-day mesocycle with three to four different workouts to stagger. Figure 5: This table shows three different workout types that are staggered with a reverse linear periodized model for training athletes.

Workout Type	Weight	Rep Range
1: Strength/Power Workout	Heavy	2-6
2: Hypertrophy Workout	Moderate	8-12
3: Endurance Strength Workout	Light	15-30+

Instead of sticking with one training phase for several weeks or more, the lifter can change intensity and volume from one workout to another. And the workouts don’t progress in a linear fashion, getting heavier in the resistance used each successive workout, or getting lighter each successive workout. The workouts jump all around from heavy to light to moderate in a random order. For example, if the athlete were following a whole body training split they might perform the Strength/Power workout (2-6 reps per set) on Monday, then the Endurance Strength workout (15-30+ reps per set) on Wednesday and the Hypertrophy workout )8-12 reps per set) on Friday. The following week they may train the Endurance strength workout on Monday, the Hypertrophy workout on Wednesday and the Strength workout on Friday.

One of the great things about undulating periodization is the fact that it requires less organization and planning than do linear periodized programs. For instance, if the individual felt tired or sick, or just the opposite and they felt exceptionally motivated and strong one day, the workout could be changed for that day to better suit their mood and physical health. Or if scheduling was a problem and the lifter was short on time one day, they could switch to a workout with lower volume.

Although it seems that such a training system that requires little planning would be less effective than a program that is scheduled out for months in advance, research has found that undulating periodized programs are just as effective as linear periodized models for the development of strength/power and muscle mass (Marx, et al. 2001; Kraemer, et al. 2000) and are far more effective than non-periodized programs. One study by Rhea et al. (2002) found that undulating periodized training was actually more effective for developing strength as compared to a linear periodized plan.

In actuality, the sporadic nature of the undulating program works as a default for building muscle, strength, and power. That’s because periodization is based on the fact that a physiological system makes adaptations to a stress that it is exposed to (GAS). Yet if it is exposed to the stress for too long, the adaptations will plateau and even reverse to some degree. Given that, the undulating periodized scheme allows the stress (strength training) to be encountered for very short periods before it is changed and then cycled back in. In this model, the different types of strength training (heavy, light, moderate, etc.) are cycled repeatedly from day to day. So it helps to keep the muscle from getting used to the stimulus, yet exposes it frequently enough to cause progressive adaptations. This is often referred to as the principle of Muscle Confusion. So in other words, undulating periodization is basically the principle of muscle confusion, as described by Joe Weider many decades earlier.

One confusing issue with undulating periodization is the fact that is usually described in the scientific literature and textbooks as a system that changes up the resistance used and rep ranges performed every single workout. And this is true IF the athlete is using a whole-body training split where they train their entire body every workout. Since the literature and textbooks focus on strength training for athletes, such as football players and track athletes, who often do train using a whole-body training split, many trainers are confused over how to use undulating periodization using a training split that takes 2, 3, 4 or more workouts to train the entire body.

For example, let's consider a 4-day training split where the individual trains chest and triceps on Monday, Legs on Tuesday, shoulders on Thursday, and back and biceps on Friday. Many trainers assume that to apply undulating periodization the rep ranges might progress like this over two weeks: Week 1 - Monday (chest and triceps): 2-6 reps/set, Tuesday (legs): 15-30+ reps/set, Thursday (shoulders): 8-12 reps/set, Friday (back and biceps): 15-30+ reps/set; Week 2 – Monday (chest and triceps): 8-12 reps/set, Tuesday (legs): 2-6 reps/set, Thursday (shoulders): 15-30+ reps/set, Friday (back and biceps): 2-6 reps/set. While this is fine to train this way, it can get a bit daunting making sure that the same rep range is not repeated for a muscle group. A better option for a 4-day split like the one above would look like the example I have in Figure 6 below. Figure 6: This table shows a sample undulating periodized scheme for a 4-day training split that trains the entire body once per week.

Week 1:

Day	Workout	Weight	Reps
Monday	Chest/Triceps	Heavy	2-6
Tuesday	Legs	Heavy	2-6
Thursday	Shoulders	Heavy	2-6
Friday	Back/Biceps	Heavy	2-6

Week 2:

Day	Workout	Weight	Reps
Monday	Chest/Triceps	Light	15-30+
Tuesday	Legs	Light	15-30+
Thursday	Shoulders	Light	15-30+
Friday	Back/Biceps	Light	15-30+

Week 3:

Day	Workout	Weight	Reps
Monday	Chest/Triceps	Moderate	8-12
Tuesday	Legs	Moderate	8-12
Thursday	Shoulders	Moderate	8-12
Friday	Back/Biceps	Moderate	8-12

Week 4:

Day	Workout	Weight	Reps
Monday	Chest/Triceps	Light	15-30+
Tuesday	Legs	Light	15-30+
Thursday	Shoulders	Light	15-30+
Friday	Back/Biceps	Light	15-30+

Week 5:

Day	Workout	Weight	Reps
Monday	Chest/Triceps	Heavy	2-6
Tuesday	Legs	Heavy	2-6
Thursday	Shoulders	Heavy	2-6
Friday	Back/Biceps	Heavy	2-6

Week 6:

Day	Workout	Weight	Reps
Monday	Chest/Triceps	Moderate	8-12
Tuesday	Legs	Moderate	8-12
Thursday	Shoulders	Moderate	8-12
Friday	Back/Biceps	Moderate	8-12

The form of undulating periodization shown in Figure 6 changes the rep ranges every week, which means it’s an undulating periodized scheme that uses microcycles. This way each muscle group is trained with the same intensity (resistance) and rep range. And each week the resistance and rep ranges change in a random, non-linear fashion.

Combining Periodized Schemes

There is no rule that states that one has to pick one and only one form or periodization and follow it till the end of the program. A great way to really experience gains in muscle size and strength is by using programs that combine periodized models into one program.

A good example of this is the periodized model known as Pendulum Training. In pendulum training, you start off using a classic linear periodized model usually with microcycles. Therefore, you might start off with reps in the 8-12 rep range in week 1. Then in week 2 reps drop down to 6-8 reps per set. In week 3 reps drop down again to 3-5 reps per set. In week 4 the order now switches to a reverse linear periodized model with reps going back up to the 6-8 rep range and then in week 5 to the 8-12 rep range. Then in week 6 it is back to a linear progression with reps dropping down to the 6-8 rep range. The program would continue swinging back and fourth like this similar to a pendulum, hence the name. See table 3.6 for a sample pendulum scheme. Figure 7: Pendulum Scheme

This table shows the weight and rep range changes that occur each week/microcyle when using a pendulum scheme:

Week/Microcycle	Weight	Rep Range
1: Hypertrophy	Moderate	8-12
2: Strength	Moderate-Heavy	6-8
3: Power	Heavy	3-5
4: Strength	Moderate-Heavy	6-8
5: Hypertrophy	Moderate	8-12
6: Strength	Moderate-Heavy	6-8
7: Power	Heavy	3-5

If you have done my Micro Muscle (a.k.a Shortcut To Size) program already, a good way to repeat it but mix it up would be to follow it in a pendulum training order. So the first four weeks would follow the normal program as prescribed in Phase 1. Week 1 would involve reps in the 12-15 rep range, week 2 would be reps in the 9-11 range, week 3 would use reps in the 6-8 range and week 4 would involve reps in the 3-5 range. Then instead of jumping back up to 12-15 reps as you normally would in Phase 2, you move to 6-8 reps in week 5, then 9-11 reps for week 6 and then up to 12-15 reps in week 7. Then in week 8 you move back down to 9-11 reps, in week 9 you are at 6-8 reps per set and in week 10 you are down to 3-5 reps per set. You could end the program here at week 10 or swing back up the rep range for another 3 weeks, ending with 12-15 reps in week 13.

Another way to combine periodized models is to use both linear and reverse linear models simultaneously. This works well with programs that train each muscle group twice per week. For example, with a program that uses a two-day split with chest, back and shoulders worked in workouts 1 and 3 and legs and arms trained in workouts 2 and 4, workouts 1 and 2 could follow a linear order using a microcycle system of getting heavier in weight and lower in reps with each week and weeks 3 and 4 could follow a reverse linear order using a microcyle system with the weight getting lighter and the reps getting higher each week. This is what my 1-2-3 Lean program involves.

And what’s really interesting is that when you then consider the order of the rep ranges with two separate rep ranges being used each week is that the scheme is similar to an undulating periodized model. Here workouts 1 and 2 progress from 9-11 reps in week 1, to 6-8 reps in week 2 and to 3-5 reps in week 3. Workouts 3 and 4 start at 12-15 reps in week 1, then jump up to 16-20 reps in week 2 and finally to 21-30 reps in week 3. But when you consider the order from workouts 1 and 2 to workouts 3 and 4 each week, the reps actually go in this order: 9-11, 12-15, 6-8, 16-20, 3-5, 21-30. That is actually an undulating order.

Comparing Periodized Schemes

Researchers from the University of Alberta put linear periodization and undulating periodization head to head to discover which form of periodization works best for increasing strength gains. They had trained male lifters follow a 12-week periodized strength-training program that consisted of either a traditional linear periodized scheme that progressively increased the amount of weight they used each week or an undulating periodized scheme, which changed weight each week but not linearly.

They reported in a 2011 issue of the Journal of Strength and Conditioning Research that the guys following the linear periodized program increased their 10-rep max strength on all exercises significantly more than the guys following the undulating program. For example, the guys training linearly increased their 10-rep max on the squat by over 90 pounds (over 50%), while the guys following the undulating plan only increased their squat by 60 pounds (30%). On the bench press, the guys following the linear program increased their 10-rep max strength by 35 pounds (25%), but the guys following the undulating program only increased by 25 pounds (20%). Although the researchers are not exactly sure why the linear training program resulted in greater strength gains, they suggested that it may have been due to the fact that the undulating group experienced more delayed onset muscle soreness and fatigue, which could have compromised their training and therefore their strength gains.

However, the fact that the guys had more muscle soreness meant that they had more muscle damage, which can result in greater muscle growth down the road. This study did not measure muscle growth, so there is no telling as to which program resulted in greater muscle mass gains. So I recommend that you use both linear periodization, as well as undulating periodization in your training. For example, after following my 12-week Micro Muscle program, I would suggest moving to an undulating periodized plan, such as my Undulating Mass program or my Train Like Jim series' Undulating Full-Body Micros.

Another study done in 2012 by researchers at the Federal University of Rio De Jeneiro compared the effects of using a linear periodized program versus an undulating periodized program on both muscle growth and muscle strength. They had untrained men follow a linear periodized weight-training program for 12 weeks or an undulating periodized program. The linear periodized group did two set of 12-15 reps per exercise for the first four weeks, then 3 sets of 8-10 reps per exercises for the next four weeks, and 4 sets of 3-5 reps per exercise in the final four weeks of the study. The undulating group used those same three set and rep ranges but cycled them each time they trained. They were using a full-body training workout program where each workout trained all major muscle groups.

One note on the undulating program is the fact that they changed the rep range each workout from 12-15 reps, to 8-10 reps, to 3-5 reps then repeated in that order. Technically that IS linear periodization, but using a microcycle plan, much like my Micro Muscle program. In Micro Muscle, it takes you four workouts to train all the major muscle groups, and then after completing all four workouts you increase the weight and decrease the rep ranges. Since they were training the full body in one workout and then changing the weight and rep range the next workout, this study really compared traditional linear periodization to microcycle linear periodization, and not undulating periodization. Undulating periodization would have cycled the rep ranges in a random fashion, such as 12-15 reps the first workout, 3-5 reps the second workout, 8-10 reps the third workout, 3-5 reps the fourth workout, etc.

Regardless, they reported that the group following the undulating plan increased triceps size by about 5%, while the linear group saw no such increase. The undulating group also increased their biceps size by 10% while the linear group only increased their biceps size by 5%. The undulating group also increased their bench press strength by over 25%, while the linear group only increased by 10%.

Anyone who has followed my Micro Muscle/Shortcut to Size program knows that these results are not that surprising. Microcycles work very well and as this study shows, much better than traditional linear periodization. Maintaining one rep range for four weeks may help you build strength in that particular rep range, but you may lose some of the benefits you gained from the previous rep ranges. For example, when training with a weight that limits you to 3-5 reps per set, strength gains are maximized, but muscle growth is not optimal in this rep range. So any increases in muscle growth during the 12-15 rep and 8-10 rep phases may be lost during the month of using just 3-5 reps. With the mircocycle plan you cycle so frequently through the rep ranges that you get the benefits of each rep range without losing the benefits you gain from the other rep ranges. Plus, the constant changing of weight and rep ranges confuses your muscles and they continue to grow because they can never grow accustomed to one style of training. This is known as the Weider Muscle Confusion Principle.

If you want to try a true undulating periodized plan, take my Micro Muscle program and follow the rep ranges in the following fashion:

Week 1:	12-15 reps
Week 2:	6-8 reps
Week 3:	9-11 reps
Week 4:	3-5 reps
Week 5:	6-8 reps
Week 6:	12-15 reps
Week 7:	3-5 reps
Week 8:	9-11 reps
Week 9:	12-15 reps
Week 10:	6-8 reps
Week 11:	9-11 reps
Week 12:	3-5 reps

Now that you are armed with the knowledge of how to utilize periodization you can take it to the gym and tweak my programs or create your own. Knowledge is power!