Principle of Variety in Fitness: Important or Not?

principle of variety

Bodybuilders of all times and peoples say with confidence that building an ideal shape and strong muscle mass is “a lifelong work.” We decided to conduct an in-depth study of this direction in order to understand the main question – “is it necessary to follow the principle of variety, or can you just make the same movement over and over again?” That is, to find a solution to painful problems – what should beginners do, why not everyone succeeds in achieving results, and what influences this, genetics or improper training?

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Well-known bodybuilders, the faces of popular glossy magazines, confidently declare that the key to success lies in working out each muscle group through individual exposure. More precisely, according to the set goal, it is necessary to build an appropriate strategy, including a set of exercises and certain equipment.

Many experts assure that a few multi-joint exercises in the form of “barbell squats, bench press, deadlift or bent over” are enough for muscle growth.

So, where is the truth, and what is the secret of success – it is worth understanding in more detail.

History of Scientific Research About the Principle of Variety

principle of variety in sport

In the 90s of the XX century, a group of Swedish scientists using magnetic resonance imaging (MRI) experimentally proved that even small variations in sports techniques affect the muscles – redistribute the load on different areas of muscle tissue that carry out the movement.

So, while lifting the bar with a wide grip by bending the forearm, a short biceps head will work, and not a long one. And when performing this exercise on the bench, the load is distributed evenly between them.

Scientists published all the results of the study in a book known in narrow circles.

Subsequently, they decided to continue this practice and conduct an analysis using electromyography (EMG), which allows measuring the “energy value” of active muscles during exercise. The studies were carried out by two methods – using electrodes externally (on the skin) and by introducing them into the muscle abdomen (wire or needle-like).

It was experimentally found that tissue activity changes, even with minor variations in exercises – grip, stance, etc. And even when adjusting the angle of inclination when pressing on the “Scott Bench” [1].

In their works, scientists have noted several reasons:

  • In contrast to the horizontal position, in the position of the head-up when pressing on an inclined bench, the pectoral and anterior beams are active.
  • The load is redistributed when performing isolation and multi-joint exercises. It goes to the back of the thigh. The activity of these segments is greater during isolation [2].
  • The bend of the legs affects the lower sectors of the biceps femoris. The activity of this area is 170%. While the lower part of the semitendinosus muscle is about 65%, in comparison with the deadlift on straight legs.

Principle of Variety: Exercise Options and Localized Hypertrophy


The fact that different exercises affect the activity of certain muscle groups is obvious and proven. But does it affect their growth (hypertrophy)? According to research by another group of scientists – definitely “Yes”.

The results of multiple tests showed:

  • A 12-week training program, including the extension of the arms with dumbbells in the supine position (3 times during this period), gives the maximum increase in the volume of that part of the triceps, which was maximally involved in the exercise [3].
  • With the same time interval and apparatus, the bench press showed similar results [4].
  • In an experiment with leg extension three times a week for 3 months, it was found that there is rapid hypertrophy of the rectus femoris muscle. That is, in the area where the loads were recorded, in relation to others (more inert) [5].

It is also phenomenal that a complex workout, based on several different leg exercises (press, lunges, squats), led to the active growth of the entire quadriceps. At the same time, the basic squat-based program was unable to provide such results [6].

Hence, we can see that the principle of variety works well for fitness goals.

Detailed Comparison of Processes and Results of Different Programs

Variety in Fitness

Two groups of volunteers were tested by Brazilian scientists for 9 weeks. They trained three times a week, working out all parts of the body [7]. The subjects went through the same program, with the exception of a small nuance… The first one performed identical exercises throughout the course, and the second one – changed them during the week (followed the principle of variety).

The permanent scheme included the following:

  1. Bench Press
  2. Front Lat Pulldown
  3. Leg Press
  4. Leg Curl
  5. Biceps Curl
  6. Triceps Extension

The alternation complex was somewhat different. It included three workouts:

Workout 1

  • Bench Press
  • Front Lat Pulldown
  • Leg Press
  • Leg Curl
  • Biceps Curl
  • Triceps Extension

Workout 2

  • Incline Bench Press
  • Rear Lat Pulldown
  • Half Squat
  • Seated Leg Curl
  • Preacher Curl
  • Seated Cable Triceps Extension

Workout 3

  • Decline Bench Press
  • Narrow Grip Lat Pulldown
  • Hack Squat
  • Single-Leg Seated Leg Curl
  • Incline Dumbbell Curl
  • Triceps Kickback

The level of progressive change in tissue thickness was assessed by ultrasound. Individual segments of the quadriceps, biceps, and triceps (proximal, distal, and middle between them) were analyzed. A total of 12 sites were examined. The best results were shown by the program which was based on the principle of variety. Moreover, in the participants of the “fixed group”, the volumes of such sections as the middle section of the lateral thigh muscle, the proximal muscle of the thigh, and the biceps were twice less.

Limitations of Electroneuromyography

Exercise Variety

There are several other factors to consider that affect muscle formation and growth.

Note! Only biomechanically similar effects on tissues can be compared. For example, the change in the angle of inclination during the bench press, and not the deadlift and squats, which in the latter case does not make it possible to establish the effectiveness of the change of exercises in ENMG studies.

In one of their studies, scientists found out what contributes to gluteal hypertrophy more – a “bridge” or a squat? [8]. According to [9] EMG data of Bret Contreras, this is the first option.

However, in one experiment, squatting showed more active growth.

The next, no less important factor is genetics, which does not allow a person to take complete control over the body and control it at their own discretion. That is why not everyone succeeds, no matter how and how much they try, to achieve such indicators as Robbie Robinson’s. Just like not everyone has the talent of Beethoven or Malevich. The lucky few who are destined to be born bodybuilders have such a phenomenon as a shortened muscular abdomen and elongated tendons. And these parameters, unfortunately, cannot be changed in any way, even with the most exhausting long workouts.

Another example is the calf muscles with a short and high abdomen. Such a structure does not allow them to stretch, despite the variety of raises (changing the position of the feet). The short Achilles tendon with a long muscular abdomen has much more potential in this regard.

Summing Up


Through their experiments, scientists have proven that it is impossible to isolate one or another muscle group for purposeful pumping at will. However, various exercises with all kinds of their variations (body position, grip width, etc.) in a complex or separately allow you to maximize the inherent genetic potential.

In conclusion, it should be added – training based on the principle of variety is much more effective than the standard set of basic exercises. This has been successfully proved by the work of experts presented in this material.


  1. An electromyography analysis of 3 muscles surrounding the shoulder joint during the performance of a chest press exercise at several angles. Arthur A Trebs, Jason P Brandenburg, William A Pitney J Strength Cond Res . 2010 Jul;24(7):1925-30.
  2. Regional differences in muscle activation during hamstrings exercise. Brad J Schoenfeld, Bret Contreras, Gul Tiryaki-Sonmez, Jacob M Wilson, Morey J Kolber, Mark D Peterson J Strength Cond Res. 2015 Jan;29(1):159-64.
  3. Association between regional differences in muscle activation in one session of resistance exercise and in muscle hypertrophy after resistance training Taku Wakahara, Naokazu Miyamoto, Norihide Sugisaki, Koichiro Murata, Hiroaki Kanehisa, Yasuo Kawakami, Tetsuo Fukunaga, Toshimasa Yanai Eur J Appl Physiol. 2012 Apr;112(4):1569-76.
  4. Nonuniform muscle hypertrophy: its relation to muscle activation in training session Taku Wakahara, Atsuki Fukutani, Yasuo Kawakami, Toshimasa Yanai Med Sci Sports Exerc. 2013 Nov;45(11):2158-65.
  5. Muscle activation during lower-body resistance training W P Ebben, C R Feldmann, A Dayne, D Mitsche, P Alexander, K J Knetzger Int J Sports Med. 2009 Jan;30(1):1-8.
  6. Changes in exercises are more effective than in loading schemes to improve muscle strength Rodrigo M Fonseca, Hamilton Roschel, Valmor Tricoli, Eduardo O de Souza, Jacob M Wilson, Gilberto C Laurentino, André Y Aihara, Alberto R de Souza Leão, Carlos Ugrinowitsch J Strength Cond Res. 2014 Nov;28(11):3085-92.
  7. Does Performing Different Resistance Exercises for the Same Muscle Group Induce Non-homogeneous Hypertrophy? Bruna Daniella de Vasconcelos Costa, Witalo Kassiano, João Pedro Nunes, Gabriel Kunevaliki, Pâmela Castro-E-Souza, Andre Rodacki, Letícia Trindade Cyrino, Edilson S Cyrino, Leonardo de Sousa Fortes Int J Sports Med. 2021 Jan 13.
  8. Back Squat vs. Hip Thrust Resistance-training Programs in Well-trained Women Matheus Barbalho, Victor Coswig, Daniel Souza, Julio Cerca Serrão, Mário Hebling Campos, Paulo Gentil Int J Sports Med. 2020 May;41(5):306-310.
  9. A Comparison of Gluteus Maximus, Biceps Femoris, and Vastus Lateralis Electromyographic Activity in the Back Squat and Barbell Hip Thrust Exercises Bret Contreras, Andrew D Vigotsky, Brad J Schoenfeld, Chris Beardsley, John Cronin J Appl Biomech. 2015 Dec;31(6):452-8.

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