Weight Training: The Importance of Genetics

At Performance U, we’ve never been into posting Weight Room Record Boards and, as Fitness Trainers & Strength Coaches, we’re not about laying down doctrines about supposed strength standards – like: one should be able to squat or bench press or deadlift ____ times his or her bodyweight to truly be strong.

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Additionally, in the group training environment – like these (sport of) fitness challenges – we don’t believe it’s a good idea to designate one (the same) weight load for females and another weight-load for all the males to use to complete the same amount of reps on a given exercise.

Furthermore, we strongly believe it’s unrealistic to create rigid standards of (functional) movement, thinking that (in unloaded function) everyone (of all different shapes & sizes) should move in the same manner anymore than we believe that a everyone should perform deadlifts (or any other exercise for that matter) in the exact same way.

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Sure there’s a general technique criterea we use for all movements (loaded or unloaded), but based on individual genetics along with their unique body structure, injury profile, ability, etc., we allow for variations in the style each individual performs the exercise technique or movement action.

In today’s post, Matt Brzycki, author of A Practical Approach to Strength Trainingtells us about the importance of genetics in strength training, which is one of the most important (but least discussed and considered) aspects of designing truly “personal” training programs that are safe and effective.


By Matt Brzycki

   It’s well known that genetics influences a variety of physical traits.  These traits are most evident in physical appearance and include eye color, hair color and skeletal height.

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     What’s often overlooked, though, is that genetics also plays an extremely important role in your response to weight training.  Because of their genetics, some people make superior gains in size and strength while others make inferior ones, even when employing an identical strength program (doing the same exercises and using the same number of sets and reps).

     Think about it: If all you had to do was follow the strength program of champion bodybuilders and powerlifters, then there’d be millions of individuals walking around with a bench press of triple bodyweight and a 20-inch difference between their chest and waist.  But those individuals are few and far between.

     A number of genetic factors determine your response to weight training.  These include the following:

     Muscle-to-Tendon Ratio –  The potential for a muscle to increase in size is related to the length of its belly and tendon.  Everything else being equal, those who have long bellies and short tendons have a greater potential for achieving muscular size than those who have short bellies and long tendons.

     The dramatic impact of muscle-to-tendon ratios can be seen in the photograph of two individuals who are contracting their calves.  Note that the lengths of their lower legs are roughly the same.  But the lengths of their muscle bellies and tendons are very different.  The individual on the right has a much longer muscle belly and shorter tendon than the individual on the left.  At the time of the photograph, both individuals – female collegiate gymnasts in their freshman year – were training partners who had been doing the same strength program for nearly eight months, performing the same exercises and set/rep scheme.

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     What about strength?  Well, a bigger muscle has a larger cross-sectional area.  A larger cross-sectional area contains a greater number of protein filaments and cross-bridges thereby increasing the capacity to produce force.  Therefore, a bigger muscle – in terms of its cross-sectional area – is also a stronger muscle.  This means that individuals with long muscle bellies have the potential to be quite strong.

     Lever Lengths and Body Proportions – Some individuals have lever (bone) lengths and body proportions that give them greater leverage in lifting weights and a greater potential for increasing strength than other individuals.

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“Give me a place to stand and with a lever I will move the whole world.” Archimedes

This can be readily seen in powerlifting.  Favorable lever lengths and body proportions in the bench press are a thick chest and short arms (aka alligator arms); favorable lever lengths and body proportions in the squat and deadlift are a short torso, wide hips and short legs.  (Long arms also help in the deadlift.)  Everything else being equal, those who have favorable lever lengths and body proportions have a greater strength potential in certain exercises because they don’t have to move the weight as far as those who have less favorable lever lengths and body proportions.  The end result is that they can lift extraordinarily heavy weights.

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     A classic example of desirable lever lengths and body proportions in powerlifting is Andrzej Stanaszek of Poland.  By definition, Stanaszek is a dwarf, having extremely short arms and legs.  In a 2003 meet, he set world records by squatting 662.5 pounds and bench pressing 402.3 pounds . . . at a bodyweight of 114.  While short arms are highly desirable in most exercises, the deadlift favors long arms.

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In a 1988 meet, Lamar Gant of the United States set a world record by deadlifting 683.4 pounds . . . at a bodyweight of 132.  His arms are so long that he can almost literally scratch his knees without bending over.

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     Here’s another way to look at it: Consider two individuals who are tasked with lifting 200 pounds in the bench press.  Because of lever lengths and body proportions, suppose that Lifter A has to move the weight a distance of 20 inches and Lifter B has to move the weight 22 inches.  Since work is defined as force (or weight) times distance, Lifter A must do 4,000 inch-pounds of work [20 inches x 200 pounds] and Lifter B must do 4,400 inch-pounds of work [22 inches x 200 pounds] to accomplish the identical task.  In other words, Lifter A doesn’t need to make anywhere near as much effort as Lifter B to lift the same weight.  Lifter A would have greater leverage than Lifter B and, everything else being equal, would have a greater strength potential.

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     Tendon Insertion –  The farther away that a tendon inserts from an axis of rotation, the greater the biomechanical advantage and strength potential.  Consider two individuals who are tasked with holding 40 pounds in their hands a distance of 12.0 inches from their elbows while keeping their lower arms parallel to the ground and maintaining a 90-degree angle between their upper and lower arms.  Suppose that Lifter A has a bicep tendon that inserts on his forearm 1.2 inches from his elbow and Lifter B has a bicep tendon that inserts on his forearm 1.0 inch from his elbow.

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     In this example, the force necessary to maintain the weight (or resistance) in a static position can be calculated by using this equation: force times force arm equals resistance times resistance arm (or, more simply, F x FA = R x RA).  Crunching the numbers shows that Lifter A must produce 400 pounds of force to hold the 40-pound weight in a static position while Lifter B must produce 480 pounds of force to accomplish the identical task.  In other words, Lifter A doesn’t need to make anywhere near as much effort as Lifter B to hold the same weight.  Lifter A would have greater leverage than Lifter B and, everything else being equal, would have a greater strength potential.

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See how Sergio Oliva has a shorter Biceps tendon attachment than Ah-nald!

     The effect that the insertion point of a tendon has on a bone can be likened to the position of a knob on a door.  Placing the knob (tendon) away from the hinge (elbow) gives you greater leverage, making it easier for you to pull the door (bone) than if the knob was closer to the hinge.

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Closing Comments

With all due respect to Abraham Lincoln, all men (and women) aren’t created equal.  If two individuals perform the same strength program, it’s highly unlikely that they’ll end up having the same level of size and strength.  Each individual responds in a different manner because – other than identical twins – everyone has a different potential for improving their size and strength.  Simply, some people are predisposed toward developing high levels of size and strength while others are not.  And that’s why the same strength program can result in one person who looks like Arnold Schwarzenegger and another who looks like Arnold Palmer.


   So, following the routines of champion bodybuilders doesn’t mean that you’ll attain their same level of size; following the routines of champion powerlifters doesn’t mean that you’ll attain their same level of strength.

     For all intents and purposes, you can’t change the traits that you’ve inherited.  However, this doesn’t mean that there isn’t any hope for you to get bigger and stronger; just be realistic about it.

 A Note from Coach Nick…

To bring home what I said at the start of this article – Of course we appreciate the usefulness of setting goals, but we feel it’s these genetic factors (along with others) that help us to grasp the reality that those goals should be relative to ourselves, not trying to perform like another athlete, or attempting to look exactly like another lifter, or chasing certain weight-room numbers (unless you’re a competitive powerlifter).

At Performance U, our programs are about helping each individual to make continued progress (from where they started) toward the goal(s) they’re training for, using the best exercises for the way they move. That’s how we judge the success of our personal training!

 In other words, we could care less about what anyone else has achieved  – even our other clients – because we believe that YOUR personal performance and/or physique gains are the ultimate evaluation criteria.

Author Bio:

HS MB 47a 150x150 1Matt Brzycki is the Assistant Director of Campus Recreation, Fitness at Princeton University.  A former competitive powerlifter and bodybuilder, he has authored, co-authored and edited 17 books including his latest, the fourth edition of A Practical Approach to Strength Training.

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