This guy claims that Olympic powerlifters working in the 1-6 rep range can increase strength without increasing muscle size.


Trained Olympic lifters, for example, were shown over a two-year period to have significant strength increases with barely noticeable increases in muscle mass (Hakkinen et al, 1988). I had a similar experience when I used AST's Max-OT principals. My strength went up like crazy, but I gained very little size.

Obviously, traditional strength training with low volume and low sets (1-6 reps, 3 or less sets) is not the best approach. Strength training does cause hypertrophy (Hakkinen et al, 1985), but it won't cause maximum hypertrophy.

What is the scientific explanation for this? Is the inverse true? That is, can a buff guy (with lots of prominent muscle) actually be weak?


3 Answers 3


Certainly there is a correlation between muscle mass and strength, but there is more to the story. Two reasons why muscle mass and strength may not be completely congruous are:

  1. Muscle fiber density
  2. Muscle utilization

Density: Your muscles are composed of four different types of fibers (slow-twitch, and three forms of fast-twitch). These fibers have different profiles in terms of force applied and recovery time. Slow twitch fibers, for example, recover quickly but have less force as there are fewer muscle fibers per bundle, compared with the fast-twitch fibers.

Extra water in the form of glycogen can also cause muscles to take up more volume with the same amount of actual muscle. This glycogen can be a ready source of energy for the muscles, but isn't going to increase their maximum theoretical force for a single heavy lift (per Olympic competition) where endurance through a long set isn't at issue.

Utilization: The average person is able to utilize 20-30% of their total theoretical muscle strength when trying their hardest. (Ref. Tsatsouline, Power To The People) Top lifters use perhaps 50% of their theoretical strength. Olympic and powerlifting-style training focuses on training the neural pathways to utilize a greater percentage of the available muscle mass. Since muscle fibers contract all internal cells (the all-or-nothing principal), this training is focused on convincing a greater proportion of fiber bundles to contract during a lift.

Can a buff guy be weak?

Well, it depends on your definition of buff. A cut guy can be weak (compared to a strength athlete), because muscle definition is more about having low body fat covering the muscle than it is about having large muscles.

A bodybuilder with decent volume won't be able to lift as much as a comparable powerlifter because he/she doesn't train for strength per se. It seems worth noting that Olympic/power lifters also want to minimize their size (except for the heavyweights) because it affects their weight class in competition, so there is an added incentive to train for neural utilization over additional muscle mass.

  • 1
    How exactly do the muscle fibers change when training for powerlifting VS bodybuilding?
    – JoJo
    Commented May 15, 2011 at 23:09
  • It's a focus on which fibers are being targeted by the exercise. High-rep/low-weight exercise (i.e. bodybuilding) will target slow-twich fibers; endurance is needed but not extreme force. Powerlifters to very few reps with heavy weight (and correspondingly a lot more rest) to hit the fast-twitch fibers.
    – G__
    Commented May 15, 2011 at 23:22
  • type 1 muscle will not grow that large bodybuilders and powerlifters both target type 2 muscle fibers they just train in different repetition ranges. bodybuilders lift in the 10-20 rep range which causes Sarcoplasmic hypertrophy which increases non-contractile elements within a muscle (collagen, glycogen, etc.) powerlifters train in the 1-5 range which causes sarcomere hypertrophy. i think humans only have slow twitch type 1 muscles and fast twitch type 2 a and x muscles so thats 3 types. i was reading that theres type 2 b muscle but thats really fast muscle in small animals.
    – DFG4
    Commented Aug 15, 2011 at 16:49
  • 1
    Actually, the 1-5 range is often too low to cause any type of hypertrophy (except some changes in connective tissue due to the increased tension). That range induces neuronal changes, which increases neural drive to the muscles and as such only affects strength/power. There needs to be a metabolic demand on the muscle, such as in the 6-12 range, for myofibrillar hypertrophy to occur. Also, doing body building strength (6-12) and strength endurance (>15) both induce a fiber type switch to slow fibers, something that research has shown to be almost irreversible (see Supertraining by Mel Siff) Commented Jul 31, 2014 at 11:06

Low reps with high weights don't add mass because the duration of the exercise is kept short. As a result it is an anaerobic exercise that utilizes the ATP-CP energy system and never enters the glycolytic energy system. The breakdown of ATP-CP creates the energy and Oxygen isn't used.

If one rests long enough for this system to recharge (about 3-5 minutes) and then tries another set of low reps, high weight lasting less than 10 seconds in total duration, strength will increase greatly and mass will not.

Decreasing rest and/or increasing work time will cause mass gain as the body works into the glycolitic and/or aerobic energy systems.

  • Do you mean "LOW reps with high weights" in your opening sentence?
    – Mike S
    Commented Sep 6, 2012 at 23:41
  • Yes, oops. Corrected now. Thanks for the catch.
    – csi
    Commented Sep 7, 2012 at 2:24
  • So what energy system does hypotrophy training utilise? Some kind of hybrid between the oxygen & glucose energy systems? I've always thought that all weight training was indiscriminately placed under the anaerobic banner.
    – Mike S
    Commented Sep 7, 2012 at 5:28
  • What?! Low reps with high weights don't add mass? Can you reference that?
    – Liv
    Commented Sep 5, 2016 at 15:28

A muscle cell is comprised of
- fibers known as myofibrils
- cytoplasm, known as sarcoplasm.

It is the contraction of the myofibrils which generates the force a muscle produces. Therefore the more myofibrils you have, the stronger you will be.

Sarcoplasm is a liquid (mostly water) which can provide nutrients to the myofibrils. One can "bulk up" by increasing the amount of water in the sarcoplasm, which makes the muscle look bigger. This however does not make you stronger. It is therefore possible for strength to not be in proportion to muscle size.

That was the science. Now in order to increase the fluid in the sarcoplasm, making your muscles look bigger, you should do many reps, many sets.

In order to increase the number of myofibrils, you should do less reps and less sets.

There is no best option. It depends if you want to train for strength or for size.

  • You missed the science where it is physically impossible to increase the number of myofibrils. However, you are correct in your approach (less reps and less sets), and on your contention of their goals. You are also correct in stating that an increase in sarcoplasm will increase size but not function. This is how supplements like Creatine work.
    – BryceH
    Commented Jan 10, 2013 at 2:14
  • Can you provide any evidence that myofibril number cannot be increased? See this book books.google.com.au/…. It sates "in some fibers the number of myofibrils increases by as much as 15 times". Myofibirls first enlarge and then split. I don't know where you got your science from.
    – Kenshin
    Commented Jan 10, 2013 at 2:45
  • If you read the myofibrils increase in number when studying rats. The very next paragraph observes body-builders and weight lifters and how weight training "induces the formation of new sarcomeres." While "resulting in the synthesis of new myofilaments around existing myofilaments." Just because something has been observed in a species that has similar structure or comparable muscular design doesn't mean the same thing happens in humans. Mice can squish themselves flat enough to fit under a standard door...
    – BryceH
    Commented Jan 10, 2013 at 3:10
  • While the studies were done in mice, you have yet to provide evidence that the effect does not occur in humans. The author obviously thinks it does as he says "If this is true of all human muscles, then the increased strength at puberty can only have resulted from the synthesis of new myofibrils in existing muscle fibers."
    – Kenshin
    Commented Jan 10, 2013 at 4:27
  • Also see comment made here: skeptics.stackexchange.com/questions/14542/…. There is no difference between rats and humans in this regard.
    – Kenshin
    Commented Jan 10, 2013 at 9:15

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