Why Strength Training is a Dead End

Part 2: Data equals knowledge?

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In part 1 of this series I have asked quite a few troubling questions regarding the concept of strength as a biomotor ability and therewith strength training for sport performance as a whole. Is strength truly a fundamental ability of the body or is it something else?

With the hype surrounding big data, the idea of data equaling knowledge seems to be more popular than ever. Let us then take a look at what it exactly is that is measured in scientific research on strength training. With a bit of luck we might actually know something afterwards!

Measuring strength

There are numerous studies in which a relationship between strength and athletic skills such as jumping, throwing and sprinting is concluded. In part 5 of this series I’ll take a closer look at these, but for now the key question is: how exactly was this strength measured?

The answer is remarkably simple: by having people perform a certain exercise as heavy as possible. In a study on the relationship with jumping it was a half squat (1), in a study on that with throwing it were a bench press and a pull-over (2), and in one on that with sprinting it was a full squat (3). The heavier you could perform the exercise, the stronger you were considered to be.

Strength as a construct

Hopefully you’ll see that in the first instance no fundamental bodily property has been measured here, but simply the amount of weight you can move in a specific movement pattern. Look at it this way:

When shopping for new curtains it’s useful to know their required dimensions. Therefore you’d probably put a measuring tape across your windows and read it. That’s all you’d have to do. But maybe you hadn’t thought of this and you manage to return home with curtains that are too small. Your spouse doesn’t feel that this is your best stroke of genius and ‘advises’ you to take an IQ-test. After all, it’s kind of hard to assess one’s intelligence with a measuring tape!

As such, intelligence is a construct: something that possibly exists but isn’t directly observable. Therefore people try to assess it through all kinds of ingenious procedures. The same holds true for strength as a biomotor ability: you could reason it’s real, but you cannot gain access to it directly.

Intelligence is a construct; so is strength.

Testing hypotheses

Fortunately, there are a number of predictions that we can evaluate directly. For starters, if strength is a fundamental ability, then an increase in it should lead to an increase in strength in every exercise. Do we find this in reality? No. Someone who only squats for a couple of months is unlikely to all of a sudden increase his bench press.

That’s incredibly lame! Those exercises target entirely different muscles! That’s true, but then does that mean that strength in fact refers to the force capability of isolated muscles? Not really now, is it? Every decent strength coach nowadays (rightly so) prioritizes compound exercises in which multiple muscles are loaded in a chain: squats instead of leg extensions, pull-ups instead of bicep curls, etc. This is said to be more ‘specific’ or more ‘functional’. So besides ‘pure strength’ there apparently is another factor that we take into account, whatever that may be (technique/coordination/motor control?).

But does pure strength even exist at all? In part 3 I’ll address this question more thoroughly, but for now let’s take a quick peak at classic from 1957 (4). In this investigation, the researchers looked (among other things) at the effect of 6 weeks of strength training on flexion strength in the elbow (think biceps training); this was assessed through various tests in which only flexion was required. The abstract describes the findings strikingly:

“Whereas subjects showed strength gains in the tests when muscles were employed in a familiar way, little or no gain in strength was observed when unfamiliar procedures were employed.”

Short and sweet! Ergo, THE flexion strength doesn’t appear to exist.

Strength as a task-specific output

In short, strength is not something fundamental, but it’s specific for the task in which it is required (5). It itself is in fact the result of more fundamental factors. The peculiar thing is that many strength coaches actually know this: strength is a skill. To put it somewhat roughly, the force output in a strength exercise is the result of muscles with certain structural properties and the specific manner in which these are controlled by the central nervous system.

But in fact the output of all movements is the result of muscles with certain structural properties and their specific control! The only difference is that the output of ‘non-strength’ exercises is rarely expressed in terms of force. But here things get messy, because the aforementioned ‘strength skill’ is still believed to form a fundamental base, which leads to the nearly exact same questions and problems that we already encountered in part 1! As such, strength almost becomes something magical.

‘Evidence’… The studies that were reviewed here show that performing certain exercises may enhance endurance performance. The fact that many interpret these findings in terms of a fundamental strength ability, is a dubious choice at best.

An alternative

But then what’s the alternative? Simple: strength exercises don’t improve some general force production capability, but rather may induce specific structural and/or coordinative adaptations that may or may not lead to better sport-specific movements (6). For clarity’s sake, sport-specific or goal movements refer to the movements that actually occur in the particular sport (e.g. running and jumping in basketball). And for connoisseurs, structural adaptations refer to muscle properties such as cross-sectional area, fascicle length and pennation angle; structural adaptations refer to intra- and intermuscular control.

If these adaptations actually contribute to better goal movements, we call this transfer of training. This is where our focus should be on and not so much on improving force values on somewhat arbitrary exercises.

Here the dogma of strength as a fundamental ability becomes needlessly limiting however. After all, it wants us to believe that we should dedicate certain sessions to strength, in which we should mainly choose from a very narrow movement repertoire, that is (traditional) strength exercises. But strength exercises are not fundamentally different from other movements; they are just one of many options. And given our limited time and energy, other options are often a (much) better investment (more on this in part 5).

FYI: How transfer of training and — more specific — transfer of learning exactly work, is very complex and dynamic. An exercise that improved a goal movement for a certain athlete at a certain time, does not necessarily do so for a different athlete or at a different time. Hence we should abandon the idea that an exercise constitutes a specific input that leads to a fixed output.

To be able to understand what happens inside the ‘black box’, profound knowledge (and experience) is required. In particular, knowledge of motor coordination and learning is of great value here.

Conclusion

Data does not equal knowledge. What is measured in research on strength training is in fact the performance on specific tasks; often this boils down to the number of kilos one can move in a certain pattern.

The fact that people have started calling this performance ‘strength’, reflects a confusing choice more than anything. Strength in the sense of a task-specific output? Most definitely. Strength in the sense of a fundamental or biomotor ability of the body? A misleading interpretation.

Practical pointers

• Forget about fundamental abilities and try to point out desired adaptations as specifically as possible; these may be subdivided into structural and coordinative adaptations.
• To do so, start with a thorough analysis of the goal movements and the limiting factors of the particular athlete.
• Dare to look beyond (heavy) weights; traditional strength exercises could be of value, but there are many more (and often better) options.
• Gather knowledge on motor coordination and learning; this is priceless in these endeavors.

NB: Do I have the answer on how to train optimally? Far from it, unfortunately. The organism-environment system is incredibly complex and there still are far too many questions. There probably isn’t one optimal way to train either, but as usual there may be many ways leading to Rome. Nevertheless, the fact remains that there is enough knowledge — both from science and from practice — to at least start following a more promising road. And on this journey, it would be my pleasure to take you along!

References

1. Wisløff, U., Castagna, C., Helgerud, J., Jones, R. & Hoff, J. Strong correlation of maximal squat strength with sprint performance and vertical jump height in elite soccer players. Br. J. Sports Med. 38, 285–288 (2004).
2. Chelly, M. S., Hermassi, S. & Shephard, R. J. Relationships between power and strength of the upper and lower limb muscles and throwing velocity in male handball players. J. Strength Cond. Res. 24, 1480–1487 (2010).
3. Baker, D. & Nance, S. The relation between running speed and measures of strength and power in professional rugby league players. J. Strength Cond. Res. 13, 230–235 (1999).
4. Rasch, P. J. & Morehouse, L. E. Effect of static and dynamic exercises on muscular strength and hypertrophy. J Appl Physiol. 11, 29–34 (1957).
5. Buckner, S. L. et al. Determining Strength: A Case for Multiple Methods of Measurement. Sports Med. 47, 193–195 (2017).
6. Zatsiorsky, V. M. & Kraemer, W. J. Science and Practice of Strength Training. (Human Kinetics, 2006).

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