Technique Threshold in Resistance Training

The most common question I'm asked during strength training consults for runners is "how much weight should I use?" It's rare that I actually tell someone a starting weight instead of giving them a set/rep range and having the equation solve itself, but someone's technical proficiency is going to guide where this even starts. Blagrove et al. found that heavy strength and explosive strength training are effective for improving running economy and running performance, but a lot is still unknown, including:

1a) What is the mechanism that improves these running variables?

The reason 1a is an important question is because if a mechanism is discovered to be general rather than specific, we don't need to force one particular solution. This directly leads to question 1b:

1b) Is there a different way to achieve the same goal?

1b is an important question to ask because most runners can't just walk into a gym with 0 years of resistance training experience and start lifting heavy without risking injury. There are several barriers to entry for runners to get from non-resistance trained to well-trained and ready for heavy and explosive strength training; perhaps one of the largest is technical proficiency.

Technical proficiency is exactly what it sounds like and seems like it'd be pretty straightforward in identifying. That movement looks "bad" (large red X) and that movement looks "good" (large green O). The cutoff point between bad and good is known as our "technique threshold." Theoretically, we want everyone working at the highest intensity before they hit their technique threshold to maximize strength gains and minimize risk. If we pass threshold, form breaks down, and we start to overcompensate and risk overloading certain areas that aren't conditioned to tolerate that much load. The main issue with all subjective scales, though, is that they're... subjective. How "bad" was that squat? Is that lunge "good" enough to progress in load? All strength coaches are coming from different backgrounds with different biases that will influence how strict their technique guidelines are. It's still intuitive to think we should be on the more conservative side when grading form, but if we take both extreme examples, they have their downsides:


The "perfection is key" coach:

Well that's... I mean I guess you could... 

Pros-
Likely lower risk for injury, as the athlete has such a high bar to progress load that it takes forever to get to a higher-risk environment.

Cons-
Performance gains are minimal, as the athlete is potentially under-loaded and progression is very gradual.
Motor learning is potentially limited if the coach over-cues.


The "whatever, just squat" coach:

In Jim's defense, I've done this while he's doing his job too

Pros-
Performance gains are potentially higher as the athlete achieves higher working loads.
This coach is possibly less annoying.

Cons-
Likely higher risk for injury, as progression may be too quick because of a low standard for threshold.


Score another one for moderation? At the very least, there seems to be the need for some conditions and not a blanket statement. For now, let's carry on with this assuming:

1) For maximal running performance benefits, strength training NEEDS to be heavy and explosive

2) The runner deems the benefits to outweigh the cost (time, money, energy) starting a resistance training program

So how do we decide what someone's technique threshold is, then? While we covered that it is subjective in nature, I'm a big fan of Adam Meakins' (The Sports Physio) pragmatic approach to coaching. This is his adapted look/feel matrix for coaching:

Adam Meakins Look/Feel Matrix

It starts with how the exercise feels (internal feedback) compared to how it looks (external feedback) and results in a few different conditions:


Condition 1
Feels good? Looks good? Crack on. 


Condition 2
Feels bad? Regardless of if it looks good or bad, you're going to want to change something. There's a thousand ways to skin a cat in resistance training and there's no sense in hammering your way through something that feels bad when we can change some variable to find something that feels better. It's likely not even a permanent change, just something temporary while the original selection isn't well-tolerated. These changes may include (but are not limited to):

Different exercise cues
Extrinsic (environment) vs. internal (body) cues

Different exercise selection
Pick an exercise with a similar focus/goal that just feels better

Load
Decrease the weight used or add assistance to reduce bodyweight

Volume
Starts to feel bad at repetition number eight on each set? Let's work a few sets of six or seven.

Tempo
Slow the eccentric or concentric portion down or just focus on overall time under tension

Range of motion
Feels bad through the last 20 degrees? Stop just before and work through the range that feels good.

That all seems like common sense, right?


Condition 3
Feels good? Looks... bad? This is the tough one, and probably what most coaches get hung up on. We don't know what our actual limits are when loading an exercise with egregiously bad form. That's likely because it's based on a few key considerations:

The vomit test
How bad does it look? Is that knee just a little shaky at the bottom of the squat, or does it crank inward so far that you feel some acid building up at the back of your tongue?

Training experience
Novice athletes are at higher risk of injury than well-trained athletes, pretty much across the board in sports. It's likely that the well-trained athlete has adapted to being able to tolerate higher and more variable loads. Barbell Medicine has a very comprehensive multi-part review of resistance training in youth athletes that emphasizes the process of technical skill training in this population. When someone is less experienced (whatever that means), we should probably err on the side of caution with our coaching.

Load and volume
Under a minimal amount of weight and with few repetitions, one ugly movement isn't going to be what breaks someone. The heavier the load and/or under a high volume of training, "good" form likely decreases the chance that we overload less tolerant structures (while certainly not guaranteeing that we don't).

Frequency
How often is the task in question? Is this something someone does once a week? Bi-weekly? Three times per week? Training with "bad" form but with low frequency (plenty of time to recover) may even be less stressful than "good" form at too high of a frequency for adequate recovery.

This still seems like common sense, but it's unsettling to not have concrete answers sometimes. Actually, most of the time. There are extremes and exceptions, but largely this stuff is pretty grey. Something to think about the next time you see this guy working out in the gym:

Vomit test?

One more thing, this was all carried out under the assumption that strength training needs to be heavy for runners to benefit. We don't actually know this to be true for all runners. Some runners may still see performance benefits at lower intensities, the same way some runners can improve performance with different cross-training modalities. This likely lowers the barrier to entry a bit, as it may not be as much of a time investment before getting a significant return.

In summary, it's sensible to try to achieve "good" form most of the time, but we probably don't need to 1) obsess over it or 2) shout that nothing matters from the highest mountain.

Next post will be entirely on that coach who's spotting the lifter pictured above.


Jason Tuori, PT, DPT, CSCS 



References:

1. Blagrove RC, Howatson G, Hayes PR. Effects of Strength Training on the Physiological Determinants of Middle- and Long-Distance Running Performance: A Systematic Review. Sports Med. 2018;48(5):1117-1149.
2. Trowell D, Vicenzino B, Saunders N, Fox A, Bonacci J. Effect of Strength Training on Biomechanical and Neuromuscular Variables in Distance Runners: A Systematic Review and Meta-Analysis. Sports Med. 2020;50(1):133-150.
3. https://www.thesports.physio/
4. https://www.barbellmedicine.com/blog/resistance-training-for-the-youth-population-part-ii/
5. Paquette MR, Peel SA, Smith RE, Temme M, Dwyer JN. The Impact of Different Cross-Training Modalities on Performance and Injury-Related Variables in High School Cross Country Runners. J Strength Cond Res. 2018;32(6):1745-1753.