WHY ARE HIGHER INTENSITIES BETTER FOR STRENGTH? PART 4: Application and Critical Assessment

Brian Minor, MS, CSCS

In Parts 2 and 3 of this series we discussed some of the main morphological and neurological adaptations which have a strong influence on increasing maximal strength. To close out this article series, we will discuss how experienced athletes can apply this information within program design in a conceptual manner.  Before we go on, let’s do a brief recap of the main points from earlier in order to frame the subsequent discussion:

• High(er) intensities are (typically) more effective than low(er) intensities on strength outcomes in the short term in trained populations.
• Muscle size is what establishes your capacity for force production. Therefore, an increase in muscle size (hypertrophy) increases your capacity to produce force at the muscular level. However, this does not automatically mean you will operate at that capacity.
• Differences in muscle size explain the majority of strength differences in experienced trainees, and the relative role of hypertrophy in increasing 1 RM strength appears to increase with training experience.
• Hypertrophy is not intensity specific. When matched for sets and effort, similar hypertrophy can occur across a wide spectrum of loading. This is due to the fact hypertrophy is dependent on mechanical tension at the high threshold fiber level, which can occur with both heavy and light loads due to the size principle.
• Lateral force transmission and tendon stiffness are morphological adaptations which have significant roles in improving strength by increasing the efficiency of force transfer, and are more influenced by high(er) rather than low(er) intensities. This is likely due to the greater degrees of whole muscle tension experienced by heavier loads.
• Increases in rate of strength gain are disproportionately greater than the rate of  muscle gain, illustrating the importance of neurological adaptations.
• Increased agonist activation and coordination are two very important areas of adaptation which benefit max strength.
• An increase in agonist activation is primarily responsible for the increase in strength in beginners, and responds more favorably to high intensities.
• The impact of coordination and motor skill is greater in compound movements. The nature of these coordinated efforts are specific to the intensity being trained.

So how can we use this information to inform our programming decisions to ultimately maximize strength? To start, there are a couple questions worth asking yourself which will help apply an initial layer of context to your decision making:

When is it most important for you to be at your strongest? 

Lets use a couple examples which I imagine will be a good representation of the demographic reading this article.

If you are a competitive powerlifter, you would probably agree (I hope) that the most important time to be at peak strength would be at your meet(s). Non competitors, however, may have a less defined need to peak at a specific time and are just looking for an ongoing strategy to improve their overall strength while looking like they lift.   

Where are you currently in relation to the above timeline?

This can have significant implications in establishing the short term objectives since high intensities are generally the most efficient way to increase strength in the short term for reasons already discussed. However, an over reliance on high intensities further out from a meet may lead to excessive wear and tear and require volumes below what may be optimal for hypertrophy, and thus limit your overall strength potential downstream when it matters. In many cases, maximizing long term strength potential (via hypertrophy) requires that individuals accept the possibility of temporary maintenance or regression in their 1 RM. Sure, some people may set PRs within blocks biasing more sub-maximal loading and/or hypertrophy, but these periods of development are generally an investment in downstream strength.

How narrow should your focus be as a well trained strength athlete?

As mentioned already, the relative role of hypertrophy in increasing 1 RM strength appears to increase with training experience. With that said, what should you do if you are already well trained, your rate of muscle growth may have already slowed to a crawl, and when considering the evidence that neural adaptations appear to be less of factor with training experience? What direction should you take things that will yield the highest long term return on investment? In practice, it’s generally less of a conundrum than it may sound. 

If you recall, in Part 2 we mentioned a 2018 study (3) that examined the EMG-torque relationship between groups of different training experience and found similar amounts of agonist activation between groups who had been training for 12 weeks and for 4 years, despite a greater torque produced in the 4 year group. Considering the increase in cross sectional area (CSA) that also occurred in the 4 yr group, hypertrophy likely played a significant (and perhaps primary) role in the strength increases that occurred sometime between 12 weeks and 4 years, with neurological adaptations primarily driving the increases inside 12 weeks.  However, we also mentioned how this research was performed using leg extensions, which require less skill and coordinated effort as something like the squat, bench, and deadlift. In saying that, firmly applying these findings to explain strength increases in a demographic like experienced powerlifters may create an inflated representation of hypertrophies’ relative role to dynamic movements late in a training career, as well as potentially down play the value of coordination mediated efforts. With that in mind, regardless of experience, lifters may have inefficiencies in technique and should capitalize on opportunities to improve it. Based on observation alone, technical proficiency can continue to improve well into the careers of many high level powerlifters.

Additionally, as mentioned in Part 3, it appears possible to increase conduction velocity and rate of force development (RFD) well into a training career (4) While there are likely diminishing returns there, if you struggle to grind through near max weights then it very well may be an area from which you can squeeze out some additional kilos independent of coordination mediated efforts. The manner in which one can optimize RFD appears to be highly individual, with some people responding very well to traditional training (and not at all to speed work), and vice versa (5)

What about hypertrophy? With rates of muscle growth usually slowing to what some may consider dismal rates late in a career, one may ask what the point is? Well, for starters, muscle growth doesn’t completely stop assuming an adequate stimulus continues to be presented. However, even if it did, we still need to make sure we are performing sufficient volume to at least maintain our muscle mass, and thus our capacity for strength. Submaximal loading is generally going to be a more time efficient means in accruing that volume. There is also the benefit of potentially increasing work capacity which can be beneficial if it’s a limiting factor in performing what may otherwise be optimal amounts of volume.

When considering the alternative of using high intensity loads in an effort to maximize neurological adaptations and still meet your volume requirement for growth (or maintenance), you may run into an increase in injury risk (6), and mental burnout. Plus, if you are using the comp lifts as the primary vehicles for that volume (because the adaptations from overall specificity is the point of using heavy loads anyway right?), then you can likely add in the probability of a greater amount of fatigue for the provided hypertrophy stimulus compared to something perhaps less structurally or psychologically demanding.

Submaximal phases biasing hypertrophy still serve an important role, even if the hypertrophy is relatively minimal, especially when considering the alternative. 

That being said, if a meet is occurring within say, the next 8-12 weeks, then it may be time to dial in specificity both in terms of exercise selection and load in order to maximally express strength to the highest degree.

Where should experienced individuals place their focus, who are primarily interested in biasing development while either maintaining/increasing general 1 RM strength?  

The above scenario can actually be used to describe either a powerlifter in a volume/hypertrophy phase, or what some may consider the recreational “power-builder”. Given that we already have a generally good idea of the relationship between volume and hypertrophy, the other area to consider here is how little can we get away with in terms of high intensity work to maintain/promote new positive adaptations in the categories we discussed? Or said better, how much high intensity work is required to see a beneficial impact on 1 RM strength?

Fortunately, we have some useful research on the latter. A recent 2020 meta-analysis  (2) examined where the minimum effective volume may be for 1 RM strength outcomes. What they found was that performing as little as a single set of 6-12 reps to failure at 70-85% 1 RM, 2 to 3 times a week was sufficient to increase 1 RM for both squat and bench in trained populations. That isn’t a lot!  

The idea of using a conservative single to kick off volume work is a pretty popular strategy in the past couple years (one which I have actually employed with really good success). How effective is performing 1-3 slightly conservative heavy singles a week?  Is it doing much outside of maintaining familiarity with the heavy loads? A couple years prior, the same lab from above took a group of powerlifters prepping for competition and compared the effects of performing either heavy singles @ ~9-9.5 RPE, performed 1-3 times per week (squat-2, bench-3, deadlift-1), to a higher volume group whose intensities ranged anywhere from 70-93% (1). The study lasted 10 weeks, and while 3 out of the  5 lifters in the daily max group decreased their total at the competition compared to their pre testing total (other 2 lifters saw an increase), 4 out of the 5 lifters in that same daily max group saw an increase in their pre testing total occur at a point within the overall training duration. It is also worth pointing out that attempt selection alone at the competition itself could have plausibly contributed to the 3 lifters in the max group seeing a decrease in their total at the competition itself. Overall, this study provides evidence that low volume heavy singles alone can be an effective means of increasing strength, but perhaps primarily in the shorter term (inside 10 weeks). 

Since performing only daily singles can confer a benefit to 1 RM when performed 1-3 times a week in the short term, it’s reasonable to speculate they could carry a similar or potentially an enhanced benefit when applied within phases primarily aimed at gaining muscle. By keeping the dosing of their high intensity work at low, but sufficient levels, both powerlifters training within a volume block and our recreational “power-builder” could stand to really benefit from the inclusion of these kinds of singles before placing their focus on more submaximal intensities and higher overall volumes. 

As a meet approaches, there is generally an increase in specificity, particularly in load and exercise selection. On average, the absolute intensity (%1 RM) of the work increases as volume comes down to manage fatigue. While exposures to intensities of 85%+ tend to be more prevalent in peaking phases, the role and method of programming the submaximal volume work is less discussed. Recently, the coaches at Data Driven Strength (Zac Robinson and Josh Pelland) wrote a great guest article for my blog that builds a very compelling case for programming submaximal loading further away from failure when aiming to maximize strength in the short to moderate term. The rationale is in mitigating velocity loss across a set, thus increasing the average force production per rep for a given volume-load. So not only is force production greater, the overall fatigue cost associated with it would likely be less than than if its constituent sets were performed closer to failure. Both of those elements are extremely important when it comes to peaking strength.

Closing

In the end, strength will always be multifaceted. We must regularly and honestly negotiate with ourselves: “Does this intervention show promise in achieving the adaptation I am after?”, and

“Does the benefit in pushing for optimization in a specific area exceed the potential opportunity cost of being outside optimal for others?” There will always be a give and a take. If there wasn’t, there would simply be “the way”. Think critically, refine your approaches, and enjoy the process!

References

1. Androulakis-Korakakis, P, Fisher, JP, Kolokotronis, P, Gentil, P, and Steele, J. Reduced Volume “Daily Max” Training Compared to Higher Volume Periodized Training in Powerlifters Preparing for Competition-A Pilot Study. Sports (Basel) 6, 2018.

2. Androulakis-Korakakis, P, Fisher, JP, and Steele, J. The Minimum Effective Training Dose Required to Increase 1RM Strength in Resistance-Trained Men: A Systematic Review and Meta-Analysis. Sports Med 50: 751–765, 2020.

3. Balshaw, TG, Massey, GJ, Maden-Wilkinson, TM, Lanza, MB, and Folland, JP. Neural adaptations after 4 years vs 12 weeks of resistance training vs untrained. Scand J Med Sci Sports 29: 348–359, 2019.

4. Del Vecchio, A, Negro, F, Falla, D, Bazzucchi, I, Farina, D, and Felici, F. Higher muscle fiber conduction velocity and early rate of torque development in chronically strength trained individuals. J Appl Physiol , 2018.

5. Peltonen, H, Walker, S, Hackney, AC, Avela, J, and Häkkinen, K. Increased rate of force development during periodized maximum strength and power training is highly individual. European Journal of Applied Physiology 118: 1033–1042, 2018.

6. Schoenfeld, B, Ratamess, N, Peterson, M, Contreras, B, Tiryaki-Sonmez, R, and Alvar, B. Effects of Different Volume-Equated Resistance Training Loading Strategies on Muscular Adaptations in Well-Trained Men. Journal of strength and conditioning research / National Strength & Conditioning Association 28, 2014.