Tyler Robbins Fitness

B.Sc. Biochemistry, Certified Strength and Conditioning Specialist (CSCS), Certified CrossFit Trainer (CCFT/CF-L3), USA Weightlifting Level 1

Filtering by Tag: Power

Explosive training is also the fountain of youth...

This title may look familiar since I just recently wrote about how resistance training is the fountain of youth. Although I certainly am not here to discredit my recent blog, I am certainly here to elaborate on it a bit further based on a recent study.

When you hear about "explosive training," your mind probably leans towards young athletes and how fast and powerful they seem. You almost certainly never think about grandma and her slower pace. Well, according to the above study, explosive training is not only tolerated by individuals well into their 80's, but is highly recommended for healthy aging as well.

Resistance (strength) training is still extremely important. Using maximal, or even sub maximal loads to increase the strength and durability of muscles, bones, connective tissues, etc. is regarded as one of the most effective ways of aging gracefully.

Explosive or power training involves moving less weight, but moving said weight quicker. A really simple example would be either pushing or throwing a ball. Throwing is an explosive action. The above study found that training older individuals with explosive actions helped to improve their reflexive actions.

Strength training involves learning how to activate more muscle in order to move a desired load. Your muscles are made up of many muscle fibers. Although all muscle fibers shorten at once when a muscle contracts, only a certain percentage of them does the work at any given time. Strength training can then be considered a skill by learning how to activate more muscle fibers and therefore generate more force.

Power or explosive training is all about increasing the reaction time between your brain and muscles. The faster your brain can not only get a signal to the muscle fibers, but to also have them contract at a faster rate, the more explosive they can be.

As the study points out, many age-related problems occur due to the risk of falling. Falling happens for a number of reasons, but most often occur due to a slow reaction time. Your brain is usually pretty efficient and effective at recognizing the signs that balance is off, but the time it takes to react to being off balance and therefore correcting the balance can deteriorate over time. Explosive training helps to keep that quickness needed.

This doesn't necessarily mean that grandma needs to do plyometrics, but instead, learn to safely and effectively lift lighter weights safely and quickly.

Genetics Series: Strength and Power

My old boss used to say, "You know, God made us (humans) all about the same." Sure, it is often said that humans, when compared genetically, are about 99.9% similar, however there are still some pretty remarkable variances between how we look and perform.

The 99.9% similarities between us controls things as common as having skin, hair, teeth, a stomach, high-level brains, etc., but can had differences in how those things look and work. For example, how tall we are, how long our limbs are, how big our noses are, etc. We also mostly act the same too - although this is heavily influenced by your surroundings.

If you keep looking deeper into that rabbit hole you can begin to understand that not only do our muscles oftentimes look differently, but they can act and perform differently as well. I always say to people, "You can't choose your parents," because your genetic lineage can have a drastic outcome on all of these factors that influence you. Some folks are able to build big muscles. It just comes easy (easier) to them. 

So what about athleticism? Do you remember growing up and playing with your friends? Do you remember that one friend of yours that just seemed to be better than everyone else at everything (or most things)? They could run faster, jump higher, were better at Mario Kart, and could be the best with little to no effort at all! Was this friend in the gym spending hours a day getting bigger, faster, and stronger? Of course not, they were just gifted in ways that maybe you weren't. The effectiveness of their neural pathways were better than yours. They had better coordination, better strength, better reaction time, etc.

Why are some people so good at some things? Is it because they work harder? Is it because they are more committed? Possibly, but not necessarily.

Take this review, for example:

Genetics of muscle strength and power: polygenic profile similarity limits skeletal muscle performance.


Environmental and genetic factors influence muscle function, resulting in large variations in phenotype between individuals. Multiple genetic variants (polygenic in nature) are thought to influence exercise-related phenotypes, yet how the relevant polymorphisms combine to influence muscular strength in individuals and populations is unclear. In this analysis, 22 genetic polymorphisms were identified in the literature that have been associated with muscular strength and power phenotypes. Using typical genotype frequencies, the probability of any given individual possessing an "optimal" polygenic profile was calculated as 0.0003% for the world population. Future identification of additional polymorphisms associated with muscular strength phenotypes would most likely reduce that probability even further. To examine the genetic potential for muscular strength within a human population, a "total genotype score" was generated for each individual within a hypothetical population of one million. The population expressed high similarity in polygenic profile with no individual differing by more than seven genotypes from a typical profile. Therefore, skeletal muscle strength potential within humans appears to be limited by polygenic profile similarity. Future research should aim to replicate more genotype-phenotype associations for muscular strength, because only five common genetic polymorphisms identified to date have positive replicated findings.

So although this isn't ground-breaking or particularly new, we are starting to discover just how advantageous you may or may not be due to the genetic lottery that you have played when you were born. The above review details 22 genes (that we know of) that are beneficial for strength and power performance in individuals. In these 22 genes, the more you personally have, the greater likelihood you have to being a strength or power athlete.

There are 3 "options" when it comes to these gene phenotypes. You can either have a favourable gene expression, a neutral expression, or a negative expression. In other words, whether or not you have a specific genotype can either make you good at something, potentially bad at something, or no real positive or negative effect at all.

One well-known gene, for example, is one that encodes for the protein ACTN3 has been shown to be favourable for sprinting (in those that contain the correct gene), and can actually be favourable for endurance athletes with a mutated ACTN3 protein.

Studies have linked the fiber twitch type with ACTN3, i.e. fast twitch fiber abundant individuals carry the non-mutant gene version. Also, studies in elite athletes have shown that the ACTN3 gene may influence athletic performance. While the non-mutant version of the gene is associated with sprint performance, the mutant version is associated with endurance.

What's notable in the above review is that the researchers calculated 0.003% of the population to have "optimal" gene expression for strength and power attributes. This certainly makes sense, especially in a country like Canada - population around 30,000,000, that about 9,000 individuals (give or take) have more optimal strength and power characteristics.

Does this mean that other individuals can't be strong and powerful? Absolutely not, but those individuals with favourable genetic phenotypes are certainly at an advantage when it comes to producing strength and power. On the flip side of that coin, as we have seen with ACTN3, it is entirely possible to be not all that great at something.

It should also be noted that although an individual may have a genetic potential for something, does not mean that they are going to be the best. Although this number has been associated with strength and power, let's use the same figure (for argument's sake) to discuss genetic potential for other attributes as well. Assume that even at 0.003% of the population has a genetic advantage for something, that still creates a lot of competition between yourself and the other "elites" in that category. Being strong and powerful, especially compared to your less-than-genetically-gifted friends will only take you so far. If you wanted to compete on an Olympic level, for example, then you still need to hone your skills and work hard to be even better than those around you.

I will once again remind my readers that this is not to sound like an old curmudgeon, saying that talent and athleticism is "all luck." There is certainly advantages that make some of us better than others at certain things. It is not impossible, just highly unlikely that you would see a 7 foot tall man competing at the Olympic games in weightlifting. The limb lengths and joint angles are not as advantageous for maximal torque and power required for Olympic lifting. On the other hand, although we have seen some shorter individuals play in the NBA before, the game certainly favours taller individuals. Being tall, or having a long torso (advantageous for weightlifting) cannot be trained. If, however, you are tall, and you work hard, then you have a chance to make it big.

Your Complete Guide to Sets and Reps

This is an updated guide to reflect the latest science and research surrounding sets and reps and how they relate to muscular strength, endurance, and hypertrophy (muscular growth).


Focus on the areas in yellow, as these are the "optimal" zones for each training goal. Keep in mind that although you may benefit in various training ranges, there are just rep ranges to focus on based on what your training goal is. For example, you will gain some muscular strength from doing a 20+ rep set of an exercise, however choosing a resistance that keeps you in a 5 or under repetition range is optimal for strength gains.

Strength training is generally most improved in the 1-5/6 repetition range.

Power is generally most improved in the 1-4/5 repetition range.

Endurance is generally most improved in the 12+ repetition range.

Hypertrophy has generally been thought to be most improved in the 6-12 repetition range, although this is the one section that will be most discussed in this guide as some of our current knowledge is being challenged by recent research.

Core vs. Assistance Exercise

You may think a "core" exercise is one that involves the abdominals. The true meaning of a core exercise refers to one that recruits one or more large muscle areas (chest, shoulder, back, hip, thigh), involve two or more primary joints, and receive priority when one is selecting exercises because of their direct application to sport. An example of a core exercise would be a squat because it involves large muscle groups such as the gluteals, quadriceps, hamstrings, etc. and involve more than one primary joint (knees, hips).

"Assistance exercises" on the other hand, usually recruit smaller muscle areas (upper arm, abdonminals, calf, neck, forearm, lower back, or anterior lower leg), involve only one primary joint, and are considered less important to improving sport performance. An example of an assistance exercise would be a leg extension.

I generally don't recommend strength training for assistance exercises. For example, I wouldn't recommend using a weight that keeps you under 6 repetitions for something like a biceps curl.

How muscles contract

We sometimes perceive our muscles as self-controlling structures that abide by an "all or none" mechanism. This is simply not true. Your muscles are made up of muscle fibers, none of which are thicker than a strand of hair. When your muscle contracts, the entire length of the muscle shortens, however only a small percentage of the muscle fibers are doing the work. So, although all of the fibers are shortening in length, only a specific percentage of the fibers are actually completing the work at any given time.

For the purposes of our explanation, let's imagine a toddler biceps curling a 5lb. dumbbell. Because of the amount of overall strength required to lift the 5lb. dumbbell, the toddler will require quite a large percentage of the muscle fibers in their biceps to contract to lift the dumbbell. An average adult, on the other hand, could curl a 5lb. dumbbell with little to no effort at all meaning that a lower percentage of their muscle fibers are actually doing the contracting.

Why is this important? Well, when your muscle fibers fatigue, the fibers that were doing the work stop contracting and other fibers step in to complete the work. There are always at least a small percentage of your muscle fibers resting while others are doing the work. If we think of our dumbbell curl example again, chances are the toddler won't be able to curl the dumbbell as many times as the adult because they are recruiting a higher percentage of muscle fibers for every single repetition, leading to quicker fatigue and failure.

Muscle fiber recruitment is orchestrated by the muscle's neurons. One, often overlooked, positive adaptation to resistance training is the improvements in your mind to muscle connection. Basically, your neurons greatly improve their efficiency at "recruiting" muscle fibers.

So not unlike learning a skill, where your brain must train a synchronized orchestration of your muscles to act in a specific order of events, to say - throw a baseball, the brain must also learn how to actively recruit more muscle fibers in order to generate more force.

It should be noted that during the first 8 weeks of a resistance training program for beginners, nearly all of the "gains" achieved from resistance training can be attributed to neural adaptations. So, even though one may be experiencing strength gains, this is not due to an increase in muscle size or any measurable improvement in the strength of the muscle itself, instead, it is an improvement in the efficiency of the mind to muscle connection!

Repetition Goals

Use the following table to help yourself better estimate the loads you can lift at various repetition goals.



With our quick lesson on neural adaptations and muscle fiber motor units out of the way, let's discuss how this pertains to strength gains. In the most basic terms, strength is the ability for your muscles to generate as much force as possible. Power, on the other hand, is the ability for your muscles to generate a lot of force quickly. Strength is extremely beneficial for those looking to be able to lift or move heavy objects, but not necessarily within a specific amount of time.

Power, which is closely related, is about generating a lot of force (strength) in as short amount of time as possible. Power has very direct correlations to sport and athleticism. It should be noted that increasing your strength will also help to improve your overall power as strength and power are so closely related.

Keep a mindset that strength and power gains are primarily a "learned" skill. Like we discussed above, by training for strength, our muscles are getting stronger by training our brain how to activate high threshold muscle motor units more effectively. There is a limit to the amount of strength any given muscle in your body can produce, limited by a number of factors including limb length, joint angle, skill, technique, genetics, ratio of type 1 to type 2 muscle fibers, etc. Many of these topics will have to be covered in future blogs.

A definitive stance is proven time and time again with resistance training, strength and power output is most improved in individuals training in the 5 or fewer repetition range. Although endurance and hypertrophy training can be adjusted and benefited from varying repetition ranges (more on that later), we know that strength and power is most greatly improved with higher intensities (high weight).

Strength Repetition Goal:
Primary Energy System:
Ideal Rest Periods:
2-5 minutes


Like strength and power training, I would consider endurance training to also be a "learned" skill set for your muscle cells. Although strength and power can be considered a "learned" skill, considering the brain is becoming more effective at activating muscle fiber motor units, endurance training can be considered a skill on more of a cellular level as your muscle cells are learning how to become much more aerobically efficient.

Endurance training is highly beneficial for athletes that compete at longer-duration events such as distance running, swimming, etc. It should be noted that sports like hockey or even soccer, although they may be considered sports that requires a higher level of aerobic efficiency, are actually a series of highly intense intervals that would benefit greater from training plans intended for the work duration of such sport.

Endurance Repetition Goal:
Primary Energy System:
Aerobic or Oxidative
Ideal Rest Periods:
30-60 seconds


This is decent video to get most of you up to speed on muscle fiber types and how resistance training can cause muscular damage leading to growth (hypertrophy). I will admit that I was a bit disappointed because the video seemed very rushed and ended abruptly, missing a lot of key points. I was also quite surprised that they even made mention of muscular hyperplasia. Hypertrophy is the actual enlarging of muscle cells (increase in volume) whereas hyperplasia is the division of muscle cells - increase in overall quantity. Although it is certainly possible to increase the overall number of muscle cells, the evidence for this isn't entirely clear and most likely does not apply to the general population.

While strength/power and endurance training could be considered a "skill" as I mentioned previously, hypertrophy should be considered a stimulus. In other words, our training is creating a specific demand within our muscle cells to signal growth. This is one area that not only generates a lot of interest amongst fitness enthusiasts, but researchers as well. For years, many thought that training within a 6-12 rep range was optimal for muscular hypertrophy or growth. Research, although not necessarily refuting that evidence, is trying to explain the greater picture in how or why muscles grow and how varying stimuli can promote muscular growth.

As it turns out, the number of repetitions you do does not entirely matter how much muscular growth is promoted. In other words, rep range does not matter for hypertrophy.

In conclusion, this study showed that both bodybuilding- and powerlifting-type training promote similar increases in muscular size, but powerlifting-type training is superior for enhancing maximal strength.

Ideally, your training should meet your needs, goals, and desires. If you wish to train to improve strength and/or performance, then stick to lower repetition ranges with higher intensity. If you wish to train for more aerobic events, then lower intensities and higher repetitions should be targeted.

This study demonstrates that both intensity and exercise-induced metabolic stress can be manipulated to affect muscle anabolic signaling.

What about our previously-thought belief that rest periods determine the growth of muscles? Well, apparently not.

In conclusion, the literature does not support the hypothesis that training for muscle hypertrophy requires shorter rest intervals than training for strength development or that predetermined rest intervals are preferable to auto-regulated rest periods in this regard.

One more variable we can throw into the mix is research that has looked at oxygen restriction and how it affects hypertrophy signalling. One study used tourniquets to restrict blood flow to working muscles to discover whether or not this would alter training stimulus or signalling.

Blood flow restriction resulted in significantly greater gains in strength and hypertrophy when performed with resistance training than with walking. In addition, performing LI-BFR 2-3 days per week resulted in the greatest effect size (ES) compared to 4-5 days per week.

Sarcoplasmic Hypertrophy

Source: http://slidingfilament.webnode.com/skeletal-muscle/

Many coaches or gym bros may want to talk your ear off about how much physiology they know and spout off a very detailed explanation about the two different types of hypertrophy - myofibrillar vs. sarcoplasmic. As the story goes, you can enlarge your muscles either one way or the other. Myofibrillar hypertrophy refers to the enlarging of the structural framework of the muscle fibers whereas sarcoplasmic hypertrophy refers to the increased fluid of the muscle cell sarcomeres.

Anywhere from 70-80% of a muscle cell is made up of structural proteins. If you were to increase the volume of the sarcoplasm and therefore the sarcomere, you would have to increase the overall structural framework of the muscles too. It would be like making the inside your house bigger without actually building any additional walls. In order to increase the size of the sarcoplasm/sarcomere, you have to increase the amount of contractile proteins too. Don't believe me? Check out this study:

The linear distance between myosin filaments (38.7 +/- 0.3 nm before, 38.7 +/- 0.4 nm after training; mean +/- S.E.M.) as well as the ratio of actin to myosin filaments (3.94 +/- 0.03 before, 3.86 +/- 0.06 after training) did not change with training. 3. These results refute the concept that the increases in muscle strength or radiological density during short-term heavy-resistance training are caused by changes in myofilament spacing.

In other words, although the muscles got bigger, the framework didn't simply increase in distance, it had to increase in overall quantity. Both sarcoplasmic and myofibrillar hypertrophy happen at the same time making any discussion about differentiating them total bullshit. There is zero evidence to back up sarcoplasmic hypertrophy. Period.

Hypertrophy Repetition Goal:
Primary Energy System:
Ideal Rest Periods:
Based on goals/availability

Ok, so for the purposes of hypertrophy training, here is what we can summarize:

  • Lifting heavy things makes you better at lifting heavy things. The heavier you lift (fewer reps), the stronger you will get.
  • Lifting lighter things many times makes you better at, well, lifting lighter things multiple times. In other words, your muscles become more fatigue resistant, also known as endurance training.
  • Volume is the key. You must push your muscles to at least close to failure multiple times to promote growth.
  • Oxygen depletion seems to also promote hypertrophy signalling, so by training at a high rate of metabolism, such during high-intensity interval training (HIIT), you can still promote muscular growth.
  • Forget the term "toned." Nobody should train at higher repetitions to "tone."
  • Stimulating muscle cells to increase in size through resistance training can only take you so far, a proper diet rich in protein and sufficient calories is what makes or breaks most cases of hypertrophy. Oh yeah, hormones count too.
  • There is no such thing as sarcoplasmic hypertrophy so don't let anyone tell you otherwise.

Sets, Repetitions, and Training Goals Summary

Strength - High-load, low-repetition training to improve overall strength of the muscle(s) being trained. Should mainly be targeted by "core exercises." Long periods of rest between sets to allow full recovery of muscle fibers in order to produce maximum amount of force every subsequent set. Remember that many of the strength gains achieved come from improved neuromuscular patterns.

Power - High-load, low-repetition training similar to strength training but designed to increase the overall explosiveness of the muscles. Also designed to be targeted by "core exercises" only. Also intended to have long periods of rest between sets to promote full recovery. Like strength, many power gains are achieved by improving neuromuscular patterns.

Hypertrophy - Enough volume to challenge your muscles to fatigue as many of your overall muscle fibers as possible in order to elicit growth. There is also a potential for growth simply by working until extreme fatigue to create a lack of oxygen and energy replenishment to the muscles such as HIIT training.

Muscular Endurance - Low rest periods, higher rep goals, lower loads. Ideally used to improve the aerobic efficiency of the muscle fibers. Should be used by endurance athletes to improve muscular efficiency. Not intended to improve overall strength or power, however.