HOW to Get Jacked - 3 Mechanisms of Hypertrophy
*Disclaimer: Some of the content in the “Full Story” section is a bit dense and may not be enjoyable to read for those without a science background. The majority of the practical applications can be found in the Key Takeaways section.
Key Takeaways
The 3 mechanisms of hypertrophy include mechanical tension, muscle damage, and metabolic stress.
Mechanical Tension- Heavy strength work, 2-0-1-0 tempo, 1-5 reps, 2-5 min rest.
Muscle Damage- Slow and controlled work, (3-6)-1-1-0 tempo, 3-12 reps, 90 sec-3 min rest.
Metabolic Stress- Higher rep work >65% intensity, 2-0-1-0, 6-15 reps, 30-90 sec rest.
Although some of the results of each mechanism overlap, many are unique to the certain technique. Thus, I recommend incorporating all three techniques into each workout or training cycle to maximize hypertrophy.
Full Story
We’ve been lied to. We haven’t asked for a lot, just the answer to one simple question - how can I get bigger muscles? In response, we’ve been fed nothing but myths and empty promises:
Keep the body guessing?
Go harder than last time!!
Just lift heavy!!
Tone the body with lighter weights.
Who started the rumor that light weights are the key to get “toned”, and what does “toned” even mean? I don’t have all the answers, but I do have the research-backed blueprint of HOW to gain muscle. No ambiguous fluff, just 3 simple strategies:
Mechanical tension - heavy strength work
Muscle damage - slow and controlled negatives
Metabolic stress - “light”, high rep work
The answer to that question asked by curious, hopeful lifters, is simple; to maximize gains in muscle size, incorporate each of the three strategies into your workout routine. It’s that easy. For the full story, a deep dive into specific loading parameters and the mechanism of each technique, you’ve come to the right place.
1. Mechanical Tension
Mechanical tension is generated by force generation and stretch – in other words, it is produced by heavy strength training through a full range of motion.
How to implement
Heavy strength work, 2-0-1-0 tempo, 1-5 reps, 90 sec - 3-minute rest.
Why it works
The increase in tension from lifting heavy weights results in a series of metabolic events including the release of growth factors, cytokines, stretch-activated channels, and focal adhesion complexes. The downstream effects are regulated via the Akt/mTOR pathway, the most important muscle building system in your body. Akt enacts anabolic signaling, inhibits catabolic signaling, and activates mTOR. (1). In other words, it makes you jacked!
Activation of the mTOR pathway leads to myofibrillar (muscular) hypertrophy (2).
Training heavy will certainly result in strength gains, but oftentimes the strongest guy in the gym is not the guy with the largest muscles. This is because one gains strength through neuromuscular adaptations as well as through the hypertrophic response.
If you focus your efforts primarily on low rep strength training, without incorporating traditional high rep hypertrophy work, it is possible that you will gain strength but not significant muscle size. As it turns out, there are 2 other mechanisms that are equally important as mechanical tension to optimize hypertrophy.
2. Muscle Damage
Muscle damage is the mechanism of hypertrophy that most people think about while performing resistance training - physically breaking down their muscles to build them up stronger. This is the mechanism behind the oft-used phrase heard from both the overly aggressive personal trainer and the ill-informed casual gym goer - “no pain, no gain!”
Though this sentiment usually leads to more harm than good, and soreness is NOT an indicator of an effective workout, the sentiment is not a complete misnomer. The research shows that inflicting muscle damage is actually a crucial component of creating muscular hypertrophy.
How to implement:
Slow and controlled work, (3-6)-1-1-0 tempo, 6-12 reps, 90 sec -3 min rest.
Why it works:
We inflict muscle damage by taking a long time to lower a weight in the negative or “eccentric” portion of the lift. Trauma to the structures within the muscle results in the migration of neutrophils to the site of injury and the release of agents that attract macrophages and lymphocytes.
This action of the macrophages and lymphocytes leads to the release of anabolic growth factors that regulate satellite cell growth and differentiation (1). Additionally, it has been proposed that muscle fiber damage leads to a direct boost in satellite cell activity from nearby nerves, increasing hypertrophy.
Incorporating 3-6 second eccentrics will significantly increase muscle growth but they will also make you incredibly sore. If you’re new to this style of training, be conservative with the amounts of sets and reps you perform and prioritize recovery between sessions.
Side Note - How to Read a Lifting Tempo
If you read “2-0-1-0” and “(3-6)-1-1-0” and had nightmare flashbacks of high school algebra, don’t be alarmed! The notation is simply used to convey the lifting speed of each rep. For example, take “2-0-1-0”":
The first number, 2, in this case, indicates the speed of the eccentric or lowering phase
The second number, 0, indicates the pause at the bottom of the rep
The third number, 1, indicates the speed of the concentric or lifting phase
The final number, 0 , indicates the pause at the top.
Put differently, if I were to do a push up with a “2-0-1-0” tempo, I would take 2 seconds to lower myself to the ground, pause for 0 seconds at the bottom, take 1 second to lift myself up, and pause for 0 seconds at the top before starting the next rep.
3. Metabolic Stress
Metabolic stress is the PUMP, the increased blood flow that makes you feel like your muscles are about to explode during your workout. This “pump” is the feeling we associate with the burn we feel while lifting weights and can be attributed to a build up of hydrogen ions and other waste products in the muscle. Blood rushes to the working muscle and results in a cascade of acutely painful, albeit muscle-growing signals in the body.
“The greatest feeling you can get in a gym or the most satisfying feeling you can get in the gym is the pump. Let's say you train your biceps, blood is rushing in to your muscles and that's what we call the pump”
- Arnold Schwarzenegger (3, 4).
How to implement
High rep work, 2-0-1-0 >65% intensity, 6-15 reps, 30-90 sec rest.
Why it works
Getting a sleeve-busting pump not only makes you look and feel awesome, but it also results in a number of long-term processes that contribute to hypertrophy, including:
Cell swelling- increases protein synthesis and decreases proteolysis.
Hypoxia- increases protein synthesis, increases GH levels, and increases myogenic IL-6. Increases production of reactive oxygen species, including nitric oxide, which may increase skeletal muscle growth. Increases delivery of anabolic hormones and growth factors to muscles through increased blood flow.
Buildup of metabolites such as lactate- increases protein synthesis and may increase anabolic hormones and cytokines. The acidic environment may also result in greater fiber degradation and more sympathetic activity stimulation, leading to an increased hypertrophic response (1).
These 3 processes are only a select few that make metabolic stress such a crucial component of hypertrophy. If you’re looking to optimize muscle growth, make sure to get in a few high rep sets before you leave the gym.
Wrap Up
In short, mechanical tension, muscle damage, and metabolic stress are all very effective training strategies to maximize hypertrophy. Is one better than the others? The answer is … it depends! As a matter of fact, considering the available research, one technique does not reign supreme. The muscle building strategy that you’re not currently accustomed to is the most effective one for you.
For instance, if you’ve primarily been performing strength work under 5 reps over the past year, throwing in a cycle of 12 rep working sets could spark new growth. If you’ve been constantly chasing the pump, training to increase your max strength on doubles or triples could be the key to new gains.
Although the concept of “keep the body guessing” is misunderstood and misused, introducing a novel hypertrophic stimulus into your routine challenges your body and gives it no choice but to adapt to the new training demands. By introducing one or more of these research backed techniques into your routine, you will jumpstart your progress and accelerate your muscle building goals.
Sources (Information):
3. https://tvtropes.org/pmwiki/pmwiki.php/Quotes/ArnoldSchwarzenegger