by Christian Thibaudeau
Mechanical & Metabolic Stress for Muscle Growth
Some muscles respond better to different training methods. Here's which methods to use for these muscle groups.
Not all muscles respond the same way to the same training method. Why? It mostly has to do with where the tension is in the range of motion.
Some muscles grow better when you apply mechanical stress: muscle fiber damage and mTOR activation. Causing micro-trauma to your muscle fibers and activating mTOR will get your body to rebuild the muscle, adding more protein to the fibers to make them more resilient. This naturally makes the muscle fibers bigger and stronger.
Muscle damage occurs when a muscle fiber is being lengthened/stretched while it’s producing tension. The more tension there is and the more you’re stretching a fiber, the more damage you get.
So what does that mean? First, you need to have a full range of motion. Second, the amount of intramuscular tension (force) has to be higher, so you need fairly heavy weights. Third, the tension needs to still be present when the muscle fibers are lengthened.
Other muscle groups respond better when you induce metabolic stress and increase the level of local anabolic growth factors. This is maximized by accumulating a lot of lactate inside the muscle as well as starving the muscle of oxygen.
So, you need a fairly long set duration (at least 30 seconds and up to 70) and constant tension. Releasing tension will allow some lactate to get out and some oxygen to get in.
Got it? Good. That’ll help you understand why the exercises and methods below work so well.
Triceps: The California Press
The triceps are among the most fast-twitch dominant muscles in the human body. They respond well to heavier work as well as accentuated eccentric work. For those reasons, I love the California press – an extension/press combo.
Use a weight that’s heavier than what you’d use on a skull-crusher/lying triceps extension, but lighter than you’d use on a close-grip bench press. Do the lowering portion slowly (5 seconds) as a skull-crusher. Do the lifting part as a close-grip bench press.
- Use a shoulder-width or slightly narrow grip.
- Lower the weight to the top of your head slowly (5 seconds) as you would for a triceps extension.
- When you reach the low position, bring the bar to your chest while keeping your elbows bent (imagine doing a pullover).
- Press the weight up.
You can even take it up a notch: when you can no longer lower the weight as a triceps extension, finish your set by doing as many reps of close-grip bench presses as you can. Use a weight you can get 6-8 reps with (as a California press) and then you should be able to get 3-4 more “normal” close-grip bench reps.
Traps: The Stato-Dynamic Method
The main issue with traps is the short range of motion. To get the most growth, you’ll either need to do really high reps (20-30) or find another way to increase the time under load of the set.
I prefer the second method. When you use very high reps on traps, forearms, and calf exercises, you tend to do them quick and choppy. That defeats the purpose of the doing higher reps in the first place.
So my favorite method for building traps is to use a 2-3 second hold at the top of the movement of each rep.
Don’t just hold the weight there, but try to contract the traps as hard as possible.
Also pause briefly in the bottom position of each rep to avoid bouncing the weight up. Because of the short range of motion, a slight cheat or stretch reflex greatly diminishes the efficacy of each rep.
Do 10-12 reps with a 2-3 second hold at the top. It will lead to a lot of lactate and growth factor accumulation.
Lats: The Pre-Fatigue Superset Method
The lats have two main functions: shoulder extension (think straight-arm pulldowns) and shoulder adduction (think wide-grip lat pulldowns).
So my favorite method to develop the lats is a pre-fatigue superset of straight-arm pulldowns and wide-grip lat pulldowns (pronated grip).
Do 10-12 reps for the straight-arms pulldown and 6-10 for the wide lat pulldown. On the lat pulldown, focus on pulling your elbows toward your ribs and don’t shorten the pull – bring it all the way down to the upper chest.
Quads: Slow Eccentrics
Nothing beats the big basic lifts to stimulate the quads: squats, front squats, hack squat machine, leg press, or Bulgarian split squats.
The best way to grow the quads even more with any of these exercises is to lower slowly while going for the maximum range of motion you can reach while staying in a proper mechanical position.
How slowly? I like 4-6 seconds per rep using a constant speed. Do 6-12 reps with that repetition style.
Advanced method: Once you reach close to failure with the slow eccentric, switch to faster/normal eccentrics to squeeze out a few more reps.
Hamstrings: The 2/1 Technique
To maximize hamstring size, include leg curls in your program. The best method is the 2/1 technique.
Lift the weight up with both legs, hold briefly at the peak of contraction, remove one leg while keeping the pad on your butt, lower slowly with one leg, then repeat, alternating legs.
Accentuating the eccentric (negative) will lead to more strength gains. The reasons are related to structural as well as neural adaptations. Also, the eccentric portion of a movement is the main stimulus for muscle growth since it causes most of the microtrauma. This acts as the signal to kick the muscle-building process into overdrive.
The hamstrings are fast-twitch dominant and thus respond even better to accentuating the eccentric phase (during an eccentric overload, the body primarily relies on the fast-twitch fibers).
The load should be light enough so that you can accelerate it during the lifting, but heavy enough to make the single-limb lowering portion hard. A load of around 70 percent of your maximum two-limb rep is a good place to start.
The lifting portion should be done quickly while the lowering portion should take around 5 seconds. Do 6-10 total reps per set (that’s 3-5 reps per leg).
Calves: Loaded Stretching Method
Calves have a very short range of motion, which makes it hard to get enough time under load to accumulate lactate and growth factors. And if you go heavy to create muscle damage, the stretch reflex of the Achilles tendons will take over and the muscle itself won’t do that much work.
You not only need to lengthen the duration of the set by using an isometric hold at the top of the movement, but you also need to add a pause in the bottom to get rid of the stretch reflex. It takes a stretch of around 2 seconds to get rid of the stretch reflex.
- Go down fairly slowly until you reach the fully-stretched position.
- Hold that bottom position for 2 seconds while keeping the calves tensed.
- Slowly start to lift the weight up. You need to go slow on purpose at the start of your rep.
- Once you reach the top of the movement, hold the peak contraction for 2 seconds. Don’t just hold there, fully contract the calves.
- After you’ve completed 8-12 reps, slowly go back down to the lowest position and hold the stretch as long as tolerable. This is a loaded stretch. Do it.
This is the thermonuclear weapon for calf growth. If this doesn’t make your calves blow up, nothing will!
Are Advanced Training Methods Necessary?
Advanced methods aren’t required to progress. However, a properly selected method can dramatically speed up the growth you get from the time you invest in the gym. It also makes this training thing a lot more fun and varied.
But no method, regardless of how effective it is, will be optimal for every major muscle. Understanding which tool to use for what job will save you time, effort, and frustration.
