I've mostly used isometrics to strengthen a weak point by using short sets (6-9 seconds) with maximal effort. I began to realize the hypertrophy benefits of longer-duration isometrics when I started to include loaded stretching in the workouts of my athletes. From that point, I started exploring the potential application of isometrics for muscle growth.

The most effective application? Shoulder development. Here's how it works:

Apply force against an immovable resistance as if you're trying to do lateral raises. The closer your hands are together in the bottom – stretching the medial delts in the process – the more effective it'll be. This is a long-duration set: 2 to 2:30 minutes. It's obviously impossible to sustain a near-maximal effort for that long, so here's how you do it:

• Push out at around 90% of your max effort until you start shaking or can't keep up the force output. This should take 30-40 seconds.
• Release tension, keeping only around a 10% effort for a few seconds.
• Ramp back up to a high effort level and sustain it for as long as possible.
• Rest or do another set.

Do that until you hit two to two-and-a-half minutes. Taking fewer 10% effort "breaks" during the set will make it more effective. This will not only stimulate a lot of muscle growth, but it'll improve the muscle tone of your delts tremendously (sometimes in only one workout), making them look and feel harder even at rest.

Why Does It Work?

With isometrics, you can accumulate a lot more maximal or near-maximal time under tension than with dynamic lifting. For example, if you do a lateral raise, you'll have a high level of tension for around half the range of motion for probably 1 to 1.5 seconds per rep, if that.

For a set of 10 reps, that gives you 10-15 seconds under a high-ish level of tension. In fact, because of the nature of the exercise, you likely won't have a near-maximal level of tension until the last 2-3 reps of your set. In reality, you might spend only 3-4 seconds under near-maximal tension, which leads to the recruitment of the growth-prone fast-twitch fibers.

With the overcoming isometric set, you'll get 100-120 seconds under a high level of tension. As fatigue sets in, your actual force production will go down (just like in a normal set), but tension remains. Even in a fatigued state, the amount of tension produced is still higher than in a normal rep. This is mostly because of the nature of the contraction and the position where you're producing maximum force. This is the bottom position versus mid-range or top position for a dynamic lateral raise.

Plus, the constant muscle contraction (versus the contract/relax nature of regular reps) leads to an occlusion effect. The muscles that are contracting super hard compress the capillaries that bring blood in or out of the muscles. Oxygen can't come in; lactate can't come out.

This is beneficial for two main reasons:

First, because oxygen can't come in, your body will favor the recruitment of fast-twitch fibers over the slow-twitch fibers, which are aerobic fibers. A study on occlusion training found that it changed the recruitment pattern, increasing fast-twitch and decreasing slow-twitch fiber recruitment and damage/stimulation (1).

Second, the occlusion effect increases local growth-factor production. These growth factors (mechanical growth factors) are highly anabolic and can facilitate muscle growth. And the cool thing is, despite the long duration, you're using fast-twitch fibers more and providing a heckuva stimulation for them!

It can even improve your capacity to recruit fast-twitch fibers in the future because you spend so much time recruiting them.

Farmers walks – especially of fairly long duration – are one of the most underrated exercises for delts.

Sets lasting 1-3 minutes (for 3-4 sets) are best for most people, although crazy things like walking a mile with 15-25 pound dumbbells can work magic too. You can make the farmers walks even more effective for your delts by "pushing out" your arms slightly (or attempting to) as if you were doing lateral raises or the isometric exercise version above.

Farmers walks can be done with specific implements, dumbbells, kettlebells, or a loaded trap bar. For the specific purpose of making the yoke more jacked, I prefer the trap bar because it allows you to do a better "push away" isometric action.

Determine the number of sets based on the duration of each carry:

• 1-Minute Sets: Do 4 Sets
• 2-Minute Sets: Do 3 Sets
• 3-Minute Sets: Do 2 Sets

Why Does It Work?

Micro-oscillations cause the main effect. These are subtle but sudden changes in position that require the body to make a rapid and opposite action to return (or stay) in the original position. Often, these movements are so small that you don't notice them, but they're happening and require reactive force production to maintain a stable position.

These bouts of reactive force production will typically use the fast-twitch fibers because of the speed of action required to counter the movement. Remember, the fast-twitch fibers are those with the highest growth capacity. The more you can recruit and stimulate them, the more hypertrophy you'll get.

With farmers walk, the shoulder joint has lots of micro-oscillations in several different directions, which greatly increases delt activation. If your set lasts 1-3 minutes (or more), you'll place a significant growth stimulus on those fibers.

Now add the "pushing your arms out" action. You'll further increase delt work (especially the medial head), and you'll get all the benefits of the isometric method mentioned above, on top of the micro-oscillation.

For this technique, use the hanging band method. Pass a small resistance band inside weight plates (5 to 20-pounds per side).

• Start at the top of the range of motion, arms parallel to the floor.
• From that position, suddenly and rapidly move down the arms a few centimeters and quickly come back to the starting position. This will create a "bouncing effect" of the plates.
• When the plates move down, they try to pull your arm down too. Your goal is to avoid that and keep your arms fixed as much as possible. When the bouncing action stops or becomes easy to resist, create more bouncing.
• Do this until you've reached the prescribed set duration.

Try durations of 60-90 seconds per set. If you can't resist the bouncing action because of fatigue, bring your arms down, take two deep breaths, and resume.

Why Does It Work?

Why not just use a regular isometric hold at the top? Because the bouncing action is not regular in its intensity, frequency, and direction. And the unloaded phase (when the plates are bouncing up) leads to muscle relaxation, which forces a reactive contraction when the plates move down.

This will lead to more fast-twitch fiber recruitment (micro-oscillation effect). It will also greatly improve shoulder stability, which will help you gain strength and reduce your risk of injuries.

Maybe. I'm a big-basics kinda guy, too. But when you understand physiology and neurology, it's possible to create methods that provide a unique stimulus. In my experience, these exercises provide an accelerated rate of gains for 6-8 weeks. Who wouldn't want that?

1. Krustrup P et al. Heterogeneous recruitment of quadriceps muscle portions and fibre types during moderate intensity knee-extensor exercise: effect of thigh occlusion. Scand J Med Sci Sports. 2009 Aug;19(4):576-84. PubMed.