Here's what you need to know...

  1. An intense isometric contraction is great for muscle growth. It quickly recruits the largest motor units because it's a maximum voluntary contraction. Plus, isometrics increase the neural drive between the motor cortex in your brain and the trained muscle.
  2. If you experienced subpar results from isometrics in the past, it's probably because you did them when you were already fatigued, such as at the end of a set.
  3. To make isometrics work for you, you need to do them separate from your main workouts, perform 5 sets of an intense 10-second squeeze, and progress by increasing the training frequency.
Maximum hypertrophy of most muscle groups is best accomplished with a combination of three different approaches to training:
  1. You should train heavy with loads that are around 85% of your one-rep max for 8-10 sets. You can't go wrong with 10 sets of 3 reps.
  2. During a different workout, you should rip off the maximum number of reps in 10 seconds with a load that's 60-70% of 1RM for 8-10 sets.
  3. Trigger muscle growth is with isometrics.
You might've experimented with isometrics in the past and if you're like most lifters, that experimentation was limited to holding the last rep of a set for as long as possible. And it probably didn't help much. Isometrics are something I didn't experiment with nearly enough in my early training days. Like most of you, I considered it nothing more than an afterthought – just hold the last rep for as long as possible and hope that something magical happens. But magical stuff never did happen, so I tried to figure out why.
My approach for troubleshooting muscle growth doesn't consist of experimenting with dozens of different training parameters for months on end with all of my clients. That takes too long and it doesn't guarantee success. Instead, I troubleshoot by looking at athletes that have extraordinary development in a specific muscle group. Then I try to figure out what they're doing that the rest of us aren't doing.

What I Learned From Ballet and Gymnasts

If you were born with genetically inferior calves or biceps, you know how tough it is to get those damn things to grow. We all know that biceps-building articles get the most hits on the Internet and there's an endless discussion of theories on how to trigger growth in the calves. Indeed, if you haven't figured out how to make your biceps or calves bigger, you're definitely not alone.
A while ago I happened to watch a documentary on ballet dancers, and what really caught my attention was their calf development. It didn't matter if the dancer was young, old, male or female, they all had calves that were well above the norm. That's quite an accomplishment considering that most of them spend their training days completely malnourished, consuming nothing more than glasses of distilled water and a bowls of tofu-scented oxygen. Likewise, we've all seen the mind-blowing arms and shoulders on those Olympic dudes who master the rings. You won't find a better pair of proportionally large biceps on any athlete, including professional bodybuilders.
So what are ballet dancers and rings gymnasts doing to their calves and biceps that you probably aren't doing? A whole lot of isometrics, that's what. Ballet dancers spend considerable time during their routines with their heels elevated in the peak-contraction calf raise position. And the routines that gymnasts do from the rings consist of moving from one isometric hold to the next as opposed to busting out endless reps.

Why Are Isometrics So Powerful?

An intense isometric contraction is terrific for muscle growth for two reasons. First, it quickly recruits the largest motor units because it's a maximum voluntary contraction. Second, isometrics increase the neural drive between the motor cortex in your brain and the trained muscle. When you perform a regular, full range of motion rep, the tension in the working muscle will vacillate due to biomechanical changes throughout the movement. This makes it more difficult to really feel the muscle working. It's no surprise that most guys who can't get their biceps or calves to grow also have a tough time squeezing the muscle to the highest possible level of tension.
If you experienced subpar results from isometrics in the past, it's probably because you did them when you were already fatigued, such as at the end of a set. This is the least effective time to use an isometric because your descending neural drive and largest motor units are already fatigued from the reps that preceded it.

How to Add Isometrics Into Your Plan

There are three rules to follow in order to get the best muscle-building results from isometrics:
  1. Do Them Separately From Your Main Workouts. Fatigue is a complex animal that consists of peripheral and central nervous system components, and it's most accurately defined as "an inability to reach your highest level of performance." In order to trigger the most growth with isometrics it's important to do them when your neural drive and largest motor units are free from any fatigue. Therefore, do them at least six hours away from your primary workouts, or on a different day.
  2. Perform 5 Sets of an Intense 10-Second Squeeze. Virtually all of my training parameters for concomitant gains in size and strength stemmed from Bill Starr's 5x5 program. I've found that when you're training with an intense contraction, or a relatively heavy load, five work sets hits the sweet spot for almost everyone. And a 10-second continuous contraction is the top end for keeping the largest motor units recruited. Rest 2-3 minutes before repeating the isometric hold, but feel free to perform another isometric for a different muscle group during that time.
  3. Progress by Increasing the Training Frequency. A higher training frequency is the common key element among athletes that have developed proportionally large muscle groups. A gymnast hangs from the rings every day, and a ballet dancer is constantly up on the toes throughout the week. When you have a stubborn body part, the best solution is to increase the number of times you train it each week. Isometrics are an ideal supplement to your regular training program because they represent a unique training stimulus that doesn't require an extended recovery time. Start training your most underdeveloped muscle group twice per week with isometrics, in addition to your current training program. Every other week add another session until you reach 4-6 sessions per week, depending on your recovery capacity.

The Best Exercises

Biceps/Forearms/Upper Back: Single-Arm Hang

Want to know how those rings gymnasts built such incredible biceps? One word: maltese. That exercise is, without a doubt, the most effective strength exercise to add biceps mass.
maltese
It's also the most dangerous biceps exercise. In fact, training your way up to a maltese is so risky that I've hesitated for years to even mention the correlation between it and massive biceps. The likelihood of tearing your biceps, jacking up your elbows, or screwing up your shoulders is enormous. You should only embark on that journey with an Olympic-level gymnastics coach.
Alternately, the isometric exercise I recommend for biceps development is the single-arm hang.
How to do it: Hang from a pull-up bar with an underhand (palms up) grip with the pinky fingers touching each other. Pull yourself up so the elbows are at 90 degrees. Next, quickly grab your left wrist with your right hand so the left hand is the only one gripping the bar. Maintain the 90-degree left elbow angle as your forearms, biceps, and upper-back fire to maintain your body position. Switch sides and repeat with the right hand gripping the bar.

Calves: Single-Leg Standing Calf Raise Peak Contraction

How to do it: Let's say you're training the right calf first. Stand barefoot on your right foot, spread the toes as wide as possible, and then perform one calf raise to the peak contraction, keeping your right leg locked straight. Squeeze the peak contraction as intensely as possible by pushing through the big toe. Limit the amount of assistance you give your balance and challenge yourself to be able to perform the calf raise and hold without any balance support. That's much harder than it sounds. Repeat with the left calf.

Hamstrings: Nordic Hamstring

Nordic-start
Nordic-Lowering
How to do it: Place a firm foam roller on the floor, rest your upper shins on it, hook your heels under a padded, secure structure, then shift your body as far forward as your strength allows. There should be no hip hinge in the forward position – your body should be in a straight line from the neck to the knees. Most guys only need to shift their body forward around 10-15 degrees before the hamstrings start firing intensely.
The Nordic hamstring is excellent for adding muscle to the hamstrings, but it's also an exception to the frequency guidelines mentioned earlier. This intense exercise shouldn't be performed more than three times per week, and you should work up to that frequency very slowly.

Glutes: Hip Hinge With Abduction/External Rotation

How to do it: Place a strong mini-band around your thighs, just above the knees. The feet are slightly wider than shoulder width and pointed straight ahead. From a standing position, place the palm of your hands against the front of the thighs, then push your hips back and let the knees bend slightly while sliding your fingertips forward. When your fingertips reach your knees, you're at the correct knee, hip and torso position. Maintain this body position as you push your knees out to the side, against the resistance of the band, without rolling the feet outward. Hold your arms straight out in front during the exercise.
The purpose of this drill is to maximally engage the glute fibers that abduct and externally rotate the hip since those are the fibers that are most underdeveloped on almost everyone.

Chest: Push-Up Peak Contraction
How to do it: Get in the top position of a push-up, hands wider than shoulder width and elbows just short of lockout. Brace your abs, squeeze the glutes, and then attempt to pull the hands together as intensely as possible. Your hands won't move, but your pectorals will be firing like hell. You can also do this drill with your feet elevated on a bench or Swiss ball.

Triceps: Dip Peak Contraction
How to do it: Get in the top position of a dip on rings or parallel bars. Push your palms down to remove any shoulder shrug and then maximally squeeze the triceps to lock out the elbow joints at the end range of motion. There should be some slight hyperextension in your elbow joint at full lockout. Strong guys can do this drill with extra weight added to a chin/dip belt, but most people should start with just body weight.
Importantly, your elbows must slightly hyperextend at the end range lockout to take full advantage of this drill. If your elbow(s) can't slightly hyperextend naturally (without load), get soft tissue work around the elbow to free up the restriction because it will eventually lead to problems with all upper body exercises.

Deltoids: Crucifix
How to do it: Stand with a weight in each hand, lift your arms up and out to the sides until they're parallel with the ground. Maintain this arm position while keeping the palms facing down and without shrugging the shoulders. Keep the shoulder blades pulled down throughout the hold.

What About the Quads?

You probably noticed that I didn't mention an isometric exercise for the quadriceps.
I'm not a fan of the leg extension machine, even though it's popular for isometrics. Furthermore, I haven't been satisfied with the times I've experimented with free weight or body weight isometric exercises to challenge the quads because most of them irritate the knee joint.
While isometric holds are intended to increase hypertrophy, the best way to grow the quads with extra workouts is to pedal on an exercise bike with the highest resistance you can handle for 3-5 minutes straight. The quads thrive on long duration sets. Just ask any cyclist, speed skater, or downhill skier.