In simple terms, muscle can only contract in a few ways. It can do the obvious and contract to shorten the distance between joints, such as when doing a bicep curl. This is called aconcentric contraction, where the muscle tenses while shortening.One of the main benefits of isometric training is that the body is able to activate nearly all the available motor units – something that is usually very difficult to do.
How to Use Isometrics
I’m going to give you two versions of application. Both will work, but one will require some equipment and the other can be done on your own. The equipment variation is suitable for someone looking for fast increases in strength, while the solo version can be used for performance but is also great for injury rehabilitation.
Version #1: Isometrics With Equipment
To do the equipment variation you’ll need a bar, a bench, a power rack, and a lot of weight. We’re going to use three exercises – the bench press, squat, and deadlift. Bench press and squat: To perform these two we’re going to set the bar on one set of pins at the mid-range of the movement, usually where a sticking point occurs, with a second set of pins slightly above it.
You don’t even need load on the bar for either of these variations. On most power racks simply set the second set of pins at the next available height. Performing the isometric contraction is simple. Assume your position with either the squat or the bench press and drive the bar into the higher set of pins as hard as you can for six to eight seconds.
Dead lift: To perform the deadlift variation load the bar with a weight that is well beyond your one-rep max. It is important that the bar will not budge at all once you start the pull. (As a side note, you will get a lot of looks at the gym when you just load plate after plate after plate onto the bar). Like with the bench and squat variations, you will pull as hard as possible for six to eight seconds.
Version #2: Isometrics With Body weight Only
The main problem many will have with these body weight variations is the lack of sensation of actually pushing or pulling the weight. These exercises are performed as static contractions in a single position. The three exercises to be used are the squat, lunge, and push up. For any of the three, assume a position midway through the range of movement and tense everything you can in your body as hard as possible. What makes this tricky is that not only will you have to tense what would be the agonists (the muscles contracting while you squat or lunge), but also the antagonists (muscles that oppose the action, such as the back in the push up).
My experience is that many people don’t have good enough body control to be able to execute this well. Regardless, many will still find that a single rep is spent chasing tension around the body. As soon as you have one thing tight, you’ll realise that your calves aren’t turned on, and then that will switch your glutes off, which in turn will cause you quads to let go, and on and on.
With practice this chase does go away and you will become more skilled at getting everything switched on quickly and fully, which is the exact purpose of this training – to teach you to recruit more motor units. In either plan, you can change the joint angle workout-by-workout, or week-by-week to minimize any potential loss of ability at different angles. For the deadlift, either raise the bar a few inches or work from a slight deficit in successive workouts.
So, take heed – isometrics work, just use them like any other high intensity method, and a little goes a long way