Although an integral part of fitness, isometric muscle strength is an often ignored component. The importance of isometric strength in almost all functional (carrying a heavy box) and sporting activities (a bat swing) is undeniable – yet for some reason or the other – isometric exercises are just not done by many. They are just not popular – in fact, you will be hard pressed to find too much information about these awesome exercises.
Before we get into some of the isometric exercises, let us have a look at what isometric strength is and its importance.
What is isometric strength?
Isometric strength is a measure of how intense an isometric contraction is – an isometric contraction is flexing of a muscle at a specific joint angle without any change in the length of the muscle belly or there being no change in the joint angle (Fleck & Kraemer, 2004).
Isometric contraction involves tension being created in the muscle belly without any movement through the joints. So, if you were standing up against a wall and pushing at it, you’d be creating isometric contraction in the whole body without any movement occurring at any of the joint.
Flexing your abdominals is a brilliant example of isometric contraction – thus ‘the plank’ qualifies as an isometric exercise. A person with a crushing handshake will have higher isometric strength in the forearms than most.
There are very tests for testing isometric strength, as opposed to a number of tests available for evaluating dynamic strength. Even these are not very often used by trainers or conditioning coaches. As you may very well guess, the devices for testing isometric strength are also few – usually dynamometers and tensiometers are used for this purpose.
Tests for isometric strength
As mentioned earlier, dynamometers and tensiometers are the only gadgets available for testing isometric strength.
Testing is usually carried out for establishing a baseline before prescribing a resistance or isometric training protocol. Re-test is usually order after 5 weeks to monitor progress.
How is isometric strength and isometric training important?
Isometric strength and training is a much neglected part of modern sports and fitness training. Although, strength and conditioning coaches have always known that muscle power (how quickly you can move the bar while cleaning or snatching) and isometric strength (how intensely you can contract the muscles where not much movement is occurring – upper and lower back in squat) are perhaps more important that just muscle strength in the strictest sense!
Improved isometric strength will also reflect in improved sporting performances. Intense isometric contraction of forearms will mean you’ll be able to hold the bat or the golf club firmer and thus hit higher and longer. Similarly, isometric contraction of the core and hamstrings of the front leg will help in stabilizing during the swing phase. Likewise, isometrically stronger forearms will help you last longer on the pull-up bar and thus will maximize your back training. Needless to say, you will able to hold the bar for longer in almost all exercises thus enabling you to work over a higher range of repetitions!
Similarly, shoulder, core, hip and knee and ankle stabilization which are so important in sports – are all cases of using isometric contraction of the muscle around these joints.
Isometrics of submaximal intensity find application in injury rehab. Injuries to bones or ligaments or some other structure of the joint can benefit from strengthening the musculature around the joint. This is when flexing your muscles without causing much movement around the joint comes in handy.
In addition to improving sports performance and playing an important role in injury rehab, isometric training also causes muscle hypertrophy (Kitai & Sale, 1989; Schott, McCully, & Rutherford, 1995).
Sports which require isometric exercises as a bigger part of their training arsenal are climbing, skiing, and gymnastics. However, isometrics are an integral part of almost all sports since throwing or kicking will involve stabilisation of half of the body and the core.
In a nutshell, elite sportsmen and women, powerlifters, Olympic lifters, sports injury rehab and fitness fanatics to those who are just starting out, isometric training is for everyone – PERIOD!
Some isometric exercises
Planks & Side-Planks
Holding position for a fixed time and building up on it will improve core strength and stability.
Hold the ‘mid-press up’ position for a minute; build up on the time over weeks.
With legs parallel to the floor, place your back up against the wall; legs should be parallel to the wall. Hold for as long as possible – build up on the ‘holding time’ over weeks. 2-3 sets during a session should suffice.
In addition to these, isometric calf, leg and hip extension should be included in your training routines.
Fleck, S. & Kraemer, W. (2004). Designing Resistance Training Programs. (3rd ed.) Campaign, IL: Human Kinetics.
Kitai, T. A. & Sale, D. G. (1989). Specificity of joint angle in isometric training. Eur J Appl.Physiol Occup.Physiol, 58, 744-748.
Schott, J., McCully, K., & Rutherford, O. M. (1995). The role of metabolites in strength training. II. Short versus long isometric contractions. Eur J Appl.Physiol Occup.Physiol, 71, 337-341.