Isometric Exercise – How Yoga Completes Your Fitness Training

By Lauren Green – Vinyasa Yoga Instructor

When it comes to fitness, there is so much advice out there it can be hard to know where to start. A little understanding of the way muscles work in yoga can go a long way to helping you design a fitness program that works for you and also meets your goals.

To increase our fitness we ‘work-out’, which involves working our muscles. We can work our muscles in different ways while exercising (or just in everyday life). Exercising our muscles requires us to exert force through the muscle fibers. This can occur while the muscle is shortening, lengthening or staying the same length.

Muscle shortening, known as concentric contraction, forces a joint angle to decrease (bending your knee or elbow is decreasing a joint angle). Muscle lengthening, known as eccentric contraction, causes a joint angle to increase (straightening out your bent knee or elbow is increasing a joint angle). Concentric and eccentric muscle contractions, when grouped together, are called isotonic muscle contraction.  This type of muscle contraction generates joint movement – whether it’s lifting and lowering dumbbells or walking through a shopping center.

When tension develops in a muscle but the length does not change, the joint does not move, and the contraction is said to be isometric. This type of muscle contraction is static – there is no movement. An example is when you hold your hands out in front of you and someone places something heavy into your hands. You don’t allow yourself to lower the object so your body doesn’t move – however your muscles are still working hard to support the weight of the object. Another example of an isometric muscle contraction is holding a plank position for 10 seconds.

When we think of exercise we generally think of things like; treadmills, burpees, lifting weights, bike riding, aerobics etc. All these activities involve isotonic contraction. In fact most gym equipment and popular exercise styles involve isotonic contraction. Push-ups, sit-ups, weight machines and lunges are also isotonic. However, a complete exercise regime should include both isotonic and isometric exercises.

Because muscles of the core perform the important function of stabilizing the spine throughout the day, isometric exercises like holding a plank position can be useful for strengthening those muscles. Isometric exercise is intense and contributes to burning fat and building muscle. It can also be useful when you are trying to rebuild strength around the area of an old injury. Just remember we aim to hold our muscles but not our breath! Breathing throughout the hold is vital – it should be continuous and slow.

The beauty of yoga is that it incorporates both styles of muscle contraction. We use isotonic contraction when we move into each posture. Then we use isometric contraction when we hold our bodies in that particular posture.

So next time someone who has never tried yoga suggests that it isn’t really exercise because you are ‘just holding still and breathing deeply’, you can reply that, in fact, you are incorporating a balance of isotonic and isometric exercises into your training and bring them with you next time to try yoga for themselves!


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To Book in for a yoga class with Lauren, email [email protected] or give us a call on 1300 318 817