What Is an Extreme ISO Exercise?

ISO refers to isometric exercise, a form of resistance training in which you maintain the contraction in a muscle or muscle group with no change in length, often referred to as a static contraction. Isometrics are used to increase muscular endurance and tone, or to maintain strength without straining joints, particularly in rehabilitation settings. However, it is not very effective for increasing muscle strength or size. A simple example of an isometric contraction is supporting your body weight, leaning forward, with both hands on a wall.

  1. Extreme, Meaning Not Your Regular Isometrics

    • Extreme ISO is to standard isometrics as sprinting is to running. As its name suggests, it is a super-intense, longer-duration version of the original. Resistance is supplied by body weight, dumbbells or balancing on a stability ball. Doing a half bicep curl and holding it is isometric. Holding it until muscle failure is extreme ISO. Some extreme ISO movements can be challenging enough to increase strength, although not necessarily through a full range of motion. Extreme ISO sometimes is used in sports training to learn proper execution of movement.

    The Extreme ISO Lunge

    • An extreme ISO move that targets multiple muscle groups in the lower body is the static lunge. Those new to it should try it without hand weights at first. Stand with both feet together and take a giant step back with one foot, keeping the front leg bent at a 90-degree angle. Drop the back knee down almost to the floor while keeping the torso upright, contract the glutes and engage the hamstrings of the front leg. Try to hold the position for up to five minutes.

    The Extreme ISO Plank

    • The plank targets the lower abdominal area. From an upper pushup position, drop down to your forearms and toes. Engage the lower ab muscles by pulling your navel toward your spine. Breathe and hold the plank as long as you can. A variation is the side plank, which targets the obliques. Flip to the side, resting on one elbow or forearm, and either place your upper hand on your hip or reach toward the ceiling. Make sure that your hips are vertically stacked, and hold the position as long as you possibly can.

    It’s Extreme – So Apply Caution

    • Beginners should consult a qualified fitness professional before attempting extreme ISO to minimize the risk of injury. Isometric exercise can significantly increase blood pressure, warns Edward R. Laskowski, a medical doctor writing for MayoClinic.com. Although the increase is temporary, extreme ISO should never be attempted by anyone with uncontrolled hypertension or cardiac issues. In addition to helping avoid injury, it is important that a professional teach proper alignment and techniques to achieve goals, such as strength, extreme endurance or proper movement patterns.