You’re probably thinking that subject line sounds too good to be true. And under one specific assumption—that “without moving” means “without effort”—you’d be right.
Getting stronger without effort is impossible. Even pharmaceutically enhanced individuals—that is, anabolic steroid users—need to move heavy weights, eat, and rest in order to get stronger and build muscle.
And yet, getting stronger without moving is actually possible. In fact, you already reflexively apply the technique throughout most of your waking hours, albeit to a smaller degree than what’s needed to increase strength. Becoming aware of the technique and how to use it effectively will enable you to intentionally apply it in a variety of situations.
What is this technique at which I’m hinting?
It’s the isometric muscle action.
Types of muscle actions
There are two types of muscle actions: isotonic, meaning “constant tension”, and isometric, meaning “constant length”. (Technically there’s a third type, but it’s typically only performed in limited situations and isn’t useful for our purposes here.)
Isotonic actions are composed of two phases. Concentric and eccentric muscle actions occur when a muscle exerts force greater than or less than the resistance applied against it, respectively. Concentric action results in the shortening of a muscle while eccentric action results in its lengthening. This produces movement around a joint and, in the case of weight training, causes a weight to be lifted or lowered.
Based on those definitions and the subject of this tip, you might (correctly) assume that isometric muscle action occurs when a muscle exerts force equal to the resistance applied against it and causes no movement. And then you might think of an exercise like the plank, in which numerous muscles contract but no observable movement is produced.
But isometric actions occur at the very top and bottom of any movement at the moment when the working muscles switch between shortening (concentric) and lengthening (eccentric), and vice versa. They also occur throughout the body to dynamically stabilize (or balance) it while movement occurs elsewhere.
All of this is important for two reasons. It illustrates that isometric actions are an almost constant part of everyday and athletic movements and indicates that they’re an integral part of developing strength. In fact, studies have shown that training with isometric actions can both maintain and improve strength and rate of force production.
Pros and cons
Of course, that doesn’t mean you should only perform isometric exercises to improve your strength. Perhaps the most prominent downside of isometric muscular tension is that it improves strength only at the joint angle at which it’s performed.
For example, let’s say you wanted to improve your biceps strength while sitting at your desk. (Biceps are the muscles in the front of your upper arm that bend your elbow.) To do so, you bend your elbows to 90°, place your palms on the underside of your desk, and attempt to bend your elbows more. Obviously neither the desk nor your arms should actually move.
Over time this practice will increase your biceps strength, but only at about 90° of elbow flexion. Meaning, you’ll notice minimal strength improvements when your arm is either mostly straight (< 90°) or mostly bent (> 90°). To experience strength improvements throughout your elbows’ entire range of motion, you’d need to do this isometric exercise at a variety of elbow angles. In that case, it would be more efficient to perform dumbbell curls, kettlebell cleans, barbell rows, or pull-ups—all exercises that move the elbow through most of its range of motion.
But isometric exercises really shine in other cases, such as when you’re:
- Beginning an exercise program after a long layoff: Isometric exercises place a high demand on connective tissue (tendons & ligaments) and other stabilizer muscles while inducing less fatigue than other types of contraction. This prepares both the tissues and the nervous system for more easily progressing to a traditional training program.
- Working up to a body weight exercise which you can’t yet perform (e.g. pistols, pull-ups, push-ups): If you’re struggling with a particular range of motion for the exercise, you can practice isometric holds just above or below your “sticking point” to build strength at the joint angle you find challenging.
- Limited on time, space, or equipment: Body weight “pushing” movements like push-ups or squats don’t require any equipment, but body weight “pulling” movements like pull-ups or hamstring/glute exercises do. (Hamstrings are the muscles in the back of your thighs; glutes are the muscles in your butt.) However, even those movements and muscles can be trained isometrically with just a wall or the floor.
- Recovering from injury or surgery: When moving a joint is not recommended—which may happen for numerous reasons—muscles around the joint can often still be trained isometrically to maintain their strength during the recovery process. Ask your doctor or physical therapist for more details!
Putting it into practice
If you’d like to add isometric work to your regimen for any of the cases immediately above, there are just a few guidelines to apply.
First, find a way to use the floor, wall, or some other heavy or immobile object as resistance against the muscle you want to work. Then simply pull or push against that object without moving it or yourself. Exert as much (or almost as much) tension as you are able for up to 5–10 seconds. Rest five to seven times longer than you exerted tension, and repeat the process. Accumulate up to 30–120 seconds of total contraction time per session using a variety of joint angles.
Like with any form of training, consistency is key. Aim to practice for a few minutes every day. Even if you occasionally miss a day or two, you should notice some improvements within a couple weeks.